The timing of birds' breeding seasons : the Perrins hypothesis revisited especially for migrants

NARCIS (Netherlands)

Drent, Rudolf H.

2006-01-01

Perrins (1970) galvanized thinking on the timing of birds' breeding seasons by pointing out that most individuals laid too late for the offspring to profit fully from the seasonal peak of food abundance, and suggested that the proximate cause was a shortage of food for the female when forming the

Arctic sea ice a major determinant in Mandt's black guillemot movement and distribution during non-breeding season

Science.gov (United States)

Divoky, G.J.; Douglas, David C.; Stenhouse, I. J.

2016-01-01

Mandt's black guillemot (Cepphus grylle mandtii) is one of the few seabirds associated in all seasons with Arctic sea ice, a habitat that is changing rapidly. Recent decreases in summer ice have reduced breeding success and colony size of this species in Arctic Alaska. Little is known about the species' movements and distribution during the nine month non-breeding period (September–May), when changes in sea ice extent and composition are also occurring and predicted to continue. To examine bird movements and the seasonal role of sea ice to non-breeding Mandt's black guillemots, we deployed and recovered (n = 45) geolocators on individuals at a breeding colony in Arctic Alaska during 2011–2015. Black guillemots moved north to the marginal ice zone (MIZ) in the Beaufort and Chukchi seas immediately after breeding, moved south to the Bering Sea during freeze-up in December, and wintered in the Bering Sea January–April. Most birds occupied the MIZ in regions averaging 30–60% sea ice concentration, with little seasonal variation. Birds regularly roosted on ice in all seasons averaging 5 h d−1, primarily at night. By using the MIZ, with its roosting opportunities and associated prey, black guillemots can remain in the Arctic during winter when littoral waters are completely covered by ice.

Effect of breeding method and season on pregnancy rate and embryonic and fetal losses in lactating Nili-Ravi buffaloes.

Science.gov (United States)

Qayyum, Arslan; Arshad, Usman; Yousuf, Muhammad Rizwan; Ahmad, Nasim

2018-03-01

The aim of this study was to determine the effect of breeding method and season on pregnancy rate and cumulative embryonic and fetal losses in Nili-Ravi buffalo. Estrus detection was performed twice a day by teaser buffalo bull for 1 hour each. A 2 × 2 factorial design was used to address the breeding method and season. Buffaloes (n = 130) exhibiting estrus were randomly assigned to be bred either in peak breeding season (PBS; n = 80) or low breeding season (LBS; n = 50). Within each season, buffaloes were divided to receive either natural service (NS; n = 65) or artificial insemination (AI; n = 65). NS buffaloes, in estrus, were allowed to remain with the bull until mating. AI was achieved, using frozen thawed semen of bull of known fertility. PBS comprised of September to December and LBS were from May to July. Serial ultrasonography was performed on days 30, 45, 60, and 90 after breeding (day 0) to monitor pregnancy rate and embryonic and fetal losses. The pregnancy rate on day 30 after breeding was higher in NS as compared to AI group (63 vs. 43%; P  0.05) in LBS. The cumulative embryonic and fetal losses between days 31 and 90 were significantly lower in PBS than LBS (33 vs. 60%; P losses were higher in LBS in Nili-Ravi buffalo.

REPRODUCTIVE SEASONALITY AND ITS CONTROL IN SPANISH SHEEP AND GOATS

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Amelia Gómez Brunet

2011-12-01

Full Text Available Sheep and goat breeds from subtropical, middle and high latitudes show seasonal changes in reproductive activity. In general, the breeding season starts in autumn and ends in winter, with anoestrus in spring/summer. An endogenous circannual rhythm driven and synchronised by the annual photoperiod cycle regulates the onset and offset of the breeding season. However, the timing and duration of the breeding season can be affected by interactions between the photoperiod and factors such as breed, geographical origin, nutritional and lactational status, social interactions, and the season of parturition. Seasonality in reproduction is naturally accompanied by variation in the availability and price of meat, milk and cheese over the year, affecting the economy of farmers, consumers and the food industry alike. The control of reproduction outside the normal breeding season by inducing and synchronizing oestrus and ovulation plus the use of artificial insemination and/or natural mating would help ensure the year-round availability of products. This review describes the seasonal variation in the sexual activity of ovine and caprine species with special regard to local Spanish sheep and goats breeds, examines how the photoperiod regulates their annual reproductive cycle, and discusses a number of strategies that can be used to induce and synchronise ovulation outside the natural breeding season.

Breeding phenology of birds: mechanisms underlying seasonal declines in the risk of nest predation.

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Kathi L Borgmann

Full Text Available Seasonal declines in avian clutch size are well documented, but seasonal variation in other reproductive parameters has received less attention. For example, the probability of complete brood mortality typically explains much of the variation in reproductive success and often varies seasonally, but we know little about the underlying cause of that variation. This oversight is surprising given that nest predation influences many other life-history traits and varies throughout the breeding season in many songbirds. To determine the underlying causes of observed seasonal decreases in risk of nest predation, we modeled nest predation of Dusky Flycatchers (Empidonax oberholseri in northern California as a function of foliage phenology, energetic demand, developmental stage, conspecific nest density, food availability for nest predators, and nest predator abundance. Seasonal variation in the risk of nest predation was not associated with seasonal changes in energetic demand, conspecific nest density, or predator abundance. Instead, seasonal variation in the risk of nest predation was associated with foliage density (early, but not late, in the breeding season and seasonal changes in food available to nest predators. Supplemental food provided to nest predators resulted in a numerical response by nest predators, increasing the risk of nest predation at nests that were near supplemental feeders. Our results suggest that seasonal changes in foliage density and factors associated with changes in food availability for nest predators are important drivers of temporal patterns in risk of avian nest predation.

Breeding phenology of birds: mechanisms underlying seasonal declines in the risk of nest predation.

Science.gov (United States)

Borgmann, Kathi L; Conway, Courtney J; Morrison, Michael L

2013-01-01

Seasonal declines in avian clutch size are well documented, but seasonal variation in other reproductive parameters has received less attention. For example, the probability of complete brood mortality typically explains much of the variation in reproductive success and often varies seasonally, but we know little about the underlying cause of that variation. This oversight is surprising given that nest predation influences many other life-history traits and varies throughout the breeding season in many songbirds. To determine the underlying causes of observed seasonal decreases in risk of nest predation, we modeled nest predation of Dusky Flycatchers (Empidonax oberholseri) in northern California as a function of foliage phenology, energetic demand, developmental stage, conspecific nest density, food availability for nest predators, and nest predator abundance. Seasonal variation in the risk of nest predation was not associated with seasonal changes in energetic demand, conspecific nest density, or predator abundance. Instead, seasonal variation in the risk of nest predation was associated with foliage density (early, but not late, in the breeding season) and seasonal changes in food available to nest predators. Supplemental food provided to nest predators resulted in a numerical response by nest predators, increasing the risk of nest predation at nests that were near supplemental feeders. Our results suggest that seasonal changes in foliage density and factors associated with changes in food availability for nest predators are important drivers of temporal patterns in risk of avian nest predation.

Seasonal Patterns in Hydrogen Isotopes of Claws from Breeding Wood-Warblers (Parulidae: Utility for Estimating Migratory Origins

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Kevin C. Fraser

2008-06-01

Full Text Available The global decline in many species of migratory birds has focused attention on the extent of migratory connectivity between breeding and wintering populations. Stable-hydrogen isotope (δD analysis of feathers is a useful technique for measuring connectivity, but is constrained by features of molt location and timing. Claws are metabolically inert, keratinous tissues that grow continuously and can be sampled at any point in the annual cycle, thus providing potentially useful clues about an individual's previous movements. However, variation in the rate at which claws incorporate local δD values is not well described. We measured δD values in claws of two species of Neotropical-Nearctic migrant wood-warblers (Golden-winged Warbler and Cerulean Warbler breeding in eastern Ontario, Canada to investigate the rate of δD change through the breeding season and the utility of claw δD values for estimating migratory origins. δD values of claw tips from 66 different individuals, each sampled once during the breeding season, showed an average change of -0.3‰ to -0.4‰ per day in the direction of the expected local Ontario value. There were no significant sex or species differences in the rate of change. These results suggest δD values of claw tips in Parulids may reflect those of the non-breeding area for 3-7 weeks after arrival on the breeding grounds, and are useful estimators of non-breeding migratory origin. Our results also suggest that these species may leave the breeding ground before claw tips fully incorporate a local δD signature, as claws sampled at the end of the breeding season did not match locally grown feather and claw δD values. This is the first study to examine the seasonal rate of the change in δD values of claws in long-distance, insectivorous, migratory birds.

Environmental and hormonal factors in seasonal breeding in free-living male Indian rose-ringed parakeets (Psittacula krameri).

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Krishnaprasadan, T N; Kotak, V C; Sharp, P J; Schmedemann, R; Haase, E

1988-12-01

Seasonal changes in testicular activity, plasma luteinizing hormone (LH), estradiol (E2), testosterone (T), and 5 alpha-dihydrotestosterone (5 alpha-DHT) were related to pair bond formation, nest building, nest defense, and parental behavior in free-living Indian rose-ringed parakeets (Psittacula krameri) in northwest India. Spermatozoa production occurred between January and March when daylengths were short (10-12 hr) and ambient temperature was seasonally low (8-20 degrees C). At other times of the year the testes were regressed. Plasma LH levels increased during the prebreeding period (September-December) when the birds were forming pairs and selecting or defending nest sites. Plasma LH levels increased further between January and March and decreased to seasonal low values during the post breeding period between April and June when the birds were caring for young. Concentrations of plasma androgens and estrogens were similar during the prebreeding and postbreeding phases of the breeding cycle. During the breeding period, the ratios between plasma 5 alpha-DHT and testosterone and between plasma estradiol and testosterone increased. It is proposed that the absence of marked seasonal changes in plasma steroid levels is related to nest defense behavior which occurs during the prebreeding, breeding, and postbreeding phases of the breeding cycle. Winter breeding makes it possible for the parakeets to avoid competition with other birds for nesting sites, to avoid fledging young during the monsoon period, and to take advantage of the winter pea crop which provides the female with extra nutrients for egg production.

Environmental concentrations of an androgenic progestin disrupts the seasonal breeding cycle in male three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Svensson, Johan; Fick, Jerker; Brandt, Ingvar; Brunström, Björn

2014-02-01

Synthetic steroid hormones from contraceptive pharmaceuticals have become global aquatic contaminants. Progestins, the synthetic analogs to progesterone, are receiving increasing attention as contaminants and have been shown to impair reproduction in fish and amphibians at low ng L(-1) concentrations. Certain progestins, such as levonorgestrel have androgenic properties and seem to be several orders of magnitude more potent in terms of reproductive impairment in fish than non-androgenic progestins and progestagens. We recently reported that levonorgestrel has strong androgenic effects in female three-spined sticklebacks (Gasterosteus aculeatus), including induction of the normally male-specific glue protein spiggin and suppression of vitellogenesis. In light of this we investigated if exposure to levonorgestrel could disrupt the highly androgen-dependent seasonal reproductive cycle in male sticklebacks. Male sticklebacks that were in the final stage of a breeding period were exposed to various concentrations of levonorgestrel for six weeks in winter conditions in terms of light and temperature, after which reproductive status was evaluated from gross morphology, histology and key gene transcript levels. During the experimental period the controls had transitioned from full breeding condition into the non-breeding state, including regression of secondary sex characteristics, cessation of spiggin production in the kidney, and resumption of spermatogenesis in the testes. This is ascribed to the natural drop in plasma androgen levels after breeding. However, in the groups concurrently exposed to levonorgestrel, transition to the non-breeding condition was dose-dependently inhibited. Our results show that levonorgestrel can disrupt the seasonal breeding cycle in male sticklebacks. The fitness costs of such an effect could be detrimental to natural stickleback populations. Some effects occurred at a levonorgestrel concentration of 6.5 ng L(-1), well within the range of

Agriculture modifies the seasonal decline of breeding success in a tropical wild bird population

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Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

2014-01-01

Habitat conversion for agriculture is a major driver of biodiversity loss, but our understanding of the demographic processes involved remains poor. We typically investigate the impacts of agriculture in isolation even though populations are likely to experience multiple, concurrent changes in the environment (e.g. land and climate change). Drivers of environmental change may interact to affect demography, but the mechanisms have yet to be explored fully in wild populations. Here, we investigate the mechanisms linking agricultural land use with breeding success using long-term data for the formerly Critically Endangered Mauritius kestrel Falco punctatus, a tropical forest specialist that also occupies agricultural habitats. We specifically focused on the relationship between breeding success, agriculture and the timing of breeding because the latter is sensitive to changes in climatic conditions (spring rainfall) and enables us to explore the interactive effects of different (land and climate) drivers of environmental change. Breeding success, measured as egg survival to fledging, declines seasonally in this population, but we found that the rate of this decline became increasingly rapid as the area of agriculture around a nest site increased. If the relationship between breeding success and agriculture was used in isolation to estimate the demographic impact of agriculture, it would significantly under-estimate breeding success in dry (early) springs and over-estimate breeding success in wet (late) springs. Analysis of prey delivered to nests suggests that the relationship between breeding success and agriculture might be due, in part, to spatial variation in the availability of native, arboreal geckos. Synthesis and applications. Agriculture modifies the seasonal decline in breeding success in this population. As springs are becoming wetter in our study area and since the kestrels breed later in wetter springs, the impact of agriculture on breeding success will

CRYOPRESERVATION OF RAM SPERM FROM AUTOCHTHONOUS BREEDS DURING A NON-MATING SEASON

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Milko SABEV

2007-07-01

Full Text Available It is possible to collect and successfully cryopreserve ejaculates in a non-mating season from rams of the autochthonous breeds Karakachan, Cooper-red Shumen and Karnobat-local, raised in Bulgaria. Studies are in progress aiming the elaboration of optimal cryoprotective extenders and freezing technology.

Efficient induction of spawning of northern leopard frogs (Lithobates pipiens) during and outside the natural breeding season.

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Trudeau, Vance L; Schueler, Frederick W; Navarro-Martin, Laia; Hamilton, Christine K; Bulaeva, Elizabeth; Bennett, Amanda; Fletcher, William; Taylor, Lisa

2013-02-25

Amphibian declines are now recognized globally. It is also well known that many anurans do not reproduce easily in captivity, especially when held over long periods, or if they require hibernation before breeding. A simple method to induce spawning and subsequent development of large numbers of healthy tadpoles is therefore required to meet research and conservation goals. The method is based on simultaneous injection of both female and male leopard frogs, Lithobates pipiens (formerly called Rana pipiens) with a cocktail of a gonadotropin-releasing hormone agonist (GnRH-A) and a dopamine antagonist. We call this the AMPHIPLEX method, which is derived from the combination of the words amphibian and amplexus. Following injection, the animals are thereby induced, and perform amplexus and natural fertilization under captive conditions. We tested combinations of a GnRH agonist with 2 different dopamine antagonists in L. pipiens in the breeding season. The combination of des-Gly(10), D-Ala(6), Pro-NHEt(9)-GnRH (0.4 micrograms/g body weight; GnRH-A) with metoclopramide hydrochloride (10 micrograms/g body weight; MET) or domperidone (DOM) were equally effective, producing 89% and 88% successful spawning, respectively. This yielded more than 44,000 eggs for the 16/18 females that ovulated in the GnRH-A+MET group, and more than 39,000 eggs for the 15/17 females that ovulated in the GnRH-A+DOM group. We further tested the GnRH-A+MET in frogs collected in the wild in late autumn and hibernated for a short period under laboratory conditions, and report a low spawning success (43%). However, GnRH-A priming 24 hours prior to injections of the GnRH-A+MET cocktail in animals hibernated for 5-6 weeks produced out-of-season spawning (89%) and fertilization (85%) comparable to those we observed for in-season spawning. Assessment of age and weight at metamorphosis indicated that L. pipiens tadpoles resulting from out-of-season spawning grew normally and metamorphosed successfully. We

Repeated embryo collection and interspecies transfer in alpacas and llamas during non-breeding season

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Pacheco J

2015-08-01

Full Text Available Sexual behavior evaluation was evaluated, collecting and interspecies embryo transfer inter species in llamas and alpacas during non-breeding season, 10 and 10 donor alpacas llamas, alpacas and 20 receiving 20 llamas, 5 alpacas and 5 llamas males were used. Sexual behavior by libido in males and acceptance of female to male in the presence of a dominant follicle was evaluated, the collection of embryos simple ovulation by non-surgical technique was performed and the fresh embryos are transferred directly into the horn left. It was observed that only 40% of alpaca accept the male and female in all cases had to use two males for mating, but all llama males mounted on the first attempt and accepted all females breeding. Embryos were collected at 25 and 60% of alpacas and llamas washes respectively, all were grade 1 embryos transferable; the embryo transfer fertility evaluated by ultrasound at 25 days was 100 and 41.6% respectively for donor alpaca and llama, however ultrasound evaluation at 60 days fertility was 50 and 25% respectively for donor alpaca and llama. We conclude that there is greater reproductive seasonality in alpaca regard to llamas, all were grade 1 embryos collected, fertility evaluated by ultrasound 25 days down to 60 days, demonstrating embryonic mortality, possibly due to the non-breeding season of both species.

Effects of food provisioning and habitat management on spatial behaviour of Little Owls during the breeding season

DEFF Research Database (Denmark)

Jacobsen, Lars Bo; Chrenkova, Monika; Sunde, Peter

2016-01-01

The population of Little Owls in Denmark is close to extinction. The main cause is food limitation during the breeding season. Efforts to improve breeding success include providing breeding pairs with supplementary food and attempts to improve foraging habitats by creating short grass areas near ...... reproductive output in an endangered raptor, but also to decreased working effort, which in turn may improve adult survival....

Better late than never? Interannual and seasonal variability in breeding chronology of gentoo penguins at Stranger Point, Antarctica

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Mariana A. Juáres

2013-05-01

Full Text Available Rapid climate change recorded in the western Antarctic Peninsula confronts species with less predictable conditions in the marine and terrestrial environments. We analysed the breeding chronology and nesting site selection of gentoo penguins (Pygoscelis papua at King George Island (Isla 25 de Mayo, Antarctica, during four seasons in which differences in snow presence and persistence on the ground were observed. We recorded an overall delay as well as seasonal asynchrony at the beginning of reproduction for those years with higher snow deposition. A redistribution of breeding groups was also observed. Nevertheless, the population breeding success and chicks’ weight at fledging remained relatively constant, despite the delay in breeding chronology, the increased duration of foraging trips during the guard stage and the decreased weight of stomach contents during the crèche stage. We suggest that the plasticity of their trophic biology, along with the flexibility of their breeding phenology and relocation of breeding groups, may be complementary reasons why gentoo penguin populations in the region have remained stable in spite of the changing conditions currently registered.

Breeding seasons, molt patterns, and gender and age criteria for selected northeastern Costa Rican resident landbirds

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Jared D. Wolfe; Peter Pyle; C. John. Ralph

2009-01-01

Detailed accounts of molt and breeding cycles remain elusive for the majority of resident tropical bird species. We used data derived from a museum review and 12 years of banding data to infer breeding seasonality, molt patterns, and age and gender criteria for 27 common landbird species in northeastern Costa Rica. Prealternate molts appear to be rare, only occurring...

Induction of estrus during the non-breeding season in Egyptian Baladi goats.

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Medan, Mohamed; Shalaby, Abdel-Hamid; Sharawy, Sayed; Watanabe, Gen; Taya, Kazuyoshi

2002-01-01

The induction of estrus during the non-breeding season was investigated in 100 Egyptian Baladi goats (Capra hircus). All animals assigned to treatments had low progesterone concentrations (Baladi goats using norgestomet and PGF2alpha and the injection of GnRH 24 hr after norgestomet implant removal synchronized ovulation in a higher percentage of goats.

Modulation of heart rate response to acute stressors throughout the breeding season in the king penguin Aptenodytes patagonicus.

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Viblanc, Vincent A; Smith, Andrew D; Gineste, Benoit; Kauffmann, Marion; Groscolas, René

2015-06-01

'Fight-or-flight' stress responses allow animals to cope adaptively to sudden threats by mobilizing energy resources and priming the body for action. Because such responses can be costly and redirect behavior and energy from reproduction to survival, they are likely to be shaped by specific life-history stages, depending on the available energy resources and the commitment to reproduction. Here, we consider how heart rate (HR) responses to acute stressors are affected by the advancing breeding season in a colonial seabird, the king penguin (Aptenodytes patagonicus). We subjected 77 birds (44 males, 33 females) at various stages of incubation and chick-rearing to three experimental stressors (metal sound, distant approach and capture) known to vary both in their intensity and associated risk, and monitored their HR responses. Our results show that HR increase in response to acute stressors was progressively attenuated with the stage of breeding from incubation to chick-rearing. Stress responses did not vary according to nutritional status or seasonal timing (whether breeding was initiated early or late in the season), but were markedly lower during chick-rearing than during incubation. This pattern was obvious for all three stressors. We discuss how 'fight-or-flight' responses may be modulated by considering the energy commitment to breeding, nutritional status and reproductive value of the brood in breeding seabirds. © 2015. Published by The Company of Biologists Ltd.

Effects of season and artificial photoperiod on semen and seminal plasma characteristics in bucks of two goat breeds maintained in a semen collection center

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Francisco Arrebola

2017-05-01

Full Text Available Aim: This study quantified the effects of season and photoperiodic treatment on semen and seminal plasma (SP characteristics in 12 bucks of two Spanish goat breeds (Murciano-Granadina, and Payoya for the past 1 year. Materials and Methods: A total of 6 bucks (three of each breed were exposed to the natural day length and the other six males (three of each breed were exposed to alternating conditions of 2 months of long days (16 h light and 2 months of short days (8 h light. Weekly concentrations of glutamic oxaloacetic transaminase/aspartate aminotransferase (GOT/AST, lactate dehydrogenase (LDH, potassium, testosterone, and protein in SP were measured. Reaction time and scrotal circumference were recorded, and plasma testosterone concentrations were measured before semen collection. Results: Sperm volume, LDH, and potassium concentration in SP, and reaction time did not differ significantly between breeds, seasons, and photoperiodic treatment. Sperm concentrations were higher (p<0.001 in spring and summer than they were in autumn and winter. Mean percentage of positive hypo-osmotic swelling test sperm was the highest in summer and under the artificial photoperiod (p<0.01. GOT/AST concentrations differed (p<0.01 between breeds and seasons. Breed, season, and photoperiod had significant (p<0.001 effects on protein and testosterone levels in SP. Plasma testosterone concentrations were highest in summer (p<0.001, and differed significantly (p<0.01 between breeds. Scrotal perimeter differed significantly (p<0.001 between breeds and photoperiod. Conclusion: Recognition of those seasonal and breed-specific differences in the performance of bucks should help to improve the management of individual semen samples for use in artificial insemination programs.

Short-term progestagen treatment in ewes during the breeding season

OpenAIRE

Almeida, José Carlos; Simões, João; Valentim, Ramiro; Mascarenhas, R.; Fontes, Paulo; Azevedo, Jorge

2006-01-01

To characterize the efficiency of oestrus synchronization with short-term progestagen treatment (stFGA), 20 Ile de France (IF) and 19 Churra da Terra Quente (CTQ) ewes were used during the mid-breeding season. At day 0 (D0), a 40 mg FGA sponge was inserted in all animals and 120 µg cloprostenol was injected. Five days later (D5), all sponges were removed and ewes were divided into two groups: group A (10 IF and 10 CTQ), treated with eCG (250 UI) at sponge withdrawal and group II (10 IF and 9 ...

Neuroendocrine regulation of gonadotropin secretion in seasonally breeding birds

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Takayoshi eUbuka

2013-03-01

Full Text Available Seasonally breeding birds detect environmental signals, such as light, temperature, food availability and presence of mates to time reproduction. Hypothalamic neurons integrate external and internal signals, and regulate reproduction by releasing neurohormones to the pituitary gland. The pituitary gland synthesizes and releases gonadotropins which in turn act on the gonads to stimulate gametogenesis and sex steroid secretion. Accordingly, how gonadotropin secretion is controlled by the hypothalamus is key to our understanding of the mechanisms of seasonal reproduction. A hypothalamic neuropeptide, gonadotropin-releasing hormone (GnRH, activates reproduction by stimulating gonadotropin synthesis and release. Another hypothalamic neuropeptide, gonadotropin-inhibitory hormone (GnIH, inhibits gonadotropin synthesis and release directly by acting on the pituitary gland or indirectly by decreasing the activity of GnRH neurons. Therefore, the next step to understand seasonal reproduction is to investigate how the activities of GnRH and GnIH neurons in the hypothalamus and their receptors in the pituitary gland are regulated by external and internal signals. It is possible that locally-produced triiodothyronine resulting from the action of type 2 iodothyronine deiodinase on thyroxine stimulates the release of gonadotropins, perhaps by action on GnRH neurons. The function of GnRH neurons is also regulated by transcription of the GnRH gene. Melatonin, a nocturnal hormone, stimulates the synthesis and release of GnIH and GnIH may therefore regulate a daily rhythm of gonadotropin secretion. GnIH may also temporally suppress gonadotropin secretion when environmental conditions are unfavorable. Environmental and social milieus fluctuate seasonally in the wild. Accordingly, complex interactions of various neuronal and hormonal systems need to be considered if we are to understand the mechanisms underlying seasonal reproduction.

Population trends of Rhinolophus affinis during the breeding and non-breeding season roosting at the Kota Gelanggi limestone complex, Pahang

Science.gov (United States)

Sia, Ting Jin; Zubaid, Akbar; Foo, Ng Yong

2015-09-01

Monitoring population trends of bats in caves is difficult but is very important for their conservation. Their vulnerability to decline cannot be taken lightly and must be monitored for future management purposes especially in places open to the public. No studies have been done on bats roosting in caves at Kota Gelanggi and there are very few published studies of cave-dwelling bats in Malaysia. To fill this gap, a study on monitoring the population trends of Rhinolophus affinis was carried out in two caves namely, Gua Kepala Gajah and Gua Tongkat. This study was conducted from October 2013 until December 2014. The population size was estimated by direct visual counts and photographic methods during the day. The bats were caught by using mists net and harp traps. The reproductive condition of both female and male individuals was examined. The mean estimated population size for R. affinis in Gua Kepala Gajah was 221 individuals and 464 in Gua Tongkat. The population size of R. affinis showed an obvious decline during the breeding season and increased gradually after that for both caves. Pregnant R. affinis were found in April 2014 and lactating in June 2014 in both caves. It is important to know the breeding and non-breeding season of bats in both caves and their roosting behaviour in order to protect the bats from human disturbance as these caves are open to the public. The findings will enable the TEKAM management to come out with a proper conservation and management plan for protecting the bat fauna in these caves.

The effect of Lameness before and during the breeding season on fertility in 10 pasture-based Irish dairy herds.

Science.gov (United States)

Somers, Joris R; Huxley, Jon; Lorenz, Ingrid; Doherty, Michael L; O'Grady, Luke

2015-01-01

The effects of lameness on fertility have been documented frequently but few data are available from seasonally breeding, pasture-based herds (such as those used in Ireland) where cows are housed during the winter months but managed at pasture for the remainder of the year. This study determined the prevalence of lameness in a group of 786 cows in 10 pasture-based Irish dairy herds before, during and after the breeding season and assessed the relationship between lameness and the reproductive performance in these herds through serial locomotion scoring during the grazing period. Lameness prevalences of 11.6 % before, 14.6 % during and 11.6 % after the breeding season were found and these compared favourably to results from housed cattle and are similar to other studies carried out in grazing herds. A Cox proportional hazards model with locomotion score as time varying covariate was used. After controlling for the effect of farm, month of calving, body condition score at calving, body condition score loss after calving and economic breeding index, cows identified as lame during the study were less likely to become pregnant. Cows lame before the earliest serve date but no longer lame during the breeding season, cows becoming lame after the earliest serve date and cows identified lame both before and after this date were respectively 12 %, 35 % and 38 % less likely to become pregnant compared to cows never observed lame during the study. However, these findings were only significant for cows becoming lame after the earliest serve date and cows lame both before and after the start of breeding. This study found that the reproductive efficiency was significantly (p  0.05) lower in these animals compared to cows never diagnosed as lame. In addition to lameness status, nutritional status and genetics were found to influence the reproductive performance in pasture-based Irish dairy herds.

Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus.

Science.gov (United States)

Kvarnemo, C; Svensson, O; Manson, W

2010-05-01

This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.

Effect of Calcium Soap of Fatty Acids Supplementation on Serum Biochemical Parameters and Ovarian Activity during Out-of-the-Breeding Season in Crossbred Ewes

Science.gov (United States)

El-Nour, Hayat H. M.; Nasr, Soad M.; Hassan, Walid R.

2012-01-01

This experiment aimed to evaluate the effect of calcium soap of fatty acid (CSFA) supplementation on serum biochemical and hormones and ovarian activity during out-of-the-breeding season in ewes. Twelve crossbred ewes, 2-3 years of age and weighting 45–55 kg, were allocated into two equal groups. The first group was control and the other was treated with 50 g/head of CSFA. All ewes were fed basal diet and treated with 60 mg of medroxy progesterone acetate intravaginal sponge for 12 day. At the third day of sponge removal, the CSFA-treated group was given 50 g/head of CSFA daily for two estrous cycles. During the estrus phase, ovarian activity was detected using ultrasonography in both groups. All ewes were then subjected to natural breeding and conception rate. Blood samples were collected from all ewes during treatment period. Results revealed significant (P < 0.05) increases in serum cholesterol, triglycerides, low-density lipoprotein cholesterol, glucose, and progesterone levels with decrease in calcium and phosphorous levels in treated group. In treated group, normal-size ovaries and more than one follicle on the ovaries were detected and pregnancy rate increased. In conclusion, CSFA supplementation was effective to maintain the reproductive performance when ewes were out of the breeding season. PMID:22629155

Effect of Calcium Soap of Fatty Acids Supplementation on Serum Biochemical Parameters and Ovarian Activity during Out-of-the-Breeding Season in Crossbred Ewes

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Hayat H. M. El-Nour

2012-01-01

Full Text Available This experiment aimed to evaluate the effect of calcium soap of fatty acid (CSFA supplementation on serum biochemical and hormones and ovarian activity during out-of-the-breeding season in ewes. Twelve crossbred ewes, 2-3 years of age and weighting 45–55 kg, were allocated into two equal groups. The first group was control and the other was treated with 50 g/head of CSFA. All ewes were fed basal diet and treated with 60 mg of medroxy progesterone acetate intravaginal sponge for 12 day. At the third day of sponge removal, the CSFA-treated group was given 50 g/head of CSFA daily for two estrous cycles. During the estrus phase, ovarian activity was detected using ultrasonography in both groups. All ewes were then subjected to natural breeding and conception rate. Blood samples were collected from all ewes during treatment period. Results revealed significant (<0.05 increases in serum cholesterol, triglycerides, low-density lipoprotein cholesterol, glucose, and progesterone levels with decrease in calcium and phosphorous levels in treated group. In treated group, normal-size ovaries and more than one follicle on the ovaries were detected and pregnancy rate increased. In conclusion, CSFA supplementation was effective to maintain the reproductive performance when ewes were out of the breeding season.

Saccular Transcriptome Profiles of the Seasonal Breeding Plainfin Midshipman Fish (Porichthys notatus), a Teleost with Divergent Sexual Phenotypes.

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Faber-Hammond, Joshua; Samanta, Manoj P; Whitchurch, Elizabeth A; Manning, Dustin; Sisneros, Joseph A; Coffin, Allison B

2015-01-01

Acoustic communication is essential for the reproductive success of the plainfin midshipman fish (Porichthys notatus). During the breeding season, type I males use acoustic cues to advertise nest location to potential mates, creating an audible signal that attracts reproductive females. Type II (sneaker) males also likely use this social acoustic signal to find breeding pairs from which to steal fertilizations. Estrogen-induced changes in the auditory system of breeding females are thought to enhance neural encoding of the advertisement call, and recent anatomical data suggest the saccule (the main auditory end organ) as one possible target for this seasonal modulation. Here we describe saccular transcriptomes from all three sexual phenotypes (females, type I and II males) collected during the breeding season as a first step in understanding the mechanisms underlying sexual phenotype-specific and seasonal differences in auditory function. We used RNA-Seq on the Ion Torrent platform to create a combined transcriptome dataset containing over 79,000 assembled transcripts representing almost 9,000 unique annotated genes. These identified genes include several with known inner ear function and multiple steroid hormone receptors. Transcripts most closely matched to published genomes of nile tilapia and large yellow croaker, inconsistent with the phylogenetic relationship between these species but consistent with the importance of acoustic communication in their life-history strategies. We then compared the RNA-Seq results from the saccules of reproductive females with a separate transcriptome from the non-reproductive female phenotype and found over 700 differentially expressed transcripts, including members of the Wnt and Notch signaling pathways that mediate cell proliferation and hair cell addition in the inner ear. These data constitute a valuable resource for furthering our understanding of the molecular basis for peripheral auditory function as well as a range of

Saccular Transcriptome Profiles of the Seasonal Breeding Plainfin Midshipman Fish (Porichthys notatus, a Teleost with Divergent Sexual Phenotypes.

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Joshua Faber-Hammond

Full Text Available Acoustic communication is essential for the reproductive success of the plainfin midshipman fish (Porichthys notatus. During the breeding season, type I males use acoustic cues to advertise nest location to potential mates, creating an audible signal that attracts reproductive females. Type II (sneaker males also likely use this social acoustic signal to find breeding pairs from which to steal fertilizations. Estrogen-induced changes in the auditory system of breeding females are thought to enhance neural encoding of the advertisement call, and recent anatomical data suggest the saccule (the main auditory end organ as one possible target for this seasonal modulation. Here we describe saccular transcriptomes from all three sexual phenotypes (females, type I and II males collected during the breeding season as a first step in understanding the mechanisms underlying sexual phenotype-specific and seasonal differences in auditory function. We used RNA-Seq on the Ion Torrent platform to create a combined transcriptome dataset containing over 79,000 assembled transcripts representing almost 9,000 unique annotated genes. These identified genes include several with known inner ear function and multiple steroid hormone receptors. Transcripts most closely matched to published genomes of nile tilapia and large yellow croaker, inconsistent with the phylogenetic relationship between these species but consistent with the importance of acoustic communication in their life-history strategies. We then compared the RNA-Seq results from the saccules of reproductive females with a separate transcriptome from the non-reproductive female phenotype and found over 700 differentially expressed transcripts, including members of the Wnt and Notch signaling pathways that mediate cell proliferation and hair cell addition in the inner ear. These data constitute a valuable resource for furthering our understanding of the molecular basis for peripheral auditory function as well

Breeding phenology of African Black Oystercatchers Haematopus ...

African Journals Online (AJOL)

The timing of the start and duration of breeding and the effect of these on breeding productivity were analysed for African Black Oystercatchers Haematopus moquini on Robben Island, South Africa, over three breeding seasons from 2001 to 2004. African Black Oystercatchers have a long breeding season, from November ...

Induction of synchronized oestrous in indigenous Damascus goats outside the breeding season

International Nuclear Information System (INIS)

Zarkawi, M.

2000-01-01

Synchronized oestrous was induced in indigenous Damascus goats, outside the breeding season, using intravaginal progestogen sponges containing 60 mg of medroxyprogesterone acetate (MAP), plus pregnant mare serum gonadotrophin (PMSG). A total of 78 female Damascus goats of mixed ages (1.5 to 5 years) were divided randomly into 2 equal groups, T and C. The females in Group T were treated with MAP for 18 days and injected intramuscularly with either 150 of 200 IU PMSG at sponge withdrawal, whereas, animals in Group C (control) received no treatment. The results indicated that oestrous was induced between 21 to 68 h post-sponge withdrawal in all treated animals, resulting in oestrous response of 100%. all animals in Group C were in anoestrous during the treatment period. In the Group T, conception rate and fecundity rate were 65.8% and 195.2%, respectively. There was no significant difference in pregnancy duration between animals carrying singles and twins (149 versus 184.5 days, respectively). The average birth weight of kids was 3.8 kg. However, single-born kids were significantly (p < 0.05) heavier at birth than individual twins (4.8 versus 3.8 kg). The results suggest that it is possible to induce synchronized and fertile oestrous, obtain successful pregnancy and kidding in Damascus goats outside the breeding season, using intravaginal sponges and successful. (author)

A biomechanical assessment to evaluate breed differences in normal porcine medial collateral ligaments.

Science.gov (United States)

Germscheid, Niccole M; Thornton, Gail M; Hart, David A; Hildebrand, Kevin A

2011-02-24

Little information is available on the role of genetic factors and heredity in normal ligament behaviour and their ability to heal. Assessing these factors is challenging because of the lack of suitable animal models. Therefore, the purpose of this study was to develop a porcine model in order to evaluate and compare the biomechanical differences of normal medial collateral ligaments (MCLs) between Yorkshire (YK) and red Duroc (RD) breeds. It was hypothesized that biomechanical differences would not exist between normal YK and RD MCLs. Comparisons between porcine and human MCL were also made. A biomechanical testing apparatus and protocol specific to pig MCL were developed. Ligaments were subjected to cyclic and static creep tests and then elongated to failure. Pig MCL morphology, geometry, and low- and high-load mechanical behaviour were assessed. The custom-designed apparatus and protocol were sufficiently sensitive to detect mechanical property differences between breeds as well as inter-leg differences. The results reveal that porcine MCL is comparable in both shape and size to human MCL and exhibits similar structural and material failure properties, thus making it a feasible model. Comparisons between RD and YK breeds revealed that age-matched RD pigs weigh more, have larger MCL cross-sectional area, and have lower MCL failure stress than YK pigs. The effect of weight may have influenced MCL geometrical and biomechanical properties, and consequently, the differences observed may be due to breed type and/or animal weight. In conclusion, the pig serves as a suitable large animal model for genetic-related connective tissue studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

Timing of breeding and reproductive performance in murres and kittiwakes reflect mismatched seasonal prey dynamics

Science.gov (United States)

Shultz, M.T.; Piatt, John F.; Harding, A.M.A.; Kettle, Arthur B.; van Pelt, Thomas I.

2009-01-01

Seabirds are thought to time breeding to match the seasonal peak of food availability with peak chick energetic demands, but warming ocean temperatures have altered the timing of spring events, creating the potential for mismatches. The resilience of seabird populations to climate change depends on their ability to anticipate changes in the timing and magnitude of peak food availability and 'fine-tune' efforts to match ('Anticipation Hypothesis'). The degree that inter-annual variation in seabird timing of breeding and reproductive performance represents anticipated food availability versus energetic constraints ('Constraint Hypothesis') is poorly understood. We examined the relative merits of the Constraint and Anticipation Hypotheses by testing 2 predictions of the Constraint Hypothesis: (1) seabird timing of breeding is related to food availability prior to egg laying rather than the date of peak food availability, (2) initial reproductive output (e.g. laying success, clutch size) is related to pre-lay food availability rather than anticipated chick-rearing food availability. We analyzed breeding biology data of common murres Uria aalge and black-legged kittiwakes Rissa tridactyla and 2 proxies of the seasonal dynamics of their food availability (near-shore forage fish abundance and sea-surface temperature) at 2 colonies in Lower Cook Inlet, Alaska, USA, from 1996 to 1999. Our results support the Constraint Hypothesis: (1) for both species, egg laying was later in years with warmer sea-surface temperature and lower food availability prior to egg laying, but was not related to the date of peak food availability, (2) pre-egg laying food availability explained variation in kittiwake laying success and clutch size. Murre reproductive success was best explained by food availability during chick rearing. ?? 2009 Inter-Research.

Seasonal influence on the thyroid gland in healthy dogs of various breeds in different weights

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Mária Fialkovičová

2012-01-01

Full Text Available The aim of our study was to evaluate the influence of seasonal ambient temperature on the thyroid gland function in terms of serum total thyroxine (TT4, free thyroxine (fT4, total triiodothyronine (TT3, and canine thyroid stimulating hormone (cTSH concentrations in healthy dogs of various breeds living outdoors and to compare them with those living indoors in flats and houses. The monitoring was conducted for 5 years and our study included 162 indoor dogs and 148 outdoor dogs of both sexes from 2 to 12 years of age, categorised into 3 groups according to their body weight: large (n = 17, medium (n = 16 and small (n = 17 breeds. Comparison of the seasonal serum TT4 and fT4 concentrations in both the indoor and outdoor dogs confirmed their fluctuation in relation to the ambient temperature in all weight groups with the lowest average of TT4 and fT4 concentrations recorded in summer and the highest ones in winter. In dogs kept outdoors, the fluctuation of hormone values was significant (P P < 0.05 only in the medium breeds living outdoors, but their concentrations did not exceed the reference ranges. The 5-year monitoring of serum TT3 in indoor and outdoor dogs of large, medium, and small breeds clearly showed that its concentrations were not influenced by varying ambient temperature. The study provides for the first time evidence that serum TT4 and fT4 concentrations in dogs kept outdoors directly depend on ambient temperature. This correlation was also expressed by mathematical equations.

Effect of Using Melatonin Implants on Postpartum Reproductive Indices in Tigaia Sheep Breed

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Ioan Padeanu

2012-10-01

Full Text Available Investigations were carried out in a commercial farm from Turnu, Arad County, on a number of 110 indigenous adultewes from the Tigaia breed. It is estimated by some authors that administration of subcutaneous melatonin implantsduring a period of 30 days, in lactating or dry ewes, would improve the reproductive performances in some sheepbreeds. Subcutaneous melatonin implants (Melovin were inserted to the ewes in doses of 18 mg. Current research,emphasized treated that from indigenous Tigaia breed, can be obtained superior reproduction indexes if the animalsare treated with melatonin implants with 35 days before the mating season, differences from the untreated groupbeing significantly (p<0.001. However, in sheep treated used melatonin implants, the lambing interval were reducedwith 40 to 50%. It seems that use of melatonin implants Melovin type near the beginning of normal breeding season,increases the reproductive performance of adult ewes from the Tigaia breed.

Environmental, dietary, and hormonal factors in the regulation of seasonal breeding in free-living female Indian rose-ringed parakeets (Psittacula krameri).

Science.gov (United States)

Sailaja, R; Kotak, V C; Sharp, P J; Schmedemann, R; Haase, E

1988-12-01

The roles of environmental, dietary, and hormonal factors in the timing of seasonal breeding were assessed in free-living female Indian rose-ringed parakeets, Psittacula krameri, in northwest India (22 degrees 2'N, 73 degrees E). The ovaries and oviducts began to enlarge in January, were fully developed in February, and began to regress in March. During this time there was no significant change in the concentration of plasma luteinizing hormone (LH) or estradiol. The concentration of plasma LH decreased (P less than 0.01) at the end of the breeding season. Pair bond formation occurred between September and December and was associated with an increase in levels of plasma LH but no change in plasma estradiol. Concentrations of plasma testosterone (T) and 5 alpha-dihydrotestosterone (5 alpha-DHT) did not vary significantly during the year and were similar to those in males except for higher values of 5 alpha-DHT and lower values of T during the pre- and postbreeding periods, respectively. The similar levels of plasma androgens in both sexes may be related to the equal roles that both sexes play in the defence of their nest holes. An analysis of crop sac contents showed that the birds fed chiefly on pigeon peas (Cajanus cajan) during the breeding season and on cereal grains at other times of the year. It is suggested that pigeon peas provide the extra nutrients, including calcium, required for egg production. Since pigeon peas ripen between November and March, the production of the crop may play a role in the timing of seasonal breeding. A further factor appears to be competition for nest sites. By breeding in winter, the parakeet avoids competing with other species which nest in holes.

Predictive Modelling to Identify Near-Shore, Fine-Scale Seabird Distributions during the Breeding Season.

Science.gov (United States)

Warwick-Evans, Victoria C; Atkinson, Philip W; Robinson, Leonie A; Green, Jonathan A

2016-01-01

During the breeding season seabirds are constrained to coastal areas and are restricted in their movements, spending much of their time in near-shore waters either loafing or foraging. However, in using these areas they may be threatened by anthropogenic activities such as fishing, watersports and coastal developments including marine renewable energy installations. Although many studies describe large scale interactions between seabirds and the environment, the drivers behind near-shore, fine-scale distributions are not well understood. For example, Alderney is an important breeding ground for many species of seabird and has a diversity of human uses of the marine environment, thus providing an ideal location to investigate the near-shore fine-scale interactions between seabirds and the environment. We used vantage point observations of seabird distribution, collected during the 2013 breeding season in order to identify and quantify some of the environmental variables affecting the near-shore, fine-scale distribution of seabirds in Alderney's coastal waters. We validate the models with observation data collected in 2014 and show that water depth, distance to the intertidal zone, and distance to the nearest seabird nest are key predictors in the distribution of Alderney's seabirds. AUC values for each species suggest that these models perform well, although the model for shags performed better than those for auks and gulls. While further unexplained underlying localised variation in the environmental conditions will undoubtedly effect the fine-scale distribution of seabirds in near-shore waters we demonstrate the potential of this approach in marine planning and decision making.

Predictive Modelling to Identify Near-Shore, Fine-Scale Seabird Distributions during the Breeding Season.

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Victoria C Warwick-Evans

Full Text Available During the breeding season seabirds are constrained to coastal areas and are restricted in their movements, spending much of their time in near-shore waters either loafing or foraging. However, in using these areas they may be threatened by anthropogenic activities such as fishing, watersports and coastal developments including marine renewable energy installations. Although many studies describe large scale interactions between seabirds and the environment, the drivers behind near-shore, fine-scale distributions are not well understood. For example, Alderney is an important breeding ground for many species of seabird and has a diversity of human uses of the marine environment, thus providing an ideal location to investigate the near-shore fine-scale interactions between seabirds and the environment. We used vantage point observations of seabird distribution, collected during the 2013 breeding season in order to identify and quantify some of the environmental variables affecting the near-shore, fine-scale distribution of seabirds in Alderney's coastal waters. We validate the models with observation data collected in 2014 and show that water depth, distance to the intertidal zone, and distance to the nearest seabird nest are key predictors in the distribution of Alderney's seabirds. AUC values for each species suggest that these models perform well, although the model for shags performed better than those for auks and gulls. While further unexplained underlying localised variation in the environmental conditions will undoubtedly effect the fine-scale distribution of seabirds in near-shore waters we demonstrate the potential of this approach in marine planning and decision making.

Breeding of a new early season indica rice variety Ganzaoxian 56 by irradiation, anther culture and hybridization

International Nuclear Information System (INIS)

Huang Yingjin; Liu Yibai; Kuang Huiyun; Xu Zhengjin

2005-01-01

Ganzaoxian 56 is a new early season indica rice variety, which was bred in the College of Agronomy of Jiangxi Agricultural University by the integrative breeding techniques of radiation, anther culture and hybridization. Its main characteristics were as follows: super quality, high yield, high tolerance to heat-forced maturity, suitable maturity and high resistance to rice blast. It was registered by Crop Cultivar Registration Committee of Jiangxi Province on March 19, 2004. The breeding process of Ganzaoxian 56, main characteristics and the value of its exploitation and application were described in this paper. (authors)

Nonbreeding-Season Drivers of Population Dynamics in Seasonal Migrants: Conservation Parallels Across Taxa

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Anna M. Calvert

2009-12-01

Full Text Available For seasonal migrants, logistical constraints have often limited conservation efforts to improving survival and reproduction during the breeding season only. Yet, mounting empirical evidence suggests that events occurring throughout the migratory life cycle can critically alter the demography of many migrant species. Herein, we build upon recent syntheses of avian migration research to review the role of non-breeding seasons in determining the population dynamics and fitness of diverse migratory taxa, including salmonid fishes, marine mammals, ungulates, sea turtles, butterflies, and numerous bird groups. We discuss several similarities across these varied migrants: (i non-breeding survivorship tends to be a strong driver of population growth; (ii non-breeding events can affect fitness in subsequent seasons through seasonal interactions at individual- and population-levels; (iii broad-scale climatic influences often alter non-breeding resources and migration timing, and may amplify population impacts through covariation among seasonal vital rates; and (iv changes to both stationary and migratory non-breeding habitats can have important consequences for abundance and population trends. Finally, we draw on these patterns to recommend that future conservation research for seasonal migrants will benefit from: (1 more explicit recognition of the important parallels among taxonomically diverse migratory animals; (2 an expanded research perspective focused on quantification of all seasonal vital rates and their interactions; and (3 the development of detailed population projection models that account for complexity and uncertainty in migrant population dynamics.

Reproductive performance of Ile de France ewes under dietary supplementation before and during the breeding season

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Luis Gabriel Alves Cirne

2016-02-01

Full Text Available The aim of this study was to evaluate the reproductive performance of Ile de France ewes undergoing dietary supplementation before and during the breeding season, with and without association with management conditions (pre-mating shearing. Thirty-six ewes with an average body weight of 66 kg were used in the experiment. Treatments involved ewes receiving or not receiving concentrate supplementation (flushing, with groups subdivided according to the management condition to which animals were subjected: shearing or lack of it. Thus, ewes were divided into four treatments: flushed and shorn; flushed and unshorn; unflushed and shorn; and unflushed and unshorn. Flushing increased weight gain and body condition score, and when associated with shearing, it promoted anticipation of estrus. Fertility rate (86.05%, calving rate (77.77%, birth rate (113.83%, and type of birth (single: 82.29% and twin: 17.71% were not influenced. Birth weight (3.96 kg and prolificacy (1.25% also were not affected. Despite the lack of changes in reproductive traits, flushing adopted during the breeding season associated with shearing anticipated estrus in ewes.

A Sequence of Flushing and Drying of Breeding Habitats of Aedes aegypti (L. Prior to the Low Dengue Season in Singapore.

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Osama M E Seidahmed

2016-07-01

Full Text Available In dengue-endemic areas, transmission shows both a seasonal and interannual variability. To investigate how rainfall impacts dengue seasonality in Singapore, we carried out a longitudinal survey in the Geylang neighborhood from August 2014 to August 2015. The survey comprised of twice-weekly random inspections to outdoor breeding habitats and continuous monitoring for positive ones. In addition, observations of rainstorms were collected. Out of 6824 inspected habitats, 67 contained Aedes aegypti, 11 contained Aedes albopictus and 24 contained Culex spp. The main outdoors habitat of Aedes aegypti was storm drains (54/67. We found that 80% of breeding sites in drains (43/54 were lost after intense rainstorms related to the wet phase of the Northeast monsoon (NE between November 2014 and early January 2015. Subsequently, 95% (41/43 of these flushed drains had dried out during the dry phase of the NE in late January-February 2015. A return in the outdoor breeding of Aedes aegypti was observed after the onset of Southwest monsoon (SW between May and August 2015. There was also a reduction in productivity of breeding habitats for larvae and pupae after the onset of the NE. In wet equatorial regions like Singapore, rainfall varies with the monsoons. A monsoon-driven sequence of flushing and drying shapes the outdoor seasonal abundance of Aedes aegypti. This finding can be used to optimize vector control strategies and better understand dengue in the context of climate change.

A Sequence of Flushing and Drying of Breeding Habitats of Aedes aegypti (L.) Prior to the Low Dengue Season in Singapore.

Science.gov (United States)

Seidahmed, Osama M E; Eltahir, Elfatih A B

2016-07-01

In dengue-endemic areas, transmission shows both a seasonal and interannual variability. To investigate how rainfall impacts dengue seasonality in Singapore, we carried out a longitudinal survey in the Geylang neighborhood from August 2014 to August 2015. The survey comprised of twice-weekly random inspections to outdoor breeding habitats and continuous monitoring for positive ones. In addition, observations of rainstorms were collected. Out of 6824 inspected habitats, 67 contained Aedes aegypti, 11 contained Aedes albopictus and 24 contained Culex spp. The main outdoors habitat of Aedes aegypti was storm drains (54/67). We found that 80% of breeding sites in drains (43/54) were lost after intense rainstorms related to the wet phase of the Northeast monsoon (NE) between November 2014 and early January 2015. Subsequently, 95% (41/43) of these flushed drains had dried out during the dry phase of the NE in late January-February 2015. A return in the outdoor breeding of Aedes aegypti was observed after the onset of Southwest monsoon (SW) between May and August 2015. There was also a reduction in productivity of breeding habitats for larvae and pupae after the onset of the NE. In wet equatorial regions like Singapore, rainfall varies with the monsoons. A monsoon-driven sequence of flushing and drying shapes the outdoor seasonal abundance of Aedes aegypti. This finding can be used to optimize vector control strategies and better understand dengue in the context of climate change.

Evaluation of a seasonal-breeding artificial insemination programme in Uruguay using milk progesterone radioimmunoassay

International Nuclear Information System (INIS)

Cavestany, D.; Juanbeltz, R.; Canclini, E.; ElHordoy, D.; Lanzzeri, S.; Gama, S.; Martinez, E.; Galina, C.S.

2001-01-01

To evaluate artificial insemination (AI) services and reproductive efficiency in dairy herds in Uruguay two surveys were conducted in 1995 and 1996. The 1995 survey was done in 10 dairy farms of 3 regions on 696 lactating Holstein cows. The 1996 survey was done in 5 dairy farms in one region and included 768 cows. Precision of oestrus detection and efficiency of AI services were determined by milk progesterone samples taken at days 0, 10 and 23 after breeding and by analysis of the records. In 1995 and 1996, the intervals from calving to first service were 123 and 101 days, and to conception were 158 and 134 days, respectively. Parity, body weight and body condition at calving influenced these parameters, but not body weight or body condition at breeding nor milk production. Accuracy of pregnancy diagnosis by milk progesterone was 70.4%. Heat detection rate was 37.5% and pregnancy rate was 15.6%. In 1997 a second study was done to determine the factors affecting reproductive efficiency in a seasonal breeding AI programme in 328 lactating cows on 3 dairy farms. Milk progesterone measurement revealed that 12.5% of the cows were anoestrous at the beginning of the season and remained so during the trial. The category mostly affected were first-calf heifers (82%). Also, 8.5% of the cows cycling were never reported in heat and this was influenced by farm. Oestrus detection efficiency for cows determined to be cycling by progesterone profiles was evaluated in three periods of 21 days and overall efficiency was 46.9%. Main factor affecting it was farm, with an effect of parity (67.8% in mature cows and 33.2% in first-calf heifers) but no effect of days postpartum. Mean interval from the beginning of the breeding season to first service was 27.4 days, again with a strong farm variation but no effect of parity or days postpartum. In an attempt to improve reproductive efficiency in lactating dairy cows, a treatment protocol was designed, where 414 cows in two herds were

Seasonal variation of imipramine binding in the blood platelets of normal controls and depressed patients

International Nuclear Information System (INIS)

Arora, R.C.; Meltzer, H.Y.

1988-01-01

Imipramine binding (IB) was studied in the blood platelets from normal controls and depressed patients over a 4-year period (1981-1984) to determine if seasonal variation was present in Bmax or KD. Bimonthly variation in the Bmax of IB was found in normal controls studied longitudinally. No such variation was found when individual values from normal controls were examined on a monthly or seasonal basis. Bmax in depressed patients showed a significant seasonal, but not monthly, variation. KD of IB varied in normal controls using monthly or seasonal data, but not in the probably more reliable bimonthly data. These results suggest that IB studies comparing groups of subjects should match groups for season of the year or, for greater accuracy, month of the year

Repeated embryo collection and interspecies transfer in alpacas and llamas during non-breeding season

OpenAIRE

Pacheco J; Tollig S; Von Walter AW; Pezo D; Velez V

2015-01-01

Sexual behavior evaluation was evaluated, collecting and interspecies embryo transfer inter species in llamas and alpacas during non-breeding season, 10 and 10 donor alpacas llamas, alpacas and 20 receiving 20 llamas, 5 alpacas and 5 llamas males were used. Sexual behavior by libido in males and acceptance of female to male in the presence of a dominant follicle was evaluated, the collection of embryos simple ovulation by non-surgical technique was performed and the fresh embryos are transfer...

Seasonal and Topographical Factors Affecting Breeding Sites of Culex Larvae in Nakhon Si Thammarat, Thailand

OpenAIRE

Warabhorn PREECHAPORN; Mullica JAROENSUTASINEE; Krisanadej JAROENSUTASINEE; Jirawat SAETON

2007-01-01

This study investigated how the seasons affect the key breeding sites of Culex larvae in three topographical areas: mangrove, rice paddy and mountainous areas. We examined how the number of Culex larvae varied in different types of water containers. Water containers were categorised into the following groups: indoor/outdoor containers, artificial/natural containers, earthen/plastic containers, containers with/without lids and dark/light coloured containers. Samples were collected from 300 hou...

Out-of-season breeding of milk goats - the effect of light treatment, melatonin and breed : research communication

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E.R. Du Preez

2001-07-01

Full Text Available The purpose of this study was to evaluate the effectivity of melatonin in addition to light treatment (exposure to 2 hours of light during the night = a long-day photoperiod to modify the breeding season of Saanen and cross-bred milk goats and to compare the difference between the breeds. Twenty-two Saanen and 22 cross-bred does were randomly divided into 3 treatment groups. Group 1 (controls received no treatment, Group 2 received light treatment for 37 days and Group 3 received light treatment plus melatonin implants after the light treatment. After a further 35 days the 3 groups were brought together and a billy goat that had also been exposed to the extra light at night, had received a melatonin implant and had been isolated from the does during the treatment period, was introduced to the does for natural mating. Ultrasound scanning was used to diagnose pregnancy and all the pregnant goats kidded. Significantly more Saanen does compared to cross-bred does (P = 0.018 became pregnant and kidded after natural mating, when the group that received melatonin as well as light treatment was compared to the group that received light treatment only. Compared to light treatment only, the addition of melatonin to light treatment improved (P = 0.0028 conception after natural mating, in both the Saanen and the cross-bred does.

Circannual changes in progesterone secretion in intact ewes, luteinizing hormone secretion in ovariectomized estradiol-implanted ewes, and prolactin secretion in three sheep breeds anticipated to differ in seasonality of reproduction.

Science.gov (United States)

Goff, Katherine J; Knight, James W; Pelzer, Kevin D; Akers, R Michael; Notter, David R

2013-05-01

Changes in progesterone secretion in intact ewes (7 or 9 per breed) and luteinizing hormone secretion in ovariectomized, estradiol-implanted ewes (9 or 10 per breed) were monitored for 12 mo in Suffolk, tropically adapted St. Croix, and OOS ewes. The OOS line is a composite population of 50% Dorset, 25% Rambouillet, and 25% Finnish Landrace breeding that was selected for 10 yr for ability to lamb in October and early November. Ewes were isolated from rams, and blood samples were collected twice weekly. Circulating prolactin concentrations were also determined from blood samples collected near the summer and winter solstice and vernal and autumnal equinox. Intact OOS ewes entered anestrus later, began the subsequent breeding season sooner, and had a shorter seasonal anestrus than Suffolk and St. Croix ewes (P ≤ 0.005). St. Croix ewes did not differ from Suffolk ewes in date of onset or cessation of breeding or duration of anestrus (P ≥ 0.06). Breed differences in duration of luteinizing hormone inhibition in ovariectomized ewes were essentially identical to those observed for duration of anestrous. Prolactin concentrations varied during the year: annual changes were larger in relatively seasonal Suffolk ewes than in tropically-derived St. Croix ewes (Psheep did not have a shorter seasonal anestrus than Suffolk sheep under temperate conditions and ram isolation. Copyright © 2013 Elsevier B.V. All rights reserved.

Previous success and current body condition determine breeding propensity in Lesser Scaup: evidence for the individual heterogeneity hypothesis

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Warren, Jeffrey M.; Cutting, Kyle A.; Takekawa, John Y.; De La Cruz, Susan E. W.; Williams, Tony D.; Koons, David N.

2014-01-01

The decision to breed influences an individual's current and future reproduction, and the proportion of individuals that breed is an important determinant of population dynamics. Age, experience, individual quality, and environmental conditions have all been demonstrated to influence breeding propensity. To elucidate which of these factors exerts the greatest influence on breeding propensity in a temperate waterfowl, we studied female Lesser Scaup (Aythya affinis) breeding in southwestern Montana. Females were captured during the breeding seasons of 2007–2009, and breeding status was determined on the basis of (1) presence of an egg in the oviduct or (2) blood plasma vitellogenin (VTG) levels. Presence on the study site in the previous year, a proxy for adult female success, was determined with stable isotope signatures of a primary feather collected at capture. Overall, 57% of females had evidence of breeding at the time of capture; this increased to 86% for females captured on or after peak nest initiation. Capture date and size-adjusted body condition positively influenced breeding propensity, with a declining body-condition threshold through the breeding season. We did not detect an influence of age on breeding propensity. Drought conditions negatively affected breeding propensity, reducing the proportion of breeding females to 0.85 (SE = 0.05) from 0.94 (SE = 0.03) during normal-water years. A female that was present in the previous breeding season was 5% more likely to breed than a female that was not present then. The positive correlation between age and experience makes it difficult to differentiate the roles of age, experience, and individual quality in reproductive success in vertebrates. Our results indicate that individual quality, as expressed by previous success and current body condition, may be among the most important determinants of breeding propensity in female Lesser Scaup, providing further support for the individual heterogeneity hypothesis.

NMR-metabolomics profiling of mammary gland secretory tissue and milk serum in two goat breeds with different levels of tolerance to seasonal weight loss.

Science.gov (United States)

Palma, Mariana; Hernández-Castellano, Lorenzo E; Castro, Noemí; Arguëllo, Anastasio; Capote, Juan; Matzapetakis, Manolis; de Almeida, André Martinho

2016-06-21

Goats are of special importance in the Mediterranean and tropical regions for producing a variety of dairy products. The scarcity of pastures during the dry season leads to seasonal weight loss (SWL), which affects milk production. In this work, we studied the effect of feed-restriction on two dairy goat breeds, with different tolerance levels to SWL: the Majorera breed (tolerant) and the Palmera breed (susceptible). Nuclear magnetic resonance (NMR) was used to compare the metabolome of an aqueous fraction of the mammary gland and milk serum from both breeds. Goats in mid-lactation were divided by breed, and each in two feed-regime groups: the control group and the restricted-fed group (to achieve 15-20% reduction of body weight at the end of the experiment). Milk and mammary gland samples were collected at the end of the experimental period (23rd day). (1)H NMR spectra were collected from the aqueous extract of the mammary gland biopsies and the milk serum. Profiling analysis has led to the identification of 46 metabolites in the aqueous extract of the mammary gland. Lactose, glutamate, glycine and lactate were found to be the most abundant. Analysis of milk serum allowed the identification of 50 metabolites, the most abundant being lactose, citrate and creatine. Significant differences were observed, in mammary gland biopsies and milk serum, between control and restricted-fed groups in both breeds, albeit with no differences between the breeds. Variations seem to be related to metabolism adaptation to the low-energy diet and are indicative of breed-specific microflora. Milk serum showed more metabolites varying between control and restricted groups, than the mammary gland. The Majorera breed also showed more variations than the Palmera breed in milk samples, which could be an indication of a prompt adaptation to SWL by the Majorera breed.

The interplay between seasonality and density: consequences for female breeding decisions in a small cyclic herbivore.

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Pinot, Adrien; Gauffre, Bertrand; Bretagnolle, Vincent

2014-05-28

Cyclic rodent population dynamics are subjected to both intrinsic regulatory processes such as density-dependence and extrinsic environmental forcing. Among extrinsic factors, seasonal environmental variation is understood to facilitate cycles. In rodents, these processes have been studied mostly independently and their relative importance for population dynamics is poorly known. We performed a detailed analysis of common vole (Microtus arvalis) reproduction in a cyclic population using a spatially extensive data set over 17 years in central-western France. Environmental seasonality was the main source of explained variation in common vole reproduction. Additionally, inter-annual variation in the environment explained a smaller part of the variance in reproduction in spring and summer than in winter, whereas the effect of density was only found in autumn and winter. In particular, we detected a strong impact of plant productivity on fecundity during the breeding season, with low vegetation productivity being able to bring vole reproduction nearly to a halt. In contrast, vole reproduction during autumn and winter was mainly shaped by intrinsic factors, with only the longer and heavier females being able to reproduce. The effect of population density on reproduction was negative, mediated by direct negative effects on the proportion of breeders in autumn and winter during outbreak years and by a delayed negative effect on litter size the following year. During the main breeding season, variability of female vole reproduction is predominantly shaped by food resources, suggesting that only highly productive environment may induce vole outbreaks. During fall and winter, variability of female vole reproduction is mainly controlled by intrinsic factors, with high population density suppressing reproduction. This suggests, in this cyclic population, that negative direct density dependence on reproduction could explain winter declines after outbreaks.

Comparison of sexual performance and testicular characteristics of melatonin treated Kivircik and Charollais rams during the non-breeding season

Directory of Open Access Journals (Sweden)

M. Cevik

Full Text Available ABSTRACT This study was conducted to investigate the effects of melatonin implantation on basic testicular characteristics and reproductive performance of Kivircik and Charollais rams and ewes during the non-breeding season. In this study, 8 Kivircik and 6 Charollais rams were used. Rams were implanted with 54 mg melatonin according to the manufacturer's instructions. At melatonin implantation and at ram introduction the reproductive performance and testicular characteristics were evaluated. Throughout the experimental period, rams were permanently kept outdoors under conditions of natural day length and at ambient temperature. The effects of exogenous melatonin treatments on the reproductive performances of rams and ewes, estrus response, pregnancy rate, litter size and twinning rate of ewes were evaluated in all groups. Libido values were significantly higher in Charollais rams compared to Kivircik rams (P<0.001. Testicular volume (TV was increased in both ram breeds. Scrotal length (SL was also increased in both Kivircik and Charollais rams (P<0.01. In conclusion, we showed that the treatment of rams with slow release melatonin implants increased scrotal diameters and testicular volumes in both Kivircik and Charollais rams. Furthermore, melatonin implantation improved the reproductive performances of ewes naturally mated with these melatonin implanted rams during non-breeding season.

Serum testosterone in Arabian stallions during breeding and non ...

African Journals Online (AJOL)

Jane

2011-10-12

Oct 12, 2011 ... serum testosterone concentration during the non-breeding season is lower than that of the breeding season. .... confirm no impact of the stressful environmental conditions on the reproductive function of Arabian stallions.

[Fertility after treatment with Eazi-breedTM CIDR G for 6 or 12 days outside the breeding season in Lacaune dairy sheep].

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Fleisch, A; Piechotta, M; Bollwein, H; Janett, F

2013-07-01

This study compares the fertility after short- and long-term synchronization using a progesterone intravaginal device in Lacaune dairy sheep outside the breeding season. For the experiment 108 Lacaune sheep were treated with Eazi-breed™ CIDR® G intravaginal devices (Pfizer Animal Health, Zürich) for 12 days (Group L, n = 60) or 6 days (Group K, n = 48) in combination with eCG (Group L) or with eCG and 125 μg Cloprostenol (Group K) at device removal. Thereafter the ewes were kept together with rams for 60 days, ewes in estrus were recorded and the fertility was assessed after lambing. Blood progesterone concentration was measured at device application, withdrawal and 14 days later. Results show that neither treatment nor parity had an influence on estrus rate (Group L 91.7 %, Group K 93.8 %, nulli- and pluriparous animals 96.9 % and 90.8 %, respectively). Group L showed a tendency towards a better first cycle lambing rate and a significantly (P sheep of Group K (71.7 % vs. 60.4 % and 83.3 % vs. 72.9 %). Pluriparous ewes had higher (P synchronized ewe than nulliparous sheep for the first cycle (75.0 % vs. 46.9 % and 1.4 ± 1.0 vs. 0.9 ± 1.1) as well as for the overall service period (92.1 % vs. 46.9 % and 1.7 ± 0.8 vs. 0.9 ± 1.1). Fourteen days after insert withdrawal progesterone concentrations were higher (P progesterone treatment and nulliparous ewes were less suitable for estrus induction outside the breeding season.

Induction of synchronized oestrous and early pregnancy diagnosis in Syrian awassi ewes, outside the breeding season

International Nuclear Information System (INIS)

Zarkawi, M.; Al-Merstani, M.R.; Wardeh, M.

2000-01-01

An experiment was conducted on indigenous awassi ewes to evaluate the effect of intravaginal progestogen sponges containing 60 mg of medroxyprogesterone acetate (MAP) followed by treatment with pregnant mare serum gonadotrophin (PMSG) on inducing synchronized oestrous outside the normal breeding season, improving fecundity and on early diagnosis of pregnancy using progesterone profiles. 96 awassi ewes were divided into 2 groups. ewes in the Group T, were fitted with MAP for 14 days and injected with 600 IU PMSG at the sponge withdrawal, whereas ewes in the control Group C, received no treatment. The results indicated that oestrous was induced within 36-48 h post sponge withdrawal in 82% of the treated ewes. There were significant (p<0.05) differences between groups T and C in total oestrous response, lambing rate, and fecundity. The means being 96% and 32.6%; 80% and 32.6% and 137.5% and 106.7%, respectively. The accuracy of early diagnosis of pregnancy at 17-19 days post-mating was 100%. The mean birth weight of lambs was similar in both groups (4.3 and 4,4 Kg for groups T and C, respectively).However, single born lambs were significantly (p<0.05) heavier at birth than individual twins (5.0 versus 3.9 Kg). It was concluded that it is possible to induce synchronized and fertile oestrous, successful pregnancy and lambing, and that serum progesterone measurement determinations are useful tool for early pregnancy diagnosis in awassi ewes induced oestrous and bred out of season. (author)

Effect of consecutive re-synchronization protocols on pregnancy rate in buffalo (Bubalus bubalis) heifers out of the breeding season.

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Neglia, Gianluca; Capuano, Massimo; Balestrieri, Anna; Cimmino, Roberta; Iannaccone, Francesco; Palumbo, Francesco; Presicce, Giorgio A; Campanile, Giuseppe

2018-06-01

The combined effect of six consecutive timed artificial inseminations (TAIs) on pregnancy rates, following two different synchronization protocols on buffalo heifers, over a period of seven months typically characterized by low breeding performances, were investigated in this study. A total of 2189 TAIs were performed on 1463 buffalo heifers within a large buffalo farm in the south of Italy. Individual animals were allowed to undergo synchronization protocol (either a slightly modified Ovsynch or Progesterone treatment) and TAI until establishment of pregnancy or else for not more than six consecutive times. Semen of seven proven bulls was used throughout the study, which was carried out from March to September of the same year. Therefore, other than the effect given by consecutive TAIs over time, a monthly and a seasonal effect could also be tested, once the entire period was split into a Low Breeding Season (LBS) from March to June, and a Transition to Breeding Season (TBS) from July to September. From the data recorded in this study and the statistical analysis performed, it can be stated that the two protocols for the synchronization of ovulation were similar in efficiency in determining pregnancies with an overall fertility rate of 89.4% when the comparison was run both on a monthly basis or when months were grouped into two different seasons. In addition, an average of 1.83 AI/pregnancy was reported, slightly higher for the Ovsynch when compared to the Progesterone protocol: 1.91 vs 1.70, respectively. Finally, when considering the number of progressive synchronization treatments implemented over time as covariate, neither Ovsynch nor Progesterone treatment significantly affected pregnancy rates following the first of the six synchronization sessions. However, repeating the synchronization procedure, the progesterone based protocol resulted in significantly higher probability of success in terms of established pregnancies during the second and third re

Establishing quantitative habitat targets for a "Critically Endangered" neotropical migrant (golden-cheeked warbler Dendroica chrysoparia) during the non-breeding season

Science.gov (United States)

David I. King; Carlin C. Chandler; John H. Rappole; Richard B. Chandler; David W. Mehlman

2012-01-01

The Golden-cheeked Warbler Dendroica chrysoparia is a federally endangered Neotropical migrant that inhabits montane pine-oak forests in Mexico and northern Central America during the non-breeding season. Although it is known that Golden-cheeked Warblers are closely associated with ‘encino’ oaks (...

Use of post-thaw semen quality parameters to predict fertility of water buffalo (Bubalus bubalis) bull during peak breeding season.

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Ahmed, H; Andrabi, S M H; Anwar, M; Jahan, S

2017-05-01

This study was designed to predict the fertility of water buffalo bull using post-thaw semen quality parameters during peak breeding season. Thirty ejaculates were collected from five bulls with artificial vagina and cryopreserved. At post-thaw, semen was analysed for motility parameters, velocity distribution, kinematics, DNA integrity/fragmentation, viability, mitochondrial transmembrane potential, morphology, plasma membrane and acrosome integrity. Data of 514 inseminations were collected for estimation of in vivo fertility. Pearson's correlation coefficients showed that progressive motility (PM), rapid velocity, average path velocity, straight line velocity, straightness, supravital plasma membrane integrity, viable spermatozoon with intact acrosome or with high mitochondrial activity were correlated with in vivo fertility (r = .81, p fertility was PM. However, combinations of semen quality parameters to predict fertility were better as compared to single parameter. In conclusion, fertility of buffalo bull can be predicted through some of the post-thaw in vitro semen quality tests during peak breeding season. © 2016 Blackwell Verlag GmbH.

A probabilistic risk assessment for the Kirtland's warbler potentially exposed to chlorpyrifos and malathion during the breeding season and migration.

Science.gov (United States)

Moore, Dwayne Rj; Priest, Colleen D; Olson, Adric D; Teed, R Scott

2018-03-01

Two organophosphate pesticides, chlorpyrifos and malathion, are currently undergoing reregistration in the United States and were recently used by the US Environmental Protection Agency (USEPA) as case studies to develop a national procedure for evaluating risks to endangered species. One of the endangered bird species considered by the USEPA was the Kirtland's warbler (Setophaga kirtlandii). The Kirtland's warbler is an endangered migratory species that nests exclusively in young jack pine stands in Michigan and Wisconsin, and winters in the Bahamas. We developed probabilistic models to assess the risks of chlorpyrifos and malathion to Kirtland's warblers during the breeding season and the spring and fall migrations. The breeding area model simulates acute and chronic exposure and risk to each of 10 000 birds over a 60-d period following initial pesticide application. The model is highly species specific with regard to the foraging behavior of Kirtland's warblers during the breeding season. We simulated the maximum application rate and number of applications allowed on the labels for representative use patterns that could be found within 3 km of the breeding areas of Kirtland's warbler. The migration model simulates 10 000 birds during the course of their 12- to 23-d migration between their breeding area and the Bahamas. The model takes advantage of more than a century of observations of when, where, and for how long Kirtland's warblers forage in different habitats during the course of their migration. The data indicate that warblers only infrequently stop over in habitats that could be treated with chlorpyrifos and malathion. The breeding area and migration models resulted in predictions of very low acute and chronic risk for both pesticides to Kirtland's warblers. These results were expected, given that field observations indicate that the Kirtland's warbler has dramatically increased in abundance in recent decades. Integr Environ Assess Manag 2018

Diet of the White-Tailed Eagle During the Breeding Season in the Polesski State Radiation-Ecological Reserve, Belarus

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Valeri V. Yurko

2016-04-01

Full Text Available This article presents data on the diet of the White-Tailed Eagle (Haliaeetus albicilla collected during breeding seasons of 2006–2015 in the Polesski State Radiation-Ecological Reserve. The data included 127 records of prey remains belonging to 27 species of vertebrates collected in and under the nests. We discovered that the diet of the White-Tailed Eagle mainly consists of vertebrates of three classes: fishes (Pisces 48.1 %, birds (Aves 41.7 % and mammals (Mammalia 10.2 %. At the present, the main prey species in the diet of the White-Tailed Eagle in the breeding season are: Bream (Abramis brama – 22.0 %, Black Stork (Ciconia nigra – 12.6 %, Northern Pike (Esox lucius – 10.2 %, Wild Boar (Sus scrofa – 7.1 %, White Stork (Ciconia ciconia – 6.3 %, Mallard (Anas platyrhynchos – 5.5 % and Eurasian Coot (Fulica atra – 5.5 %. Together these species makes up 69.2 % or 2/3 of the diet of this raptor. We also established that cannibalism is a character feature of the local population of White-Tailed Eagle, and its proportion is 2.4 %.

Variation in testosterone and corticosterone in amphibians and reptiles: relationships with latitude, elevation, and breeding season length.

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Eikenaar, Cas; Husak, Jerry; Escallón, Camilo; Moore, Ignacio T

2012-11-01

Latitudinal variation in life-history traits has been the focus of numerous investigations, but underlying hormonal mechanisms have received much less attention. Steroid hormones play a central role in vertebrate reproduction and may be associated with life-history trade-offs. Consequently, circulating concentrations of these hormones vary tremendously across vertebrates, yet interspecific geographic variation in male hormone concentrations has been studied in detail only in birds. We here report on such variation in amphibians and reptiles, confirming patterns observed in birds. Using phylogenetic comparative analyses, we found that in amphibians, but not in reptiles, testosterone and baseline corticosterone were positively related to latitude. Baseline corticosterone was negatively related to elevation in amphibians but not in reptiles. For both groups, testosterone concentrations were negatively related to breeding-season length. In addition, testosterone concentrations were positively correlated with baseline corticosterone in both groups. Our findings may best be explained by the hypothesis that shorter breeding seasons increase male-male competition, which may favor increased testosterone concentrations that modulate secondary sexual traits. Elevated energetic demands resulting from greater reproductive intensity may require higher baseline corticosterone. Thus, the positive relationship between testosterone and corticosterone in both groups suggests an energetic demand for testosterone-regulated behavior that is met with increased baseline glucocorticoid concentrations.

Natural immunity factors in Polish mixed breed rabbits.

Science.gov (United States)

Tokarz-Deptuła, B; Niedźwiedzka-Rystwej, P; Adamiak, M; Hukowska-Szematowicz, B; Trzeciak-Ryczek, A; Deptuła, W

2015-01-01

Mixed-breed rabbits in Poland are widely used for diagnostic and scientific research and as utility animals, therefore there is a need to know their immunological status, as well as their haematological status. In this study natural immunity factors were analyzed in Polish mixed-breed rabbits and Polish mixed-breed rabbits with addition of blood of meet-breed, considering the impact of sex and season of the year (spring, summer, autumn, winter) using measurement of non-specific cellular and humoral immunity parameters in peripheral blood. The study has revealed that there is a variety between the two commonly used mixed-breed types of rabbits, especially when sex and season is concerned, which is crucial for using these animals in experiments.

Influence of a CIDR prior to bull breeding on pregnancy rates and subsequent calving distribution.

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Lamb, G C; Dahlen, C R; Vonnahme, K A; Hansen, G R; Arseneau, J D; Perry, G A; Walker, R S; Clement, J; Arthington, J D

2008-11-01

We determined whether insertion of a CIDR for 7 days prior to the breeding season enhanced pregnancy rates and altered the date of conception in suckled beef cows mated naturally. Suckled beef cows (n=2033) from 15 locations were randomly assigned to one of two treatments: (1) cows received a CIDR 7 days prior to the breeding season for 7 days (CIDR; n=999); (2) cows received no treatment (Control; n=1034). On the first day of the breeding season bulls were introduced to herds at a rate of 15-25 cows per yearling bull or 20-30 cows per mature bull. Pregnancy status and the date of conception were determined via transrectal ultrasonography at 56 and 120 days after initiation of the breeding season. Overall pregnancy rates ranged from 59.3 to 98.9% among the 15 locations. The percentage of cows becoming pregnant during the first 30 days of the breeding season was similar between CIDR (68.2%) and Control (66.7%) cows, and overall pregnancy rates were similar between CIDR (88.9%) and Control (88.6%) cows. The average day of conception after initiation of the breeding season was shorter (Pbody condition score and nor parity affected pregnancy rates or days to conception, whereas pregnancy rates and days to conception were affected (Pconception were greater for cows that calved within 40 days (31.6+/-1.2 days) of initiation of the breeding season compared to cows calving between 40 and 50 days (25.3+/-1.2 days) prior to initiation of the breeding season, which were greater than those cows calving between 50-60 days (20.0+/-0.8 days) and 60-70 days (21.3+/-1.0 days) prior to initiation of the breeding season. Cows calving greater than 70 days (17.3+/-1.5 days) from initiation of the breeding season had the shortest interval to conception. We concluded that insertion of a CIDR prior to the breeding season failed to increase overall pregnancy rates, but did influence the average day of conception.

Updates to the Cool Season Food Legume Genome Database: Resources for pea, lentil, faba bean and chickpea genetics, genomics and breeding

Science.gov (United States)

The Cool Season Food Legume Genome database (CSFL, www.coolseasonfoodlegume.org) is an online resource for genomics, genetics, and breeding research for chickpea, lentil,pea, and faba bean. The user-friendly and curated website allows for all publicly available map,marker,trait, gene,transcript, ger...

The effect of dual-hemisphere breeding on stallion fertility.

Science.gov (United States)

Walbornn, S R; Love, C C; Blanchard, T L; Brinsko, S P; Varner, D D

2017-05-01

Breeding records were analyzed from 24 Thoroughbred stallions that were subjected to dual-hemisphere breeding (DH), including novice (first-year; NOV; n = 11) and experienced (EXP; n = 13) stallions. Fertility variables included seasonal pregnancy rate, pregnancy rate per cycle, and first-cycle pregnancy rate. In addition, values for book size, total number of covers, distribution of mare type (maiden, foaling, and barren) within a stallion's book, cycles per mare, and mare age were examined. Some data were also categorized by mare type (maiden-M, foaling-F, and barren-B). Five separate analyses of the data were performed. For Analyses 1-3, the effects of hemisphere (northern hemisphere [NH] vs. southern hemisphere [SH]) and breeding order (refers to the first [O1] or second [O2] season within the first year of dual-hemisphere breeding) were examined for all stallions (combined group [CG]), NOV stallions only, and EXP stallions only, respectively. Fertility values were generally higher in the SH than the NH (P fertility of O1 was generally similar to O2 (P > 0.05). For Analysis 4, fertility of DH breeding seasons was compared to single hemisphere (SIN) breeding seasons within the same 16 stallions and was found to be similar between the two groups (P > 0.05). For Analysis 5, the effect of the number of consecutive DH breeding seasons on fertility was examined and was found to remain unchanged (P > 0.05). In summary, no adverse effects of DH breeding on fertility were detected. Fertility was higher when stallions were bred in the SH, as compared to the NH. Potential reasons for higher fertility achieved in the SH were smaller book sizes and better mare reproductive quality. Copyright © 2017. Published by Elsevier Inc.

Effectiveness of controlled internal drug release device treatment to alleviate reproductive seasonality in anestrus lactating or dry Barki and Rahmani ewes during non-breeding season.

Science.gov (United States)

El-Mokadem, M Y; Nour El-Din, Anm; Ramadan, T A; Rashad, A M; Taha, T A; Samak, M A; Salem, M H

2018-04-01

This study aimed to evaluate the effectiveness of hormonal treatments on ovarian activity and reproductive performance in Barki and Rahmani ewes during non-breeding season. Forty-eight multiparous ewes, 24 Barki and 24 Rahmani ewes were divided into two groups, 12 lactating and 12 dry ewes for each breed. Controlled internal drug release (CIDR) device was inserted in all ewes for 14 days in conjunction with intramuscular 500 IU equine chronic gonadotrophin (eCG) at day of CIDR removal. Data were analysed using PROC MIXED of SAS for repeated measures. Breed, physiological status and days were used as fixed effects and individual ewes as random effects. Barki ewes recorded higher (p ewes. Lactating ewes recorded higher (p ewes. Number and diameter of large follicles recorded the highest (p ewes recorded longer (p ewes. In conclusion, CIDR-eCG protocol was more potent in improving ovarian activity in Barki compared to Rahmani ewes, but this protocol seems to induce hormonal imbalance in Barki ewes that resulted in increasing conception failure compared to Rahmani ewes. © 2017 Blackwell Verlag GmbH.

Income breeding allows an aquatic snake Seminatrix pygaea to reproduce normally following prolonged drought-induced aestivation.

Science.gov (United States)

Winne, Christopher T; Willson, John D; Gibbons, J Whitfield

2006-11-01

1. Capital breeding is an ideal reproductive strategy for many ectotherms because it provides a disassociation between feeding and reproduction, a necessary requirement for animals that become anorexic during pregnancy. Among ectotherms, some viviparous snakes (e.g. Viperidae) exemplify the capital breeding strategy because many species (i) do not feed during pregnancy due to behavioural conflicts between reproduction and foraging, and (ii) take more than one season to accumulate sufficient energetic stores for reproduction. 2. Isolated wetlands often exhibit extreme annual fluctuations in environmental conditions with prolonged droughts periodically leaving wetlands completely dry and devoid of prey. Following droughts, however, wetlands can be extremely productive, rendering prey resources virtually unlimited for some species. 3. This study examines drought survival strategy and reproductive ecology of a small aquatic snake Seminatrix pygaea (Cope) in an isolated wetland. Seminatrix pygaea are atypical from most sympatric snake species in that (i) their small body size, reliance on aquatic prey, and high rates of evaporative water loss make them ill-suited to overland movement, and (ii) they may not be subject to costs typically associated with feeding during pregnancy. 4. We hypothesized that S. pygaea would survive periodic multiyear droughts by aestivating within the dried wetland, a survival strategy heretofore undocumented in snakes. Further, we hypothesized that if S. pygaea rely on 'typical' snake reproductive strategies of 'adaptive anorexia' and capital breeding, reproductive output would be reduced in the first wet year following drought. 5. By encircling a 10-ha wetland with a continuous drift fence before it refilled we were able to demonstrate that S. pygaea were present within the dried wetland prior to the onset of spring rains that refilled the wetland in 2003. Our results suggest that S. pygaea are capable of surviving multiyear droughts by

Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

Science.gov (United States)

Krams, Indrikis; Krama, Tatjana

2002-01-01

When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities. PMID:12495502

Using the satellite-derived normalized difference vegetation index (NDVI) to explain ranging patterns in a lek-breeding antelope: the importance of scale.

Science.gov (United States)

Bro-Jørgensen, Jakob; Brown, Molly E; Pettorelli, Nathalie

2008-11-01

Lek-breeding species are characterized by a negative association between territorial resource availability and male mating success; however, the impact of resources on the overall distribution patterns of the two sexes in lek systems is not clear. The normalized difference vegetation index (NDVI) has recently emerged as a powerful proxy measure for primary productivity, allowing the links between the distributions of animals and resources to be explored. Using NDVI at four spatial resolutions, we here investigate how the distribution of the two sexes in a lek-breeding population of topi antelopes relates to resource abundance before and during the rut. We found that in the dry season preceding the rut, topi density correlated positively with NDVI at the large, but not the fine, scale. This suggests that before the rut, when resources were relatively scant, topi preferred pastures where green grass was widely abundant. The pattern was less pronounced in males, suggesting that the need for territorial attendance prevents males from tracking resources as freely as females do. During the rut, which occurs in the wet season, both male and female densities correlated negatively with NDVI at the fine scale. At this time, resources were generally plentiful and the results suggest that, rather than by resource maximization, distribution during the rut was determined by benefits of aggregating on relatively resource-poor leks for mating, and possibly antipredator, purposes. At the large scale, no correlation between density and NDVI was found during the rut in either sex, which can be explained by leks covering areas too small to be reflected at this resolution. The study illustrates that when investigating spatial organization, it is important: (1) to choose the appropriate analytic scale, and (2) to consider behavioural as well as strictly ecological factors.

Seasonal changes in testosterone and corticosterone levels in four social classes of a desert dwelling sociable rodent.

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Schradin, Carsten

2008-04-01

Animals have to adjust their physiology to seasonal changes, in response to variation in food availability, social tactics and reproduction. I compared basal corticosterone and testosterone levels in free ranging striped mouse from a desert habitat, comparing between the sexes, breeding and philopatric non-breeding individuals, and between the breeding and the non-breeding season. I expected differences between breeders and non-breeders and between seasons with high and low food availability. Basal serum corticosterone was measured from 132 different individuals and serum testosterone from 176 different individuals of free living striped mice. Corticosterone and testosterone levels were independent of age, body weight and not influenced by carrying a transmitter. The levels of corticosterone and testosterone declined by approximately 50% from the breeding to the non-breeding season in breeding females as well as non-breeding males and females. In contrast, breeding males showed much lower corticosterone levels during the breeding season than all other classes, and were the only class that showed an increase of corticosterone from the breeding to the non-breeding season. As a result, breeding males had similar corticosterone levels as other social classes during the non-breeding season. During the breeding season, breeding males had much higher testosterone levels than other classes, which decreased significantly from the breeding to the non-breeding season. My results support the prediction that corticosterone decreases during periods of low food abundance. Variation in the pattern of hormonal secretion in striped mice might assist them to cope with seasonal changes in energy demand in a desert habitat.

Cross-seasonal patterns of avian influenza virus in breeding and wintering migratory birds: a flyway perspective

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Hill, Nichola J.; Takekawa, John Y.; Cardona, Carol J.; Meixell, Brandt W.; Ackerman, Joshua T.; Runstadler, Jonathan A.; Boyce, Walter M.

2012-01-01

The spread of avian influenza viruses (AIV) in nature is intrinsically linked with the movements of wild birds. Wild birds are the reservoirs for the virus and their migration may facilitate the circulation of AIV between breeding and wintering areas. This cycle of dispersal has become widely accepted; however, there are few AIV studies that present cross-seasonal information. A flyway perspective is critical for understanding how wild birds contribute to the persistence of AIV over large spatial and temporal scales, with implications for how to focus surveillance efforts and identify risks to public health. This study characterized spatio-temporal infection patterns in 10,389 waterfowl at two important locations within the Pacific Flyway--breeding sites in Interior Alaska and wintering sites in California's Central Valley during 2007-2009. Among the dabbling ducks sampled, the northern shoveler (Anas clypeata) had the highest prevalence of AIV at both breeding (32.2%) and wintering (5.2%) locations. This is in contrast to surveillance studies conducted in other flyways that have identified the mallard (Anas platyrhynchos) and northern pintail (Anas acuta) as hosts with the highest prevalence. A higher diversity of AIV subtypes was apparent at wintering (n=42) compared with breeding sites (n=17), with evidence of mixed infections at both locations. Our study suggests that wintering sites may act as an important mixing bowl for transmission among waterfowl in a flyway, creating opportunities for the reassortment of the virus. Our findings shed light on how the dynamics of AIV infection of wild bird populations can vary between the two ends of a migratory flyway.

Changing nest placement of Hawaiian Common Amakihi during the breeding cycle

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van Riper, Charles; Kern, M. D.; Sogge, M. K.

1993-01-01

We studied the nesting behavior of the Common Amakihi (Hemignathus virens) from 1970-1981 on the island of Hawaii to determine if the species alters nest placement over a protracted 9-month breeding season. Birds preferentially chose the southwest quadrant of trees in which to build nests during all phases of the breeding season. It appeared that ambient temperature (Ta) was a contributing factor to differential nest placement between early and late phases of the annual breeding cycle. When Ta is low during the early (December-March) breeding period, Common Amakihi selected exposed nesting locations that benefitted them with maximum solar insolation. However, in the later phase of the breeding period (April-July) when Ta was much higher, renesting birds selected nest sites deeper in the canopy in significantly taller trees. This is one of the few documented examples in which a species changes location of nest during a breeding season, thus allowing exploitation of temporally differing microclimatic conditions.

Breeding phenology and winter activity predict subsequent breeding success in a trans-global migratory seabird.

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Shoji, A; Aris-Brosou, S; Culina, A; Fayet, A; Kirk, H; Padget, O; Juarez-Martinez, I; Boyle, D; Nakata, T; Perrins, C M; Guilford, T

2015-10-01

Inter-seasonal events are believed to connect and affect reproductive performance (RP) in animals. However, much remains unknown about such carry-over effects (COEs), in particular how behaviour patterns during highly mobile life-history stages, such as migration, affect RP. To address this question, we measured at-sea behaviour in a long-lived migratory seabird, the Manx shearwater (Puffinus puffinus) and obtained data for individual migration cycles over 5 years, by tracking with geolocator/immersion loggers, along with 6 years of RP data. We found that individual breeding and non-breeding phenology correlated with subsequent RP, with birds hyperactive during winter more likely to fail to reproduce. Furthermore, parental investment during one year influenced breeding success during the next, a COE reflecting the trade-off between current and future RP. Our results suggest that different life-history stages interact to influence RP in the next breeding season, so that behaviour patterns during winter may be important determinants of variation in subsequent fitness among individuals. © 2015 The Authors.

Coastal waterbirds of El Chorro and Majahuas, Jalisco, México, during the non-breeding season, 1995-1996

OpenAIRE

Salvador Hernández-Vázquez; Eric Mellink

2001-01-01

We studied how waterbirds used two small estuaries during the non-breeding season of 1995-1996. These estuaries, El Chorro and Majahuas, were located in the middle of a large span of non-wetland habitat along the Pacific coast of México. Whereas El Chorro was basically a large and open waterbody, Majahuas was a long and narrow corridor flanked by mangroves. The two estuaries had 77 species throughout our study, but shared only 58, due to differences in their habitat. Seabirds comprised 66% of...

Effect of Melatonin Implants during the Non-Breeding Season on the Onset of Ovarian Activity and the Plasma Prolactin in Dromedary Camel

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Khalid El Allali

2018-03-01

Full Text Available To examine a possible control of reproductive seasonality by melatonin, continual-release subcutaneous melatonin implants were inserted 4.5 months before the natural breeding season (October–April into female camels (Melatonin-treated group. The animals were exposed to an artificial long photoperiod (16L:8D for 41 days prior to implant placement to facilitate receptivity to the short-day signal that is expected with melatonin implants. The treated and control groups (untreated females were maintained separately under outdoor natural conditions. Ovarian follicular development was monitored in both groups by transrectal ultrasonography and by plasma estradiol-17β concentrations performed weekly for 8 weeks and then for 14 weeks following implant insertion. Plasma prolactin concentrations were determined at 45 and 15 days before and 0, 14, 28, 56, and 98 days after implant insertion. Plasma melatonin concentration was determined to validate response to the artificial long photoperiod and to verify the pattern of release from the implants. Results showed that the artificial long photoperiod induced a melatonin secretion peak of significantly (P < 0.05 shorter duration (about 2.5 h. Melatonin release from the implants resulted in higher circulating plasma melatonin levels during daytime and nighttime which persisted for more than 12 weeks following implants insertion. Treatment with melatonin implants advanced the onset of follicular growth activity by 3.5 months compared to untreated animals. Plasma estradiol-17β increased gradually from the second week after the beginning of treatment to reach significantly (P < 0.01 higher concentrations (39.2 ± 6.2 to 46.4 ± 4.5 pg/ml between the third and the fifth week post insertion of melatonin implants. Treatment with melatonin implants also induced a moderate, but significant (P < 0.05 suppressive effect on plasma prolactin concentration on the 28th day. These

Effect of Melatonin Implants during the Non-Breeding Season on the Onset of Ovarian Activity and the Plasma Prolactin in Dromedary Camel

Science.gov (United States)

El Allali, Khalid; Sghiri, Abdelmalek; Bouâouda, Hanan; Achaâban, Mohamed Rachid; Ouzir, Mounir; Bothorel, Béatrice; El Mzibri, Mohammed; El Abbadi, Najia; Moutaouakkil, Adnane; Tibary, Ahmed; Pévet, Paul

2018-01-01

To examine a possible control of reproductive seasonality by melatonin, continual-release subcutaneous melatonin implants were inserted 4.5 months before the natural breeding season (October–April) into female camels (Melatonin-treated group). The animals were exposed to an artificial long photoperiod (16L:8D) for 41 days prior to implant placement to facilitate receptivity to the short-day signal that is expected with melatonin implants. The treated and control groups (untreated females) were maintained separately under outdoor natural conditions. Ovarian follicular development was monitored in both groups by transrectal ultrasonography and by plasma estradiol-17β concentrations performed weekly for 8 weeks and then for 14 weeks following implant insertion. Plasma prolactin concentrations were determined at 45 and 15 days before and 0, 14, 28, 56, and 98 days after implant insertion. Plasma melatonin concentration was determined to validate response to the artificial long photoperiod and to verify the pattern of release from the implants. Results showed that the artificial long photoperiod induced a melatonin secretion peak of significantly (P < 0.05) shorter duration (about 2.5 h). Melatonin release from the implants resulted in higher circulating plasma melatonin levels during daytime and nighttime which persisted for more than 12 weeks following implants insertion. Treatment with melatonin implants advanced the onset of follicular growth activity by 3.5 months compared to untreated animals. Plasma estradiol-17β increased gradually from the second week after the beginning of treatment to reach significantly (P < 0.01) higher concentrations (39.2 ± 6.2 to 46.4 ± 4.5 pg/ml) between the third and the fifth week post insertion of melatonin implants. Treatment with melatonin implants also induced a moderate, but significant (P < 0.05) suppressive effect on plasma prolactin concentration on the 28th day. These results

Evaluation of Off-season Potential Breeding Sources for Spotted Wing Drosophila (Drosophila suzukii Matsumura) in Michigan.

Science.gov (United States)

Bal, Harit K; Adams, Christopher; Grieshop, Matthew

2017-12-05

It has been suggested that fruit wastes including dropped and unharvested fruits, and fruit byproducts (i.e., pomace) found in fruit plantings and cideries or wine-making facilities could serve as potential off-season breeding sites for spotted wing Drosophila (Drosophila suzukii Matsumura (Diptera: Drosophilidae)). This idea, however, has yet to be widely tested. The goal of our study was to determine the potential of dropped fruit and fruit wastes as Fall spotted wing Drosophila breeding resources in Michigan, USA. Fruit waste samples were collected from 15 farms across the lower peninsula of Michigan and were evaluated for spotted wing Drosophila and other drosophilid emergence and used in host suitability bioassays. All of the dropped apples, pears, grapes, and raspberries and 40% of apple and 100% of grape fruit pomace evaluated were found to contain spotted wing Drosophila with the highest numbers collected from dropped grapes and pears. Greater spotted wing Drosophila recovery was found in fruit wastes at sites attached with cideries and wine-making facilities and with multiple cultivated fruit crops than sites with no cideries and only one crop. Females oviposited in raspberry, pear, apple, grape, apple pomace and grape pomace samples with the highest rates of reproduction in raspberries. Our results demonstrate that fruit wastes including dropped berry, pomme and stone fruits, as well as fruit compost may be important late season reproductive resources for spotted wing Drosophila. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pre-breeding ovaro-uterine ultrasonography and its relationship with first service pregnancy rate in seasonal-calving dairy herds.

Science.gov (United States)

Mee, J F; Buckley, F; Ryan, D; Dillon, P

2009-04-01

The objectives of the study were to characterize an ultrasound reproductive tract scoring (URTS) system to assess suitability for breeding in dairy cows, to describe the prevalence of these scores in commercial dairy herds and to examine their relationship with subsequent fertility. Ultrasound examinations (7797) were performed on 5751 Holstein-Friesian cows prior to breeding in 62 seasonally calving herds over 2 years. Data recorded from images of both ovaries and the uterus were combined into a six point scoring system and the prevalence of cows with cystic ovarian follicles and uterine abscesses and adhesions was recorded separately. The prevalence of ovulatory cows which had completed uterine involution (score 1), or had mild (2) or moderate endometritis (3) was 62.5%, 21.7% and 2.2%, respectively. The prevalence of anovulatory cows with moderate endometritis (4), ovulatory cows with pyometra (5) and anovulatory cows which had completed uterine involution (6) was 3.3%, 2.2% and 8.1%, respectively. The interval between calving and examination differed between cows with each of the scores 1, 2, 5 and 6 (61, 46, 53 and 50 days, respectively, p scores 3 and 4 (37 and 35 days, respectively). Ovulatory cows which had completed uterine involution (score 1) had a higher likelihood of pregnancy to first service than ovulatory or anovulatory cows which had not completed uterine involution (p reproductive tract was 3.9% and 1.2%, respectively. In conclusion, 29% and 11% of cows in seasonally calving and breeding dairy herds had not completed uterine involution or were anovulatory prior to the mating start date, respectively. Both conditions, detected using a URTS system, significantly reduced first service pregnancy rate in these pasture-based dairy herds.

An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan

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Masayuki Sumida

2013-07-01

Full Text Available Anderson’s crocodile newt (Echinotriton andersoni is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4% became normal tailbud embryos, 274 (72.5% hatched normally, 213 (56.3% metamorphosed normally, and 141 (37.3% became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live Tubifex. Metamorphosed newts were transferred to plastic containers containing wet sponges kept in a temperature-controlled incubator at 22.5 °C and fed a cricket diet to promote healthy growth. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species and can be applied to the preservation of other similarly wild and endangered species such as E. chinhaiensis.

Home range utilisation and long-range movement of estuarine crocodiles during the breeding and nesting season.

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Hamish A Campbell

Full Text Available The estuarine crocodile (Crocodylus porosus is the apex-predator in waterways and coastlines throughout south-east Asia and Australasia. C. porosus pose a potential risk to humans, and management strategies are implemented to control their movement and distribution. Here we used GPS-based telemetry to accurately record geographical location of adult C. porosus during the breeding and nesting season. The purpose of the study was to assess how C. porosus movement and distribution may be influenced by localised social conditions. During breeding, the females (2.92 ± 0.013 metres total length (TL, mean ± S.E., n = 4 occupied an area<1 km length of river, but to nest they travelled up to 54 km away from the breeding area. All tagged male C. porosus sustained high rates of movement (6.49 ± 0.9 km d(-1; n = 8 during the breeding and nesting period. The orientation of the daily movements differed between individuals revealing two discontinuous behavioural strategies. Five tagged male C. porosus (4.17 ± 0.14 m TL exhibited a 'site-fidelic' strategy and moved within well-defined zones around the female home range areas. In contrast, three males (3.81 ± 0.08 m TL exhibited 'nomadic' behaviour where they travelled continually throughout hundreds of kilometres of waterway. We argue that the 'site-fidelic' males patrolled territories around the female home ranges to maximise reproductive success, whilst the 'nomadic' males were subordinate animals that were forced to range over a far greater area in search of unguarded females. We conclude that C. porosus are highly mobile animals existing within a complex social system, and mate/con-specific interactions are likely to have a profound effect upon population density and distribution, and an individual's travel potential. We recommend that impacts on socio-spatial behaviour are considered prior to the implementation of management interventions.

Normal sperm morphology and changes of semen characteristics and abnormal morphological spermatozoa among peri-mating seasons in captive japanese black bears (Ursus thibetanus japonicus).

Science.gov (United States)

Okano, Tsukasa; Murase, Tetsuma; Nakamura, Sachiko; Komatsu, Takeshi; Tsubota, Toshio; Asano, Makoto

2009-04-01

The objectives of this study were to obtain morphological data for normal spermatozoa and to investigate seasonal changes (the early, mid- and post-mating seasons) in abnormal morphology of spermatozoa and the characteristics of semen in Japanese black bears. Semen was collected by electroejaculation from 34 captive male Japanese black bears a total of 74 times. Length of head, width of head, length of midpiece and total length of the spermatozoa were 6.3 +/- 0.4, 4.5 +/- 0.3, 10.4 +/- 0.7 and 69.6 +/- 3.1 mum (mean +/- SD; 20 semen, 200 spermatozoa), respectively. In the semen collected during the mid-mating season, ejaculate volume, ejaculate pH, sperm concentration, total sperm count, motility, viability and intact acrosomes were 0.46 +/- 0.36 ml, 7.3 +/- 0.4, 659 +/- 644 x 10(6)/ml, 214 +/- 208 x 10(6), 82.9 +/- 9.6%, 89.3 +/- 9.5% and 97.0 +/- 3.2% (mean +/- SD; n=21, in ejaculate pH n=8), respectively. Sperm motility and viability in the early (n=7) and mid-mating (n=21) seasons were significantly higher than in the post-mating (n=8) season. The rates of detached heads in the early and mid-mating season were significantly lower than in the post-mating season. The main abnormal morphologies observed (mean +/- SD%; n=23) were simply bent tail (19.9 +/- 22.6), distal droplets (13.5 +/- 11.7), proximal droplets (9.6 +/- 7.8), teratoid spermatozoa (6.7 +/- 10.7), knobbed acrosome (4.9 +/- 8.6), acrosome damage (3.7 +/- 2.8) and bent midpiece (3.7 +/- 5.1). The data will be useful for artificial breeding and further research on male reproductive physiology in this species.

Abundance, food habits, and breeding season of exotic T ilapia zillii and native O reochromis niloticus L. fish species in Lake Zwai , Ethiopia

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Padanillay C. Prabu

2008-05-01

Full Text Available Relative abundance, diet and breeding season overlap in the reproduction of exotic Tilapia zillii and native Oreochromis niloticus in Lake Zwai were studied from samples collected over 12 months. Younger fish of both species collected were also evaluated for food composition.Food items from stomachs of both species were collected and analysed using the frequency of occurrence method. In terms of number, T. zillii dominated O. niloticus at the sampling sites. In both species, macrophytes, detritus, blue green algae, diatoms, green algae, Ceratium, Euglena,and Phacus constituted foods of plant origin, whereas chironomid larvae, Copepoda, Cladocera,Rotifera, Nematoda, fish eggs, and fish scales constituted foods of animal origin. Foods of the latter type such as Ephemeroptera and mollusks were also noted in the diet of adult T. zillii.Despite the extensive overlap in food habits of the two species, however, the food items were found in the diet of the species with different average percentage frequencies of occurrence. The level of gonad maturation and gonadosomatic index (GSI values showed that in Lake Zwai breeding was year-round for both T. zillii and O. niloticus, with a peak during April-September and February-August respectively, indicating extended breeding season overlap in reproduction. The two species were always found together in the catches from the sampling sites, which indicated some niche overlap between them.

Radiographic liver size in Pekingese dogs versus other dog breeds.

Science.gov (United States)

Choi, Jihye; Keh, Seoyeon; Kim, Hyunwook; Kim, Junyoung; Yoon, Junghee

2013-01-01

Differential diagnoses for canine liver disease are commonly based on radiographic estimates of liver size, however little has been published on breed variations. Aims of this study were to describe normal radiographic liver size in Pekingese dogs and to compare normal measurements for this breed with other dog breeds and Pekingese dogs with liver disease. Liver measurements were compared for clinically normal Pekingese (n = 61), normal non-Pekingese brachycephalic (n = 45), normal nonbrachycephalic (n = 71), and Pekingese breed dogs with liver disease (n = 22). For each dog, body weight, liver length, T11 vertebral length, thoracic depth, and thoracic width were measured on right lateral and ventrodorsal abdominal radiographs. Liver volume was calculated using a formula and ratios of liver length/T11 vertebral length and liver volume/body weight ratio were determined. Normal Pekingese dogs had a significantly smaller liver volume/body weight ratio (16.73 ± 5.67, P dogs (19.54 ± 5.03) and normal nonbrachycephalic breed dogs (18.72 ± 6.52). The liver length/T11 vertebral length ratio in normal Pekingese (4.64 ± 0.65) was significantly smaller than normal non-Pekingese brachycephalic breed dogs (5.16 ± 0.74) and normal nonbrachycephalic breed dogs (5.40 ± 0.74). Ratios of liver volume/body weight and liver length/T11 vertebral length in normal Pekingese were significantly different from Pekingese with liver diseases (P dogs have a smaller normal radiographic liver size than other breeds. We recommend using 4.64× the length of the T11 vertebra as a radiographic criterion for normal liver length in Pekingese dogs. © 2012 Veterinary Radiology & Ultrasound.

Variation in melatonin receptors (Mel(1a) and Mel(1b)) and androgen receptor (AR) expression in the spleen of a seasonally breeding bird, Perdicula asiatica.

Science.gov (United States)

Yadav, S K; Haldar, C; Singh, S S

2011-12-01

Daily variation in the peripheral level of melatonin plays a major role in integrating reproduction and environmental information for seasonally breeding birds. However, the variation in immunity and reproduction has never been assessed in any avian species on a 24 h time scale. Therefore, to understand the relationship between immune function and reproductive phases in a seasonally breeding bird, Perdicula asiatica, the Indian jungle bush quail, we studied the daily variation of melatonin and testosterone levels along with expression of their receptors Mel(1a), Mel(1b), and androgen receptor in the spleen during the reproductively active phase. Immunocytochemistry for the melatonin receptors Mel(1a) and Mel(1b) presented a differential distribution pattern. Western blot of splenic protein suggested a daily rhythm of melatonin receptors, while acrophases for the two melatonin receptors Mel(1a) and Mel(1b) differed by 4 h, suggesting that the expression of the receptors may peak at different times, causing more of either Mel(1a) or Mel(1b) to be available at a particular time to mediate function. The circulatory melatonin level correlated with percentage stimulation ratio of splenocytes and plasma interleukin-2 level, but did not correlate with testosterone or androgen receptor, suggesting that melatonin could be a major hormone imparting a time-of-day effect on the modulation of immune function in a seasonally breeding bird during the reproductively active phase. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Ultrasound Imaging of Testes and Epididymides of Normal and Infertile Breeding Bulls

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Khalid Mahmood Ali, Nazir Ahmad*, Nafees Akhtar, Shujait Ali, Maqbool Ahmad and Muhammad Younis1

2011-10-01

Full Text Available Echotexture of testes and epididymides from 10 slaughtered male buffaloes was studied. Diameter of testis and mediastinum testis was measured by ultrasound and compared with respective values taken by calipers. Testes and epididymides of another 10 fertile and 10 infertile breeding bulls were examined in vivo through manual palpation and ultrasound imaging. Semen quality of these bulls was also monitored. There were significant (P<0.01 positive correlations between ultrasound and calipers values of all parameters. The testicular parenchyma of fertile bulls was uniformly homogeneous and moderately echogenic. Epididymal tail was more heterogeneous and less echogenic, while epididymal head was homogeneous and less echogenic, than the testicular parenchyma. The epididymal body appeared as hypoechoic structure with echogenic margin. Among 10 infertile bulls, nine had poor semen quality, while one bull failed to give any ejaculate. On ultrasonography, six bulls showed abnormalities in their scrotal echotexture. Among these, one had an abundance of hyperechoic areas scattered in the testicular parenchyma, some of these showed acoustic shadowing, showing testicular degenerations with mineralization. The second bull showed many anechoic areas in the testes and epididymal head, demarcated from the rest of the organ by well defined margins. In the third bull, three-fourth of the right testis showed hyperechoic areas, suspected of testicular degeneration with mineralization. The fourth bull had two anechoic areas in one testis assumed to represent dilated blood vessel. The fifth bull showed small hyperechoic areas within the testicular parenchyma. The sixth bull showed an anechoic area with distinct hyperechogenic margin below the testicular tunics. The remaining four bulls had normal echogenicity of testes and epididymides in spite of poor semen quality. In conclusion, diagnostic ultrasound may be included in breeding soundness examination of breeding

Pied Flycatchers Ficedula hypoleuca travelling from Africa to breed in Europe : differential effects of winter and migration conditions on breeding date

NARCIS (Netherlands)

Both, Christiaan; Sanz, Juan Jose; Artemyev, Aleksandr V.; Blaauw, Bert; Cowie, Richard J.; Dekhuizen, Aarnoud J.; Enemar, Anders; Jarvinen, Antero; Nyholm, N. Erik I.; Potti, Jaime; Ravussin, Pierre-Alain; Silverin, Bengt; Slater, Fred M.; Sokolov, Leonid V.; Visser, Marcel E.; Winkel, Wolfgang; Wright, Jonathan; Zang, Herwig

2006-01-01

In most bird species there is only a short time window available for optimal breeding due to variation in ecological conditions in a seasonal environment. Long-distance migrants must travel before they start breeding, and conditions at the wintering grounds and during migration may affect travelling

Pied Flycatchers Ficedula hypoleuca travelling from Africa to breed in Europe: differential effects of winter and migration conditions on breeding date

NARCIS (Netherlands)

Both, C.; Sanz, J.J.; Artemyev, A.V.; Blaauw, B.; Cowie, R.J.; Dekhuijzen, A.J.; Enemar, A.; Järvinen, A.; Nyholm, N.E.I.; Potti, J.; Ravussin, P.-A.; Silverin, B.; Slater, F.M.; Sokolov, L.V.; Visser, M.E.; Winkel, W.; Wright, J.; Zang, H.

2006-01-01

In most bird species there is only a short time window available for optimal breeding due to variation in ecological conditions in a seasonal environment. Long-distance migrants must travel before they start breeding, and conditions at the wintering grounds and during migration may affect travelling

Reasons for the decline in bird numbers breeding near the Ravenglass Estuary

International Nuclear Information System (INIS)

Anderson, N.; Evans, P.R.

1987-07-01

Black-headed Gulls breeding at Ravenglass (and at other coastal sites in Cumbria) fed exclusively inland during the breeding season and so could not have acquired any radionuclide contaminants present in the estuarine muds and invertebrates. They, and two other ground-nesting bird species have suffered severe disturbance and predation by foxes at Ravenglass in recent years. In contrast, the Shelduck, which nests in holes (and so does not suffer fox predation) but feeds at Ravenglass on estuarine invertebrates, has bred successfully. Levels of heavy metal contaminants in gull tissues and eggs were too low to have caused the observed breeding failures at Ravenglass. Gulls feeding on the estuary before the breeding season, but which then moved to other (inland) breeding sites, nested successfully. (author)

Breeding of Greater and Lesser Flamingos at Sua Pan, Botswana ...

African Journals Online (AJOL)

to fledging was unknown owing to the rapid drying of the pan in late March 1999. No Greater Flamingo breeding was seen that season. Exceptional flooding during 1999–2000 produced highly favourable breeding conditions, with numbers of Greater and Lesser Flamingos breeding estimated to be 23 869 and 64 287 pairs, ...

Acoustic, genetic and observational evidence indicate the presence of humpback whales (Megaptera novaeangliae) from both hemispheres in Cape Verdean waters during their respective breeding seasons

NARCIS (Netherlands)

Ryan, Conor; Berrow, Simon D.; Romagosa, Miriam; Boisseau, Oliver; Lopes-Suarez, Pedro; Jann, Beatrice; Wenzel, F.; Bérubé, Martine; Palsboll, Per

2018-01-01

A small population of humpback whales breeds around the Cape Verde Islands off West Africa. These whales exhibit a boreal seasonality, albeit two months later than that in the West Indies. Based on aseasonal observations of humpback whales and calves, Hazevoet et al. (2011) postulated that whales

External factors determining breeding season in the red mangrove crab Goniopsis cruentata (Latreille (Crustacea, Brachyura, Grapsidae on the São Paulo State northern coast, Brazil

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Cobo Valter José

2003-01-01

Full Text Available This study evaluated the influence of the water and air temperatures, pluviosity and photoperiod on the breeding season of Goniopsis cruentata (Latreille, 1803, in Ubatuba littoral, southeastern Brazilian coast. Monthly collections were conducted out from January/95 to December/96 in an estuarine area from 23º29'10"-23º29'45"S to 45º09'10"-45º10'00"W. Water and air temperature variation showed the highest correlation coefficient with the frequency of ovigerous females, r² = 0.73 and 0.68, respectively. However, an analysis of the set of environmental variables, revealed the photoperiod as the factor of highest association with the ovigerous frequency (r² = 0.68. This degree of association allow us to suggest that the breeding season duration of G. cruentata might have some variations over different latitudes, and such results could be quite diverse in populations from different latitudes.

Breeding season, length-weight relationship and condition factor

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Poor body conditions coincided with time of peak breeding activity. The interaction effects of sex and month on Fulton's and Relative condition factors were not significant. (p=0.127 ..... reach bigger size in Lake Zwai environment, which is worth ...

Northern bobwhite breeding season ecology on a reclaimed surface mine

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Brooke, Jarred M.; Tanner, Evan P.; Peters, David C.; Tanner, Ashley M.; Harper, Craig A.; Keyser, Patrick D.; Clark, Joseph D.; Morgan, John J.

2017-01-01

Surface coal mining and subsequent reclamation of surface mines have converted large forest areas into early successional vegetative communities in the eastern United States. This reclamation can provide a novel opportunity to conserve northern bobwhite (Colinus virginianus). We evaluated the influence of habitat management activities on nest survival, nest-site selection, and brood resource selection on managed and unmanaged units of a reclaimed surface mine, Peabody Wildlife Management Area (Peabody), in west-central Kentucky, USA, from 2010 to 2013. We compared resource selection, using discrete-choice analysis, and nest survival, using the nest survival model in Program MARK, between managed and unmanaged units of Peabody at 2 spatial scales: the composition and configuration of vegetation types (i.e., macrohabitat) and vegetation characteristics at nest sites and brood locations (i.e., microhabitat). On managed sites, we also investigated resource selection relative to a number of different treatments (e.g., herbicide, disking, prescribed fire). We found no evidence that nest-site selection was influenced by macrohabitat variables, but bobwhite selected nest sites in areas with greater litter depth than was available at random sites. On managed units, bobwhite were more likely to nest where herbicide was applied to reduce sericea lespedeza (Lespedeza cuneata) compared with areas untreated with herbicide. Daily nest survival was not influenced by habitat characteristics or by habitat management but was influenced by nest age and the interaction of nest initiation date and nest age. Daily nest survival was greater for older nests occurring early in the breeding season (0.99, SE < 0.01) but was lower for older nests occurring later in the season (0.08, SE = 0.13). Brood resource selection was not influenced by macrohabitat or microhabitat variables we measured, but broods on managed units selected areas treated with herbicide to control sericea lespedeza

Time Budget and Diet of the Booted Eagles in the Breeding Season in Xinjiang, China

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Daoning Wu

2017-01-01

Full Text Available During the breeding seasons of 2010-2016, we have found seven nests of the Booted Eagle (Hieraaetus pennatus in Xinjiang, the west of China. We used a method of focal sampling and infrared cameras to continually observe behaviors and nestlings’ growth. Nestling behaviors were different between nestling period and post-nestling period. Attendance at the nests by both adults decreased as the nestling aged. The female brooded significantly more than the male did during daylight hours (P=0.016, F= 8.38, df =1. The daily mean number of food items delivered to the nests by adults was 3.2 times/day in nestling period, and 0.96/day in post-nestling period. Seven orders of wild birds, three orders of mammals and domestic poultry were documented as prey.

Nest ectoparasites increase physiological stress in breeding birds: an experiment.

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Martínez-de la Puente, Josué; Merino, Santiago; Tomás, Gustavo; Moreno, Juan; Morales, Judith; Lobato, Elisa; Martínez, Javier

2011-02-01

Parasites are undoubtedly a biotic factor that produces stress. Heat shock proteins (HSPs) are important molecules buffering cellular damage under adverse conditions. During the breeding season, blue tit Cyanistes caeruleus (L.) adults are affected by blood parasites, nest-dwelling parasites and biting flies, potentially affecting their HSP-mediated responses. Here, we treated females with primaquine to reduce blood parasites and fumigated nests with permethrin to reduce nest-dwelling parasites to test whether these treatments affect HSP60 level during the breeding season. Medicated females, but not controls, had a significant reduction of the intensity of infection by Haemoproteus spp. blood parasites. However, final intensity of infection did not differ significantly between groups, and we did not find an effect of medication on change in HSP60 level. Fumigation reduced the abundance of nest-dwelling parasites (mites, fleas and blowfly larvae) and engorged biting midges in nests. Females breeding in non-fumigated nests increased HSP60 levels during the season more than those breeding in fumigated nests. Furthermore, the change in HSP60 level was positively correlated with the abundance of biting midges. These results show how infections by nest ectoparasites during the breeding period can increase the level of HSPs and suggest that biting midges impose physiological costs on breeding female blue tits. Although plausible, the alternative that biting midges prefer to feed on more stressed birds is poorly supported by previous studies.

REPRODUCTIVE SEASONALITY OF SHEEP IN MEXICO

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Jaime Arroyo

2011-07-01

Full Text Available In order to discuss and analyze the available information concerning the seasonal breeding behavior of sheep in Mexico, this review was conducted. We analyzed the neuroendocrine basis that modulate the annual reproductive cycle in sheep and then discussed the degree of reproductive seasonality in Creole sheep wool, breeds originating in high latitudes and hair sheep, mainly in Pelibuey ewes. The Creole sheep wool show continuous annual reproductive activity and short seasonal anestrous. The females of northern origin, express seasonal reproductive activity, similar to that observed in individuals geographically located at latitudes above 35º. Pelibuey sheep show variable annual reproductive behavior with reduced anestrus or lack thereof.  It is suggested that the neuroendocrine mechanisms regulating seasonal anestrus in ewes, are active in the sheep of northern origin that live in Mexico, in a manner contrary is not activated in Creole and hair sheep.

Captive breeding of the white rhinoceros, Ceratotherium simum, and the Cape buffalo, Syncerus caffer : research communication

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J.D. Skinner

2006-09-01

Full Text Available Breeding records of 40 white rhinoceros and 155 Cape buffalo were analysed. Three rhinoceros cows bred in captivity, themselves conceived for the first time at 84, 87 and 95 months of age, respectively. Rhinoceros cows breed throughout the year. There is no evidence of a relationship between calving interval and month of birth. Calving intervals were normally distributed about the mean of 34 months and there were no significant differences between bulls, cows or sex of calf. There was no difference in the sex ratio of calves born to young cows nor older cows. The male:female ratio of the calves was Younger cows did not have shorter birth intervals. Although captive Cape buffaloes breed throughout the year, there is a preponderance of births in midsummer. There was some evidence that larger cows produce heavier calves and that season of birth may influence birth weight. Male calves weighed 41.20 + 0.68 kg vs 39.00 + 0.73 kg (range 24-60 kg for female calves but this difference was not significant. Calving intervals were normally distributed about the mean of 395 days and the male:female ratio of the calves was 1:1.2.

Ocean control of the breeding regime of the sooty tern in the southwest Indian Ocean

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Jaquemet, S.; Le Corre, M.; Quartly, G. D.

2007-01-01

Food availability, which is often seasonal, is regarded as a key factor in the breeding success of seabirds. In oceanic tropical areas, the resources are mostly patchy and ephemeral at the surface, and the seasonality is less marked than at higher latitudes. Such a situation influences greatly the breeding strategies of the oceanic seabird species. We conducted a comparative study of the breeding phenology of the sooty tern ( Sterna fuscata) in relation to the local and regional oceanographic conditions around the four major colonies (Europa, Juan de Nova, Lys and Bird Islands) of the southwest Indian Ocean. Over the 1997-2003 period, around all the studied locations, the sea-surface temperature (SST) and the chlorophyll concentration in the Mozambique Channel and the Seychelles area showed clear seasonal differences related to the southern climate and the monsoon phenomena. The breeding activity is synchronized at each studied colony, but the timings are very different. Seasonal reproduction occurs in austral winter at Europa and Bird Island and in austral summer at Juan de Nova; at Lys Island the reproduction is non-seasonal. For the seasonal colonies, there is a large monthly change in SST just before the beginning of reproduction, which is a proxy indicating the annual phytoplankton bloom. This variation is accompanied by the development of oceanic features such as fronts that favour aggregation of prey, and may also play an important role in the presence of schools of surface tuna, which are very important for the foraging success of sooty terns. Conversely, around Lys Island the seasonal variations of the marine environment do not lead to pronounced development of oceanic structures, and consequently, the longer-lasting phytoplankton bloom could explain the non-seasonal breeding regime there. Further studies will help discern the advantages and disadvantages of seasonal and non-seasonal reproduction regime in response to unpredictable fluctuations of the

Neural correlates of behavioural olfactory sensitivity changes seasonally in European starlings.

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Geert De Groof

2010-12-01

Full Text Available Possibly due to the small size of the olfactory bulb (OB as compared to rodents, it was generally believed that songbirds lack a well-developed sense of smell. This belief was recently revised by several studies showing that various bird species, including passerines, use olfaction in many respects of life. During courtship and nest building, male European starlings (Sturnus vulgaris incorporate aromatic herbs that are rich in volatile compounds (e.g., milfoil, Achillea millefolium into the nests and they use olfactory cues to identify these plants. Interestingly, European starlings show seasonal differences in their ability to respond to odour cues: odour sensitivity peaks during nest-building in the spring, but is almost non-existent during the non-breeding season.This study used repeated in vivo Manganese-enhanced MRI to quantify for the first time possible seasonal changes in the anatomy and activity of the OB in starling brains. We demonstrated that the OB of the starling exhibits a functional seasonal plasticity of certain plant odour specificity and that the OB is only able to detect milfoil odour during the breeding season. Volumetric analysis showed that this seasonal change in activity is not linked to a change in OB volume. By subsequently experimentally elevating testosterone (T in half of the males during the non-breeding season we showed that the OB volume was increased compared to controls.By investigating the neural substrate of seasonal olfactory sensitivity changes we show that the starlings' OB loses its ability during the non-breeding season to detect a natural odour of a plant preferred as green nest material by male starlings. We found that testosterone, applied during the non-breeding season, does not restore the discriminatory ability of the OB but has an influence on its size.

Fitness consequences of timing of migration and breeding in cormorants.

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Phillip Gienapp

Full Text Available In most bird species timing of breeding affects reproductive success whereby early breeding is favoured. In migratory species migration time, especially arrival at the breeding grounds, and breeding time are expected to be correlated. Consequently, migration time should also have fitness consequences. However, in contrast to breeding time, evidence for fitness consequences of migration time is much more limited. Climate change has been shown to negatively affect the synchrony between trophic levels thereby leading to directional selection on timing but again direct evidence in avian migration time is scarce. We here analysed fitness consequences of migration and breeding time in great cormorants and tested whether climate change has led to increased selection on timing using a long-term data set from a breeding colony on the island of Vorsø (Denmark. Reproductive success, measured as number of fledglings, correlated with breeding time and arrival time at the colony and declined during the season. This seasonal decline became steeper during the study period for both migration and breeding time and was positively correlated to winter/spring climate, i.e. selection was stronger after warmer winters/springs. However, the increasing selection pressure on timing seems to be unrelated to climate change as the climatic variables that were related to selection strength did not increase during the study period. There is indirect evidence that phenology or abundances of preferred prey species have changed which could have altered selection on timing of migration and breeding.

Global Trends in Seasonality of Normalized Difference Vegetation Index (NDVI, 1982–2011

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Assaf Anyamba

2013-09-01

Full Text Available A 30-year series of global monthly Normalized Difference Vegetation Index (NDVI imagery derived from the Global Inventory Modeling and Mapping Studies (GIMMS NDVI3g archive was analyzed for the presence of trends in changing seasonality. Using the Seasonal Trend Analysis (STA procedure, over half (56.30% of land surfaces were found to exhibit significant trends. Almost half (46.10% of the significant trends belonged to three classes of seasonal trends (or changes. Class 1 consisted of areas that experienced a uniform increase in NDVI throughout the year, and was primarily associated with forested areas, particularly broadleaf forests. Class 2 consisted of areas experiencing an increase in the amplitude of the annual seasonal signal whereby increases in NDVI in the green season were balanced by decreases in the brown season. These areas were found primarily in grassland and shrubland regions. Class 3 was found primarily in the Taiga and Tundra biomes and exhibited increases in the annual summer peak in NDVI. While no single attribution of cause could be determined for each of these classes, it was evident that they are primarily found in natural areas (as opposed to anthropogenic land cover conversions and that they are consistent with climate-related ameliorations of growing conditions during the study period.

Retrospective and statistical analysis of breeding management on the Italian Heavy Draught Horse breed.

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Mantovani, R; Sartori, C; Pigozzi, G

2013-07-01

This study investigated some aspects of breeding management in the Italian Heavy Draught Horse breed, aiming at improving its efficiency at stud farm level. A first aim was to evaluate the risk of unsuccessful reproduction in mares after an early (3 years) or normal (4 years) age at first foaling, in interaction with different stud rearing systems. A second objective was the examination of the mean time length in which young 2-year-old stallions maintain a genetic superiority on older proven stallions, identifying a 'genetic lifespan' in which young stallions can be safely used for reducing the cost of services. Reproductive performance at first and second foaling of 1513 mares were used. Mares had a normal first foal at 3 (n = 745) or 4 years of age (n = 768) in stud farms on the basis of stable (n = 488), feral (n = 345) or semi-feral (n = 680) rearing systems. Logistic regression analysis was performed by modeling the risk of unsuccessful reproduction in the subsequent season (i.e., results at second foaling), as affected by the interaction of age at first foaling × rearing system (six classes). Genetic lifespan of young stallions was estimated by regressing the least square means from a mixed model analysis for repeated measures of individual differences in 'total merit' estimated breeding values (EBVs) between young stallions (mean no. of 45/year) and the mean EBV of all proven stallions in a given year of genetic evaluation (mean no. of 483/year). Young stallions born between 1999 and 2005 were used, following each generation (i.e., birth year) from 2 to 7 subsequent yearly genetic evaluations. In comparison with the best reproductive success of second foaling at 4 years in stable systems, the greatest risk of unsuccessful reproduction was at 3 years in feral (+167%) and 3 years in semi-feral conditions (+91%). Young stallions showed a 0.50 s.d. greater EBV at the first evaluation than proven stallions, with a mean annual decrease in EBV of 0.07 s.d./year on

Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes During the Breeding and Nonbreeding Season

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Rubianes E

2005-03-01

Full Text Available Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate (MAP-primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravaginal MAP sponge for 12 days. While the control (C ewes (n = 35 were in permanent contact with rams, the ram effect (RE ewes (n = 36 were isolated for 34 days prior to contact with rams. At sponge withdrawal, all ewes were joined with eight sexually experienced marking Corriedale rams and estrus was recorded over the next 4 days. The ovaries were observed by laparoscopy 4–6 days after estrus. Four weeks later, pregnancy was determined by transrectal ultrasonography. In eight ewes from each group, ovaries were ultrasonographically scanned; FSH, LH, and estradiol-17β were measured every 12 hours until ovulation or 96 hours after estrus. The response to the rams was not affected by the fact that ewes had been kept or not in close contact with males before teasing. No differences were found in FSH, LH, estradiol-17β concentrations, growth of the ovulatory follicle, onset of estrus, ovulation rate, or pregnancy rate. Experiment 2 was performed with 14 ewes during the nonbreeding season. Ewes were isolated from rams for 1 month, and received a 6-day MAP priming. Ovaries were ultrasonographically scanned every 12 hours, and FSH, LH, estradiol-17β, and progesterone were measured. Ewes that ovulated and came into estrus had higher FSH and estradiol-17β levels before introduction of the rams than did ewes that had a silent ovulation. The endocrine pattern of the induced follicular phase of ewes that came into estrus was more similar to a normal follicular phase, than in ewes that had a silent ovulation. The follicle that finally ovulated tended to emerge earlier and in a more synchronized fashion in those ewes that did come into estrus. All ewes that ovulated had an LH surge and reached higher maximum FSH

Impact of the breeding region and the season on the content of the selected mineral elements in the hair of cows

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Dorota CYGAN-SZCZEGIELNIAK

2015-12-01

Full Text Available The aim of the research was to analyze the effect of the season and the breeding region on the content of selected minerals (Ca, Mg, Na and K in the hair of dairy cows. The research material was made up of 114 polish Holstein-Friesians breed cows from three breeding centres in Poland: Kombinat Rolny Sp. z o. o. - Kietrz (the opolskie province, Hodowla Zarodowa Zwierząt Sp. z o.o. - Knyszyn (the podlaskie province and Ośrodek Hodowli Zarodowej Sp. z o.o. - Osięciny (the kujawsko-pomorskie province. The cows were kept in freestanding cowsheds with den boxes. The animal nutrition involved the use of the TMR system, considering the division into nutrition groups. The hair was sampled in summer and in the period of winter and spring from the side of the body, right behind the coastal arch. Determination of Ca, Mg, Na and K was performed by means of atomic absorption spectrophotometry (AAS. The study revealed seasonal variations in the content of mineral elements in the hair of dry cows and a region-dependent differentiation. The highest content of the quantity elements in question was found in the hair of the cows from Osięciny. The mean concentration of Ca, Mg, Na and K in the hair of cows from Osięciny was statistically significantly higher than in the hair collected in winter from the animals from Knyszyn and Kietrz. The lowest values of the determined elements were noted in the hair of cows bred in Knyszyn. The investigation of the correlation between the amounts of the elements, based on an analysis of all samples of hair, revealed a positive correlation between Na and K cations, as well as between Mg and Ca cations.

Spring weather conditions influence breeding phenology and reproductive success in sympatric bat populations.

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Linton, Danielle M; Macdonald, David W

2018-04-10

Climate is known to influence breeding phenology and reproductive success in temperate-zone bats, but long-term population level studies and interspecific comparisons are rare. Investigating the extent to which intrinsic (i.e. age), and extrinsic (i.e. spring weather conditions), factors influence such key demographic parameters as the proportion of females becoming pregnant, or completing lactation, each breeding season, is vital to understanding of bat population ecology and life-history traits. Using data from 12 breeding seasons (2006-2017), encompassing the reproductive histories of 623 Myotis daubentonii and 436 Myotis nattereri adult females, we compare rates of recruitment to the breeding population and show that these species differ in their relative sensitivity to environmental conditions and climatic variation, affecting annual reproductive success at the population level. We demonstrate that (1) spring weather conditions influence breeding phenology, with warm, dry and calm conditions leading to earlier parturition dates and advanced juvenile development, whilst cold, wet and windy weather delays birth timing and juvenile growth; (2) reproductive rates in first-year females are influenced by spring weather conditions in that breeding season and in the preceding breeding season when each cohort was born. Pregnancy and lactation rates were both higher when favourable spring foraging conditions were more prevalent; (3) reproductive success increases with age in both species, but at different rates; (4) reproductive rates were consistently higher, and showed less interannual variation, in second-year and older M. daubentonii (mean 91.55% ± 0.05 SD) than M. nattereri (mean 72.74% ± 0.15 SD); (5) estimates of reproductive success at the population level were highly correlated with the size of the juvenile cohort recorded each breeding season. Improving understanding of the influence of environmental conditions, especially extreme climatic

Breeding seasonality and primary moult parameters of Euplectes ...

African Journals Online (AJOL)

The grassland biome in South Africa has a summer rainfall and Southern Red Bishops Euplectes orix, Fan-tailed Widows E. axillaris, White-winged Widow E. albonotatus, Red-collared Widow E. ardens and Long-tailed Widow E. progne breed from October or November to March. Primary moult starts in late March or early ...

The Effects of Pre-slaughter Stress and Season on the Activity of Plasma Creatine Kinase and Mutton Quality from Different Sheep Breeds Slaughtered at a Smallholder Abattoir

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A. Y. Chulayo

2013-12-01

Full Text Available The objective of the current study was to determine the effect of pre-slaughter stress, season and breed on the activity of plasma creatine kinase (CK and the quality of mutton. One hundred and seventy-three (173 castrated sheep from Dormer (DM, South African Mutton Merino (SAMM, Dorper (DP and Blackhead Persian (BP sheep breeds were used in the study. The animals were grouped according to age-groups as follows: Group 1 (6 to 8 months, Group 2 (9 to 12 months and Group 3 (13 to 16 months. Blood samples were collected during exsanguinations using disposable vacutainer tubes for CK analysis. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL were collected from 84 castrated sheep, of different breeds (28 per breed 24 h after slaughter. The following physico-chemical characteristics of mutton were determined; meat pH (pH24, color (L*, a* and b*, thawing and cooking losses and Warner Braztler Shear Force (WBSF. The activity of plasma CK was significantly higher (p0.001 levels (1,358.6±191.08 of CK. South African Mutton Merino had higher values for pH24 (5.9±0.06, L* (34.2±0.97, b* (12.2±0.50 and WBSF (26.8±1.51 and Blackhead Persian had higher values (35.5±2.17 for cooking loss (CL% than the other breeds. Computed Principal Component Analyses (PCA on the activity of plasma CK and physico-chemical characteristics of mutton revealed no correlations between these variables. However, positive correlations were observed between pH24, L*, a*, b*, CL% and WBSF. Relationships between pre-slaughter stress, CK activity and physico-chemical characteristics of mutton were also observed. It was therefore concluded that although mutton quality and creatine kinase were not related, pre-slaughter stress, season and breed affected the activity of creatine kinase and mutton quality.

Manipulation of reproductive performance of lactating buffaloes using melatonin and controlled internal drug release device treatment during out-of-breeding season under tropical conditions.

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Ramadan, T A; Sharma, R K; Phulia, S K; Balhara, A K; Ghuman, S S; Singh, I

2016-09-01

Twelve lactating Murrah buffalo, divided into control and treatment group of six animals each, were used to study the effect of melatonin and controlled internal drug release (CIDR) device treatment on the resumption of ovarian activity during out-of-breeding season (summer solstice). Treated group implanted with melatonin (18-mg melatonin/50-kg body weight) for 45 days and then animals of both groups received CIDR for 9 days. All animals received intramuscular 500 IU eCG, at day before CIDR removal, and 10-μg GnRH at day after CIDR withdrawal. All animals were subjected to estrus detection daily. Blood samples in conjunction with transrectal ultrasonography were performed once a week to determine serum concentrations of melatonin, progesterone, and antioxidant enzyme activities, as well as to monitor the ovarian activity. Melatonin treatment resulted in an increase (P Day 21 and Day 30 after artificial insemination and achieved higher percentage of conception rate than control. In conclusion, the CIDR treatment preceded by melatonin improved the reproductive performance in lactating buffaloes during out-of-breeding season under tropical conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of transportation during the hot season, breed and electrical stimulation on histochemical and meat quality characteristics of goat longissimus muscle.

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Kadim, Isam T; Mahgoub, Osman; Al-Marzooqi, Waleed; Khalaf, Samera; Al-Sinawi, Shadia S H; Al-Amri, Issa

2010-06-01

The effects of transportation and electrical stimulation (90 V) on physiological, histochemical and meat quality characteristics of two breeds of Omani goats were assessed. Twenty 1-year-old male goats from each breed (Batina and Dhofari) were divided into two groups: 3 h transported during the hot season (42 degrees C day time temperature) and non-transported. Animals were blood-sampled before loading and prior to slaughter. Electrical stimulation was applied 20 min postmortem to 50% randomly selected carcasses of both breeds. Temperature and pH decline of the Longissimus was monitored. Ultimate pH, shear force, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss and colour were measured from samples of Longissimus dorsi muscles. Electrical stimulation and transportation had a significant effect on most biochemical and meat quality characteristics of Longissimus dorsi. The transported goats had higher plasma cortisol (P goats. Electrical stimulation resulted in a significantly (P Meat from transported goats had significantly higher pH, expressed juice and shear force, but contained significantly lower sarcomere length and L* values than non-transported goats. The proportion of the myosin ATPase staining did not change as a function of stimulation, transportation or breed. These results indicated that subjecting goats to transportation for 3 h under high ambient temperatures can generate major physiological and muscle metabolism responses. Electrical stimulation improved quality characteristics of meat from both groups. This indicates that electrical stimulation may reduce detrimental effects of transportation on meat quality of Omani goats.

Emperor penguins breeding on iceshelves.

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Peter T Fretwell

Full Text Available We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land. Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species.

Opportunities for detection and use of QTL influencing seasonal reproduction in sheep: a review

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Notter David R

2005-12-01

Full Text Available Abstract Genetic improvement in traits associated with seasonal breeding in sheep is challenging because these traits have low heritabilities, are generally not expressed until late in life, are commonly recorded only in females, and are expressed only in some lambing seasons and management systems. Detection of quantitative trait loci and their use in marker-assisted selection could therefore substantially enhance selection responses. A population of sheep with an extended breeding season was developed through selection for fertility in spring matings and provides opportunities for further study of candidate genes influencing seasonal breeding. In particular, the melatonin receptor 1a gene is polymorphic in many sheep breeds and appears to influence a number of seasonal reproductive responses. In addition, a variety of clock genes have been identified in laboratory mammals and shown to influence biological rhythms. Mutations in these clock genes have been identified and shown to influence circadian periodicities and reproductive patterns in golden hamster and mouse. In sheep, expression of clock genes in the suprachaismatic nucleus and pars tuberalis (PT suggests that "calendar" cells in the ovine PT play a role in maintaining circannual rhythms. Thus the various clock genes represent potentially important candidate genes that may be involved in control of seasonal breeding.

Breeding performance in the Italian chicken breed Mericanel della Brianza

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Stefano P. Marelli

2010-11-01

Full Text Available In Italy, 90 local avian breeds were described, the majority (61% were classified extinct and only 8.9 % still diffused. Therefore, efforts for conservation of Italian avian breeds are urgently required. The aim of this study was to record the breeding performance of the Italian breed Mericanel della Brianza and multiply a small population, in order to develop a conservation program. Fourteen females and 8 males were available at the beginning of the reproductive season in 2009 and organized in 8 families (1 male/1-2 females kept in floor pens. Birds received a photoperiod of 14L:10D and fed ad libitum. Breeding performance was recorded from March to June. Egg production and egg weight were recorded daily; eggs were set every 2 weeks and fertility, embryo mortality and hatchability were recorded. Mean egg production was 37% and mean egg weight was 34±3.49 g. High fertility values were recorded in the first three settings, from 94 to 87%, and the overall mean fertility value was 81.6%. Overall hatchability was only 49.6% due to a high proportion of dead embryos. Embryo mortality occurred mainly between day 2 and 7 of incubation and during hatch. Highest hatchability values were recorded in setting 1 and 2, 69 and 60% respectively, and a great decrease was found in the following settings. Great variations in egg production, fertility, hatchability and embryo mortality were found among families. The present results are the basic knowledge on reproductive parameters necessary to improve the reproductive efficiency of the breed within a conservation plan.

Breeding implications resulting from classification of patellae luxation in dogs.

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van Grevenhof, E M; Hazewinkel, H A W; Heuven, H C M

2016-08-01

Patellar luxation (PL) is one of the major hereditary orthopaedic abnormalities observed in a variety of dog breeds. When the patellae move sideways out of the trochlear groove, this is called PL. The PL score varies between dogs from normal to very severe. Reducing the prevalence of PL by breeding could prevent surgery, thereby improve welfare. Orthopaedic specialists differentiate between normal and loose patellae, where the patellae can be moved to the edge of the trochlear groove, considering scoring loose patellae as normal in the future. Loose patellae are considered acceptable for breeding so far by the breeding organization. The aim of this study was to analyse the genetic background of PL to decide on the importance of loose patellae when breeding for healthy dogs. Data are available from two dog breeds, that is Flat-coated Retrievers (n = 3808) and Kooiker dogs (n = 794), with a total of 4602 dogs. Results show that loose patellae indicate that dogs are genetically more susceptible to develop PL because family members of the dogs with loose patellae showed more severe PL. In addition, the estimated breeding values for dogs with loose patellae indicate that breeding values of dogs with loose patellae were worse than breeding values obtained for dogs with a normal score. Given these results, it is advised to orthopaedic specialists to continue to score loose patellae as a separate class and to dog breeders to minimize the use of dogs in breeding with a genetically higher susceptibility for PL. © 2015 Blackwell Verlag GmbH.

Effects of Male on Reproductive Behavior of Markhoz Female Goats in Breeding Season

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H. Daghigh Kia

2012-09-01

Full Text Available In order to study the effect of male on reproductive behavior of female goats, 88 Markhoz breed goats with initial body weight of 42±2kg, 3.5 year old, and 10 male goats were used for 6 weeks. This study was conducted in two phases. In the first experiment 48 female goats were allocated in three groups, each group included eight animals with 2 replicate on both sides of male goats, respectively, at intervals of 0-5, 10-15 and 25-30 meters. In the second experiment, 24 female goats having CIDR were used in an order similar to that of first group. However, the goats were located only in one side of the males. The third group was the control group which was treated in a separate saloon in two groups, each of them having eight animals in it. Results showed a significant effect of male animal in estrus synchronization, the earlier beginning of the reproductive cycle and fertility in the early reproductive season. The first group showed better results in creation and synchronization of estrus in comparison to CIDR received animals (respectively 116.7 vs. 91.6%.

Seasonal Canopy Temperatures for Normal and Okra Leaf Cotton under Variable Irrigation in the Field

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James R. Mahan

2016-11-01

Full Text Available Temperature affects a number of physiological factors in plants and is related to water use, yield and quality in many crop species. Seasonal canopy temperature, measured with infrared thermometers, is often used in conjunction with environmental factors (e.g., air temperature, humidity, solar radiation to assess crop stress and management actions in cotton. Normal and okra leaf shapes in cotton have been associated with differences in water use and canopy temperature. The okra leaf shape in cotton is generally expected to result in lower water use and lower canopy temperatures, relative to normal leaf, under water deficits. In this study canopy temperatures were monitored in okra and normal leaf varieties for a growing season at four irrigation levels. Differences in canopy temperature (<2 °C were measured between the two leaf shapes. As irrigation levels increased, canopy temperature differences between the leaf shapes declined. At the lowest irrigation level, when differences in sensible energy exchanges due to the okra leaf shape would be enhanced, the canopy temperature of the okra leaf was warmer than the normal leaf. This suggests that varietal differences that are not related to leaf shape may have more than compensated for leaf shape differences in the canopy temperature.

Environmental conditions during breeding modify the strength of mass-dependent carry-over effects in a migratory bird.

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Xavier A Harrison

Full Text Available In many animals, processes occurring in one season carry over to influence reproductive success and survival in future seasons. The strength of such carry-over effects is unlikely to be uniform across years, yet our understanding of the processes that are capable of modifying their strength remains limited. Here we show that female light-bellied Brent geese with higher body mass prior to spring migration successfully reared more offspring during breeding, but only in years where environmental conditions during breeding were favourable. In years of bad weather during breeding, all birds suffered reduced reproductive output irrespective of pre-migration mass. Our results suggest that the magnitude of reproductive benefits gained by maximising body stores to fuel breeding fluctuates markedly among years in concert with conditions during the breeding season, as does the degree to which carry-over effects are capable of driving variance in reproductive success among individuals. Therefore while carry-over effects have considerable power to drive fitness asymmetries among individuals, our ability to interpret these effects in terms of their implications for population dynamics is dependent on knowledge of fitness determinants occurring in subsequent seasons. 

Future prospects for ascochyta blight resistance breeding in cool season food legumes

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Diego eRubiales

2012-02-01

Full Text Available Legume cultivation is strongly hampered by the occurrence of ascochyta blights. Strategies of control have been developed but only marginal successes have been achieved. Breeding for disease resistance is regarded the most cost efficient method of control. Significant genetic variation for disease resistance exists in most legume crops with numerous germplasm lines maintained, providing an excellent resource for plant breeders. Fast and reliable screening methods have been adjusted to fulfil breeding programmes needs. However, the complex inheritance controlled quantitatively by multiple genes, have been difficult to manipulate. Successful application of biotechnology to ascochyta blight resistance breeding in legume crops will facilitate both a good biological knowledge of the crops and of the mechanisms underlying resistance. The current focus in applied breeding is leveraging biotechnological tools to develop more and better markers to speed up the delivery of improved cultivars to the farmer. To date, however, progress in marker development and delivery of useful markers has been slow. The limited saturation of the genomic regions bearing putative QTLs in legume crops makes difficult to identify the most tightly-linked markers

Experimental examination of intraspecific density-dependent competition during the breeding period in monarch butterflies (Danaus plexippus.

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D T Tyler Flockhart

Full Text Available A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to measure the strength of density-dependent intraspecific competition on egg laying rate and larval survival and then applied our results to density estimates of wild monarch populations to model the strength of density dependence during the breeding season. Egg laying rates did not change with density but larvae at high densities were smaller, had lower survival, and weighed less as adults compared to lower densities. Using mean larval densities from field surveys resulted in conservative estimates of density-dependent population reduction that varied between breeding regions and different phases of the breeding season. Our results suggest the highest levels of population reduction due to density-dependent intraspecific competition occur early in the breeding season in the southern portion of the breeding range. However, we also found that the strength of density dependence could be almost five times higher depending on how many life-stages were used as part of field estimates. Our study is the first to link experimental results of a density-dependent reduction in vital rates to observed monarch densities in the wild and show that the effects of density dependent competition in monarchs varies across space and time, providing valuable information for developing robust, year-round population models in this migratory organism.

Seasonal variation in male alternative reproductive tactics.

Science.gov (United States)

Monroe, M J; Amundsen, T; Utne-Palm, A C; Mobley, K B

2016-12-01

Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

The reproductive responses of two breeds of beef cows and the ...

African Journals Online (AJOL)

cold stress is a problem in this country, and if so, to what extent? ..... important in these analyses to establish the precise role that breed played in affecting post- ... accounting for between 20,6010 (first season) and 47,3% (se- cond season) of ...

Pre-breeding blood urea nitrogen concentration and reproductive performance of Bonsmara heifers within different management systems.

Science.gov (United States)

Tshuma, Takula; Holm, Dietmar Erik; Fosgate, Geoffrey Theodore; Lourens, Dirk Cornelius

2014-08-01

This study investigated the association between pre-breeding blood urea nitrogen (BUN) concentration and reproductive performance of beef heifers within different management systems in South Africa. Bonsmara heifers (n = 369) from five herds with different estimated levels of nitrogen intake during the month prior to the commencement of the breeding season were sampled in November and December 2010 to determine BUN concentrations. Body mass, age, body condition score (BCS) and reproductive tract score (RTS) were recorded at study enrolment. Trans-rectal ultrasound and/or palpation was performed 4-8 weeks after a 3-month breeding season to estimate the stage of pregnancy. Days to pregnancy (DTP) was defined as the number of days from the start of the breeding season until the estimated conception date. Logistic regression and Cox proportional hazards survival analysis were performed to estimate the association of pre-breeding BUN concentration with subsequent pregnancy and DTP, respectively. After stratifying for herd and adjusting for age, heifers with relatively higher pre-breeding BUN concentration took longer to become pregnant when compared to those with relatively lower BUN concentration (P = 0.011). In the herd with the highest estimated nitrogen intake (n = 143), heifers with relatively higher BUN were less likely to become pregnant (P = 0.013) and if they did, it was only later during the breeding season (P = 0.017), after adjusting for body mass. These associations were not present in the herd (n = 106) with the lowest estimated nitrogen intake (P > 0.500). It is concluded that Bonsmara heifers with relatively higher pre-breeding BUN concentration, might be at a disadvantage because of this negative impact on reproductive performance, particularly when the production system includes high levels of nitrogen intake.

An echocardiographic study of healthy Border Collies with normal reference ranges for the breed.

Science.gov (United States)

Jacobson, Jake H; Boon, June A; Bright, Janice M

2013-06-01

The objectives of this study were to obtain standard echocardiographic measurements from healthy Border Collies and to compare these measurements to those previously reported for a general population of dogs. Standard echocardiographic data were obtained from twenty apparently healthy Border Collie dogs. These data (n = 20) were compared to data obtained from a general population of healthy dogs (n = 69). Border Collies were deemed healthy based on normal history, physical examination, complete blood count, serum biochemical profile, electrocardiogram, and blood pressure, with no evidence of congenital or acquired heart disease on echocardiographic examination. Standard two dimensional, M-mode, and Doppler echocardiographic measurements were obtained and normal ranges determined. The data were compared to data previously obtained at our hospital from a general population of normal dogs. Two dimensional, M-mode, and Doppler reference ranges for healthy Border Collies are presented in tabular form. Comparison of the weight adjusted M-mode echocardiographic means from Border Collies to those from the general population of dogs showed Border Collies to have larger left ventricular systolic and diastolic dimensions, smaller interventricular septal thickness, and lower fractional shortening. There are differences in some echocardiographic parameters between healthy Border Collies and the general dog population, and the echocardiographic reference ranges provided in this study should be used as breed specific reference values for Border Collies. Copyright © 2013 Elsevier B.V. All rights reserved.

Breeding success in a Red Bishop ( Euplectes orix ) colony in the ...

African Journals Online (AJOL)

Data are presented on breeding success of Red Bishops (Euplectes orix) collected over four breeding seasons at a colony in the Addo Elephant National Park, Eastern Cape, South Africa. Overall hatching and fledging success were 53.8% and 26.0% of all eggs laid, respectively, and the overall mean number of fledglings ...

Black Sparrowhawk Accipiter melanoleucus breeding behaviour ...

African Journals Online (AJOL)

Similarly, delivery of fresh leaf material to the nest site increased with chick age. Over the 2011 and 2012 breeding seasons respectively 74% and 41% of nests successfully fledged chicks, with the majority of these producing two offspring. Keywords: brooding, incubation, nest building, parental care, reproductive success ...

Sympatric breeding auks shift between dietary and spatial resource partitioning across the annual cycle.

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Jannie Fries Linnebjerg

Full Text Available When species competing for the same resources coexist, some segregation in the way they utilize those resources is expected. However, little is known about how closely related sympatric breeding species segregate outside the breeding season. We investigated the annual segregation of three closely related seabirds (razorbill Alcatorda, common guillemot Uriaaalge and Brünnich's guillemot U. lomvia breeding at the same colony in Southwest Greenland. By combining GPS and geolocation (GLS tracking with dive depth and stable isotope analyses, we compared spatial and dietary resource partitioning. During the breeding season, we found the three species to segregate in diet and/or dive depth, but less in foraging area. During both the post-breeding and pre-breeding periods, the three species had an increased overlap in diet, but were dispersed over a larger spatial scale. Dive depths were similar across the annual cycle, suggesting morphological adaptations fixed by evolution. Prey choice, on the other hand, seemed much more flexible and therefore more likely to be affected by the immediate presence of potential competitors.

Retrospective analysis of trends and production factors associated with sow mortality on swine-breeding farms in USA.

Science.gov (United States)

Koketsu, Y

2000-09-01

Of the 825 pig farms in USA that mailed in their electronic file containing production records, 604 farms were used to observe breeding-female mortality risk and related factors (herd size, lactation length, parity and season). Multiple regression was used to determine factors associated with annual mortality risk. Analyses of variance were used for comparisons of mortality risks among parity and season groups. Average annual mortality risks during the 1997 period was 5.68%. Average breeding-female inventories and average lactation length on USA farms were 733 and 18.3 days, respectively. Higher annual breeding-female mortality risk was associated with larger herd size, greater parity at farrowing and shorter lactation length (P500 females, mortality risk increases by 0.44%. Older parity was associated with higher mortality risks. Summer season was also associated with higher mortality risk. Using five-years' records on 270 farms, annual mortality risk in 1997 was higher than those of 1993 and 1994, while average breeding-female inventory increased and lactation length decreased. It is recommended that producers, especially in large herds, pay more attention to breeding females.

Colony Development and Density-Dependent Processes in Breeding Grey Herons

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Takeshi Shirai

2013-01-01

Full Text Available The density-dependent processes that limit the colony size of colonially breeding birds such as herons and egrets remain unclear, because it is difficult to monitor colonies from the first year of their establishment, and the most previous studies have considered mixed-species colonies. In the present study, single-species colonies of the Grey Heron (Ardea cinerea were observed from the first year of their establishment for 16 years in suburban Tokyo. Colony size increased after establishment, illustrating a saturation curve. The breeding duration (days from nest building to fledging by a pair increased, but the number of fledglings per nest decreased, with colony size. The reproductive season in each year began earlier, and there was greater variation in the timing of individual breeding when the colony size was larger. The prolonged duration until nestling feeding by early breeders of the colony suggests that herons at the beginning of the new breeding season exist in an unsteady state with one another, likely owing to interactions with immigrant individuals. Such density-dependent interference may affect reproductive success and limit the colony size of Grey Herons.

Effectiveness of melatonin and controlled internal drug release device treatment on reproductive performance of buffalo heifers during out-of-breeding season under tropical conditions.

Science.gov (United States)

Ramadan, T A; Sharma, R K; Phulia, S K; Balhara, A K; Ghuman, S S; Singh, I

2014-12-01

Sixteen Murrah buffalo heifers, divided into control and treatment groups of eight animals each, were used to study the effect of melatonin and controlled internal drug release (CIDR) device treatment on the resumption of ovarian activity during out-of-breeding season (summer solstice). Treated group was implanted with melatonin (18 mg of melatonin per 50 kg of body weight) for 45 days and then heifers of both groups received CIDR for 9 days. All heifers received intramuscular 500 IU eCG on the day before CIDR removal and 10 μg GnRH on the day after CIDR withdrawal. All animals were subjected to estrus detection daily. Blood sampling in conjunction with transrectal ultrasonography were performed twice weekly to determine serum concentrations of melatonin, progesterone, LH, and antioxidant enzyme activities, as well as to monitor the ovarian follicular activity. Melatonin treatment resulted in an increase (P Days 0 and 35 of melatonin treatment. However, melatonin exhibited superior ability to maintain CL at 21 days after artificial insemenation (AI) and increased the percentage of conception to threefold higher than control. In conclusion, melatonin implantation successfully improved the diameter of largest follicles and the ability to maintain CL at 21 days after AI in buffalo heifers during out-of-breeding season under tropical conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Breeding biology of Tyrannus melancholicus (Aves: Tyrannidae in a restinga reserve of southeastern Brazil

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Hermes Daros

2018-04-01

Full Text Available ABSTRACT Existing knowledge of the breeding success and life history characteristics of most Neotropical bird species is scarce. Here, we help fill this gap by analyzing aspects of the breeding biology of the Tropical Kingbird Tyrannus melancholicus (Vieillot, 1819, which is a good model for this kind of study as it is a common species occurring in various environments, including urban areas, but little is known about its life history. We provide results concerning the breeding period, clutch size, incubation and nestling periods, description of nests, eggs and nestlings, and the plants used for nest sites by this species. Fifty-four nests were monitored over two seasons (2012-2014 in a protected area in southeastern Brazil. Nesting began at the end of the dry season and the beginning of the rainy season. The frequency of active nests varied according to variations in rainfall for each breeding season analyzed. The means and standard deviations of the incubation period (14.2 ± 1.9 days, nestling period (15.1 ± 0.8 days and clutch size (2.5 ± 0.7 eggs were similar to values reported for other Neotropical passerines. Twenty-one plant species used as nest trees and for the construction of the nests were identified. The results show that T. melancholicus is not highly selective when choosing plant species used for nest construction.

Prevalence of Mycobacterium bovis in some cattle breeds in the aids ...

African Journals Online (AJOL)

M. bovis was identified by growth rate, pigment production, colony and cell morphology and biochemical characteristics. A total of 41 heads of cattle comprising of 9 bulls and 32 cows from 7 breeds were positive for M. bovis. No isolate of M. bovis was obtained from Keteku breed and no seasonal distribution of the organism ...

Melatonin controls seasonal breeding by a network of hypothalamic targets

DEFF Research Database (Denmark)

Revel, Florent G; Masson-Pévet, Mireille; Pévet, Paul

2009-01-01

In seasonal species, the photoperiod (i.e. day length) tightly regulates reproduction to ensure that birth occurs at the most favourable time of year. In mammals, a distinct photoneuroendocrine circuit controls this process via the pineal hormone melatonin. This hormone is responsible for the sea......In seasonal species, the photoperiod (i.e. day length) tightly regulates reproduction to ensure that birth occurs at the most favourable time of year. In mammals, a distinct photoneuroendocrine circuit controls this process via the pineal hormone melatonin. This hormone is responsible...... for the seasonal timing of reproduction, but the anatomical substrates and the cellular mechanisms through which melatonin modulates seasonal functions remain imprecise. Recently, several genes have been identified as being regulated by the photoperiod in the brain of seasonal mammals. These genes are thought....../GPR54 system and to the RFamide-related peptides.Interestingly, these systems involve different hypothalamic nuclei, suggesting that several brain loci may be crucial for melatonin to regulate reproduction, and thus represent key starting points to identify the long-sought-after mode and site...

A Qualitative Evidence of the Breeding Sites of Patton (Diptera: Culicidae in and Around Kassala Town, Eastern Sudan

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Asma Mahmoud Hamza

2016-01-01

Full Text Available Anopheles arabiensis Patton (Diptera: Culicidae is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites. In the dry season, irrigation canals, seepage from water pipes, neglected wells, artificial containers, and man-made ditches serve as the main breeding sites. Breeding water showed a pH of 7.9 and a low concentration of the total dissolved salts. The results of this study may be considered in planning and implementing larval control programs in the area.

Within-season variability of fighting behaviour in an Australian alpine grasshopper.

Science.gov (United States)

Muschett, Giselle; Umbers, Kate D L; Herberstein, Marie E

2017-01-01

Throughout the breeding season, changing environmental and biological conditions can lead to variation in the reproductive landscape of many species. In alpine environments temperature is a key driver of behaviour for small ectotherms such as insects, but variable biotic factors such as mate quality and availability can also influence behaviour. Kosicuscola tristis is a small semelparous grasshopper of the Australian alpine region. In a rare behaviour among grasshoppers, K. tristis males engage in vigorous fights over access to females, involving mandible displays, kicking, biting and grappling. In this study we describe the variation in fighting behaviour of K. tristis throughout the breeding season and test several hypotheses related to temperature, body size, mating behaviour, and female quality. We show that K. tristis males are more aggressive toward each other at the end of the breeding season than at the beginning. This increased aggression is associated with decreased daily average temperatures (from ~20°C to ~9°C), decreased mating activity, increased female fecundity, and an unexpected trend toward an increase in female-to-male aggression. These results suggest that K. tristis is likely under increased selective pressure to time key life cycle events with favourable biological and climatic conditions. The stochastic nature of alpine environments combined with a relatively short life span and breeding season, as well as limited mating opportunities toward the end of the season may have contributed to the evolution of this extraordinary mating system.

Multiple breeding in the Great Tit. A trade-off between successive reproductive attempts?

NARCIS (Netherlands)

Verhulst, S.; Tinbergen, J.M.; Daan, S.

1997-01-01

1. Multiple breeding (raising more than one batch of young per breeding season) is a common life-history tactic that has received very little attention. A simple static optimization model was developed, applicable to iteroparous animals with parental care, that predicts: (1) when an animal should be

Reproductive and productive performances of Santa Inês ewes submitted to breeding in different periods of the Amazonian humid tropical climate.

Science.gov (United States)

Soares, Felipe Nogueira; Oliveira, Maria Emilia Franco; Padilha-Nakaghi, Luciana Cristina; de Oliveira, Luís Guilherme; Feliciano, Marcus Antônio Rossi; de Oliveira, Felipe Brener Bezerra; Teixeira, Pedro Paulo Maia; Vicente, Wilter Ricardo Russiano; Faturi, Cristian; Rodrigues, Luiz Fernando de Souza

2015-12-01

The objective of this study was to evaluate the reproductive and productive performance of Santa Inês ewes bred at different times of the year in humid tropical climate. One hundred and forty-eight Santa Inês ewes were grouped according to the time of the year of their breeding season (i.e., mating period) (dry/wet, wet, wet/dry, and dry season). The service type was natural mating and the ewes and rams were kept together every night for 45 days. Reproductive efficiency was assessed by service, pregnancy, lambing, prolificacy, twinning, pregnancy loss, weaning, and lamb mortality rates. Ewes were weighed at the beginning and at the end of the breeding season and before and after parturition, and sequential weighing of the lambs was performed (at birth, 15, 30, 60, and 90 days). Reproductive efficiency index (number of lambs weaned/total of served ewes) and productive efficiency (kg of weaned lamb/kg of served or lambed ewes) were calculated. All ewes expressed estrus early in the breeding season; however, a higher percentage (53.5 and 7.1 % at 30 and 45 days, respectively) of ewes returned to estrus during the wet/dry period. The lower rates (13.9 %) of return to estrus at 30 days were during the wet season (P  0.05) effects of breeding seasons on the remaining reproductive rates. Ewes that lambed during the wet/dry transition period weighted less, before (40.5 ± 2.5 kg) and after (38.6 ± 1.6 kg) parturition, than those of other groups (P ewes, respectively; P ewes served in the dry season. The reproductive performance of Santa Inês ewes was not significantly influenced by the period of the year in which the breeding seasons took place, allowing for four breeding seasons a year in the Amazon region. Variations between periods in return to estrus rates, weight of ewes close to parturition and lamb weight at weaning indicate that climate changes can also affect reproductive rates.

Sexual dimorphism of extensor carpi radialis muscle size, isometric force, relaxation rate and stamina during the breeding season of the frog Rana temporaria Linnaeus 1758.

Science.gov (United States)

Navas, Carlos A; James, Rob S

2007-02-01

Mating success of individual male frogs within explosive breeding species can depend on their ability to compete for a mate and to hold onto that mate during amplexus. Such importance of amplexus has resulted in the evolution of sexual dimorphism in the morphology and contractile characteristics of the anuran forelimb muscles used during amplexus. The aims of our study were to use an explosive breeding frog (Rana temporaria) during the breeding season to compare extensor carpi radialis (ECR) muscle length, mass, isometric activation times, relaxation times, absolute force, relative force (stress) and fatigue between male and female frogs. We found that ECR muscle mass and length were greater (tenfold and 1.4-fold, respectively), absolute tetanic muscle force and relative tetanic force (stress) were greater (16-fold and 2.2-fold, respectively) and relaxation times were slower in males than in females. Male ECR muscles incompletely relaxed during fatigue tests and showed less fatigue than female muscles. These sex differences are likely to be beneficial to the male frogs in allowing them to produce relatively high absolute muscle forces for prolonged periods of time to hold onto their mate during amplexus.

Sources of variation and genetic profile of spontaneous, out-of-season ovulatory activity in the Chios sheep

Directory of Open Access Journals (Sweden)

Kouttos Athanasios

2003-01-01

Full Text Available Abstract Organising the breeding plan of a seasonally breeding species, such as sheep, presents a challenge to farmers and the industry as a whole, since both economical and biological considerations need to be carefully balanced. Understanding the breeding activity of individual animals becomes a prerequisite for a successful breeding program. This study set out to investigate the sources of variation and the genetic profile of the spontaneous, out-of-season ovulatory activity of ewes of the Chios dairy sheep breed in Greece. The definition of the trait was based on blood progesterone levels, measured before exposing the ewes to rams, which marks the onset of the usual breeding season. Data were 707 records, taken over two consecutive years, of 435 ewes kept at the Agricultural Research Station of Chalkidiki in northern Greece. When all available pedigree was included, the total number of animals involved was 1068. On average, 29% of all ewes exhibited spontaneous, out-of-season ovulatory activity, with no substantial variation between the years. Significant sources of systematic variation were the ewe age and live weight, and the month of previous lambing. Older, heavier ewes, that had lambed early the previous autumn, exhibited more frequent activity. Heritability estimates were 0.216 (± 0.084 with a linear and 0.291 with a threshold model. The latter better accounts for the categorical nature of the trait. The linear model repeatability was 0.230 (± 0.095. The results obtained in this study support the notion that spontaneous out-of-season ovulatory activity can be considered in the development of a breeding plan for the Chios sheep breed.

[Animals' clever adaptation strategy for seasonal changes in environment].

Science.gov (United States)

Ikegami, Keisuke; Yoshimura, Takashi

2015-08-01

Organisms living outside of tropical zones experience seasonal changes in environment. Organisms are using day length as a calendar to change their physiology and behavior such as seasonal breeding, hibernation, migration, and molting. A comparative biology approach revealed underlying mechanisms of vertebrate seasonal reproduction. Here we review the current understanding of vertebrate seasonal reproduction. We Aso describe the involvement of tissue-specific post-translational modification in functional diversification of a hormone.

Seasonal prolactin secretion and its role in seasonal reproduction: a review.

Science.gov (United States)

Curlewis, J D

1992-01-01

The majority of seasonally breeding mammals show a seasonal pattern of prolactin secretion with peak concentrations in spring or summer and a nadir in autumn or winter. Photoperiod influences prolactin secretion via its effects on the secretion of the pineal hormone melatonin. Preliminary evidence suggests that the effects of melatonin on both prolactin and gonadotrophin secretion are via a common target area, possibly within the anterior hypothalamus, and that differences in response to photoperiod may be due to differences in the processing and/or interpretation of the melatonin signal. In contrast to seasonal gonadotrophin secretion, the seasonal changes in prolactin are not due to changes in the sensitivity of a feedback loop and so must be due to direct effects on the hypothalamic pathways that control prolactin secretion. Little else can be said with confidence about the neuroendocrine mechanisms that lead to the seasonal changes in prolactin secretion. Dopamine and noradrenaline turnover in the arcuate nucleus and median eminence decrease under short daylength. If catecholamine turnover in these structures is positively correlated with catecholamine concentrations in the long or short hypophysial portal vessels, it is unlikely that the decrease in prolactin concentration in winter is due to the effects of increased concentrations of dopamine or noradrenaline in the portal vessels. There is, however, evidence for increased pituitary sensitivity to dopamine under short daylength, so increased dopamine concentrations may not be required for suppression of prolactin secretion at this time. In addition to the diminished secretion of prolactin under short daylength, rate of prolactin synthesis and pituitary content of prolactin also decline although the mechanisms that regulate these changes are poorly understood. Although all seasonal breeders show a seasonal change in prolactin secretion, there are continuously breeding species in which prolactin secretion is

Characterization of seasonal reproduction in Virginia Tech Selection Line, St. Croix, and Suffolk ewes

OpenAIRE

Jordan, Katherine Mead

2008-01-01

This dissertation research contained three studies. The first two studies were conducted to investigate the ability of ewes to rebreed while lactating during seasonal anestrus. Breeds studied included the Virginia Tech Out-of-season (OOS) Line, which is a wool line genetically selected to lamb in the fall, and the St. Croix, a hair breed of tropical origin thought to be lowly seasonal. When January-lambing ewes were exposed to rams while lactating in April, significantly more OOS than St. ...

Induced mutations in pomoid trees breeding

International Nuclear Information System (INIS)

Hamed, Faysal

1986-01-01

Induction of mutations in fruit trees by ionizing radiation complements a cross-breeding program. The objectives are: 1) the improvements of methods of induction, identification and selection of useful mutations, and 2) the initiation of useful mutations either for immediate use as improved cultivars or as a parent material for conventional cross-breeding. The induction of mutants in pomoid fruits, with special emphasis on apple, was realized by gamma-ray treatment of dormant scions subsequently propagated on a rootstoch in the nursery. The aim was to obtain compacts, presuming the feasibility of selecting compact shoots formed by the irradiated scions in the first vegetative generation and also assuming that chance of finding (e.g. fruit mutants) would be thus increased rather than lessened. Selection was carried out on one-season old shoots, formed on the same material for two or three seasons, by using a cut-back at the end of the first and second season. The procedure was highly effective. Moderate exposures, resulting in 60% survival gave high mutation frequencies. Buds 6-10 on the primary shoot gave higher frequencies of recognizable mutations than either buds 1-5 or 11-15. Preliminary results seem to indicate that, at least in some apple cultivars, there is opportunity to obtain compact growth types with good biological characteristics. 8 refs. (author)

Mating strategy and breeding patterns of the foothill yellow-legged frog (Rana boylii)

Science.gov (United States)

Clara A. Wheeler; Hartwell H. Welsh Jr.

2008-01-01

The Foothill Yellow-legged Frog (Rana boylii) has declined across much of its native range in California. Improper stream management may lower egg mass survival and reduce the availability of suitable breeding habitats. We collected data during six breeding-seasons (2002-2007) along an unregulated stream in northwestern California. We monitored...

Seasonality in basal metabolic rate and thermal conductance in a long-distance migrant shorebird, the knot (Calidris canutus)

NARCIS (Netherlands)

Piersma, T.; Cadée, N.; Daan, S.

Knots Calidris canutus live highly seasonal lives, breeding solitarily on high arctic tundra and spending the non-breeding season in large social flocks in temperate to tropical estuaries. Their reproductive activities and physiological preparations for long flights are reflected in pronounced

Evaluation of pre-breeding reproductive tract scoring as a predictor of long term reproductive performance in beef heifers.

Science.gov (United States)

Holm, D E; Nielen, M; Jorritsma, R; Irons, P C; Thompson, P N

2015-01-01

In a 7-year longitudinal study 292 Bovelder beef cows in a restricted breeding system in South Africa were observed from 1 to 2 days before their first breeding season, when reproductive tract scoring (RTS, scored from 1 to 5) was performed, until weaning their 5th calves. The objective was to determine whether pre-breeding RTS in heifers is a valid tool to predict long-term reproductive performance. Outcomes measured were failure to show oestrus during the first 24 days of the first 50-day AI season (24-day anoestrus), failure to become pregnant during each yearly artificial insemination (AI) season (reproductive failure), number of days from the start of each AI season to calving, and number of years to reproductive failure. The effect of RTS on each outcome was adjusted for year of birth, pre-breeding age, BW and body condition score (BCS), and for 24-day anoestrus, bull, gestation length, previous days to calving and previous cow efficiency index, the latter two in the case of the 2nd to the 5th calving season. During their first breeding season, heifers with RTS 1 and 2 combined were more likely to be in anoestrus for the first 24 days (OR=3.0, 95% CI 1.5, 6.4, P=0.003), and were also more likely to fail to become pregnant even after adjusting for 24-day anoestrus (OR=2.1, 95% CI 1.1, 3.9, P=0.025), compared to those with RTS 4 and 5 combined. Animals with RTS 1 and 2 combined were at increased risk of early reproductive failure compared to those with RTS 4 and 5 combined (HR=1.4, 95% CI 1.0, 1.9, P=0.045) although RTS was not associated with calving rate or days to calving after the second calving season. Low RTS at a threshold of 1 had consistent specificity of ≥94% for both 24-day anoestrus and pregnancy failure, however its predictive value was lower in the age cohort with a higher prevalence of anoestrus. We conclude that RTS is a valid management tool for culling decisions intended to improve long-term reproductive success in a seasonal breeding system

Ruddy Shelduck Tadorna ferruginea home range and habitat use during the non-breeding season in Assam, India

Science.gov (United States)

Namgail, T.; Takekawa, John Y.; Sivananinthaperumal, B.; Areendran, G.; Sathiyaselvam, P.; Mundkur, T.; Mccracken, T.; Newman, S.

2011-01-01

India is an important non-breeding ground for migratory waterfowl in the Central Asian Flyway. Millions of birds visit wetlands across the country, yet information on their distribution, abundance, and use of resources is rudimentary at best. Limited information suggests that populations of several species of migratory ducks are declining due to encroachment of wetland habitats largely by agriculture and industry. The development of conservation strategies is stymied by a lack of ecological information on these species. We conducted a preliminary assessment of the home range and habitat use of Ruddy Shelduck Tadorna ferruginea in the northeast Indian state of Assam. Seven Ruddy Shelducks were fitted with solar-powered Global Positioning System (GPS) satellite transmitters, and were tracked on a daily basis during the winter of 2009-2010. Locations from all seven were used to describe habitat use, while locations from four were used to quantify their home range, as the other three had too few locations (2 (range = 22-87 km2) and an average home range (95% contour) of 610 km2 (range = 222-1,550 km2). Resource Selection Functions (RSF), used to describe habitat use, showed that the birds frequented riverine wetlands more than expected, occurred on grasslands and shrublands in proportion to their availability, and avoided woods and cropland habitats. The core use areas for three individuals (75%) were on the Brahmaputra River, indicating their preference for riverine habitats. Management and protection of riverine habitats and nearby grasslands may benefit conservation efforts for the Ruddy Shelduck and waterfowl species that share these habitats during the non-breeding season.

Normal Variability of Weekly Musculoskeletal Screening Scores and the Influence of Training Load across an Australian Football League Season.

Science.gov (United States)

Esmaeili, Alireza; Stewart, Andrew M; Hopkins, William G; Elias, George P; Lazarus, Brendan H; Rowell, Amber E; Aughey, Robert J

2018-01-01

Aim: The sit and reach test (S&R), dorsiflexion lunge test (DLT), and adductor squeeze test (AST) are commonly used in weekly musculoskeletal screening for athlete monitoring and injury prevention purposes. The aim of this study was to determine the normal week to week variability of the test scores, individual differences in variability, and the effects of training load on the scores. Methods: Forty-four elite Australian rules footballers from one club completed the weekly screening tests on day 2 or 3 post-main training (pre-season) or post-match (in-season) over a 10 month season. Ratings of perceived exertion and session duration for all training sessions were used to derive various measures of training load via both simple summations and exponentially weighted moving averages. Data were analyzed via linear and quadratic mixed modeling and interpreted using magnitude-based inference. Results: Substantial small to moderate variability was found for the tests at both season phases; for example over the in-season, the normal variability ±90% confidence limits were as follows: S&R ±1.01 cm, ±0.12; DLT ±0.48 cm, ±0.06; AST ±7.4%, ±0.6%. Small individual differences in variability existed for the S&R and AST (factor standard deviations between 1.31 and 1.66). All measures of training load had trivial effects on the screening scores. Conclusion: A change in a test score larger than the normal variability is required to be considered a true change. Athlete monitoring and flagging systems need to account for the individual differences in variability. The tests are not sensitive to internal training load when conducted 2 or 3 days post-training or post-match, and the scores should be interpreted cautiously when used as measures of recovery.

Effect of crude protein levels and organic selenium supplementation in the diets fed during the breeding season on reproductive parameters of red-winged tinamous (Rhynchotus rufescens)

OpenAIRE

Felipe, L. [UNESP; Santos, E. C.; Tavian, A. F.; Góes, P. A. A.; Moraes, V. M. B. [UNESP; Tonhati, Humberto [UNESP; Boleli, I. C. [UNESP; Malheiros, E. B. [UNESP; Barnabé, V. H.; Queiroz, S. A. [UNESP

2010-01-01

There is little information on the nutrition of red-winged tinamous (Rhynchotus rufescens) reared in captivity, and their nutritional requirements still need to be determined. This study aimed at determining dietary crude protein requirements and testing four organic selenium supplementation levels in the diet of red-winged tinamous during the breeding season. Birds were housed in a conventional broiler house divided in 16 boxes with one male and three females each. Iso-energy (2800kcal ME/kg...

Temporal concentrations of cortisol and LH in virgin ewes acutely exposed to rams during the transition into the breeding season.

Science.gov (United States)

McCosh, R B; Berry, E M; Wehrman, M E; Redden, R R; Hallford, D M; Berardinelli, J G

2015-03-01

The objectives of this study were to determine if exposing seasonally anovular ewes to rams would alter patterns of cortisol concentrations, and if these changes are associated with changes in characteristics of LH concentrations. Seasonally anestrous ewes were assigned to be exposed to rams (RE; n=11) or wethers (NE; n=12). Blood samples were collected at 15-min intervals beginning 120 min before introduction of males (time=0 min), and continued for 360 min after male exposure. Characteristics of cortisol and LH concentrations included: mean and baseline concentrations, pulse amplitude, duration, frequency, and time to first pulse. Mean and baseline cortisol concentrations, and cortisol pulse amplitude, frequency, and time to first pulse after male exposure did not differ between RE and NE ewes. Cortisol pulse duration was longer (Pewes than in NE ewes. Mean LH and LH pulse amplitude, duration, and time to first pulse after male exposure did not differ between RE and NE ewes. Baseline LH concentrations and LH pulse frequency were greater (Pewes. In RE ewes, but not NE ewes, LH pulse frequency tended to increase (P=0.06) as pulse frequency of cortisol decreased. In conclusion, exposing ewes to mature rams during the transition into the breeding season increased LH pulse frequency which hastened ovulatory activity. However, the results do not support the hypothesis that changes in cortisol concentrations plays a significant role in the 'ram effect'. Copyright © 2015 Elsevier B.V. All rights reserved.

Disentangling the effects of date, individual, and territory quality on the seasonal decline in fitness.

Science.gov (United States)

Pärt, Tomas; Knape, Jonas; Low, Matthew; Öberg, Meit; Arlt, Debora

2017-08-01

The seasonal timing of reproduction is a major fitness factor in many organisms. Commonly, individual fitness declines with time in the breeding season. We investigated three suggested but rarely tested hypotheses for this seasonal fitness decline: (1) time per se (date hypothesis), (2) late breeders are of lower quality than early ones (individual quality hypothesis), and (3) late breeders are breeding at poorer territories than early breeders (territory quality hypothesis). We used Bayesian variance component analyses to examine reproductive output (breeding success, number fledged, and number of recruits) from repeated observations of female Northern Wheatears (Oenanthe oenanthe) and individual territories from a 20-yr population study. The major part of the observed seasonal decline in reproductive output seemed to be driven by date-related effects, whereas female age and territory type (i.e., known indicators of temporary quality) contributed to a smaller degree. Other, persistent effects linked to individual and territory identity did not show any clear patterns on the seasonal decline in reproductive output. To better disentangle the quality effects (persistent and temporary) of individual and territory from effects caused by the deterioration of the environment we suggest a protocol combining experimental manipulation of breeding time with a variance-covariance partitioning method used here. © 2017 by the Ecological Society of America.

Induction and estrous synchronization during the non-breeding season in Saanen goats

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Anamaria Luciana Blaga Petrean

2016-11-01

Full Text Available The purpose of this study was to perform the induction and estrous synchronization of Saanen goats in the non-breeding season. The study was conducted from July 2014 - April 2015 on 77 Saanen goats, aged between 1.5 to 5 years. The goats were divided into three experimental groups: in group I (n =37 goats intravaginal sponge (Ovigest containing 60 mg of MPA was left in the vagina for 14 days. Immediately after sponge removal the animals received two injections: prostaglandin (Prosolvin at the dose of 0.75 mg (1 ml/animal and PMSG hormone (Folligon at the dose of 500 IU/animal. In group II (n=20 induction and estrous synchronization was performed using synthetic prostaglandin (Proliz - 1 ml containing 0.2 mg isopropyl ester of cloprostenol and 9 mg benzyl alcohol at the dose of 0.5 ml/animal. The group III (n=20 was considered the control group and estrous synchronization was performed using fertile bucks. In group I the results showed that all goats expressed signs of estrous. The average value of the estrous interval was 33 hours and the average of estrous duration was 20 hours. The number of kids obtained in group I was 94, and prolificacy was P (% = 2.54. In group II and III was not observed occurrence of estrous. Induction and estrous synchronization show economic benefits by shortening the time needed for pregnancy installation, possibility of births grouping, preparation and organization of mating, only if we use a hormone associated protocol and we rigorous respect therapy steps.

Post-breeding migration of Dutch-breeding black-tailed godwits: timing, routes, use of stopovers, and nonbreeding destinations

Science.gov (United States)

Hooijmeijer, Jos C. E. W.; Senner, Nathan R.; Tibbitts, T. Lee; Gill, Robert E.; Douglas, David C.; Bruinzeel, Leo W.; Wymenga, Eddy; Piersma, Theunis

2014-01-01

Conservation of long-distance migratory shorebirds is complex because these species use habitats spread across continents and hemispheres, making identification of critical habitats and potential bottlenecks in the annual cycle especially difficult. The population of Black-tailed Godwits that breeds in Western Europe, Limosa limosa limosa, has declined precipitously over the past few decades. Despite significant efforts to identify the root causes of this decline, much remains unclear. To better understand the migratory timing, use of stopover and nonbreeding sites, and the potential impact of breeding success on these parameters, we attached 15 Argos satellite transmitters and 10 geolocation tracking devices to adult godwits nearing completion of incubation at breeding sites in southwest Friesland, The Netherlands during the spring of 2009. We successfully tracked 16 adult godwits for their entire southward migration and two others for part of it. Three migration patterns and four regions of use were apparent. Most godwits left their breeding sites and proceeded south directly to stopover sites in the Mediterranean — e.g. Spain, Portugal, and Morocco — before flying on to non-breeding sites in West Africa. Other individuals spent the entire nonbreeding season in the Mediterranean. A third pattern included a few individuals that flew nonstop from their Dutch breeding sites to nonbreeding sites in West Africa. Tracking data from this study will be immediately useful for conservation efforts focused on preserving the dispersed network of sites used by godwits during their southward migration.

Estimating breeding season abundance of golden-cheeked warblers in Texas, USA

KAUST Repository

Mathewson, Heather A.; Groce, Julie E.; Mcfarland, Tiffany M.; Morrison, Michael L.; Newnam, J. Cal; Snelgrove, R. Todd; Collier, Bret A.; Wilkins, R. Neal

2012-01-01

relied on localized population studies on public lands and qualitative-based methods. Our goal was to estimate breeding population size of male warblers using a predictive model based on metrics for patches of woodland habitat throughout the species

Multiple breeding in the Great Tit, II. The costs of rearing a second clutch

NARCIS (Netherlands)

Verhulst, S.

1998-01-01

1. Multiple breeding (raising more than one batch of young per breeding season) is a common life-history tactic, but little is known as yet of the accompanying costs and benefits. Second clutches of Great Tits, a facultative multiple breeder, were removed over three years to investigate the costs of

Multiple breeding in the Great Tit, II. The costs of rearing a second clutch

NARCIS (Netherlands)

Verhulst, S

1. Multiple breeding (raising more than one batch of young per breeding season) is a common life-history tactic, but little is known as yet of the accompanying costs and benefits. Second clutches of Great Tits, a facultative multiple breeder, were removed over three years to investigate the costs of

Effects of breed on milk fatty acid profile in dairy ewes, with particular ...

African Journals Online (AJOL)

The objective of this study was to determine and compare the fatty acid profile of milk fat, with particular reference to cis-9, trans-11 conjugated linoleic acid (CLA), in two indigenous Romanian sheep breeds (Spanca and Turcana), irrespective of the effects of diet and season. The ewes (n = 25 for each breed) received the ...

Challenging the present definition of "normal" vitamin D levels obtained by a single blood test. Can we develop a formula to predict vitamin D levels in the 4 seasons from a single season's measure?

Science.gov (United States)

Tandeter, Howard

2014-08-01

Publications on the health effects of vitamin D (25(OH) D) had almost triplicate in the last 10years, not only for its known "calcemic effects" (calcium, phosphor, PTH), but for the more recent findings on its "non-calcemic effects" (all-cause and cardiovascular mortality, and relation with certain types of cancer). Part of these publications deal with the definition of what is a "normal" circulating level of 25(OH) D that may distinguish between health and disease. The literature also deals with seasonal variations of vitamin D, showing levels that rise in summer and fall in winter and with DBP phenotypes and geographical location that affect seasonality of 25(OH) D measurements. Despite the knowledge of the existence of these phenomena many studies on vitamin D fail to acknowledge the time of the year the blood sample was extracted. Thus, when we compare results from different studies without defining the season that the samples were drawn, we compare incomparable figures. Furthermore, it is quite absurd to define "normal levels" as a static measure (over or under a certain value) using a single blood test when the value measured is known to change with seasons. Knowing that people have different vitamin D levels in different seasons of the year, we should ask ourselves which of these measurements should be used to define a "real" or "normal" level? Is it the lower one? Is there a "mean measure" that should be used for this matter? If yes, how do we obtain it? Do we have to make 4 seasonal measurements in each patient? Alternatively, might there be a possibility of developing a formula to help us obtain the mean from a single season's measure or one season's prediction from another season's measurement? And knowing that DBP phenotypes and geographical location affect seasonality of 25(OH) D measurements; shouldn't we include this in the equation? In this article I will discuss the hypothetical existence of an Individual Mean Annual vitamin D level that I will

Malaria-infected female collared flycatchers (Ficedula albicollis do not pay the cost of late breeding.

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Katarzyna Kulma

Full Text Available Life-history theory predicts that the trade-off between parasite defense and other costly traits such as reproduction may be most evident when resources are scarce. The strength of selection that parasites inflict on their host may therefore vary across environmental conditions. Collared flycatchers (Ficedula albicollis breeding on the Swedish island Öland experience a seasonal decline in their preferred food resource, which opens the possibility to test the strength of life-history trade-offs across environmental conditions. We used nested-PCR and quantitative-PCR protocols to investigate the association of Haemosporidia infection with reproductive performance of collared flycatcher females in relation to a seasonal change in the external environment. We show that despite no difference in mean onset of breeding, infected females produced relatively more of their fledglings late in the season. This pattern was also upheld when considering only the most common malaria lineage (hPHSIB1, however there was no apparent link between the reproductive output and the intensity of infection. Infected females produced heavier-than-average fledglings with higher-than-expected recruitment success late in the season. This reversal of the typical seasonal trend in reproductive output compensated them for lower fledging and recruitment rates compared to uninfected birds earlier in the season. Thus, despite different seasonal patterns of reproductive performance the overall number of recruits was the same for infected versus uninfected birds. A possible explanation for our results is that infected females breed in a different microhabitat where food availability is higher late in the season but also is the risk of infection. Thus, our results suggest that another trade-off than the one we aimed to test is more important for explaining variation in reproductive performance in this natural population: female flycatchers appear to face a trade-off between the risk

Population ecology of the mallard: II. Breeding habitat conditions, size of the breeding populations, and production indices

Science.gov (United States)

Pospahala, Richard S.; Anderson, David R.; Henny, Charles J.

1974-01-01

This report, the second in a series on a comprehensive analysis of mallard population data, provides information on mallard breeding habitat, the size and distribution of breeding populations, and indices to production. The information in this report is primarily the result of large-scale aerial surveys conducted during May and July, 1955-73. The history of the conflict in resource utilization between agriculturalists and wildlife conservation interests in the primary waterfowl breeding grounds is reviewed. The numbers of ponds present during the breeding season and the midsummer period and the effects of precipitation and temperature on the number of ponds present are analyzed in detail. No significant cycles in precipitation were detected and it appears that precipitation is primarily influenced by substantial seasonal and random components. Annual estimates (1955-73) of the number of mallards in surveyed and unsurveyed breeding areas provided estimates of the size and geographic distribution of breeding mallards in North America. The estimated size of the mallard breeding population in North America has ranged from a high of 14.4 million in 1958 to a low of 7.1 million in 1965. Generally, the mallard breeding population began to decline after the 1958 peak until 1962, and remained below 10 million birds until 1970. The decline and subsequent low level of the mallard population between 1959 and 1969 .generally coincided with a period of poor habitat conditions on the major breeding grounds. The density of mallards was highest in the Prairie-Parkland Area with an average of nearly 19.2 birds per square mile. The proportion of the continental mallard breeding population in the Prairie-Parkland Area ranged from 30% in 1962 to a high of 600/0 in 1956. The geographic distribution of breeding mallards throughout North America was significantly related to the number of May ponds in the Prairie-Parkland Area. Estimates of midsummer habitat conditions and indices to

Capital versus income breeding in a seasonal environment

DEFF Research Database (Denmark)

Sainmont, Julie; Andersen, Ken Haste; Varpe, Oystein

2014-01-01

and thereby achieve a high annual growth rate, outcompeting capital breeders in long feeding seasons. Therefore, we expect to find a dominance of small income breeders in temperate waters, while large capital breeders should dominate high latitudes where the spring is short and intense. This pattern...

CALVING ANALYSIS IN COWS OF CHAROLAIS BREED AT SELECTED FARM

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KLÁRA VAVRIŠÍNOVÁ

2001-09-01

Full Text Available At our work we have analysed the organisation of calving in Charolais breed during the years from 1998 to 2001 at selected farm. Our monitoring of calving during winter season (from January to February shows the percentage of calving was in particular years ranged from 43.2 to 71.1. The most calves were born in February. We found out (total all years diffi cult calving (value 3 in 2 cases in April (1998 and 1999 and 1 case in February (1998 and 1 in March (1999. Calving marked with value 2 (total of all years we found out in January (2 cases, February (3 cases, March (4 cases and from September to December past one case. From 18 cases of diffi cult calving what we found out, 11 calves (61.11 % come from CHV 529 bull. In calves born by normal calving was found out average weight 34.75 kg, in ones born by calving with level 2 of diffi culty 36.36 kg, and in calves born by calving with diffi culty 3 was recorded average weight 41.5 kg. Recorded weight at 210 days of age in mostly cases was similar like in published breed standard.

Reliable effective number of breeders/adult census size ratios in seasonal-breeding species: Opportunity for integrative demographic inferences based on capture-mark-recapture data and multilocus genotypes.

Science.gov (United States)

Sánchez-Montes, Gregorio; Wang, Jinliang; Ariño, Arturo H; Vizmanos, José Luis; Martínez-Solano, Iñigo

2017-12-01

The ratio of the effective number of breeders ( N b ) to the adult census size ( N a ), N b / N a , approximates the departure from the standard capacity of a population to maintain genetic diversity in one reproductive season. This information is relevant for assessing population status, understanding evolutionary processes operating at local scales, and unraveling how life-history traits affect these processes. However, our knowledge on N b / N a ratios in nature is limited because estimation of both parameters is challenging. The sibship frequency (SF) method is adequate for reliable N b estimation because it is based on sibship and parentage reconstruction from genetic marker data, thereby providing demographic inferences that can be compared with field-based information. In addition, capture-mark-recapture (CMR) robust design methods are well suited for N a estimation in seasonal-breeding species. We used tadpole genotypes of three pond-breeding amphibian species ( Epidalea calamita , Hyla molleri, and Pelophylax perezi , n  =   73-96 single-cohort tadpoles/species genotyped at 15-17 microsatellite loci) and candidate parental genotypes ( n  =   94-300 adults/species) to estimate N b by the SF method. To assess the reliability of N b estimates, we compared sibship and parentage inferences with field-based information and checked for the convergence of results in replicated subsampled analyses. Finally, we used CMR data from a 6-year monitoring program to estimate annual N a in the three species and calculate the N b / N a ratio. Reliable ratios were obtained for E. calamita ( N b / N a  = 0.18-0.28) and P. perezi (0.5), but in H. molleri, N a could not be estimated and genetic information proved insufficient for reliable N b estimation. Integrative demographic studies taking full advantage of SF and CMR methods can provide accurate estimates of the N b / N a ratio in seasonal-breeding species. Importantly, the SF method provides results that can be

[Seasonal variations in estrus behavior and ovulatory activity in Chios and Serres ewes in Greece].

Science.gov (United States)

Avdi, M; Driancourt, M A; Chemineau, P

1993-01-01

Sheep are seasonal breeders, but a lower seasonality has been reported for sheep breeds from the Mediterranean countries enabling spring matings. To further substantiate this, the present study compared seasonal variation in oestrus behaviour and ovulation in two Greek breeds (Chios and Serres) maintained in the same environment. In 27 adult ewes of each breed, oestrus behaviour, the occurrence of ovulation and ovulation rate were monitored during 2 successive years by daily inspection by rams, weekly progesterone assay in circulating blood plasma and monthly ovarian laparoscopy. The periods of anoestrus (109 +/- 8 (wk) vs 178 +/- 5 d) and anovulation (63 +/- 8 vs 149 +/- 6 d) were significantly shorter (P duration of oestrus was also longer in Chios ewes (1.8 +/- 0.05 vs 1.5 +/- 0.06 d; P = 0.002). There were significant correlations between the duration of anovulatory periods of the 2 successive years in Chios (r = 0.43) but not Serres ewes. Ovulation rate was positively related to the onset of the sexual season in Serres but not in Chios ewes. The present data suggest that: i) the efficiency of Serres but not in Chios ewes. The present data suggest that: i) the efficiency of spring mating in these breeds is suboptimal since it is a period when the percentage of ewes exhibiting oestrus and ovulation as well as ovulation rate are limited, ii) owing to the large variation in seasonality within Chios ewes and to the good between year correlation in features of seasonality, selection against seasonality in Chios ewes could be worthwhile.

Does the reproductive season account for more records of birds in a marked seasonal climate landscape in the state of São Paulo, Brazil?

Directory of Open Access Journals (Sweden)

Vagner Cavarzere

2013-01-01

Full Text Available Investigators have reported that birds from temperate regions are more detectable during their breeding seasons, which should be used to adequately survey avifaunas. In the state of São Paulo, southeastern Brazil, the rainiest months of the year are usually associated with a peak in the reproduction of birds. To test the hypothesis that birds are equally detectable throughout the year, I conducted transect counts of birds in a predominantly open Cerrado landscape in São Paulo during 2005 and 2006. There was no significant difference in the number of species or individuals between breeding (rainy and nonbreeding (dry seasons; 24% of the species with > 50 contacts was likely to be recorded more often in a particular season. Unlike temperate regions, where vocal behavior plays an important role in detections of birds during and after reproductive seasons, my results suggest that Cerrado birds may be evenly detected throughout the year.

The phenology of a rare salamander (Salamandra infraimmaculata in a population breeding under unpredictable ambient conditions: a 25 year study

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Michael R. Warburg

2007-11-01

Full Text Available This is a long-term study (1974-1999 on the phenology of the rare, xeric- inhabiting salamander Salamandra infraimmaculata in a small isolated population during the breeding season near the breeding ponds on Mt. Carmel. This is a fringe area of the genus’ south-easternmost Palaearctic distribution. Salamanders were captured during the 25 year long study. The first years up to the 1980s the total number of salamanders increased but during the last years there seems to have been a decline. Although this could be a phase in normal population cyclic oscillations nevertheless when compared with long-term data on a European Salamandra it does not seem so. The interpretation of the species’ status is dependent on numbers of salamanders captured as well as on the duration of the study. These subjects are reviewed and discussed in this paper.

Androgen receptor-beta mRNA levels in different tissues in breeding and post-breeding male and female sticklebacks, Gasterosteus aculeatus

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Hoffmann Erik

2012-03-01

Full Text Available Abstract Background Androgens induce male characters by activating androgen receptors (AR. Previous quantitative studies on AR in fishes have been limited to few tissues and/or a single season/reproductive state. The aim of this investigation was to study the possible role of AR-beta expression levels in the control of male traits in the three-spined stickleback. To that end, AR-beta expression levels in major tissues in breeding and post-breeding male and female sticklebacks were examined. Methods AR-beta mRNA levels were quantified in ten tissues; eye, liver, axial muscle, heart, brain, intestine, ovary, testis, kidney and pectoral muscle in six breeding and post-breeding males and females using reverse transcription quantitative PCR. Results Breeding in contrast to post-breeding males built nests and showed secondary sexual characters (e.g. kidney hypertrophy and elevated androgen levels. Post-breeding females had lower ovarian weights and testosterone levels than breeding females. AR-beta was expressed in all studied tissues in both sexes and reproductive states with the highest expression in the gonads and in the kidneys. The kidney is an androgen target organ in sticklebacks, from which breeding males produce the protein spiggin, which is used in nest-building. There was also high AR-beta expression in the intestine, an organ that appears to take over hyperosmo-regulation in fresh water when the kidney hypertrophies in mature males and largely loses this function. The only tissue that showed effects of sex or reproductive state on AR-beta mRNA levels was the kidneys, where post-breeding males displayed higher AR-beta mRNA levels than breeding males. Conclusion The results indicate that changes in AR-beta mRNA levels play no or little role in changes in androgen dependent traits in the male stickleback.

Seasonal changes in hepatocytic lipid droplets, glycogen deposits, and rough endoplasmic reticulum along the natural breeding cycle of female ohrid trout (Salmo letnica Kar.)-A semiquantitative ultrastructural study.

Science.gov (United States)

Jordanova, Maja; Rebok, Katerina; Malhão, Fernanda; Rocha, Maria J; Rocha, Eduardo

2016-08-01

This study on wild female Ohrid trout was primarily designed to provide a general overview of the breeding cycle influence upon selected aspects of hepatocytes. According with a semiquantitatively evaluation, some of these cell's structural compartments change during the breeding cycle. Structural modifications were disclosed in the relative occurrence of lipid, glycogen, and RER content during breeding cycle. The relative amount of lipid deposits in the hepatocytes was much greater in previtellogenesis, and decreased postspawning. So, while the seasonal changes in RER were positively related with the ovary maturation status, those of the lipid droplets followed an opposite trend. The hepatocytic glycogen occurred rarely, mainly in late-vitellogenesis and spawning, suggesting that in this species such kind of energy storage is comparatively unimportant. Lipid accumulation and later usage is, probably, the relevant biochemical pathway for Ohrid trout in the wild. While glycogen and RER contents were positively correlated with the gonadosomatic index, lipids were negatively correlated. Additionally, glycogen inclusions were positively correlated with the plasma estradiol levels. When comparing seasonal patterns from wild Ohrid trout with those from well-studied rainbow and brown trout (specimens studied were from aquaculture), there are contradicting results as to lipid and glycogen reserves, and also as to RER loads. The differences among the mentioned trout can result from intrinsic interspecies differences or may be associated with natural feeding conditions versus feeding with commercially prepared diets, or other factors. This study offers new data useful as standard to access liver pathology in wild and aquacultured Ohrid trout. Microsc. Res. Tech. 79:700-706, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Long distance migratory songbirds respond to extremes in arctic seasonality

Science.gov (United States)

Boelman, N.; Asmus, A.; Chmura, H.; Krause, J.; Perez, J. H.; Sweet, S. K.; Gough, L.; Wingfield, J.

2017-12-01

Arctic regions are warming rapidly, with extreme weather events increasing in frequency, duration and intensity, as in other regions. Many studies have focused on how shifting seasonality in environmental conditions affect the phenology and productivity of vegetation, while far fewer have examined how arctic fauna responds. We studied two species of long-distance migratory songbirds, Lapland longspurs, Calcarius lapponicus, and White-crowned sparrows, Zonotrichia leucophrys gambelii, across seven consecutive breeding seasons in northern Alaskan tundra. We aimed to understand how spring environmental conditions affected breeding cycle phenology, food availability, body condition, stress physiology, and ultimately, reproductive success. Spring temperatures, precipitation, storm frequency, and snow-free dates differed significantly among years, with 2013 characterized by unusually late snow cover, and 2015 and 2016 characterized by unusually early snow-free dates and several late spring snowstorms. In response, we found that relative to other study years, there was a significant delay in breeding cycle phenology for both study species in 2013, while breeding cycle phenology was significantly earlier in 2015 only. For both species, we also found significant variation among years in: the seasonal patterns of arthropod availability during the nesting stage; body condition, and; stress physiology. Finally, we found significant variation in reproductive success of both species across years, and that daily survival rates were decreased by snow storm events. Our findings suggest that arctic-breeding passerine communities may be able to adjust phenology to unpredictable shifts in the timing of spring, but extreme conditions during the incubation and nestling stages are detrimental to reproductive success.

Adaptability and stability of soybean genotypes in off-season cultivation.

Science.gov (United States)

Batista, R O; Hamawaki, R L; Sousa, L B; Nogueira, A P O; Hamawaki, O T

2015-08-14

The oil and protein contents of soybean grains are important quantitative traits for use in breeding. However, few breeding programs perform selection based on these traits in different environments. This study assessed the adaptability and stability of 14 elite early soybean breeding lines in off-season cultivation with respect to yield, and oil and protein contents. A range of statistical methods was applied and these analyses indicated that for off-season cultivation, the lines UFUS 5 and UFUS 10 could be recommended due to their superior performance in grain yield, oil content, and specific adaptability to unfavorable environments along with high stability in these characteristics. Also recommended were UFUS 06, which demonstrated superior performance in all three tested characteristics and showed adaptation to favorable environments, and UFUS 13, which showed high adaptability and stability and a superior performance for protein content.

Periodic matrix models for seasonal dynamics of structured populations with application to a seabird population.

Science.gov (United States)

Cushing, J M; Henson, Shandelle M

2018-02-03

For structured populations with an annual breeding season, life-stage interactions and behavioral tactics may occur on a faster time scale than that of population dynamics. Motivated by recent field studies of the effect of rising sea surface temperature (SST) on within-breeding-season behaviors in colonial seabirds, we formulate and analyze a general class of discrete-time matrix models designed to account for changes in behavioral tactics within the breeding season and their dynamic consequences at the population level across breeding seasons. As a specific example, we focus on egg cannibalism and the daily reproductive synchrony observed in seabirds. Using the model, we investigate circumstances under which these life history tactics can be beneficial or non-beneficial at the population level in light of the expected continued rise in SST. Using bifurcation theoretic techniques, we study the nature of non-extinction, seasonal cycles as a function of environmental resource availability as they are created upon destabilization of the extinction state. Of particular interest are backward bifurcations in that they typically create strong Allee effects in population models which, in turn, lead to the benefit of possible (initial condition dependent) survival in adverse environments. We find that positive density effects (component Allee effects) due to increased adult survival from cannibalism and the propensity of females to synchronize daily egg laying can produce a strong Allee effect due to a backward bifurcation.

Breeding Birds Associated with Seasonal Pools in the Northeastern United States

Science.gov (United States)

Seasonal pools in the northeast US are important habitats for amphibians and invertebrates, but little is known of their importance for birds. We examined avian community composition at seasonal pools across an urbanization gradient in Rhode Island to test the hypotheses that se...

Breeding biology of the Black-bellied Sandgrouse Pterocles ...

African Journals Online (AJOL)

Aspects of the breeding biology of the Black-bellied Sandgrouse Pterocles orientalis were investigated in an arid area of west-central Morocco in the 2003 and 2004 seasons. Back-dating clutches and broods indicated that successful nesting lasted 13–18 weeks from mid-April to late August. The clutch frequency ...

Breeding biology of a winter-breeding procellariiform in the North Atlantic, the Macaronesian shearwater Puffinus lherminieri baroli.

Science.gov (United States)

Fagundes, Ana Isabel; Ramos, Jaime A; Ramos, Urtelinda; Medeiros, Renata; Paiva, Vitor H

2016-10-01

The breeding success of burrow-nesting seabirds may be influenced by both nest site characteristics and oceanographic conditions influencing food availability at sea. In this study we describe the breeding biology of the winter-breeding Macaronesian shearwater (Puffinus lherminieri baroli), including nest site characteristics and interspecific competition. We also evaluate the possible effects of changing oceanographic conditions on breeding phenology and breeding success. The study was carried out over two breeding seasons on two islands in the North Atlantic Ocean, Cima Islet and Selvagem Grande. Oceanographic characteristics differed between years. On a regional scale, the North Atlantic Oscillation (NAO) index was low and negative in 2011, and on a local scale, birds used areas with significantly lower values of chlorophyll a concentration and significantly higher values of sea surface temperature anomalies. Hatching success was higher in 2012 than in 2011. At both colonies, egg cracking was the main cause of hatching failure, but in 2011 several eggs on Selvagem Grande were deserted. In 2012 birds laid earlier and chicks had longer wings and were heavier. At both colonies, nests that were deeper, were sheltered from prevailing winds and had small chambers and a soil substrate had a higher probability of being used successfully by the birds. Nests occupied solely by Macaronesian shearwaters were much deeper and had less volume than nests shared with other species. Our study suggests that the breeding success of Macaronesian shearwaters is strongly related to nest site characteristics and that at-sea environmental conditions exert a strong influence on reproductive parameters, with birds breeding in a poor year (evaluated in terms of lower marine productivity) laying much later and their chicks growing at a slower rate than in a good year. The influence of nest site characteristics and environmental conditions may be very important for understanding the breeding

Influence of breed and environmental factors on litter parameters of ...

African Journals Online (AJOL)

Influence of breed and environmental factors on litter parameters of rabbits ... There was a non-significant effect of season on litter site at birth, kits alive at birth and ... to rabbit reproduction as it influenced negatively more litter parameters than ...

Veterinary dairy herd fertility service provision in seasonal and non-seasonal dairy industries - a comparison

Directory of Open Access Journals (Sweden)

Mee JF

2010-04-01

Full Text Available Abstract The decline in dairy herd fertility internationally has highlighted the limited impact of traditional veterinary approaches to bovine fertility management. Three questionnaire surveys were conducted at buiatrics conferences attended by veterinary practitioners on veterinary dairy herd fertility services (HFS in countries with a seasonal (Ireland, 47 respondents and non-seasonal breeding model (The Netherlands, 44 respondents and Portugal, 31 respondents. Of the 122 respondents, 73 (60% provided a HFS and 49 (40% did not. The majority (76% of all practitioners who responded stated that bovine fertility had declined in their practice clients' herds with inadequate cow management, inadequate nutrition and increased milk yield as the most important putative causes. The type of clients who adopted a herd fertility service were deemed more educated than average (70% of respondents, and/or had fertility problems (58% and/or large herds (53%. The main components of this service were routine postpartum examinations (95% of respondents, fertility records analysis (75% and ultrasound pregnancy examinations (69%. The number of planned visits per annum varied between an average of four in Ireland, where breeding is seasonal, and 23 in Portugal, where breeding is year-round. The benefits to both the practitioner and their clients from running a HFS were cited as better fertility, financial rewards and job satisfaction. For practitioners who did not run a HFS the main reasons given were no client demand (55% and lack of fertility records (33%. Better economic evidence to convince clients of the cost-benefit of such a service was seen as a major constraint to adoption of this service by 67% of practitioners.

Cost of living in free-ranging degus (Octodon degus) : seasonal dynamics of energy expenditure

NARCIS (Netherlands)

Bozinovic, F; Bacigalupe, LD; Vasquez, RA; Visser, GH; Veloso, C; Kenagy, GJ

Animals process and allocate energy at different seasons at variable rates, depending on their breeding season and changes in environmental conditions and resulting physiological demands. Overall total energy expenditure, in turn, should either increase in some seasons due to special added demands

Does wintering north or south of the Sahara correlate with timing and breeding performance in black-tailed godwits?

NARCIS (Netherlands)

Kentie, R.; Marquez-Ferrando, R.; Figuerola, J.; Gangoso, L.; Hooijmeijer, C.E.W.; Loonstra, A.H.J.; Robin, F.; Sarasa, M.; Senner, N.; Valkema, H.; Verhoeven, M.A.; Piersma, T.

2017-01-01

Migrating long distances requires time and energy, and may interact with an individual’sperformance during breeding. These seasonal interactions in migratoryanimals are best described in populations with disjunct nonbreeding distributions.The black-tailedgodwit (Limosa limosa limosa), which breeds

Are environmental factors responsible for changed breeding behaviour in emperor penguins?

OpenAIRE

Zitterbart, Daniel; Richter, Sebastian; Spiekermann, Georg; Behrens, Lisa Katharina; Regnery, Julia; Fontes, René Pascal; Hänssler, Thedda; König-Langlo, Gert; Weller, Rolf; Fabry, Ben

2014-01-01

Emperor penguins (Aptenodytes forsteri Gray) are the only vertebrate species that breed during the Antarctic winter. From the beginning of the breeding season in April until fledging of the chicks in January, emperor penguins rely on the stability of sea (fast) ice. The International Union for Conservation of Nature (IUCN) has recently listed the species as ‘near threatened’ because the habitat of emperor penguins may deteriorate significantly over the coming years with the anticipated change...

Fine structure of the free-living parakeet pineal in relation to the breeding cycle.

Science.gov (United States)

Prasadan, T N; Kotak, V C

1993-10-01

Seasonal changes in the ultrastructure of the free-living Rose-Ringed Parakeet Psittacula krameri pineal were examined in relation to the sub-tropical environment and seasonal reproduction. Dark and light pinealocytes of the presumptive neuroendocrine cell line predominated, while supporting cells, ependymal cells, myelinated and non-myelinated nerve fibers with nerve endings, and regressed photoreceptor elements were also observed. Unlike in pineals of many animals, particularly mammals, the presence of dense-core vesicles (DCVs) with varying core density, and absence of clear vesicles and vacuoles with flocullent material, indicate the involvement of DCVs in the synthesis and secretion of pineals principle/s. In November (pre-breeding) when the day length registered a drop to LD 10:14, pinealocytes showed significantly decreased and smaller DCVs and mitochondria, nuclei with heterochromatin, and greater distribution of glycogen and lipid droplets, all indicating low pineal metabolic activity. During the shortest day regime from December to March, when the birds peaked breeding, the number and size of DCVs and mitochondria increased, and Golgi body-endoplasmic reticulum-lysosome complex (GERL) was very well defined. Images of DCVs suggested possible secretion of pineal principle/s by dissolution, and exocytosis. Coincidence of these features with peak gonadotrophic (circulating LH) and spermatogenic and testicular endocrine activity described previously suggested an active turnover of pineal products during this short day length regime when parakeets breed. In contrast, during the post-breeding season (April onwards), when the day-length increased to LD 13:11 and hypophyseal-gonadal function was down, nuclei and RER continued to show active profile, the Golgi body and associated complex were moderately seen, and the DCVs and mitochondria were significantly smaller and lesser. It is therefore probable that the pineal is an important relay to translate cues related

Variation in the gonadotrophin-releasing hormone-1 and the song control system in the tropical breeding rufous-collared sparrow (Zonotrichia capensis) is dependent on sex and reproductive state.

Science.gov (United States)

Stevenson, Tyler J; Small, Thomas W; Ball, Gregory F; Moore, Ignacio T

2012-08-01

Seasonal breeding in temperate zone vertebrates is characterised by pronounced variation in both central and peripheral reproductive physiology as well as behaviour. In contrast, many tropical species have a comparatively longer and less of a seasonal pattern of breeding than their temperate zone counterparts. These extended, more "flexible" reproductive periods may be associate with a lesser degree of annual variation in reproductive physiology. Here we investigated variation in the neuroendocrine control of reproduction in relation to the changes in the neural song control system in a tropical breeding songbird the rufous-collared sparrows (Zonotrichia capensis). Using in situ hybridization, we show that the optical density of GnRH1 mRNA expression is relatively constant across pre-breeding and breeding states. However, males were found to have significantly greater expression compared to females regardless of breeding state. Both males and females showed marked variation in measures of peripheral reproductive physiology with greater gonadal volumes and concentrations of sex steroids in the blood (i.e. testosterone in males; estrogen in females) during the breeding season as compared to the pre-breeding season. These findings suggest that the environmental cues regulating breeding in a tropical breeding bird ultimately exert their effects on physiology at the level of the median eminence and regulate the release of GnRH1. In addition, histological analysis of the song control system HVC, RA and Area X revealed that breeding males had significantly larger volumes of these brain nuclei as compared to non-breeding males, breeding females, and non-breeding females. Females did not exhibit a significant difference in the size of song control regions across breeding states. Together, these data show a marked sex difference in the extent to which there is breeding-associated variation in reproductive physiology and brain plasticity that is dependent on the reproductive

Impact of Eucalyptus plantations on the avian breeding community ...

African Journals Online (AJOL)

The nesting bird species in natural forests and Eucalyptus plantations on the Amani Plateau, East Usambara, were studied during the breeding season of September 2003 to March 2004. Some forest birds — like barbets, batis, broadbills, doves, flycatchers, greenbuls, hornbills, and tinkerbirds — utilised similar nest sites ...

Migration redefined? Seasonality, movements and group ...

African Journals Online (AJOL)

The migration of Southern Hemisphere humpback whales Megaptera novaeangliae between their feeding and breeding areas has thus far been considered a highly predictable and seasonal event. However, previous observations on the humpbacks that pass through the nearshore waters of the west coast of South Africa ...

NOAA predicts near-normal or below-normal 2014 Atlantic hurricane season

Science.gov (United States)

Related link: Atlantic Basin Hurricane Season Outlook Discussion El Niño/Southern Oscillation (ENSO ) Diagnostic Discussion National Hurricane Preparedness Week FEMA Media Contact Maureen O'Leary 301-427-9000 tips, along with video and audio public service announcements in both English and Spanish, featuring

Seasonal changes of progesterone and testosterone contents in hair of giant pandas

International Nuclear Information System (INIS)

Guo Dazhi; Liu Xianyi; Chen Faju

1994-01-01

Seasonal changes of progesterone content (PSC) in hair of three female giant pandas and testosterone content (TSC) in hair of two male giant pandas were tested by radioimmunoassay. During March to early June, PSC in two non-pregnant giant pandas (x-bar+-SD = 13.40 +- 10.06 and 10.60 +- 8.88 ng/g hair respectively) were higher than those in non-breeding season (3.07 +-1.07 and 3.20 +- 1.15 ng/g, P<0.01). PSC in a 18-year-old female giant panda remained at low levels (2.72 +- 1.49 ng/g) during March to December. In a twin-bear giant panda, PSC (6.77 +- 3.66 ng/g) appeared higher than that in non-pregnant giant pandas in non-breeding season. Around February to the end of May, TSC in two male giant pandas (1.89 +- 1.71 and 1.82 +- 1.04 ng/g respectively) were also higher than that in non-breeding season (0.98 +- 0.57 and 0.75 +- 0.39 ng/g, P<0.01). the findings from the study implied that giant panda's hair is possible to be used as a specimen to carry out steroids research in the endangered species

Corticosterone stress response and plasma metabolite levels during breeding and molt in a free-living migratory songbird, the wood thrush (Hylocichla mustelina).

Science.gov (United States)

Done, Tyler; Gow, Elizabeth A; Stutchbury, Bridget J M

2011-04-01

Many birds face energetic trade-offs between different life history stages, such as reproductive effort, feather molt and the non-breeding period. Little is known about how physiological measures of condition (corticosterone, plasma metabolites) in free-living birds change from nesting stages to the post-breeding molt period or whether this is influenced by prior reproductive effort. We evaluated whether corticosterone (CORT) and plasma metabolite levels vary with date, nest stage and sex in a free-living migratory songbird, the wood thrush (Hylocichla mustelina). We also tested whether (1) baseline CORT levels early in the season were predictive of subsequent reproductive success and (2) whether prior reproductive effort influenced CORT levels and blood metabolites during molt. Baseline CORT levels decreased with date during both the incubation stage and nestling stage, but did not vary significantly across stage of breeding season. Stress-induced CORT declined with date during incubation and varied significantly across breeding stage, with lower levels during feather molt. Profiles of the metabolites of β-hydroxybutyrate, glycerol, and triglyceride did not vary significantly with date or breeding stage. Only triglycerides varied significantly with sex, with females having higher levels than males. Reproductive output was highly variable (0-10 fledglings per season) but baseline CORT levels in females during the first incubation period of the season was not related to subsequent reproductive output. Prior reproductive effort, measured as the cumulative number of young hatched during the breeding season, was positively related to stress-induced CORT during molt. High reproductive effort in wood thrush appears to have physiological carry-over effects into the molt period which could potentially affect rate of molt and preparation for fall migration. Copyright © 2011. Published by Elsevier Inc.

Large forest patches promote breeding success of a terrestrial mammal in urban landscapes.

Directory of Open Access Journals (Sweden)

Masashi Soga

Full Text Available Despite a marked increase in the focus toward biodiversity conservation in fragmented landscapes, studies that confirm species breeding success are scarce and limited. In this paper, we asked whether local (area of forest patches and landscape (amount of suitable habitat surrounding of focal patches factors affect the breeding success of raccoon dogs (Nyctereutes procyonoides in Tokyo, Central Japan. The breeding success of raccoon dogs is easy to judge as adults travel with pups during the breeding season. We selected 21 forest patches (3.3-797.8 ha as study sites. In each forest patch, we used infra-red-triggered cameras for a total of 60 camera days per site. We inspected each photo to determine whether it was of an adult or a pup. Although we found adult raccoon dogs in all 21 forest patches, pups were found only in 13 patches. To estimate probability of occurrence and detection for raccoon in 21 forest fragments, we used single season site occupancy models in PRESENCE program. Model selection based on AIC and model averaging showed that the occupancy probability of pups was positively affected by patch area. This result suggests that large forests improve breeding success of raccoon dogs. A major reason for the low habitat value of small, isolated patches may be the low availability of food sources and the high risk of being killed on the roads in such areas. Understanding the effects of local and landscape parameters on species breeding success may help us to devise and implement effective long-term conservation and management plans.

Impacts of mesquite distribution on seasonal space use of lesser prairie-chickens

Science.gov (United States)

Boggie, Matthew A.; Strong, Cody R.; Lusk, Daniel; Carleton, Scott A.; Gould, William R.; Howard, Randy L.; Nichols, Clay T.; Falkowski, Michael J.; Hagen, Christian A.

2017-01-01

Loss of native grasslands by anthropogenic disturbances has reduced availability and connectivity of habitat for many grassland species. A primary threat to contiguous grasslands is the encroachment of woody vegetation, which is spurred by disturbances that take on many forms from energy development, fire suppression, and grazing. These disturbances are exacerbated by natural- and human-driven cycles of changes in climate punctuated by drought and desertification conditions. Encroachment of honey mesquite (Prosopis glandulosa) into the prairies of southeastern New Mexico has potentially limited habitat for numerous grassland species, including lesser prairie-chickens (Tympanuchus pallidicinctus). To determine the magnitude of impacts of distribution of mesquite and how lesser prairie-chickens respond to mesquite presence on the landscape in southeastern New Mexico, we evaluated seasonal space use of lesser prairie-chickens in the breeding and nonbreeding seasons. We derived several remotely sensed spatial metrics to characterize the distribution of mesquite. We then used these data to create population-level resource utilization functions and predict intensity of use of lesser prairie-chickens across our study area. Home ranges were smaller in the breeding season compared with the nonbreeding season; however, habitat use was similar across seasons. During both seasons, lesser prairie-chickens used areas closer to leks and largely avoided areas with mesquite. Relative to the breeding season, during the nonbreeding season habitat use suggested a marginal increase in mesquite within areas of low intensity of use, yet aversion to mesquite was strong in areas of medium to high intensity of use. To our knowledge, our study is the first to demonstrate a negative behavioral response by lesser prairie-chickens to woody encroachment in native grasslands. To mitigate one of the possible limiting factors for lesser prairie-chickens, we suggest future conservation

Mammary gland and milk fatty acid composition of two dairy goat breeds under feed-restriction

DEFF Research Database (Denmark)

Palma, Mariana; Alves, Susana P.; Hernandez Castellano, Lorenzo E

2017-01-01

Goat dairy products are an important source of animal protein in the tropics. During the dry season, pasture scarcity leads animals to lose up to 40% of their body weight, a condition known as Seasonal Weight Loss (SWL) that is one of the major constraints in ruminant production. Breeds with high...

Estrus Synchronization and Artificial Insemination in Goats during Low Breeding Season-A Preliminary Study

Directory of Open Access Journals (Sweden)

A. Mehmood*, S. M. H Andrabi, M. Anwar and M. Rafiq

2011-04-01

Full Text Available A pilot project was initiated to introduce artificial insemination (AI in goats at farmer level with chilled semen. Does (n=18 were synchronized with progesterone impregnated vaginal sponges (60 mg Medroxyprogesterone acetate; MAP for 11 days. At 48 hrs prior to removal of the sponges, intramuscular injection of 400 IU equine chorionic gonadotropin (eCG and cloprostenol (0.075 mg was given. Fixed time vaginal insemination (43-45 hrs after sponge removal was done twice (at 12 hrs interval in 17 does with chilled Beetal buck semen (4°C extended with Tris-citric acid (TCA or skimmed milk (SM based extender (75 x 106 sperm/ml. Pregnancy test was performed at 45 days post insemination through ultrasonography. An overall 94.5% (17/18 of does showed heat signs and 78% of them were detected in heat between 12 - 24 hrs after sponge removal. An overall 29.4% (5/17 pregnancy rate was recorded. Higher pregnancy rate (44.4% was obtained in does inseminated with SM extended semen as compared to 12.5% for TCA extended semen. Results were encouraging in the sense that to the best of our knowledge it was the first report of kidding through AI in heat induced does in Pakistan. Moreover, it indicated the feasibility of using synchronization and fixed time AI during low breeding season to enhance the reproductive efficiency in local goats.

Multi-Spectral Imaging from an Unmanned Aerial Vehicle Enables the Assessment of Seasonal Leaf Area Dynamics of Sorghum Breeding Lines

Directory of Open Access Journals (Sweden)

Andries B. Potgieter

2017-09-01

Full Text Available Genetic improvement in sorghum breeding programs requires the assessment of adaptation traits in small-plot breeding trials across multiple environments. Many of these phenotypic assessments are made by manual measurement or visual scoring, both of which are time consuming and expensive. This limits trial size and the potential for genetic gain. In addition, these methods are typically restricted to point estimates of particular traits, such as leaf senescence or flowering and do not capture the dynamic nature of crop growth. In water-limited environments in particular, information on leaf area development over time would provide valuable insight into water use and adaptation to water scarcity during specific phenological stages of crop development. Current methods to estimate plant leaf area index (LAI involve destructive sampling and are not practical in breeding. Unmanned aerial vehicles (UAV and proximal-sensing technologies open new opportunities to assess these traits multiple times in large small-plot trials. We analyzed vegetation-specific crop indices obtained from a narrowband multi-spectral camera on board a UAV platform flown over a small pilot trial with 30 plots (10 genotypes randomized within 3 blocks. Due to variable emergence we were able to assess the utility of these vegetation indices to estimate canopy cover and LAI over a large range of plant densities. We found good correlations between the Normalized Difference Vegetation Index (NDVI and the Enhanced Vegetation Index (EVI with plant number per plot, canopy cover and LAI both during the vegetative growth phase (pre-anthesis and at maximum canopy cover shortly after anthesis. We also analyzed the utility of time-sequence data to assess the senescence pattern of sorghum genotypes known as fast (senescent or slow senescing (stay-green types. The Normalized Difference Red Edge (NDRE index which estimates leaf chlorophyll content was most useful in characterizing the leaf area

Costs of Reproduction in Breeding Female Mallards: Predation Risk during Incubation Drives Annual Mortality

Directory of Open Access Journals (Sweden)

Todd W. Arnold

2012-06-01

Full Text Available The effort expended on reproduction may entail future costs, such as reduced survival or fecundity, and these costs can have an important influence on life-history optimization. For birds with precocial offspring, hypothesized costs of reproduction have typically emphasized nutritional and energetic investments in egg formation and incubation. We measured seasonal survival of 3856 radio-marked female Mallards (Anas platyrhynchos from arrival on the breeding grounds through brood-rearing or cessation of breeding. There was a 2.5-fold direct increase in mortality risk associated with incubating nests in terrestrial habitats, whereas during brood-rearing when breeding females occupy aquatic habitats, mortality risk reached seasonal lows. Mortality risk also varied with calendar date and was highest during periods when large numbers of Mallards were nesting, suggesting that prey-switching behaviors by common predators may exacerbate risks to adults in all breeding stages. Although prior investments in egg laying and incubation affected mortality risk, most relationships were not consistent with the cost of reproduction hypothesis; birds with extensive prior investments in egg production or incubation typically survived better, suggesting that variation in individual quality drove both relationships. We conclude that for breeding female Mallards, the primary cost of reproduction is a fixed cost associated with placing oneself at risk to predators while incubating nests in terrestrial habitats.

Sex-biased disruptive behaviour in breeding crested penguins

OpenAIRE

Poisbleau, M.; Demongin, L.; Eens, M.; Quillfeldt, P.

2013-01-01

Colonial breeding is common in seabirds, and may provide individuals with benefits such as increased protection from predators by joint defence, improved information exchange and enhanced access to mates. However, the presence of large numbers of individuals in breeding colonies may also lead to interference, especially where conspecific behaviour disrupts the normal chick-rearing routine. Using standardised video recordings, we describe and quantify for the first time such disruptive behavio...

Blastocysts production and collection in albino Syrian hamster using superovulation and intrauterine artificial insemination in non-breeding season

Directory of Open Access Journals (Sweden)

A. Amiri Divani

2017-06-01

Full Text Available In vivo blastocyst production and collection using superovulation and intrauterine insemination was established in albino Syrian hamsters. Twenty female albino hamsters were injected pregnant mare serum gonadotropin (PMSG, 25 IU in non-breeding season and 48 h or 56 h later, 25 IU of human chorionic gonadotropin (hCG were injected. Both groups were divided into two subgroups of natural mating and artificial insemination. The former group was mated with a fertile male (1 male for 2 fe-males after hCG injection and in the next morning, the hamsters with vaginal plug were regarded as pregnant. In the artificial insemination group, intrauterine artificial insemination of 1×108 sperms was done 12 h after hCG injection. Blastocysts were counted at 3.5 days after mating or insemination. However, 48 h and 56 h hCG and natural mating and 48 h hCG and artificial insemination were without blastocyst; however the method of 56 h hCG and artificial insemination produced of 15±5 (mean and standard deviation blastocysts in each albino hamster in the winter.

Factors influencing long-term and seasonal waterbird abundance ...

African Journals Online (AJOL)

... influence waterbird communities include rainfall quantity and distribution, waterbird movement, breeding and moulting; anthropogenic drivers include activities such as fishing and agriculture. Results suggest that seasonal variations in resource availability influenced the waterbird community composition and abundance, ...

Experimental dissociation of individual quality, food and timing of breeding effects on double-brooding in a migratory songbird.

Science.gov (United States)

O'Brien, Erin L; Dawson, Russell D

2013-07-01

Annual reproductive success in many species is influenced by the number of breeding attempts within a season. Although previous studies have shown isolated effects of female quality, food, and timing of breeding on the probability of female birds producing second broods, to our knowledge, none have tested the relative importance of multiple factors and their interactions using simultaneous manipulations within populations of free-living birds. In this study, we show that individual quality and timing of breeding interact to affect the probability of double-brooding in female mountain bluebirds (Sialia currucoides). High-quality females (those that naturally initiated clutches early in the season) were more likely to double-brood, regardless of whether their hatching date was advanced or delayed, whereas later breeding, lower quality females were much less likely to double-brood when their first attempt was delayed. This indicates that annual fecundity of poorer quality (or younger) female bluebirds may be more sensitive to seasonal variation in environmental conditions. In addition, birds that were provided with supplemental food throughout first breeding attempts were more likely to double-brood in one of the study years, suggesting that female bluebirds may be energetically limited in their capacity to initiate a second brood. Females that had their first brood delayed also had a shorter inter-brood interval and were moulting fewer feathers during second broods compared to controls, while females in better condition showed more advanced moult in second breeding attempts. Taken together, our results demonstrate the combined effects of age- or individual quality-mediated energetic trade-offs between current and future reproduction, and between investments in offspring and self-maintenance, on annual fecundity of female birds.

Home range size and breeding dispersal of a common buzzard (Buteo buteo

Directory of Open Access Journals (Sweden)

Väli Ülo

2017-12-01

Full Text Available Telemetric studies have provided ample information on threatened raptors, but still little is known about space use and dispersal of common species. Here I describe the home range and breeding dispersal of a GPS-tracked adult male common buzzard, studied in south-eastern Estonia in 2014–16. This buzzard’s home range covered 8.3 km2 (kernel 95% estimate with the core range being 2.1 km2 (kernel 50%. The home range increased in the course of the breeding season but decreased again before migration. Surprisingly, the nests in the two successive breeding years were located in the opposite margins of the home range, 1.7 km from each other.

Breeding season-specific sex diagnostics in the monomorphic House Martin Delichon urbicum

NARCIS (Netherlands)

Piersma, Theunis; Van Der Velde, Marco

Capsule Breeding adult females show a bare brood patch and a smaller cloacal protuberance than males. Aims To examine the degree of sexual dimorphism in various phenotypic traits in House Martins. Methods In the summers of 2005-07 in the northern Netherlands, 160 House Martins were captured. We

Factors influencing the breeding success of Cape Gannets Morus ...

African Journals Online (AJOL)

In the 2002/2003 breeding season at Malgas Island, South Africa, 125 nests of Cape Gannets Morus capensis, of which at least one partner was of known age, were monitored. The age of birds at these nests ranged from five to 22 years. At five nests, the ages of both partners were known; ages were similar for birds ...

Status of breeding seabirds on the Northern Islands of the Red Sea, Saudi Arabia.

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Shobrak, Mohammed Y; Aloufi, Abdulhadi A

2014-07-01

We undertook breeding surveys between 2010 and 2011 to assess the status of breeding birds on 16 islands in the northern Saudi Arabia. Sixteen bird species were found breeding at three different seasons; i.e. winter (Osprey), spring (Caspian and Saunder's Terns), and summer (Lesser Crested, White-cheeked, Bridled Terns). It is postulated that food availability is an important factor influencing the breeding of seabirds in the northern Saudi Arabian Red Sea. Several species laid eggs earlier in northern parts of the Red Sea than in southern parts. The predicted increases in temperatures (Ta ) could have a negative effect on species survival in the future, especially on those whose nests that are in the open. Finally, disturbance, predation and egg collection were probably the main immediate threats affecting the breeding seabird species in the northern Red Sea.

Non-invasive assessment of glucocorticoid and androgen metabolite levels in cooperatively breeding Damaraland mole-rats (Fukomys damarensis).

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Medger, Katarina; Bennett, Nigel C; Lutermann, Heike; Ganswindt, Andre

2018-05-18

Dominant females of cooperative breeding species often use aggression to suppress reproduction of subordinate females, resulting in subordinates experiencing stress-related increases in glucocorticoid levels, which may cause reproductive down-regulation. This would suggest a general pattern with higher glucocorticoid levels in subordinate compared to dominant individuals; however, the opposite was found in a number of cooperatively breeding species. Furthermore, breeding females of the cooperatively breeding Damaraland mole-rats (Fukomys damarensis) exhibit very high androgen concentrations during the wet season, presumably to support their breeding monopoly. Hormone analysis in Damaraland mole-rats have typically been measured using plasma and urine, but faecal analysis offers additional advantages especially for field studies on this species. The present study examines the suitability of Damaraland mole-rat faecal samples for determining glucocorticoid metabolite (fGCM) and androgen metabolite (fAM) concentrations using enzyme immunoassays. Using these assays, we further evaluated the effects of breeding status on fGCM and fAM concentrations in wild-caught and captive Damaraland mole-rats. Wild-caught breeding and non-breeding males and females exhibited no differences in fAM concentrations. Immunoreactive fGCM concentrations were only high in male breeders and comparatively low in non-breeders and breeding females. Concentrations of fAMs and fGCMs were similar in captive males and females, but fAM concentrations were elevated in captive compared to wild-caught individuals, which may be related to a higher reproductive activity due to removal from the breeding female. The relatively uniform fAM and fGCM concentrations found in wild-caught mole-rats may be explained by a stable colony structure during the dry season during which this study was conducted. Limited dispersal opportunities result in lower aggression and stress levels within a colony and as a result

Evaluation of pre-breeding reproductive tract scoring as a predictor of long term reproductive performance in beef heifers

NARCIS (Netherlands)

Holm, D E; Nielen, M; Jorritsma, R; Irons, P C; Thompson, P N

2015-01-01

In a 7-year longitudinal study 292 Bovelder beef cows in a restricted breeding system in South Africa were observed from 1 to 2 days before their first breeding season, when reproductive tract scoring (RTS, scored from 1 to 5) was performed, until weaning their 5th calves. The objective was to

Breeding biology of passerines in a subtropical montane forest in northwestern Argentina

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Auer, S.K.; Bassar, R.D.; Fontaine, J.J.; Martin, T.E.

2007-01-01

The breeding ecology of south temperate bird species is less widely known than that of north temperate species, yet because they comprise a large portion of the world's avian diversity, knowledge of their breeding ecology can contribute to a more comprehensive understanding of the geographic diversity of avian reproductive traits and life history strategies. We provide the first detailed examination of the reproductive strategies of 18 forest passerines of subtropical, northwestern Argentina. Mean clutch sizes were smaller and egg mass was greater than for north temperate birds, but differed among species and nest types, with cavity-nesters having larger clutches than species with open-cup and enclosed nests. Across all species, the average breeding season duration was 50 days; thus, the common perception that southern species have smaller clutch sizes because of longer breeding seasons is not supported in this community. Daily nest predation rates were influenced by nest type, cavity nests suffering the least from predation, as found in north temperate systems. Only females incubated eggs in all but one species, whereas both parents fed and cared for nestlings in all species. Mean nest attentiveness was low compared to north temperate passerines. Mean hourly nestling feeding rates differed among species and were negatively related to nest predation risk. In short, coexisting species in this subtropical forest varied in their life history strategies, in part correlated with variation in nest predation risk, but also differing from north temperate species. ?? The Cooper Ornithological Society 2007.

[Investigation of Acaroid mites breeding in stored dry fruits].

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Tao, Ning; Zhan, Xiao-dong; Sun, En-tao; Li, Chao-pin

2015-12-01

To study the species and density of Acaroid mites breeding in stored dry fruits. The samples from the dried fruit stores and warehouses were collected, and the mites breeding in them were separated, then the slides with mites were prepared and observed by a light microscope for species identification and counting. The indexes such as the breeding density, species richness index, diversity index and evenness index were calculated. Totally 12 species of Acaroid mites belonging to 6 families and 10 genera were obtained from the total 49 samples. The dominant mite species were Carpoglyphus lactis, Tyrophagus putrescentiae, Acarus siro, and Caloglyphus berlesei. The breeding densities of mites in longans, filberts and plum candies were 79.78, 48.91, 35.73 mites/g, respectively, which were higher than those in other dry fruits. The seasonal variation experiment of mites found that the average breeding density of acaroid mites was higher in July and October, the richness index and diversity index reached the highest value in July, and the evenness index was higher in January and April. The observation of the growth and decline of Acaroid mites under the artificial condition found the number of Caloglyphus berlesei declined sharply and Tyrophagus putrescentiae first increased and then decreased. The pollution of Acaroid mites is serious in the stored dried fruits, for which the positive prevention and control measures to the mite breeding should be taken to reduce the harm.

Seasonal variations of melatonin in ram seminal plasma are correlated to those of testosterone and antioxidant enzymes

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Muiño-Blanco Teresa

2010-06-01

Full Text Available Abstract Background Some breeds of sheep are highly seasonal in terms of reproductive capability, and these changes are regulated by photoperiod and melatonin secretion. These changes affect the reproductive performance of rams, impairing semen quality and modifying hormonal profiles. Also, the antioxidant defence systems seem to be modulated by melatonin secretion, and shows seasonal variations. The aim of this study was to investigate the presence of melatonin and testosterone in ram seminal plasma and their variations between the breeding and non-breeding seasons. In addition, we analyzed the possible correlations between these hormones and the antioxidant enzyme defence system activity. Methods Seminal plasma from nine Rasa Aragonesa rams were collected for one year, and their levels of melatonin, testosterone, superoxide dismutase (SOD, glutathione reductase (GRD, glutathione peroxidase (GPX and catalase (CAT were measured. Results All samples presented measurable quantities of hormones and antioxidant enzymes. Both hormones showed monthly variations, with a decrease after the winter solstice and a rise after the summer solstice that reached the maximum levels in October-November, and a marked seasonal variation (P Conclusions These results show the presence of melatonin and testosterone in ram seminal plasma, and that both hormones have seasonal variations, and support the idea that seasonal variations of fertility in the ram involve interplay between melatonin and the antioxidant defence system.

Reproductive effort and seasonality associated with male-biased parasitism in Gracilinanus agilis (Didelphimorphia: Didelphidae) infected by Eimeria spp. (Apicomplexa: Eimeriidae) in the Brazilian cerrado.

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Strona, A L S; Levenhagem, M; Leiner, N O

2015-07-01

The aggregation of parasites among hosts is associated with differential host exposure and susceptibility to parasites, which varies according to host gender, body size, reproductive status and environmental factors. We evaluated the role of these factors on infestation by Eimeria spp. (Eimeriidae) in the agile gracile mouse opossum (Gracilinanus agilis), a semelparous didelphid inhabiting neotropical savannahs. Eimeria spp. abundance and prevalence among G. agilis were associated with the breeding status of individuals and to a lesser extent to climatic season, with both sexes presenting higher Eimeria spp. burdens during late breeding/wet season. On the other hand, male-biased parasitism was restricted to dry/mating season. We suggest that male spatial organization and diet may account for increased parasite burdens within this sex, although future studies should evaluate the role of physiological differences associated with androgen hormones. Finally, a rapid increase in Eimeria spp. loads among females during the late breeding/wet season seems associated with seasonal changes in susceptibility, due to breeding costs related to semelparity, and exposure to infective propagules, while male-die off seems to explain maintenance of higher Eimeria spp. burdens within this sex in the same period.

Environmental influences on Adelie penguin breeding schedules, endocrinology, and chick survival.

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Ninnes, C E; Waas, J R; Ling, N; Nakagawa, S; Banks, J C; Bell, D G; Bright, A; Carey, P W; Chandler, J; Hudson, Q J; Ingram, J R; Lyall, K; Morgan, D K J; Stevens, M I; Wallace, J; Möstl, E

2011-08-01

To understand how the social and physical environment influences behaviour, reproduction and survival, studies of underlying hormonal processes are crucial; in particular, interactions between stress and reproductive responses may have critical influences on breeding schedules. Several authors have examined the timing of breeding in relation to environmental stimuli, while others have independently described endocrine profiles. However, few studies have simultaneously measured endocrine profiles, breeding behaviour, and offspring survival across seasons. We measured sex and stress hormone concentrations (oestrogens, testosterone, and corticosterone), timing of breeding, and chick survival, in Adelie penguins (Pygoscelis adeliae) at two colonies in two different years. Clutch initiation at Cape Bird South (CBS; year 1, ~14,000 pairs) occurred later than at Cape Crozier East (CCE; year 2, ~ 25,000 pairs); however, breeding was more synchronous at CBS. This pattern was probably generated by the persistence of extensive sea ice at CBS (year 1). Higher corticosterone metabolite and lower sex hormone concentrations at CBS correlated with later breeding and lower chick survival compared to at CCE - again, a likely consequence of sea ice conditions. Within colonies, sub-colony size (S, 50-100; M, 200-300; L, 500-600; XL, >1000 pairs) did not influence the onset or synchrony of breeding, chick survival, or hormone concentrations. We showed that the endocrine profiles of breeding Adelie penguins can differ markedly between years and/or colonies, and that combining measures of endocrinology, behaviour, and offspring survival can reveal the mechanisms and consequences that different environmental conditions can have on breeding ecology. Copyright © 2011 Elsevier Inc. All rights reserved.

Sperm production, testicular size, serum gonadotropins and testosterone levels in Merino and Corriedale breeds.

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Fernandez-Abella, D; Becu-Villalobos, D; Lacau-Mengido, I M; Villegas, N; Bentancur, O

1999-01-01

The relationships between testis size, hormone secretion and sperm production were studied during the spring (December) and autumn (May) in rams of two breeds with different breeding seasons and body weights (Corriedale and Australian Merino) maintained on native pastures and under natural photoperiods in Uruguay. Blood samples were collected at 20-min intervals during a 260-360-min period in 13 rams (four Corriedale, nine Australian Merino) during the late spring and autumn. Rams were weighed and testis size was estimated by orchimetry at each time period. Sperm production was estimated during a 2-week period, 2 months before blood collection and during each week following every blood collection. There was no relationship between testicular size and sperm production measured at the same time, nor between live weight and sperm production. In contrast, testicular volume during the late spring was correlated with sperm production in the autumn (r = 0.65; P = 0.02). The autumn serum LH was higher in Corriedale than in Merino rams. LH pulsatility was unaffected by season, but LH pulse frequency tended to be higher in Corriedale than in Merino rams, particularly in the late spring (2.37 versus 1.56 pulses/6 h; P = 0.08). Serum testosterone concentration was similar in both breeds and seasons. FSH levels were higher in the late spring than in the autumn in both breeds (Corriedale: 2.83 +/- 0.48 versus 2.17 +/- 0.24 ng x mL(-1); Merino: 2.23 +/- 0.24 versus 1.88 +/- 0.17 ng x mL(-1)). FSH and testosterone concentrations during the late spring were positively correlated with autumn sperm production (P = 0.07 and P = 0.03, respectively). In conclusion, the present experiment suggests that LH secretion is not a good parameter for the prediction of sperm production. In contrast, in our conditions (breeds and native pastures) testicular size and testosterone or FSH concentrations from the late spring may be used to predict sperm production in the autumn.

The reproductive seasons of some mammals in the Kruger National

African Journals Online (AJOL)

It seems, therefore, that although these animals exhibit an inherent rhythm in their breeding activities, this may be considerably influenced by prevailing climatic conditions. The picture ... Brand (1963) finds no calving season in his analysis.

Multi-scale factors influencing the characteristics of avian communities in urban parks across Beijing during the breeding season

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Xie, Shilin; Lu, Fei; Cao, Lei; Zhou, Weiqi; Ouyang, Zhiyun

2016-07-01

Understanding the factors that influence the characteristics of avian communities using urban parks at both the patch and landscape level is important to focus management effort towards enhancing bird diversity. Here, we investigated this issue during the breeding season across urban parks in Beijing, China, using high-resolution satellite imagery. Fifty-two bird species were recorded across 29 parks. Analysis of residence type of birds showed that passengers were the most prevalent (37%), indicating that Beijing is a major node in the East Asian-Australasian Flyway. Park size was crucial for total species abundance, but foliage height diversity was the most important factor influencing avian species diversity. Thus, optimizing the configuration of vertical vegetation structure in certain park areas is critical for supporting avian communities in urban parks. Human visitation also showed negative impact on species diversity. At the landscape level, the percentage of artificial surface and largest patch index of woodland in the buffer region significantly affected total species richness, with insectivores and granivores being more sensitive to the landscape pattern of the buffer region. In conclusion, urban birds in Beijing are influenced by various multi-scale factors; however, these effects vary with different feeding types.

Breeding-season sympatry facilitates genetic exchange among allopatric wintering populations of Northern Pintails in Japan and California

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Flint, Paul L.; Ozaki, Kiyoaki; Pearce, John M.; Guzzetti, Brian; Higuchi, Hiroyoshi; Fleskes, Joseph P.; Shimada, Tetsuo; Derksen, Dirk V.

2009-01-01

The global redistribution of pathogens, such as highly pathogenic avian influenza, has renewed interest in the connectivity of continental populations of birds. Populations of the Northern Pintail (Anas acuta) wintering in Japan and California are considered separate from a management perspective. We used data from band recoveries and population genetics to assess the degree of biological independence of these wintering populations. Distributions of recoveries in Russia of Northern Pintails originally banded during winter in North America overlapped with distributions of Northern Pintails banded during winter in Japan. Thus these allopatric wintering populations are partially sympatric during the breeding season. The primary areas of overlap were along the Chukotka and Kamchatka peninsulas in Russia. Furthermore, band recoveries demonstrated dispersal of individuals between wintering populations both from North America to Japan and vice versa. Genetic analyses of samples from both wintering populations showed little evidence of population differentiation. The combination of banding and genetic markers demonstrates that these two continental populations are linked by low levels of dispersal as well as likely interbreeding in eastern Russia. Although the levels of dispersal are inconsequential for population dynamics, the combination of dispersal and interbreeding represents a viable pathway for exchange of genes, diseases, and/or parasites.

Foraging plasticity in seabirds: A non-invasive study of the diet of greater crested terns breeding in the Benguela region

Science.gov (United States)

2018-01-01

Marine predators, such as seabirds, are useful indicators of marine ecosystem functioning. In particular, seabird diet may reflect variability in food-web composition due to natural or human-induced environmental change. Diet monitoring programmes, which sample diet non-invasively, are valuable aids to conservation and management decision-making. We investigated the diet of an increasing population of greater crested terns Thalasseus bergii in the Western Cape, South Africa, during three successive breeding seasons (2013 to 2015), when populations of other seabirds feeding on small pelagic schooling fish in the region were decreasing. Breeding greater crested terns carry prey in their bills, so we used an intensive photo-sampling method to record their diet with little disturbance. We identified 24,607 prey items from at least 47 different families, with 34 new prey species recorded. Fish dominated the diet, constituting 94% of prey by number, followed by cephalopods (3%), crustaceans (2%) and insects (1%). The terns mainly targeted surface-schooling Clupeiformes, with anchovy Engraulis encrasicolus the most abundant prey in all three breeding seasons (65% overall). Prey composition differed significantly between breeding stages and years, with anchovy most abundant at the start of the breeding season, becoming less frequent as the season progressed. The proportion of anchovy in the diet also was influenced by environmental factors; anchovy occurred more frequently with increasing wind speeds and was scarce on foggy days, presumably because terns rely in part on social facilitation to locate anchovy schools. The application of this intensive and non-invasive photo-sampling method revealed an important degree of foraging plasticity for this seabird within a context of locally reduced food availability, suggesting that, unlike species that specialise on a few high-quality prey, opportunistic seabirds may be better able to cope with reductions in the abundance of

Breeding biology of the European Blackbird Turdus merula in orange orchards

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Ali Zeraoula

2016-10-01

Full Text Available During two successive years (2013–2014, we studied the breeding ecology of the European Blackbird Turdus merula in Guelma province, north-east of Algeria. The study was carried out in orange orchards of the region. We investigated nest placement in the orange trees and determined the factors of reproductive failure at this study area. Nests were placed at low height (mean ± SD = 1.42 ± 0.04 m and located near the trunk (mean ± SD = 0.61 ± 0.04 m. The breeding season occurred between mid-May and mid-June and the peak of egg laying took place during the first half of May. The mean clutch size was 2.96 ± 0.05, density of breeding pairs was 0.83 ± 0.30 p/ha. The breeding success reported in the present study was higher than that recorded in other studies. Predation was the leading cause of nest failure of the population under investigation. The present study shows that the orange orchards appear to be the preferred breeding area for Blackbird population.

Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia

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Bogh Claus

2008-08-01

Full Text Available Abstract Background Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. Methods Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores, and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June. Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. Results Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%, with An. gambiae s.s. (10% and An. arabiensis (3% also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709 contained sporozoites. Larvae (mostly An. gambiae s.s. were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. Conclusion During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative

Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia.

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Jawara, Musa; Pinder, Margaret; Drakeley, Chris J; Nwakanma, Davis C; Jallow, Ebrima; Bogh, Claus; Lindsay, Steve W; Conway, David J

2008-08-18

Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores), and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June). Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%), with An. gambiae s.s. (10%) and An. arabiensis (3%) also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709) contained sporozoites. Larvae (mostly An. gambiae s.s.) were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative numbers of An. gambiae s.s. adults, and with the increase in this

Diversity of Sex Types and Seasonal Sexual Plasticity in a Cucumber Germplasm Collection

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Dou Xinxin

2015-09-01

Full Text Available The sex type of a cucumber plant is determined by the proportion of male, female and hermaphrodite flowers that it bears and is an important factor that affects fruit yield. In this paper, the sex types and seasonal sexual stabilities of 322 accessions of cucumber germplasm were identified. This germplasm collection displayed a great variety of sex types. We used an updated 10-type sex classification system based on the flower types present and the proportion of nodes with pistillate flowers (PNPF. The PNPF ranges of all the accessions were 2.12%–100% in spring and 0–100% in autumn. A total of 81.37% of the accessions had PNPFs of 10%–50% in spring, but most (84.78% accessions were reduced to 0–20% PNPF in autumn. The range of reduction of PNPF from spring to autumn was 0–67.91%. In other words, most of the germplasm was normal monoecious (31.68% or subandroecious (62.73% in spring, but 94.10% of the accessions were subandroecious in autumn. According to the statistical evaluation of the difference in PNPFs between the two seasons, each accession could be classified into one of three groups: seasonally stable, seasonally sensitive and highly seasonally sensitive, accounting for 10.56%, 20.50% and 68.94% of the accessions, respectively. With a few exceptions, the seasonal PNPF differences were positively correlated with the PNPFs in a given season for most accessions. These results provided useful information and materials for sex expression mechanism research and for breeding cucumbers with high and stable yields.

Population dynamics of mallards breeding in eastern Washington

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Dugger, Bruce D.; Coluccy, John M.; Dugger, Katie M.; Fox, Trevor T.; Kraege, Donald K.; Petrie, Mark J.

2016-01-01

Variation in regional population trends for mallards breeding in the western United States indicates that additional research into factors that influence demographics could contribute to management and understanding the population demographics of mallards across North America. We estimated breeding incidence and adult female, nest, and brood survival in eastern Washington in 2006 and 2007 by monitoring female mallards with radio telemetry and tested how those parameters were influenced by study year (2006 vs. 2007), landscape type (agricultural vs. natural), and age (second year [SY] vs. after second year [ASY]). We also investigated the effects of female body condition and capture date on breeding incidence, and nest initiation date and hatch date on nest and brood survival, respectively. We included population parameters in a stage-based demographic model and conducted a perturbation analysis to identify which vital rates were most influential on population growth rate (λ). Adult female survival was best modeled with a constant weekly survival rate (0.994, SE = 0.003). Breeding incidence differed between years and was higher for birds in better body condition. Nest survival was higher for ASY females (0.276, SE = 0.118) than SY females (0.066, SE = 0.052), and higher on publicly managed lands (0.383, SE = 0.212) than agricultural (0.114, SE = 0.058) landscapes. Brood survival was best modeled with a constant rate for the 7-week monitoring period (0.50, SE = 0.155). The single variable having the greatest influence on λ was non-breeding season survival, but the combination of parameters from the breeding grounds explained a greater percent of the variance in λ. Mallard population growth rate was most sensitive to changes in non-breeding survival, nest success, brood survival, and breeding incidence. Future management decisions should focus on activities that improve these vital rates if managers want to increase the production of

Seasonality of reproduction and production in farm fishes, birds and mammals.

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Chemineau, P; Malpaux, B; Brillard, J P; Fostier, A

2007-03-01

A very large majority of farm animals express seasonal variations in their production traits, thus inducing seasonal availability of fresh derived animal products (meat, milk, cheese and eggs). This pattern is in part the consequence of the farmer's objective to market his products in the most economically favourable period. It may also be imposed by the season-dependent access to feed resources, as in ruminants, or by the specific requirements derived from adaptation to environmental conditions such as water temperature in fish. But seasonal variations in animal products are also the consequence of constraints resulting from the occurrence of a more or less marked seasonal reproductive season in most farm animal species including fish, poultry and mammals. Like their wild counterparts, at mid and high latitudes, most farm animals normally give birth at the end of winter-early spring, the most favourable period for the progeny to survive and thus promote the next generation. As a consequence, most species show seasonal variations in their ovulation frequency (mammals and fish: presence or absence of ovulation; birds: variations or suppression of laying rates), spermatogenic activity (from moderate to complete absence of sperm production), gamete quality (variations in fertilisation rates and embryo survival), and also sexual behaviour. Among species of interest for animal production, fishes and birds are generally considered as more directly sensitive to external factors (mainly temperature in fish, photoperiod in birds). In all species, it is therefore advisable that artificial photoperiodic treatments consisting of extra-light during natural short days (in chickens, turkeys, guinea fowl, sheep and goats) or melatonin during long days (in goats, sheep) be extensively used to either adjust the breeding season to animal producer needs and/or to completely overcome seasonal variations of sperm production in artificial insemination centres (mammals) and breeder flock

Seasonal Habitat Use by Greater Sage-Grouse (Centrocercus urophasianus) on a Landscape with Low Density Oil and Gas Development.

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Rice, Mindy B; Rossi, Liza G; Apa, Anthony D

2016-01-01

Fragmentation of the sagebrush (Artemisia spp.) ecosystem has led to concern about a variety of sagebrush obligates including the greater sage-grouse (Centrocercus urophasianus). Given the increase of energy development within greater sage-grouse habitats, mapping seasonal habitats in pre-development populations is critical. The North Park population in Colorado is one of the largest and most stable in the state and provides a unique case study for investigating resource selection at a relatively low level of energy development compared to other populations both within and outside the state. We used locations from 117 radio-marked female greater sage-grouse in North Park, Colorado to develop seasonal resource selection models. We then added energy development variables to the base models at both a landscape and local scale to determine if energy variables improved the fit of the seasonal models. The base models for breeding and winter resource selection predicted greater use in large expanses of sagebrush whereas the base summer model predicted greater use along the edge of riparian areas. Energy development variables did not improve the winter or the summer models at either scale of analysis, but distance to oil/gas roads slightly improved model fit at both scales in the breeding season, albeit in opposite ways. At the landscape scale, greater sage-grouse were closer to oil/gas roads whereas they were further from oil/gas roads at the local scale during the breeding season. Although we found limited effects from low level energy development in the breeding season, the scale of analysis can influence the interpretation of effects. The lack of strong effects from energy development may be indicative that energy development at current levels are not impacting greater sage-grouse in North Park. Our baseline seasonal resource selection maps can be used for conservation to help identify ways of minimizing the effects of energy development.

Organic breeding: New trend in plant breeding

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Berenji Janoš

2009-01-01

Full Text Available Organic breeding is a new trend in plant breeding aimed at breeding of organic cultivars adapted to conditions and expectations of organic plant production. The best proof for the need of organic cultivars is the existence of interaction between the performances of genotypes with the kind of production (conventional or organic (graph. 1. The adaptation to low-input conditions of organic production by more eddicient uptake and utilization of plant nutrients is especially important for organic cultivars. One of the basic mechanism of weed control in organic production is the competition of organic cultivars and weeds i.e. the enhanced ability of organic cultivars to suppress the weeds. Resistance/tolerance to diseases and pests is among the most important expectations toward the organic cultivars. In comparison with the methods of conventional plant breeding, in case of organic plant breeding limitations exist in choice of methods for creation of variability and selection classified as permitted, conditionally permitted and banned. The use of genetically modified organisms and their derivated along with induced mutations is not permitted in organic production. The use of molecular markers in organic plant breeding is the only permitted modern method of biotechnology. It is not permitted to patent the breeding material of organic plant breeding or the organic cultivars. .

Successful induction of oestrus, ovulation and pregnancy in adult ewes and ewe lambs out of the breeding season using a GnRH+progesterone oestrus synchronisation protocol.

Science.gov (United States)

Martinez, M F; McLeod, B; Tattersfield, G; Smaill, B; Quirke, L D; Juengel, J L

2015-04-01

A series of experiments was designed to assess the effect of a treatment protocol (U-synch) for inducing oestrus and ovulation out of the breeding season in adult ewes and ewe lambs. The protocol consisted of a 7-day treatment with an intravaginal progesterone-releasing device (IPRD), administration of GnRH at IPRD insertion on Day 0, and equine chorionic gonadotropin (eCG) and prostaglandin F2α at IPRD removal on Day 7. In Experiment 1, 50 or 100 μg GnRH were sufficient to induce ovulation at the beginning of the protocol in 3/9 and 4/9 ewes, respectively; while the resulting proportion of sheep ovulating after the treatment protocol was 88.9% and 77.8% in ewes initially treated with 50 or 100 μg GnRH, respectively. In Experiment 2, the proportion of Romney-cross ewe lambs ovulating was greater (P<0.0001) in the U-synch group (95.4%) than in the untreated Control group (3.2%). In Experiment 3, pregnancy rates of Dorset-cross sheep in the U-synch (60.7%) and Standard (12-day IPRD and eCG treatment; 56.5%) groups were greater (P=0.01) than in the untreated Control group (43.4%). The incidence of twin pregnancies was greater (P=0.005) in the U-synch group than in the Control group. A 7-day IPRD treatment including GnRH treatment at device insertion and eCG treatment at device removal induced oestrus and ovulation during the non-breeding season in a high proportion of mature ewes and ewe lambs. High pregnancy rates to natural mating, with a low rate of triplet pregnancies, were also observed. Copyright © 2015 Elsevier B.V. All rights reserved.

Timing of initial arrival at the breeding site predicts age at first reproduction in a long-lived migratory bird

Science.gov (United States)

Becker, Peter H.; Dittmann, Tobias; Ludwigs, Jan-Dieter; Limmer, Bente; Ludwig, Sonja C.; Bauch, Christina; Braasch, Alexander; Wendeln, Helmut

2008-01-01

In long-lived vertebrates, individuals generally visit potential breeding areas or populations during one or more seasons before reproducing for the first time. During these years of prospecting, they select a future breeding site, colony, or mate and improve various skills and their physical condition to meet the requirements of reproduction. One precondition of successful reproduction is arrival in time on the breeding grounds. Here, we study the intricate links among the date of initial spring arrival, body mass, sex, and the age of first breeding in the common tern Sterna hirundo, a long-lived migratory colonial seabird. The study is based on a unique, individual-based, long-term dataset of sexed birds, marked with transponders, which allow recording their individual arrival, overall attendance, and clutch initiation remotely and automatically year by year over the entire lifetime at the natal colony site. We show that the seasonal date of initial arrival at the breeding grounds predicts the individual age at first reproduction, which mostly occurs years later. Late first-time arrivals remain delayed birds throughout subsequent years. Our findings reveal that timing of arrival at the site of reproduction and timing of reproduction itself are coherent parameters of individual quality, which are linked with the prospects of the breeding career and may have consequences for fitness. PMID:18711134

Weather effects on avian breeding performance and implications of climate change

Science.gov (United States)

Skagen, Susan K.; Yackel Adams, Amy A.

2012-01-01

The influence of recent climate change on the world’s biota has manifested broadly, resulting in latitudinal range shifts, advancing dates of arrival of migrants and onset of breeding, and altered community relationships. Climate change elevates conservation concerns worldwide because it will likely exacerbate a broad range of identified threats to animal populations. In the past few decades, grassland birds have declined faster than other North American avifauna, largely due to habitat threats such as the intensification of agriculture. We examine the effects of local climatic variations on the breeding performance of a bird endemic to the shortgrass prairie, the Lark Bunting (Calamospiza melanocorys) and discuss the implications of our findings relative to future climate predictions. Clutch size, nest survival, and productivity all positively covaried with seasonal precipitation, yet relatively intense daily precipitation events temporarily depressed daily survival of nests. Nest survival was positively related to average temperatures during the breeding season. Declining summer precipitation may reduce the likelihood that Lark Buntings can maintain stable breeding populations in eastern Colorado although average temperature increases of up to 38C (within the range of this study) may ameliorate declines in survival expected with drier conditions. Historic climate variability in the Great Plains selects for a degree of vagility and opportunism rather than strong site fidelity and specific adaptation to local environments. These traits may lead to northerly shifts in distribution if climatic and habitat conditions become less favorable in the drying southern regions of the Great Plains. Distributional shifts in Lark Buntings could be constrained by future changes in land use, agricultural practices, or vegetative communities that result in further loss of shortgrass prairie habitats.

Effect of breed on performance and meat quality of first parity sows in a seasonal organic rearing system

DEFF Research Database (Denmark)

Kongsted, Anne Grete; Claudi-Magnussen, Chris; Hermansen, John Erik

2011-01-01

to be characterized by a special nutty taste. CONCLUSION: The traditional breed has lower productivity and thereby higher costs of production compared to the modern genotypes. On the other hand, the meat and fat of the traditional purebred have special characteristics that might trigger a market premium......BACKGROUND: The objective was to compare the performance and meat quality of two different pig breeds: the modern crossbred Landrace × Yorkshire (LY) and the traditional Danish Black-Spotted (BS) breed. The LY gilts and four of the BS gilts were inseminated with semen from Duroc (D) boars...

Proximo-distal patellar position in three small dog breeds with medial patellar luxation.

Science.gov (United States)

Wangdee, C; Theyse, L F H; Hazewinkel, H A W

2015-01-01

Medial patellar luxation is thought to be associated with a high proximal position of the patella in the trochlear groove. To determine whether the ratio of patellar ligament length and patellar length (L:P) is influenced by the stifle angle (75°, 96°, 113°, 130°, and 148°) in small dog breeds and to compare the L:P ratio in dogs of three small dog breeds with and without medial patellar luxation. A mediolateral radiograph of the stifle joint was used to measure the L:P ratio in the stifle joints of dogs of three small breeds with and without medial patellar luxation. The L:P ratio was evaluated at five stifle angles (75°, 96°, 113°, 130°, and 148°) in 14 cadavers (26 stifle joints) of small dog breeds in order to identify the best stifle angle to measure the L:P ratio. Then the mean ± SD L:P ratio was calculated for normal stifles and stifles with medial patellar luxation grades 1, 2, and 3 in 194 Pomeranians, 74 Chihuahuas, and 41 Toy or Standard Poodles. The L:P ratio was the same for all five stifle angles in the cadavers (p = 0.195). It was also not significantly different in the three breeds (p = 0.135), in normal and medial patellar luxation-affected stifles overall (p = 0.354), and in normal and medial patellar luxation-affected joints within each breed (p = 0.19). We conclude that a proximo-distal patellar position is not associated with medial patellar luxation in Pomeranians, Chihuahuas, and Toy or Standard Poodles. Thus a longer patellar ligament length does not play a role in the pathophysiology of medial patellar luxation in these small dog breeds.

Serum levels at moment of breeding of triiodothyronine (T3), thyroxine (T4), and progesterone in Saanen goats females during normal and induced heat and testosterone in 12 Saanen goats males

International Nuclear Information System (INIS)

Prestes, Nereu C.; Vulcano, Luiz C.; Mamprim, Maria J.; Oba, Eunice

1996-01-01

The aim of this experiment was to measure the level of triiodothyronine(T 3 ), thyroxine(T 4 ) and progesterone in the serum of females Saanen goats. The progesterone levels were: 0.59 and 0.79 ng/μl considering breeding during normal and induced heat respectively. The T 3 values were: 192.8 and 251.32 ng/dl while T 4 values were: 36.38 and 31.68 ng/dl in the same condition above. The average testosterone level at the moment of breeding in the serum of 12 males was 1.38 pg/ml. (author)

Impact of Genomic Technologies on Chickpea Breeding Strategies

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Rajeev K. Varshney

2012-08-01

Full Text Available The major abiotic and biotic stresses that adversely affect yield of chickpea (Cicer arietinum L. include drought, heat, fusarium wilt, ascochyta blight and pod borer. Excellent progress has been made in developing short-duration varieties with high resistance to fusarium wilt. The early maturity helps in escaping terminal drought and heat stresses and the adaptation of chickpea to short-season environments. Ascochyta blight continues to be a major challenge to chickpea productivity in areas where chickpea is exposed to cool and wet conditions. Limited variability for pod borer resistance has been a major bottleneck in the development of pod borer resistant cultivars. The use of genomics technologies in chickpea breeding programs has been limited, since available genomic resources were not adequate and limited polymorphism was observed in the cultivated chickpea for the available molecular markers. Remarkable progress has been made in the development of genetic and genomic resources in recent years and integration of genomic technologies in chickpea breeding has now started. Marker-assisted breeding is currently being used for improving drought tolerance and combining resistance to diseases. The integration of genomic technologies is expected to improve the precision and efficiency of chickpea breeding in the development of improved cultivars with enhanced resistance to abiotic and biotic stresses, better adaptation to existing and evolving agro-ecologies and traits preferred by farmers, industries and consumers.

Do hair-crested drongos reduce prospective territory competition by dismantling their nest after breeding?

NARCIS (Netherlands)

Lv, Lei; Li, Jianqiang; Kingma, Sjouke A.; Gao, Chang; Wang, Yong; Komdeur, Jan; Zhang, Zhengwang

Animals that breed seasonally often use the same territory where they successfully produced young previously. Intra-specific competition may be intense for these high-quality territories, and therefore, natural selection should favour behaviour of territory owners to reduce such competition.

Seasonal variation in the incidence of double broods: The date hypothesis fits better than the quality hypothesis

NARCIS (Netherlands)

Verboven, N.; Verhulst, S.

1996-01-01

1. In three great tit (Parus major) populations the probability that a pair starts a second clutch, a clutch produced after a successful first brood, varied between years and areas but generally declined through the breeding season. 2. By exchanging first clutches between early and late breeding

Seasonal variation in the incidence of double broods : The date hypothesis fits better than the quality hypothesis

NARCIS (Netherlands)

Verboven, N; Verhulst, S

1. In three great tit (Parus major) populations the probability that a pair starts a second clutch, a clutch produced after a successful first brood, varied between years and areas but generally declined through the breeding season. 2. By exchanging first clutches between early and late breeding

Foraging plasticity of breeding Northern Rockhopper Penguins, Eudyptes moseleyi, in response to changing energy requirements

KAUST Repository

Booth, Jenny Marie; Steinfurth, Antje; Fusi, Marco; Cuthbert, Richard J.; McQuaid, Christopher D.

2018-01-01

During the breeding season, seabirds must balance the changing demands of self- and off-spring provisioning with the constraints imposed by central-place foraging. Recently, it was shown that Northern Rockhopper Penguins at Tristan da Cunha

The Effects of Supplementary Food on the Breeding Performance of Eurasian Reed Warblers Acrocephalus scirpaceus; Implications for Climate Change Impacts.

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James O Vafidis

Full Text Available Understanding the mechanisms by which climate variation can drive population changes requires information linking climate, local conditions, trophic resources, behaviour and demography. Climate change alters the seasonal pattern of emergence and abundance of invertebrate populations, which may have important consequences for the breeding performance and population change of insectivorous birds. In this study, we examine the role of food availability in driving behavioural changes in an insectivorous migratory songbird; the Eurasian reed warbler Acrocephalus scirpaceus. We use a feeding experiment to examine the effect of increased food supply on different components of breeding behaviour and first-brood productivity, over three breeding seasons (2012-2014. Reed warblers respond to food-supplementation by advancing their laying date by up to 5.6 days. Incubation periods are shorter in supplemented groups during the warmest mean spring temperatures. Nestling growth rates are increased in nests provisioned by supplemented parents. In addition, nest predation is reduced, possibly because supplemented adults spend more time at the nest and faster nestling growth reduces the period of vulnerability of eggs and nestlings to predators (and brood parasites. The net effect of these changes is to advance the fledging completion date and to increase the overall productivity of the first brood for supplemented birds. European populations of reed warblers are currently increasing; our results suggest that advancing spring phenology, leading to increased food availability early in the breeding season, could account for this change by facilitating higher productivity. Furthermore, the earlier brood completion potentially allows multiple breeding attempts. This study identifies the likely trophic and behavioural mechanisms by which climate-driven changes in invertebrate phenology and abundance may lead to changes in breeding phenology, nest survival and net

Seasonal differences in the testicular transcriptome profile of free-living European beavers (Castor fiber L. determined by the RNA-Seq method.

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Iwona Bogacka

Full Text Available The European beaver (Castor fiber L. is an important free-living rodent that inhabits Eurasian temperate forests. Beavers are often referred to as ecosystem engineers because they create or change existing habitats, enhance biodiversity and prepare the environment for diverse plant and animal species. Beavers are protected in most European Union countries, but their genomic background remains unknown. In this study, gene expression patterns in beaver testes and the variations in genetic expression in breeding and non-breeding seasons were determined by high-throughput transcriptome sequencing. Paired-end sequencing in the Illumina HiSeq 2000 sequencer produced a total of 373.06 million of high-quality reads. De novo assembly of contigs yielded 130,741 unigenes with an average length of 1,369.3 nt, N50 value of 1,734, and average GC content of 46.51%. A comprehensive analysis of the testicular transcriptome revealed more than 26,000 highly expressed unigenes which exhibited the highest homology with Rattus norvegicus and Ictidomys tridecemlineatus genomes. More than 8,000 highly expressed genes were found to be involved in fundamental biological processes, cellular components or molecular pathways. The study also revealed 42 genes whose regulation differed between breeding and non-breeding seasons. During the non-breeding period, the expression of 37 genes was up-regulated, and the expression of 5 genes was down-regulated relative to the breeding season. The identified genes encode molecules which are involved in signaling transduction, DNA repair, stress responses, inflammatory processes, metabolism and steroidogenesis. Our results pave the way for further research into season-dependent variations in beaver testes.

Influence of breed, year season and lactation stage on the buffalo milk mineral content

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G. Crudeli

2010-02-01

Full Text Available This study was conducted to determine the milk mineral composition of buffalo raised in Corrientes, Argentina, as well as to investigate variations attributed to breed, lactation period and time of the year. Milk samples (n = 105 were collected from 25 Murrah, Mediterranean, Jafarabadi and half-breed Murrah x Mediterranean buffaloes of second and fifth lactation. Animals were located in a dairy farm area with subtropical wet climate with 1.690 mm annual rains and annual mean temperature of 22°C. Mean records were: Ca (1.12 ± 0.40 g.kg-1, P (0.99 ± 0.32 g.kg-1, Mg (0.08± 0.02 g.kg-1, K (0.92 ± 0.25 g.kg-1, Na (0.35 ± 0.11 g.kg-1, Cu (0.35 ± 0.16 mg.kg-1, Mn (0.27 ± 0.10 mg.kg-1, Zn (4.10 ± 1.40 mg.kg-1 y Fe (1.61 ± 0.61 mg.kg-1. These parameters did not reveal significant differences attributable to breed, except for Mg. The time of the year affected the composition of the minerals, except for the Mg and Zn. The nursing stages affect the Ca, P, K and Cu concentrations. From the results obtained, it can be concluded that the mineral content in the milk of buffaloes, it is considerably influenced by regional factors.

Reproductive performance of different breeds of broiler rabbits under sub-temperate climatic conditions

Directory of Open Access Journals (Sweden)

D. Kumar

2013-09-01

Full Text Available This study was conducted to assess the effect of breed, season, age and weight of doe at mating on reproductive performance of 4 broiler rabbit breeds, Grey Giant, White Giant, Soviet Chinchilla, and New Zealand White, reared under standard management practices in sub-temperate climatic conditions of India. They were first mated at 6 to 7 mo of age, whereupon an extensive breeding system (re-mating after weaning was followed. Weaning was done 42 d after kindling. The data from the records on reproduction consisting of 503 matings and 377 kindlings were analysed. The parameters considered were fertility rate, litter size at birth (LSB, litter weight at birth (LWB, litter size at weaning (LSW, litter weight at weaning (LWW, doe weight at mating (DWM, gestation length and sex ratio. Among 4 breeds, the LSB, LWB and LSW were higher in Grey Giant followed by White Giant, Soviet Chinchilla and New Zealand White. The LSB and LSW in Grey Giant breed differed significantly (P<0.05 from Soviet Chinchilla and New Zealand White. Season had significant (P<0.05 effect on LSW with higher values during spring (5.68±0.24, followed by summer (5.29±0.30, winter (5.13±0.25 and autumn (4.17±0.49. The body weight of doe at service significantly influenced fertility. The fertility increased as body weight increased. The age of the doe at mating had a significant effect on LSW, with higher values for does more than 2 yr and less than 1 yr old compared to 1- to 2-yr old does. The parity did not affect any of the parameters studied. It is concluded that the factors studied affect the reproductive performance of rabbit does. Grey Giant breed showed the highest litter size at birth and weaning, and the highest litter size and weight at weaning was in spring.

Breeding biology and variable mating system of a population of introduced dunnocks (Prunella modularis in New Zealand.

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Eduardo S A Santos

Full Text Available Species with variable mating systems provide a unique opportunity to investigate whether females receive direct fitness benefits from additional male partners. The direct benefits provide an obvious explanation for why females would breed polyandrously, in a situation where males clearly do not attain their optimal reproductive success. Evidence for these direct benefits is, however, mixed. Here, we present a detailed study of the breeding biology of the dunnock, Prunella modularis, which inform an investigation into the effects of the social mating system on the reproductive success in a population of dunnocks in Southern New Zealand. We studied 80 different social groups over the course of three breeding seasons. Dunnocks in our population presented a variable mating system, with socially monogamous (45%, socially polyandrous (54% and socially polygynandrous (1% groups being observed in the same breeding season. We did not observe any polygynous social units in our study period although polygyny exists in the population. We found little difference in the numbers of eggs laid, and egg volume between monogamous and polyandrous nests. However, polyandrous groups had better hatching and fledging success than monogamous groups (composite d = 0.385, 95% CI: 0.307 to 0.463. Overall our results support the notion that polyandry is beneficial for females.

Seasonal Variation in Group Size Is Related to Seasonal Variation in Neuropeptide Receptor Density.

Science.gov (United States)

Wilson, Leah C; Goodson, James L; Kingsbury, Marcy A

2016-01-01

In many species, seasonal variation in grouping behavior is widespread, with shifts towards territoriality in the breeding season and grouping in the winter. Compared to the hormonal and neural mechanisms of seasonal territorial aggression, the mechanisms that promote seasonal grouping have received little attention. We collected brains in spring and winter from wild-caught males of two species of emberizid sparrows that seasonally flock (the field sparrow, Spizella pusilla, and the dark-eyed junco, Junco hyemalis) and two species that do not seasonally flock (the song sparrow, Melospiza melodia, and the eastern towhee, Pipilo erythrophthalmus). We used receptor autoradiography to quantify seasonal plasticity in available binding sites for three neuropeptides known to influence social behavior. We examined binding sites for 125I-vasoactive intestinal polypeptide (VIP), 125I-sauvagine (SG, a ligand for corticotropin-releasing hormone receptors) and 125I-ornithine vasotocin analog (OVTA, a ligand for the VT3 nonapeptide). For all species and ligands, brain areas that exhibited a seasonal pattern in binding density were characterized by a winter increase. Compared to nonflocking species, seasonally flocking species showed different binding patterns in multiple brain areas. Furthermore, we found that winter flocking was associated with elevated winter 125I-VIP binding density in the medial amygdala, as well as 125I-VIP and 125I-OVTA binding density in the rostral arcopallium. While the functional significance of the avian rostral arcopallium is unclear, it may incorporate parts of the pallial amygdala. Our results point to this previously undescribed area as a likely hot spot of social modulation. © 2016 S. Karger AG, Basel.

Estimation of occupancy, breeding success, and predicted abundance of golden eagles (Aquila chrysaetos) in the Diablo Range, California, 2014

Science.gov (United States)

Wiens, J. David; Kolar, Patrick S.; Fuller, Mark R.; Hunt, W. Grainger; Hunt, Teresa

2015-01-01

We used a multistate occupancy sampling design to estimate occupancy, breeding success, and abundance of territorial pairs of golden eagles (Aquila chrysaetos) in the Diablo Range, California, in 2014. This method uses the spatial pattern of detections and non-detections over repeated visits to survey sites to estimate probabilities of occupancy and successful reproduction while accounting for imperfect detection of golden eagles and their young during surveys. The estimated probability of detecting territorial pairs of golden eagles and their young was less than 1 and varied with time of the breeding season, as did the probability of correctly classifying a pair’s breeding status. Imperfect detection and breeding classification led to a sizeable difference between the uncorrected, naïve estimate of the proportion of occupied sites where successful reproduction was observed (0.20) and the model-based estimate (0.30). The analysis further indicated a relatively high overall probability of landscape occupancy by pairs of golden eagles (0.67, standard error = 0.06), but that areas with the greatest occupancy and reproductive potential were patchily distributed. We documented a total of 138 territorial pairs of golden eagles during surveys completed in the 2014 breeding season, which represented about one-half of the 280 pairs we estimated to occur in the broader 5,169-square kilometer region sampled. The study results emphasize the importance of accounting for imperfect detection and spatial heterogeneity in studies of site occupancy, breeding success, and abundance of golden eagles.

Achievements in NS rapeseed hybrids breeding

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Marjanović-Jeromela Ana

2016-01-01

Full Text Available The increased production of oilseed rape (Brassica napus L. is evident on a global scale, but also in Serbia in the last decade. Rapeseed is used primarily for vegetable oil and processing industry, but also as a source of protein for animal feed and green manure. Following the cultivation of varieties, breeding and cultivation of hybrid rapeseed started in the 1990's, to take advantage of heterosis in F1 generation, while protecting the breeder's rights during seed commercialization. The breeding of hybrid oilseed rape requires high quality starting material (lines with good combining abilities for introduction of male sterility. Ogura sterility system is primarily used at the Institute of Field and Vegetable Crops, Novi Sad, Serbia. To use this system, separate lines are modified with genes for cytoplasmic male sterility (cms female line - mother line and restoration of fertility (Rf male lines - father line. In order to maintain the sterility of the mother line it is necessary to produce a maintainer line of cytoplasmic male sterility. Creation of these lines and hybrids at the Institute of Field and Vegetable Crops was successfully monitored with intense use of cytogenetic laboratory methods. The structure and vitality of pollen, including different phases during meiosis were checked so that cms stability was confirmed during the introduction of these genes into different lines. Rapeseed breeding program in Serbia resulted in numerous varieties through collaboration of researchers engaged in breeding and genetics of this plant species. So far, in addition to 12 varieties of winter rapeseed and two varieties of spring rapeseed, a new hybrid of winter rapeseed NS Ras was registered in Serbia. NS Ras is an early-maturing hybrid characterized by high seed yield and oil content. Average yield of NS Ras for two seasons and three sites was 4256 kg ha-1 of seed and 1704 kg ha-1 of oil. Three promising winter rapeseed hybrids are in the process of

A review of morphological characteristics relating to the production and reproduction of fat-tailed sheep breeds.

Science.gov (United States)

Pourlis, Aris F

2011-10-01

The purpose of this study is to survey the literature pertinent to some morphological traits which are related with the production and reproduction of fat-tailed sheep breeds. The fat-tailed breeds were identified according to Food and Agriculture Organization databases. Articles referring to all these sheep breeds were evaluated. The morphology of udders and their measurable variables were collected and described. The particularities of pelt and fleece features which are important from an economic point of view were summarized. Linear, planar, and spatial parameters of body, slaughter, and carcass factors were compared at various ages of breeding. Testicular dimensions and semen characteristics were recorded. Their relationships with productive and reproductive performance were discussed. The pattern of ovarian follicle development and the involution of the genital tract were assessed from the anatomical point of view in normal and untreated animals. The data presented here provide useful baseline information on the normal morphological aspects which are important in the animal production of these breeds.

The Influence of Sex and Season on Conspecific Spatial Overlap in a Large, Actively-Foraging Colubrid Snake.

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Javan M Bauder

Full Text Available Understanding the factors influencing the degree of spatial overlap among conspecifics is important for understanding multiple ecological processes. Compared to terrestrial carnivores, relatively little is known about the factors influencing conspecific spatial overlap in snakes, although across snake taxa there appears to be substantial variation in conspecific spatial overlap. In this study, we described conspecific spatial overlap of eastern indigo snakes (Drymarchon couperi in peninsular Florida and examined how conspecific spatial overlap varied by sex and season (breeding season vs. non-breeding season. We calculated multiple indices of spatial overlap using 6- and 3-month utilization distributions (UD of dyads of simultaneously adjacent telemetered snakes. We also measured conspecific UD density values at each telemetry fix and modeled the distribution of those values as a function of overlap type, sex, and season using generalized Pareto distributions. Home range overlap between males and females was significantly greater than overlap between individuals of the same sex and male home ranges often completely contained female home ranges. Male home ranges overlapped little during both seasons, whereas females had higher levels of overlap during the non-breeding season. The spatial patterns observed in our study are consistent with those seen in many mammalian carnivores, in which low male-male overlap and high inter-sexual overlap provides males with greater access to females. We encourage additional research on the influence of prey availability on conspecific spatial overlap in snakes as well as the behavioral mechanisms responsible for maintaining the low levels of overlap we observed.

Differential effects of a local industrial sand lance fishery on seabird breeding performance

DEFF Research Database (Denmark)

Frederiksen, M.; Jensen, Henrik; Daunt, F.

2008-01-01

fluctuations. We evaluated the effects of an industrial sand lance (Ammodytes marinus) fishery off the North Sea coast of the United Kingdom, which has been opened and closed in a quasi-experimental fashion, on sand-lance-dependent breeding seabirds. Controlling for environmental variation ( sea surface...... or to the fact that only one study colony in the control zone was exposed to high fishery effort within the typical foraging range of Kittiwakes during the breeding season. The strong impact on Kittiwakes, but not on diving species, could result from ( 1) inherently high sensitivity to reduced prey availability...

The Role of Bioacoustic Signals in Koala Sexual Selection: Insights from Seasonal Patterns of Associations Revealed with GPS-Proximity Units

Science.gov (United States)

Whipple, Bill; Barth, Ben; Johnston, Stephen; Seddon, Jenny; Melzer, Alistair; Higgins, Damien

2015-01-01

Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus—the only extant member of the family Phascolarctidae) is poorly known and much of the koala’s sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas. PMID:26154295

The Role of Bioacoustic Signals in Koala Sexual Selection: Insights from Seasonal Patterns of Associations Revealed with GPS-Proximity Units.

Directory of Open Access Journals (Sweden)

William Ellis

Full Text Available Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus--the only extant member of the family Phascolarctidae is poorly known and much of the koala's sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas.

Milk protein concentration, estimated breeding value for fertility, and reproductive performance in lactating dairy cows.

Science.gov (United States)

Morton, John M; Auldist, Martin J; Douglas, Meaghan L; Macmillan, Keith L

2017-07-01

Milk protein concentration in dairy cows has been positively associated with a range of measures of reproductive performance, and genetic factors affecting both milk protein concentration and reproductive performance may contribute to the observed phenotypic associations. It was of interest to assess whether these beneficial phenotypic associations are accounted for or interact with the effects of estimated breeding values for fertility. The effects of a multitrait estimated breeding value for fertility [the Australian breeding value for daughter fertility (ABV fertility)] on reproductive performance were also of interest. Interactions of milk protein concentration and ABV fertility with the interval from calving date to the start of the herd's seasonally concentrated breeding period were also assessed. A retrospective single cohort study was conducted using data collected from 74 Australian seasonally and split calving dairy herds. Associations between milk protein concentration, ABV fertility, and reproductive performance in Holstein cows were assessed using random effects logistic regression. Between 52,438 and 61,939 lactations were used for analyses of 4 reproductive performance measures. Milk protein concentration was strongly and positively associated with reproductive performance in dairy cows, and this effect was not accounted for by the effects of ABV fertility. Increases in ABV fertility had important additional beneficial effects on the probability of pregnancy by wk 6 and 21 of the herd's breeding period. For cows calved before the start of the breeding period, the effects of increases in both milk protein concentration and ABV fertility were beneficial regardless of their interval from calving to the start of the breeding period. These findings demonstrate the potential for increasing reproductive performance through identifying the causes of the association between milk protein concentration and reproductive performance and then devising management

Tracking multi-generational colonization of the breeding grounds by monarch butterflies in eastern North America

Science.gov (United States)

Flockhart, D. T. Tyler; Wassenaar, Leonard I.; Martin, Tara G.; Hobson, Keith A.; Wunder, Michael B.; Norris, D. Ryan

2013-01-01

Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies (Danaus plexippus) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km2 that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America. PMID:23926146

Gestational length in Carthusian broodmares: effects of breeding season, foal gender, age of mare, year of parturition, parity and sire.

Science.gov (United States)

Satué, K; Felipe, M; Mota, J; Muñoz, A

2011-01-01

The length of gestation in Carthusian broodmares was calculated on the basis of 339 spontaneous full-term deliveries taking place in the 8-year period 1998-2005 from 158 broodmares and 29 stallions in a major farm of Spanish horses of Carthusian strain in southern Spain. Ultrasonography was used to determine follicular dehiscence, 1st day of pregnancy and to confirm conception in mares. Mean GL was 332.4 +/- 12.1 days, and a normal interval of 297-358 days was established for this breed. GL records were grouped on the basis of foal sex (colts or fillies), mating month (between November and January; February and April; May and July), age of the mare (4 to 7 years; 8 to 12 years; 13 to 17 years), breeding year, stallion and parity (primiparous vs. multiparous). GLs were 12.9 days shorter in mares mated between May and July than those mated between November and January and 15.3 days in mares mated between February and April (p < 0.001). Mares aged between 8-12 years had 5.3 days shorter GLs than those aged between 13-17 years (p < 0.05). Pregnancy was significantly 5.7 days longer when the mare gave birth to colts than fillies (p < 0.05). GL was 14.5 days longer in primiparous than in multiparous mares ( p < 0.001). No statistical differences in GL were found between the studied years. This study shows the influence of certain stallion on GL.

Seasonal changes in water metabolism of Sudan desert sheep and goats

International Nuclear Information System (INIS)

El Hadi, H.M.; Hassan, Y.M.

1982-01-01

Seasonal changes that occur in body weight, body temperature, total body water and water turnover were investigated in grazing sheep and goats at different times of the year to understand how different breeds adapt to the environmental conditions in Sudan. (author)

Effect of season on reproductive behaviors and fertilization success in cavies (Cavia aperea).

Science.gov (United States)

Hribal, Romy; Rübensam, Kathrin; Bernhardt, Sandra; Jewgenow, Katarina; Guenther, Anja

2018-04-05

Finding the optimal timing for breeding is crucial for small mammals to ensure survival and maximize lifetime reproductive success. Species living in temperate regions therefore often restrict breeding to seasons with favorable food and weather conditions. Although caviomorph rodents such as guinea pigs are described as non-seasonal breeders, a series of recent publications has shown seasonal adaptations in litter size, offspring birth mass and maternal investment. Here, we aim to test if seasonal patterns of litter size variation found in earlier studies, are mediated by seasonal differences in female estrus length, fertilization rate and mating behavior. The female estrus period was longer in fall compared to all other seasons (p < 0.001), frequently lasting 7-9 days while estrus in spring usually lasted less than 2 days. In fall, females mated later during estrus (p < 0.001), resulting in reduced fertilization rates (p < 0.001). Fertilization rate was well above 95% in summer while it dropped to less than 85% in fall and winter. While none of the male mating characteristics such as number and duration of copulations differed across seasons, the number of mating bouts was reduced in fall (p = 0.04). Finally, the developmental stages of flushed embryos were more diverse in spring and summer compared to fall and winter. These results suggest that seasonal differences in fertilization rate and quality of implanted embryos are mediated by female estrus length and timing and intensity of mating behavior. Together, these effects contribute to the observed differences in litter size across seasons. Copyright © 2018 Elsevier Inc. All rights reserved.

Análise bioeconômica da introdução de período de monta em sistemas de produção de rebanhos de cria na região do Brasil Central Bioeconomic analysis of breeding season introduction in productive systems of beef herd in Brazil Central region

Directory of Open Access Journals (Sweden)

Urbano Gomes Pinto de Abreu

2003-10-01

Full Text Available Utilizando modelo de simulação bioeconômico de produção de bovinos de corte, foram analisados quatro efeitos decorrentes da implantação de período de monta (PM no sistema de produção de bovinos de corte na fase de cria. Os efeitos foram: redução da taxa de mortalidade de bezerros de 10 para 4% (efeito A; redução na relação touro:vaca de 1:25 para 1:33 (efeito B; aumento da taxa de natalidade das vacas de 65 para 75% (efeito C; e redução na mão-de-obra permanente de vaqueiros (efeito D. Através destes efeitos foram simulados cinco cenários. O aumento percentual do valor presente líquido anual (VPL calculado a partir da receita líquida, e da margem bruta (MB anual, de toda atividade, em relação ao cenário sem estabelecimento de PM (cenário 1, ao final de seis anos de simulações, foram estimados em 7,64 e 7,68%; 12,91 e 13,84%; 25,36 e 25,25%; e 30,39 e 31,31%, respectivamente. A implementação de PM proporcionou melhoria substancial na economicidade e na eficiência biológica do sistema, sendo o aumento da taxa de natalidade o efeito de maior impacto positivo na atividade. Os efeitos acumulados da implantação de PM aumentaram a margem bruta anual da atividade em 31%.Four effects related to the establishment of breeding season in production systems were analysed using a bioeconomic simulation model arise from implantation of breeding season in production systems. The effects were: decrease calf's mortality rate (10 to 4% (effect A; reduction of bulls:cows relation from 1:25 to 1:33 (effect B; increase reproduction of cows (65 to 75% (effect C; and reduction of herdsman number (effect D. With these effects were five scenery. The rate increase of present net value and brute margin, in relation to scenery without breeding season (scenery one were respectively 7.64 and 7.68%; 12,91 and 13.84%; 25.36 and 25.25%; and 30.39 and 31.31%. The breeding season implementation provided increase in economical and biological

Normal and seasonally amplified indoor radon levels

International Nuclear Information System (INIS)

Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; King, D.

1995-01-01

Winter and summer indoor radon measurements are reported for 121 houses in Freehold, New Jersey. When presented as winter:summer ratios of indoor radon, the data closely approximate a lognormal distribution. The geometric mean is 1.49. Freehold is located on the fairly flat coastal plain. The winter:summer ratios are believed to represent the norm for regions of the U.S. with cold winters and hot summers. The Freehold data set can be compared to corresponding data sets from other locations to suggest seasonal perturbations of indoor radon arising from unusual causes

Plasma progesterone profiles, ovulation rate, donor embryo yield and recipient embryo survival in native Saloia sheep in the fall and spring breeding seasons.

Science.gov (United States)

Chagas e Silva, J; Lopes da Costa, L; Cidadão, R; Robalo Silva, J

2003-08-01

The response to superovulatory (SOV) and estrus synchronization (ES) treatments and the fertility of donor (n=68) and recipient (n=118) Saloia ewes was evaluated in the fall and spring breeding seasons. The proportion of acyclic ewes at treatment time was significantly higher in the spring than in the fall (42.6% versus 4.0%, P<0.00001). Donors treated with eCG had a significantly higher mean number of follicles over 5mm in diameter in the ovaries at embryo recovery and a significantly lower mean efficiency of recovery than FSH-treated ewes. These negative effects were more pronounced in the fall than in the spring, which resulted in a significantly lower mean number of total and fertilized ova recovered from eCG-treated ewes, compared to FSH donors in the fall, but not in the spring. Season had no significant effect on the ovulation rate and plasma P4 concentrations of recipients treated with a progestagen plus eCG combination. Although the recipient lambing and embryo survival rates were higher in the fall than in the spring the differences were not significant. No significant differences were observed in the ovulation rate or P4 concentrations of recipients that lambed compared to those that did not lamb. These preliminary results show that, in Portugal, response of Saloia ewes to SOV or ES treatments and donor fertility following the SOV treatment were similar in the spring and the fall, which suggests that in the spring acyclic ewes are in moderate anestrus. The effect of season on fertility following embryo transfer should be confirmed in further studies involving a larger number of animals. The semilaparoscopic transfer method reported here allowed lambing and embryo survival rates higher (although not significantly) than a standard surgical approach.

Demographic consequences of increased winter births in a large aseasonally breeding mammal (Bos taurus) in response to climate change.

Science.gov (United States)

Burthe, Sarah; Butler, Adam; Searle, Kate R; Hall, Stephen J G; Thackeray, Stephen J; Wanless, Sarah

2011-11-01

1. Studies examining changes in the scheduling of breeding in response to climate change have focused on species with well-defined breeding seasons. Species exhibiting year-round breeding have received little attention and the magnitudes of any responses are unknown. 2. We investigated phenological data for an enclosed feral population of cattle (Bos taurus L.) in northern England exhibiting year-round breeding. This population is relatively free of human interference. 3. We assessed whether the timing of births had changed over the last 60 years, in response to increasing winter and spring temperatures, changes in herd density, and a regime of lime fertilisation. 4. Median birth date became earlier by 1·0 days per year. Analyses of the seasonal distribution of calving dates showed that significantly fewer calves were born in summer (decline from 44% of total births to 20%) and significantly more in winter (increase from 12% to 30%) over the study period. The most pronounced changes occurred in winter, with significant increases in both the proportion and number of births. Winter births arise from conceptions in the previous spring, and we considered models that investigated climate and weather variables associated with the winter preceding and the spring of conceptions. 5. The proportion of winter births was higher when the onset of the plant growing season was earlier during the spring of conceptions. This relationship was much weaker during years when the site had been fertilised with lime, suggesting that increased forage biomass was over-riding the impacts of changing plant phenology. When the onset of the growing season was late, winter births increased with female density. 6. Recruitment estimates from a stage-structured state-space population model were significantly negatively correlated with the proportion of births in the preceding winter, suggesting that calves born in winter are less likely to survive than those born in other seasons. 7.�

The impact of fish and drought on frog breeding in temporary waters ...

African Journals Online (AJOL)

The breeding of frogs in four ponds near Harare, Zimbabwe, was investigated during a wet rainy season (2000/01) and a dry one (2001/02). During 2000/01 eight and nine species bred in two ponds in abandoned gravel pits that never contained fish, but only four species bred in these in 2001/02 and the relative abundance ...

Keeping and breeding the rescued Sunda pangolins (Manis javanica) in captivity.

Science.gov (United States)

Zhang, Fuhua; Yu, Jiaming; Wu, Shibao; Li, Shaoshan; Zou, Cuiyun; Wang, Qiaoyun; Sun, Ruyong

2017-12-01

The Sunda pangolin (Manis javanica Desmarest, 1822) is a Critically Endangered species. Given that this species lacks effective policies for in situ conservation and prevention of poaching in the wild, ex situ conservation and a captive breeding program are urgently needed to save this species from extinction. However, techniques for the maintenance and captive breeding of pangolins have not been well developed. In June 2010, we established the Pangolin Research Base for Artificial Rescue and Conservation Breeding of South China Normal University (PRB-SCNU). To date, a total of 34 Sunda pangolin cubs have been born at PRB-SCNU, 26 of which were captive bred, indicating great progress in keeping and breeding the Sunda pangolin. The techniques for maintenance-including housing, transitioning to an artificial diet, husbandry, and captive breeding-are described in this paper. The purpose of this manuscript is to share our successful experiences and techniques in the maintenance, management, and captive breeding of Sunda pangolins, and to provide guidance and a reference for the captive care and management of Sunda pangolins and other pangolin species. © 2017 Wiley Periodicals, Inc.

Use of radioimmunoassay techniques to study the effects of nutritional status and breed on reproductive performance of goats

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, N; Carmenate, C; Pedroso, R; Perez, L O; Alvarez, T R; Gonzalez, N; Felipe, N; Bravo, M [Centro de Investigaciones para el Mejoramiento Animal, Havana (Cuba)

1996-05-01

Goats from 2-5 years old in 15 herds of four breeds, (Saanen, Nubian, Toggenburg and Alpine), were used in three experiments to determine reproductive behaviour (Experiment 1), metabolic profile (Experiment 2) and fertility of induced and synchronized oestrus (Experiment 3). Season, breed and physiological status were significant factors affecting reproductive behaviour and metabolic status (P<0.05). The principal causes of infertility in induced oestrus were failures in conception, early embryonic mortality and anovulatory oestrus. The herds had long intervals from birth to first insemination (306-458 days) and to first pregnancy (471-511 days), and low fertility (14-31%). The breeding patter was similar to breeds in temperate zones. Energy and mineral imbalances were found. Further research is necessary to improve reproductive performance of these breeds under tropical conditions. (author). 25 refs, 3 figs, 4 tabs.

Nest trampling and ground nesting birds: Quantifying temporal and spatial overlap between cattle activity and breeding redshank.

Science.gov (United States)

Sharps, Elwyn; Smart, Jennifer; Mason, Lucy R; Jones, Kate; Skov, Martin W; Garbutt, Angus; Hiddink, Jan G

2017-08-01

Conservation grazing for breeding birds needs to balance the positive effects on vegetation structure and negative effects of nest trampling. In the UK, populations of Common redshank Tringa totanus breeding on saltmarshes declined by >50% between 1985 and 2011. These declines have been linked to changes in grazing management. The highest breeding densities of redshank on saltmarshes are found in lightly grazed areas. Conservation initiatives have encouraged low-intensity grazing at nest trampling. If livestock distribution is not spatially or temporally homogenous but concentrated where and when redshank breed, rates of nest trampling may be much higher than expected based on livestock density alone. By GPS tracking cattle on saltmarshes and monitoring trampling of dummy nests, this study quantified (i) the spatial and temporal distribution of cattle in relation to the distribution of redshank nesting habitats and (ii) trampling rates of dummy nests. The distribution of livestock was highly variable depending on both time in the season and the saltmarsh under study, with cattle using between 3% and 42% of the saltmarsh extent and spending most their time on higher elevation habitat within 500 m of the sea wall, but moving further onto the saltmarsh as the season progressed. Breeding redshank also nest on these higher elevation zones, and this breeding coincides with the early period of grazing. Probability of nest trampling was correlated to livestock density and was up to six times higher in the areas where redshank breed. This overlap in both space and time of the habitat use of cattle and redshank means that the trampling probability of a nest can be much higher than would be expected based on standard measures of cattle density. Synthesis and applications : Because saltmarsh grazing is required to maintain a favorable vegetation structure for redshank breeding, grazing management should aim to keep livestock away from redshank nesting habitat between mid

Epidemic spread in coupled populations with seasonally varying migration rates

Science.gov (United States)

Muzyczyn, Adam; Shaw, Leah B.

2009-03-01

The H5N1 strain of avian influenza has spread worldwide, and this spread may be due to seasonal migration of birds and mixing of birds from different regions in the wintering grounds. We studied a multipatch model for avian influenza with seasonally varying migration rates. The bird population was divided into two spatially distinct patches, or subpopulations. Within each patch, the disease followed the SIR (susceptible-infected-recovered) model for epidemic spread. Migration rates were varied periodically, with a net flux toward the breeding grounds during the spring and towards the wintering grounds during the fall. The case of two symmetric patches reduced to single-patch SIR dynamics. However, asymmetry in the birth and contact rates in the breeding grounds and wintering grounds led to bifurcations to longer period orbits and chaotic dynamics. We studied the bifurcation structure of the model and the phase relationships between outbreaks in the two patches.

Corticosterone mediated costs of reproduction link current to future breeding.

Science.gov (United States)

Crossin, Glenn T; Phillips, Richard A; Lattin, Christine R; Romero, L Michael; Williams, Tony D

2013-11-01

Life-history theory predicts that costs are associated with reproduction. One possible mediator of costs involves the secretion of glucocorticoid hormones, which in birds can be measured in feathers grown during the breeding period. Glucocorticoids mediate physiological responses to unpredictable environmental or other stressors, but they can also function as metabolic regulators during more predictable events such as reproduction. Here we show that corticosterone ("Cort") in feathers grown during the breeding season reflects reproductive effort in two Antarctic seabird species (giant petrels, Macronectes spp.). In females of both species, but not males, feather Cort ("fCort") was nearly 1.5-fold higher in successful than failed breeders (those that lost their eggs/chicks), suggesting a cost of successful reproduction, i.e., high fCort levels in females reflect the elevated plasma Cort levels required to support high metabolic demands of chick-rearing. Successful breeding also led to delayed moult prior to winter migration. The fCort levels and pre-migration moult score that we measured at the end of current breeding were predictive of subsequent reproductive effort in the following year. Birds with high fCort and a delayed initiation of moult were much more likely to defer breeding in the following year. Cort levels and the timing of moult thus provide a potential mechanism for the tradeoff between current and future reproduction. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Breeding for high production of leaves of baobab (Adansonia digitata L) in an irrigated hedge system

DEFF Research Database (Denmark)

Korbo, Adama; Kjær, Erik Dahl; Sanou, Haby

2013-01-01

evaluated monthly from the third month after establishment. We found lowered leaf productivity during the dry season despite the plants being irrigated. We provide the first estimates of heritability for leaf production and growth of the species. We assumed that the families of seed from open...... was not significantly different among provenances or families within provenances. Based on the findings, we discuss how breeding can increase the total leaf production and its seasonal distribution....

Density and climate influence seasonal population dynamics in an Arctic ungulate

DEFF Research Database (Denmark)

Mortensen, Lars O.; Moshøj, Charlotte; Forchhammer, Mads C.

2016-01-01

The locally migratory behavior of the high arctic muskox (Ovibos muschatus) is a central component of the breeding and winter survival strategies applied to cope with the highly seasonal arctic climate. However, altered climate regimes affecting plant growth are likely to affect local migration...... cover), forage availability (length of growth season), and the number of adult females available per male (operational sex ratio) influence changes in the seasonal density dependence, abundance, and immigration rate of muskoxen into the valley. The results suggested summer temperature as the major...... controlling factor in the seasonal, local-scale migration of muskoxen at Zackenberg. Specifically, higher summer temperatures, defined as the cumulative average daily positive degrees in June, July, and August, resulted in decreased density dependence and, consequently, increase in the seasonal abundance...

Social information in nest colonisation and occupancy in a long-lived, solitary breeding bird.

Science.gov (United States)

Václav, Radovan; Valera, Francisco; Martínez, Teresa

2011-03-01

Recent work increasingly reveals the importance of social information in individual dispersal decisions, population dynamics and conservation. Much of the knowledge gained to date comes from studies on short-lived and/or densely breeding species. In contrast, our understanding of the processes involved in nest-site selection for long-lived, solitary breeding species is insufficient. We increased nest-site availability by nest-box supplementation over a 5-year period in a population of a long-lived, solitary, secondary-cavity nesting bird, the European roller Coracias garrulus, breeding in natural cavities and human constructions. We tested the nest limitation and the inadvertent conspecific social information hypothesis in order to study the dynamics and mechanisms of abandonment of previously used nests and the colonisation of new ones. Our data lend support to the nest-limitation hypothesis both in terms of quantity-population and the size of breeding clusters increased, and suitability--the majority of pairs used and re-occupied nest-boxes. Nevertheless, the use of natural cavities did not decrease after 5 years. At the between-patch scale, rollers were revealed to colonise nest-boxes based on conspecific social attraction, namely distance to the nearest neighbour in the same season. Despite the unpredictability of patch productivity, at the within--patch scale, the selection of previously unoccupied cavities was consistent with the performance-based conspecific attraction hypothesis. Philopatry could account for the repeated use of cavities, because nests that were used for two successive years were more likely to also be reused in the subsequent season.

Estimating breeding season abundance of golden-cheeked warblers in Texas, USA

KAUST Repository

Mathewson, Heather A.

2012-02-15

Population abundance estimates using predictive models are important for describing habitat use and responses to population-level impacts, evaluating conservation status of a species, and for establishing monitoring programs. The golden-cheeked warbler (Setophaga chrysoparia) is a neotropical migratory bird that was listed as federally endangered in 1990 because of threats related to loss and fragmentation of its woodland habitat. Since listing, abundance estimates for the species have mainly relied on localized population studies on public lands and qualitative-based methods. Our goal was to estimate breeding population size of male warblers using a predictive model based on metrics for patches of woodland habitat throughout the species\\' breeding range. We first conducted occupancy surveys to determine range-wide distribution. We then conducted standard point-count surveys on a subset of the initial sampling locations to estimate density of males. Mean observed patch-specific density was 0.23 males/ha (95% CI = 0.197-0.252, n = 301). We modeled the relationship between patch-specific density of males and woodland patch characteristics (size and landscape composition) and predicted patch occupancy. The probability of patch occupancy, derived from a model that used patch size and landscape composition as predictor variables while addressing effects of spatial relatedness, best predicted patch-specific density. We predicted patch-specific densities as a function of occupancy probability and estimated abundance of male warblers across 63,616 woodland patches accounting for 1.678 million ha of potential warbler habitat. Using a Monte Carlo simulation, our approach yielded a range-wide male warbler population estimate of 263,339 (95% CI: 223,927-302,620). Our results provide the first abundance estimate using habitat and count data from a sampling design focused on range-wide inference. Managers can use the resulting model as a tool to support conservation planning

[Identification of anopheles breeding sites in the residual foci of low malaria transmission «hotspots» in Central and Western Senegal].

Science.gov (United States)

Sy, O; Konaté, L; Ndiaye, A; Dia, I; Diallo, A; Taïrou, F; Bâ, E L; Gomis, J F; Ndiaye, J L; Cissé, B; Gaye, O; Faye, O

2016-02-01

Malaria incidence has markedly declined in the Mbour, Fatick, Niakhar and Bambey districts (central and western Senegal) thanks to a scaling up of effective control measures namely LLINs (Long Lasting Insecticide Treated Net), ACTs (Artesunate Combination Therapy) and promoting care seeking. However malaria cases are now maintained by foci of transmission called hotspots. We evaluate the role of anopheles breeding sites in the identification of malaria hotspots in the health districts of Mbour, Fatick, Niakhar and Bambey. Surveys of breeding sites were made in 6 hotspot villages and 4 non-hotspot villages. A sample was taken in each water point with mosquito larvae by dipping method and the collected specimens were identified to the genus level. Additional parameters as name of the village and breeding sites, type of collection, original water turbidity, presence of vegetation, proximity to dwellings, geographic coordinates, sizes were also collected. Sixty-two water collections were surveyed and monitored between 2013 and 2014. Temporary natural breeding sites were predominant regardless of the epidemiological status of the village. Among the 31 breeding sites located within 500 meters of dwellings in hotspots villages, 70% carried Anopheles larvae during the rainy season while 43% of the 21 breeding sites located at similar distances in non-hotspot villages carried Anopheles larvae during the same period (P = 0.042). At the end of the rainy season, the trend is the same with 27% of positive breeding sites in hotspots and 14% in non-hotspots villages. The breeding sites encountered in hotspots villages are mostly small to medium size and are more productive by Anopheles larvae than those found in non-hotspot area. This study showed that the high frequency of smallest and productive breeding sites around and inside the villages can create conditions of residual transmission.

Reproductive performance and mortality rate in Menz and Horro sheep following controlled breeding in Ethiopia

NARCIS (Netherlands)

Berhan, A.; Arendonk, van J.A.M.

2006-01-01

The reproductive and lamb mortality data (n = 4890) of Horro and Menz ewes following controlled breeding in Ethiopia were analyzed. Sheep were treated with flugestone acetate (FGA) intravaginal sponges during the wet and dry seasons to compare the reproductive performance of the two indigenous

KASPTM genotyping technology and its use in gene­tic-breeding programs (a study of maize

Directory of Open Access Journals (Sweden)

Н. Е. Волкова

2017-06-01

Full Text Available Purpose. To review publications relating to the key point of the genotyping technology that is competitive allele-specific polymerase chain reaction (which is called now Kompetitive Allele Specific PCR, KASPTM and its use in various genetic-breeding researching (a study of maize. Results. The essence of KASP-genotyping, its advantages are highlighted. The requirements for matrix DNA are presented, since the success of the KASP-analysis depends on its qua­lity and quantity. Examples of global projects of plant breeding for increasing crop yields using the KASP genoty­ping technology are given. The results of KASP genotyping and their introduction into breeding and seed production, in particular, for determining genetic identity, genetic purity, origin check, marker-assisted selection, etc. are presented using maize as an example. It is demonstrated how geno­mic selection according to KASP genotyping technology can lead to rapid genetic enhancement of drought resistance in maize. Comparison of the effectiveness of creating lines with certain traits (for example, combination of high grain yield and drought resistance using traditional breeding approaches (phenotype selection and molecular genetic methods (selection by markers was proved that it takes four seasons (two years in case of greenhouses in order to unlock the potential of the plant genotype using traditional self-pollination, test-crossing and definitions, while using markers, the population was enriched with target alleles during one season. At the same time, there was no need for a stress factor. Conclusions. KASP genotyping technology is a high-precision and effective tool for modern genetics and breeding, which is successfully used to study genetic diversity, genetic relationship, population structure, gene­tic identity, genetic purity, origin check, quantitative locus mapping, allele mapping, marker-assisted selection, marker-assisted breeding. It is expedient and timely to

Apricot Breeding Studies and New Varieties in Turkey

Directory of Open Access Journals (Sweden)

Bayram Murat Asma

2017-11-01

Full Text Available Apricot, with high contents of vitamin A and dietary fiber, is one of most popular summer fruit with its attractive color, flavor and aroma. Losses caused by late spring frosts, poor adaptation to different climatic conditions, short serving time of fresh apricot to the market, Sharka and Monilia diseases effect on fruits are the main problems of apricot production. In addition, due mainly to rapid change in consumer preferences, the demand for new varieties with different color, size, flavor and aroma is increased. A significant part of the apricot breeding program is concentrated in the northern hemisphere with leading countries of USA (74 varieties and France (70 varieties. Meanwhile, only 11 varieties were registered in Turkey. Seven of these varieties (Alata Yıldızı, Çağataybey, Çağrıbey, Dr. Kaşka, Şahinbey, Dilbay and Eylül were bred with crossbreeding techniques and others with selection methods. Alkaya suits to both drying and fresh consumption. Eylül and Mihralibey are late ripening varieties, and others are early or mid-season ripening varieties. In this paper, apricot breeding studies in Turkey are discussed considering their contents and breeding methods, and results of those studies were summarized.

Predictors of breeding site occupancy by amphibians in montane landscapes

Science.gov (United States)

Groff, Luke A.; Loftin, Cynthia S.; Calhoun, Aram J.K.

2017-01-01

Ecological relationships and processes vary across species’ geographic distributions, life stages and spatial, and temporal scales. Montane landscapes are characterized by low wetland densities, rugged topographies, and cold climates. Consequently, aquatic-dependent and low-vagility ectothermic species (e.g., pool-breeding amphibians) may exhibit unique ecological associations in montane landscapes. We evaluated the relative importance of breeding- and landscape-scale features associated with spotted salamander (Ambystoma maculatum) and wood frog (Lithobates sylvaticus) wetland occupancy in Maine's Upper Montane-Alpine Zone ecoregion, and we determined whether models performed better when the inclusive landscape-scale covariates were estimated with topography-weighted or circular buffers. We surveyed 135 potential breeding sites during May 2013–June 2014 and evaluated environmental relationships with multi-season implicit dynamics occupancy models. Breeding site occupancy by both species was influenced solely by breeding-scale habitat features. Spotted salamander occupancy probabilities increased with previous or current beaver (Castor canadensis) presence, and models generally were better supported when the inclusive landscape-scale covariates were estimated with topography-weighted rather than circular buffers. Wood frog occupancy probabilities increased with site area and percent shallows, but neither buffer type was better supported than the other. Model rank order and support varied between buffer types, but model inferences did not. Our results suggest pool-breeding amphibian conservation in montane Maine include measures to maintain beaver populations and large wetlands with proportionally large areas of shallows ≤1-m deep. Inconsistencies between our study and previous studies substantiate the value of region-specific research for augmenting species’ conservation management plans and suggest the application of out-of-region inferences may promote

Defining global neuroendocrine gene expression patterns associated with reproductive seasonality in fish.

Directory of Open Access Journals (Sweden)

Dapeng Zhang

Full Text Available BACKGROUND: Many vertebrates, including the goldfish, exhibit seasonal reproductive rhythms, which are a result of interactions between external environmental stimuli and internal endocrine systems in the hypothalamo-pituitary-gonadal axis. While it is long believed that differential expression of neuroendocrine genes contributes to establishing seasonal reproductive rhythms, no systems-level investigation has yet been conducted. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, by analyzing multiple female goldfish brain microarray datasets, we have characterized global gene expression patterns for a seasonal cycle. A core set of genes (873 genes in the hypothalamus were identified to be differentially expressed between May, August and December, which correspond to physiologically distinct stages that are sexually mature (prespawning, sexual regression, and early gonadal redevelopment, respectively. Expression changes of these genes are also shared by another brain region, the telencephalon, as revealed by multivariate analysis. More importantly, by examining one dataset obtained from fish in October who were kept under long-daylength photoperiod (16 h typical of the springtime breeding season (May, we observed that the expression of identified genes appears regulated by photoperiod, a major factor controlling vertebrate reproductive cyclicity. Gene ontology analysis revealed that hormone genes and genes functionally involved in G-protein coupled receptor signaling pathway and transmission of nerve impulses are significantly enriched in an expression pattern, whose transition is located between prespawning and sexually regressed stages. The existence of seasonal expression patterns was verified for several genes including isotocin, ependymin II, GABA(A gamma2 receptor, calmodulin, and aromatase b by independent samplings of goldfish brains from six seasonal time points and real-time PCR assays. CONCLUSIONS/SIGNIFICANCE: Using both

Seasonal variation and annual trends of metals and metalloids in the blood of the Little Penguin (Eudyptula minor).

Science.gov (United States)

Finger, Annett; Lavers, Jennifer L; Orbell, John D; Dann, Peter; Nugegoda, Dayanthi; Scarpaci, Carol

2016-09-15

Little Penguins (Eudyptula minor) are high-trophic coastal feeders and are effective indicators of bioavailable pollutants in their foraging zones. Here, we present concentrations of metals and metalloids in blood of 157 Little Penguins, collected over three years and during three distinct seasons (breeding, moulting and non-breeding) at two locations: the urban St Kilda colony and the semi-rural colony at Phillip Island, Victoria, Australia. Penguin metal concentrations were foremostly influenced by location (St Kilda>Phillip Island for non-essential elements) and differed among years and seasons at both locations, reflecting differences in seasonal metal bioaccumulation or seasonal exposure through prey. Mean blood mercury concentrations showed an increasing annual trend and a negative correlation with flipper length at St Kilda. Notably, this study is the first to report on blood metal concentrations during the different stages of moult, showing the mechanism of non-essential metal mobilisation and detoxification. Copyright © 2016 Elsevier Ltd. All rights reserved.

El Grupo Cerúleo: Cooperation for Non-breeding Season Conservation of the Cerulean Warbler

Science.gov (United States)

David Mehlman; Paul. Hamel

2010-01-01

Without collaboration, conservation is impossible for long-distance migrants such as the Cerulean Warbler, a declining forest breeding bird in North America that overwinters in the Andes Mountains of South America. The Cerulean Warbler, one of the fastest declining woodland birds of eastern North America, is considered Vulnerable by BirdLife international, in the...

Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil's Atlantic Forest.

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Rodrigo B Ferreira

Full Text Available Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i 200 m inside the forest, ii 50 m inside the forest, iii at the forest edge, and iv 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types. By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog

Breeding Guild Determines Frog Distributions in Response to Edge Effects and Habitat Conversion in the Brazil's Atlantic Forest.

Science.gov (United States)

Ferreira, Rodrigo B; Beard, Karen H; Crump, Martha L

2016-01-01

Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil's Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i) 200 m inside the forest, ii) 50 m inside the forest, iii) at the forest edge, and iv) 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types). By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders) was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH > 15 cm) and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in

Breeds of cattle

NARCIS (Netherlands)

Buchanan, David S.; Lenstra, Johannes A.

2015-01-01

This chapter gives an overview on the different breeds of cattle (Bos taurus and B. indicus). Cattle breeds are presented and categorized according to utility and mode of origin. Classification and phylogeny of breeds are also discussed. Furthermore, a description of cattle breeds is provided.

Body live weight and milk production parameters in the Majorera and Palmera goat breeds from the Canary Islands: influence of weight loss

DEFF Research Database (Denmark)

Lérias, Joana R; Hernandez Castellano, Lorenzo E; Morales-delaNuez, Antonio

2013-01-01

Seasonal weight loss (SWL), caused by poor quality pastures during the dry season, is the major limitation to animal production in the tropics. One of the ways to counter this problem is to breed animals that show tolerance to SWL. The objective of this study was to understand the effect of feed ...

Factors influencing the movements during the breeding season of a female booted eagle (Aquila pennata tagged by satellite in central Catalonia (Spain

Directory of Open Access Journals (Sweden)

Bosch Josep

2016-12-01

Full Text Available Foraging movements during the breeding season are a poorly studied aspect of booted eagle behaviour. We have investigated the relationship between weather and other abiotic factors and foraging behaviour, and also resource use by a female booted eagle, tagged by satellite-GPS transmitter in central Catalonia, during summer 2012 and spring 2013. Generalized Linear Models (GLMs revealed that the distance travelled from the nest was significantly related to temperature, but also to the time of day and the age of chicks. Temperature also had a significant positive influence on flight altitude and the latter on flight speed. The Resource Utilization Function (RUF showed significant resource use in locations close to water (rivers and water bodies and also in agricultural areas, preferably close to urban areas and rivers. On the other hand, unlike in other areas of Spain, the use of the edges between forest and agricultural areas and forest areas themselves showed negative coefficients with values not significant, perhaps related to changes in prey availability in the traditional hunting grounds.

Home Range Size and Resource Use of Breeding and Non-breeding White Storks Along a Land Use Gradient

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Damaris Zurell

2018-06-01

Full Text Available Biotelemetry is increasingly used to study animal movement at high spatial and temporal resolution and guide conservation and resource management. Yet, limited sample sizes and variation in space and habitat use across regions and life stages may compromise robustness of behavioral analyses and subsequent conservation plans. Here, we assessed variation in (i home range sizes, (ii home range selection, and (iii fine-scale resource selection of white storks across breeding status and regions and test model transferability. Three study areas were chosen within the Central German breeding grounds ranging from agricultural to fluvial and marshland. We monitored GPS-locations of 62 adult white storks equipped with solar-charged GPS/3D-acceleration (ACC transmitters in 2013–2014. Home range sizes were estimated using minimum convex polygons. Generalized linear mixed models were used to assess home range selection and fine-scale resource selection by relating the home ranges and foraging sites to Corine habitat variables and normalized difference vegetation index in a presence/pseudo-absence design. We found strong variation in home range sizes across breeding stages with significantly larger home ranges in non-breeding compared to breeding white storks, but no variation between regions. Home range selection models had high explanatory power and well predicted overall density of Central German white stork breeding pairs. Also, they showed good transferability across regions and breeding status although variable importance varied considerably. Fine-scale resource selection models showed low explanatory power. Resource preferences differed both across breeding status and across regions, and model transferability was poor. Our results indicate that habitat selection of wild animals may vary considerably within and between populations, and is highly scale dependent. Thereby, home range scale analyses show higher robustness whereas fine-scale resource

Genomic Tools in Pea Breeding Programs: Status and Perspectives

Science.gov (United States)

Tayeh, Nadim; Aubert, Grégoire; Pilet-Nayel, Marie-Laure; Lejeune-Hénaut, Isabelle; Warkentin, Thomas D.; Burstin, Judith

2015-01-01

Pea (Pisum sativum L.) is an annual cool-season legume and one of the oldest domesticated crops. Dry pea seeds contain 22–25% protein, complex starch and fiber constituents, and a rich array of vitamins, minerals, and phytochemicals which make them a valuable source for human consumption and livestock feed. Dry pea ranks third to common bean and chickpea as the most widely grown pulse in the world with more than 11 million tons produced in 2013. Pea breeding has achieved great success since the time of Mendel's experiments in the mid-1800s. However, several traits still require significant improvement for better yield stability in a larger growing area. Key breeding objectives in pea include improving biotic and abiotic stress resistance and enhancing yield components and seed quality. Taking advantage of the diversity present in the pea genepool, many mapping populations have been constructed in the last decades and efforts have been deployed to identify loci involved in the control of target traits and further introgress them into elite breeding materials. Pea now benefits from next-generation sequencing and high-throughput genotyping technologies that are paving the way for genome-wide association studies and genomic selection approaches. This review covers the significant development and deployment of genomic tools for pea breeding in recent years. Future prospects are discussed especially in light of current progress toward deciphering the pea genome. PMID:26640470

Genomic tools in pea breeding programs: status and perspectives

Directory of Open Access Journals (Sweden)

Nadim eTAYEH

2015-11-01

Full Text Available Pea (Pisum sativum L. is an annual cool-season legume and one of the oldest domesticated crops. Dry pea seeds contain 22-25 percent protein, complex starch and fibre constituents and a rich array of vitamins, minerals, and phytochemicals which make them a valuable source for human consumption and livestock feed. Dry pea ranks third to common bean and chickpea as the most widely grown pulse in the world with more than 11 million tonnes produced in 2013. Pea breeding has achieved great success since the time of Mendel’s experiments in the mid-1800s. However, several traits still require significant improvement for better yield stability in a larger growing area. Key breeding objectives in pea include improving biotic and abiotic stress resistance and enhancing yield components and seed quality. Taking advantage of the diversity present in the pea genepool, many mapping populations have been constructed in the last decades and efforts have been deployed to identify loci involved in the control of target traits and further introgress them into elite breeding materials. Pea now benefits from next-generation sequencing and high-throughput genotyping technologies that are paving the way for genome-wide association studies and genomic selection approaches. This review covers the significant development and deployment of genomic tools for pea breeding in recent years. Future prospects are discussed especially in light of current progress towards deciphering the pea genome.

Foraging plasticity of breeding Northern Rockhopper Penguins, Eudyptes moseleyi, in response to changing energy requirements

KAUST Repository

Booth, Jenny Marie

2018-04-02

During the breeding season, seabirds must balance the changing demands of self- and off-spring provisioning with the constraints imposed by central-place foraging. Recently, it was shown that Northern Rockhopper Penguins at Tristan da Cunha in the South Atlantic Ocean switch diet from lower to higher trophic level prey throughout their breeding cycle. Here, we investigated if this switch is reflected in their foraging behaviour, using time-depth recorders to study the diving behaviour of 27 guard and 10 crèche birds during the breeding season 2010 at Tristan da Cunha and obtaining complementary stomach contents of 20 birds. While no significant effects of breeding stage were detected on any foraging trip or dive parameters, stage/prey had a significant effect on feeding dive parameters, with dive duration, bottom time, and maximum depth explaining the majority of the dissimilarity amongst categories. We verified the previously shown dietary shift from zooplankton and cephalopods during the guard stage to a higher-energy fish-based diet during the crèche stage, which was reflected in a change in dive behaviour from shorter, shallower to longer, deeper dives. This prey switching behaviour may reflect preferential selection to account for the increased physiological needs of chicks or simply mirror changes in local prey abundance. Nonetheless, we show that Northern Rockhopper Penguins demonstrate behavioural plasticity as a response to their changing energy requirements, which is a critical trait when living in a spatio-temporally heterogeneous environment. This ability is likely to be particularly important under extrinsic constraints such as long-term environmental change.

Seasonal variation in the range areas of the diurnal rodent Octodon degus.

Science.gov (United States)

Quirici, Verónica; Castro, Rodrigo A; Ortiz-Tolhuysen, Liliana; Chesh, Adrian S; Burger, Joseph Robert; Miranda, Eduardo; Cortés, Arturo; Hayes, Loren D; Ebensperger, Luis A

2010-01-01

Both breeding activity and abundance and quality of available food are expected to influence daily movements of animals. Animals are predicted to range over large areas to meet high energy demands associated with reproduction (females) or to increase mating success (males). However, animals should expand their range areas whenever food conditions deteriorate. To examine the extent to which breeding activity versus food availability influence space use, we compared the size and location of range areas (home ranges) of the degu (Octodon degus), a diurnal rodent from semiarid environments of north-central Chile, during the austral winter and summer seasons. Degus produce young during the austral spring (September-October) when high-quality food is readily available. In contrast, degus do not breed during the austral summer (January-March) when food is scarce and of low quality. We predicted that degus would range over smaller areas in winter if the availability of food has a greater influence on space than breeding activity. Individuals were radiotracked in winter and the following summer over a 3-year period. Surveys of herbaceous cover were conducted during winter and summer to determine seasonal changes in the abundance and quality of primary food. In summer degus expanded and moved the location of their range areas to locations with available food. Given that preferred food was less abundant in summer than winter, we suggest that degu range areas are strongly influenced by food conditions.

Impact of mutation breeding in rice

International Nuclear Information System (INIS)

Rutger, J.N.

1992-01-01

More cultivars have been developed in rice through the use of mutation breeding than in any other crop. Direct releases of mutants as cultivars began some 30 years ago, and now total 198 cultivars. During the last 20 years, increasing use has been made of induced mutants in cross-breeding programs, leading to 80 additional cultivars. Principal improvements through mutation breeding have been earlier maturity, short stature, and grain character modifications. Rice has been a popular subject of mutagenesis because it is the world's leading food crop, has diploid inheritance, and is highly self-pollinated. In recent years induced mutation has been exploited to develop breeding tool mutants, which are defined as mutants that in themselves may not have direct agronomic application but may be useful genetic tools for crop improvement. Examples include the eui gene, hull colour mutants, normal genetic male steriles, and environmentally sensitive genetic male steriles. The environmentally sensitive genetic male steriles, especially those in which male sterility can be turned on or off by different photoperiod lengths, show promise for simplifying hybrid rice seed production both in China and the USA. Future applications of mutation in rice include induction of unusual endosperm starch types, plant types with fewer but more productive tillers, dominant dwarfs, dominant genetic male steriles, extremely early maturing mutants, nutritional mutants, and in vitro-derived mutants for tolerance to herbicides or other growth stresses. Refs, 4 figs, 2 tabs

Transmission of influenza reflects seasonality of wild birds across the annual cycle

Science.gov (United States)

Hill, Nichola J.; Ma, Eric J.; Meixell, Brandt W.; Lindberg, Mark S.; Boyce, Walter M.; Runstadler, Jonathan A.

2016-01-01

Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008–2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality.

Asynchronous changes in phenology of migrating Broad-tailed Hummingbirds and their early-season nectar resources.

Science.gov (United States)

McKinney, Amy M; CaraDonna, Paul J; Inouye, David W; Barr, Billy; Bertelsen, C David; Waser, Nickolas M

2012-09-01

Phenological advancements driven by climate change are especially pronounced at higher latitudes, so that migrants from lower latitudes may increasingly arrive at breeding grounds after the appearance of seasonal resources. To explore this possibility, we compared dates of first arrival of Broad-tailed Hummingbirds (Selasphorus platycercus) to dates of flowering of plants they visit for nectar. Near the southern limit of the breeding range, neither hummingbird arrival nor first flowering dates have changed significantly over the past few decades. At a nearby migration stopover site, first flowering of a major food plant has advanced, but peak flowering has not. Near the northern limit of the breeding range, first and peak flowering of early-season food plants have shifted to earlier dates, resulting in a shorter interval between appearance of first hummingbirds and first flowers. If phenological shifts continue at current rates, hummingbirds will eventually arrive at northern breeding grounds after flowering begins, which could reduce their nesting success. These results support the prediction that migratory species may experience the greatest phenological mismatches at the poleward limits of their migration. A novel hypothesis based on these results posits that the poleward limit for some species may contract toward lower latitudes under continued warming.

Ram and Buck Breeding Soundness Examination

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Ahmed TIBARY

2018-06-01

Full Text Available Male breeding soundness examination (BSE is an important component of sheep and goat farming. BSE is best performed 2 months before the breeding season and is based on clinical and physical examination as well as sperm abnormalities detection. Rams are classified based on physical examination and semen evaluation finding in one of 4 categories: Unsatisfactory, questionable, satisfactory, and excellent. The satisfactory rams will achieve good reproductive performance if joined to ewes at a ratio of 1:50 for 60 days. However exceptional rams are expected to achieve good reproductive performance at a ratio of 1 ram to 100 ewes. For Buck, scrotal circumference should be at least 25 cm for breeds weighing more than 40 kg. Buck is deemed satisfactory breeder if he passes the physical examination, and has an ejaculate with at least 50% progressively motile spermatozoa and less than 30% total sperm abnormalities. This paper reviews factors affecting fertility, sperm production and quality as well as libido and mating ability in the ram. Details of genital examination and semen evaluation and interpretation of results are discussed. Classification of rams according to their reproductive potential is presented. Specific recommendations, when available for the buck, are highlighted. The main genital diseases are presented. The most frequent culling reason for ram is epididymitis due to Brucella ovis. Systematic culling of rams with epididymitis improves flock lambing rates by 10 to 15%. Overall, the examination of the reproductive capacity in the ram and the buck is an important tool for improvement of flocks/herds fertility and prevention of contagious or hereditary diseases.

Abundance and breeding distribution of seabirds in the northern part of the Danco Coast, Antarctic Peninsula

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Mariana A. Juáres

2013-02-01

Full Text Available Seabird abundances and breeding distribution have the potential to serve as ecological indicators. The western Antarctic Peninsula is one of the three sites in the world with the greatest increases in local temperature during the last 50 years. The aim of this study was to monitor the distribution and abundance of breeding populations of seabirds in the northern sector of the Danco Coast, north-west of the Antarctic Peninsula, during the breeding season 2010/11. The birds were the Wilson′s storm petrel (Oceanites oceanicus, South Polar skua (Stercorarius maccormicki, kelp gull (Larus dominicanus, Antarctic tern (Sterna vittata, snowy sheathbill (Chionis alba, chinstrap penguin (Pygoscelis antarctica, southern giant petrel (Macronectes giganteus, gentoo penguin (Pygoscelis papua, Cape petrel (Daption capense and Antarctic shag (Phalacrocorax bransfieldensis. Annual breeding population growth increased in pygoscelids, southern giant petrel and sheathbill, and for the remaining species, breeding population trends were stable. Given that seabird populations can provide valuable information on the conditions of their feeding and nesting environments, this study highlights the need to maintain basics monitoring studies.

QUALITY OF NATIVE EJACULATE IN DOG OUT AND DURING SEXUAL SEASON

OpenAIRE

Kenan Podžo; Nazif Varatanović; Mustafa Podžo; Tarik Mutevelić; Benjamin Čengić

2013-01-01

The seasonal influence, i.e. the influence of climatic changes on the dog semen was investigated. Dog age varied between 2-4. German-shepard-type dog body weight was about 25 kg, and the other mixed breed dogs about 9 kg. All were kept in good zoo-hygienic conditions (sunny, ventilated and dry rooms). Dogs were served ready-made pellet food with the daily meals adjusted to their body mass. Experimental researches were mainly performed before and during the sexual season. Sperm from the dogs w...

"Boldness" in the domestic dog differs among breeds and breed groups.

Science.gov (United States)

Starling, Melissa J; Branson, Nicholas; Thomson, Peter C; McGreevy, Paul D

2013-07-01

"Boldness" in dogs is believed to be one end of the shy-bold axis, representing a super-trait. Several personality traits fall under the influence of this super-trait. Previous studies on boldness in dogs have found differences among breeds, but grouping breeds on the basis of behavioural similarities has been elusive. This study investigated differences in the expression of boldness among dog breeds, kennel club breed groups, and sub-groups of kennel club breed groups by way of a survey on dog personality circulated among Australian dog-training clubs and internet forums and lists. Breed had a significant effect on boldness (F=1.63, numDF=111, denDF=272, ppurpose. Retrievers were significantly bolder than flushing and pointing breeds (Reg. Coef.=2.148; S.E.=0.593; pdogs. Differences in boldness among groups and sub-groups suggest that behavioural tendencies may be influenced by historical purpose regardless of whether that purpose still factors in selective breeding. Copyright © 2013 Elsevier B.V. All rights reserved.

Family living sets the stage for cooperative breeding and ecological resilience in birds.

Directory of Open Access Journals (Sweden)

Michael Griesser

2017-06-01

Full Text Available Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent-offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that favor the evolution of cooperative breeding can be confounded if this process is not considered to include 2 steps. Specifically, phylogenetic linear mixed models show that the formation of families was associated with more productive and seasonal environments, where prolonged parent-offspring associations are likely to be less costly. However, our data show that the subsequent evolution of cooperative breeding was instead linked to environments with variable productivity, where helpers at the nest can buffer reproductive failure in harsh years. The proposed 2-step framework helps resolve current disagreements about the role of environmental forces in the evolution of cooperative breeding and better explains the geographic distribution of this trait. Many geographic hotspots of cooperative breeding have experienced a historical decline in productivity, suggesting that a higher proportion of family-living species could have been able to avoid extinction under harshening conditions through the evolution of cooperative breeding. These findings underscore the importance of considering the potentially different factors that drive different steps in the evolution of complex adaptations.

Family living sets the stage for cooperative breeding and ecological resilience in birds.

Science.gov (United States)

Griesser, Michael; Drobniak, Szymon M; Nakagawa, Shinichi; Botero, Carlos A

2017-06-01

Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent-offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that favor the evolution of cooperative breeding can be confounded if this process is not considered to include 2 steps. Specifically, phylogenetic linear mixed models show that the formation of families was associated with more productive and seasonal environments, where prolonged parent-offspring associations are likely to be less costly. However, our data show that the subsequent evolution of cooperative breeding was instead linked to environments with variable productivity, where helpers at the nest can buffer reproductive failure in harsh years. The proposed 2-step framework helps resolve current disagreements about the role of environmental forces in the evolution of cooperative breeding and better explains the geographic distribution of this trait. Many geographic hotspots of cooperative breeding have experienced a historical decline in productivity, suggesting that a higher proportion of family-living species could have been able to avoid extinction under harshening conditions through the evolution of cooperative breeding. These findings underscore the importance of considering the potentially different factors that drive different steps in the evolution of complex adaptations.

Transcriptome data of peripheral white blood cells from beef heifers collected at the time of artificial insemination

Directory of Open Access Journals (Sweden)

Sarah E. Dickinson

2018-06-01

Full Text Available The reproductive performance of heifers within their first breeding season influences the success of beef cattle operations. Therefore, a means to identify infertile and late breeding heifers before the start of the breeding season holds great promise for the future of the beef industry. Pubertal beef heifers were subjected to estrous synchronization and fixed time artificial insemination (FTAI. We collected peripheral blood from the heifers at the time of artificial insemination (AI and generated RNA sequencing data to characterize the transcriptome of peripheral white blood cells (PWBC. Following insemination, heifers were exposed to natural service for a defined breeding season, and pregnancy was evaluated to classify heifers into one of three groups: AI-pregnant, natural-bred (NB pregnant, and non-pregnant. The raw transcriptome data of PWBC is available on the NCBI GEO repository (GSE103628 where the reader can also find raw read counts and normalized gene expression data. The normalized data on transcript coverage can be visualized as a genome browser at HeiferFertilityRNAseq.org. Keywords: Biomarkers, Infertility, Pregnancy

A note on captive breeding and reproductive parameters of the Chinese pangolin, Manis pentadactyla Linnaeus, 1758

Directory of Open Access Journals (Sweden)

Fuhua Zhang

2016-09-01

Full Text Available The Chinese pangolin (Manis pentadactyla Linnaeus, 1758 is a critically endangered species, and documents on its captive breeding and reproductive parameters are scarce. MP8, kept in the Pangolin Research Base for Artificial Rescue and Conservation Breeding of South China Normal University (the PRB-SCNU, gave birth to a male offspring (MP86 on 19 October 2011. The baby pangolin was well developed, with a weight of 120 g and a total length of 23.2 cm. The gestation length of MP8 was estimated to be from 182 to 225d. Reproductive parameters of the Chinese pangolin are discussed based on collected data about this species. The Chinese pangolin has an obvious reproductive seasonality and its gestation length is typically six to seven months. In this observation, estrus and mating principally occurred in a one-year period from February to July. Parturition principally took place from September to February of the next year. Chinese pangolins usually give birth to one offspring at a time (n = 27. Sex ratio at birth was 0.71:1 (♀:♂, n = 12. Average weight for the reproducible females was 3.57 ± 1.38 kg (2.14–6.8 kg, n = 15. We estimated that Chinese pangolins could reach sexual maturity before they were one year old.

Evaluation of some varieties and breeding lines of tomato (Lycopersison sp) against tomato yellow leaf curl disease in the Greater Accra Region (Ghana)

International Nuclear Information System (INIS)

Kusi-Adjei, R.

2011-01-01

A series of experiments were conducted to evaluate ten (10) tomato varieties and breeding lines against tomato yellow leaf curl virus disease in Ghana. The research was undertaken at the research farm of the Biotechnology and Nuclear Agriculture Research Institute of the Ghana Atomic Energy Commission. Ten tomato varieties and breeding lines were evaluated in the field under natural whitefly inoculation in insect-proof cages. The field trial was done in the dry season from October, 2010 to February, 2011 and wet season from March, 2011 to July, 2011. Plants in the fields and in the cage exhibited varied symptoms such as leaf curling, leaf yellowing and reduced leaf sizes. Assessment of disease incidence and symptom severity using a four point scale (0-4) showed that, in the field there was higher disease incidence in the dry season as compared to the wet season. This was attributed to the higher number of whiteflies in the dry season as demonstrated through a whitefly population survey conducted in the field. Differences among means for disease incidence and whitefly surveys on the ten tomato varieties and breeding lines were statistically significant (p≤ 0.05). Wild Tomato (Solanum pimpinellifollium) and two hybrids, Wosowoso x Wild Tomato and Cherry Red x Wild Tomato exhibited signs of resistance in the field and did not show any symptoms of TYLCV disease symptoms. All the commercial varieties were highly susceptible and showed severe symptoms. Evaluation of fruit yield in the field revealed that the commercial variety Tomato Advanta had the heaviest fruit weight (42 g/ fruit) whilst Wosowoso had the highest total fruit yield (5.74 t/ha) in the wet season. Wild Tomato and the hybrids produced higher number of fruits compared to the commercial varieties. There were highly significant differences in the means of number of fruits, fruit weight (g) and total fruit yield (t/ha) among the ten tomato varieties and breeding lines in both the wet and dry seasons

Effects of breed and feeding system on milk production, body weight, body condition score, reproductive performance, and postpartum ovarian function.

Science.gov (United States)

Walsh, S; Buckley, F; Pierce, K; Byrne, N; Patton, J; Dillon, P

2008-11-01

The objective of this study was to investigate the potential differences among Holstein-Friesian (HF), Montbéliarde (MB), Normande (NM), Norwegian Red (NRF), Montbéliarde x Holstein-Friesian (MBX), and Normande x Holstein-Friesian (NMX) across 2 seasonal grass-based systems of milk production. The effects of breed and feeding system on milk production, body weight, body condition score, fertility performance, hormone parameters, ovarian function, and survival were determined by using mixed model methodology, generalized linear models, and survival analysis. The 5-yr study comprised up to 749 lactations on 309 cows in one research herd. The HF produced the greatest yield of solids-corrected milk, the MB and NM produced the least yields, and NRF, MBX, and NMX were intermediate. The NRF had the lowest body weight throughout lactation, the NM had the highest, and the other breeds were intermediate. Body condition score was greatest for MB and NM, least for HF, and intermediate for NRF, MBX, and NMX. The HF had a lower submission rate and overall pregnancy rate compared with the NRF. The NRF survived the longest in the herd, the HF survived the shortest, and the NM, MB, MBX, and NMX were intermediate. Breed of dairy cow had no effect on selected milk progesterone parameters from 5 d postpartum until 26 d after first artificial insemination. Breed of dairy cow did not influence insulin and insulin-like growth factor-1 around parturition or at the start of the breeding season. Animals offered a high-concentrate diet had greater milk yield, but they did not have improved reproductive performance. Differences observed between the different breeds in this study are a likely consequence of the past selection criteria for the respective breeds.

Effect of geolocators on migration and subsequent breeding performance of a long-distance passerine migrant.

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Debora Arlt

Full Text Available Geolocators are small light-weight data loggers used to track individual migratory routes, and their use has increased exponentially in birds. However, the effects of geolocators on individual performance are still poorly known. We studied geolocator effects on a long-distance migrating passerine bird, the northern wheatear (Oenanthe oenanthe L.. We asked the general question of whether geolocators affect migratory behaviour and subsequent reproductive performance of small passerines by comparing arrival time, breeding time, breeding success and survival of geolocator versus control birds of known identity and breeding history. During two years geolocator birds (n=37 displayed a lower apparent survival (30% as compared to controls (45%, n=164. Furthermore, returning geolocator birds (n=12 arrived on average 3.5 days later, started laying eggs 6.3 days later, and had lower nest success (25% than control birds (78%. Our results suggest that geolocators affect migratory performance with carry-over effects to the timing of breeding and reproductive success in the subsequent breeding season. We discuss the implications of such geolocator effects for the study of migratory strategies of small passerines in general and suggest how to identify and investigate such effects in the future.

Does wintering north or south of the Sahara correlate with timing and breeding performance in black-tailed godwits?

NARCIS (Netherlands)

Kentie, Rosemarie; Marquez-Ferrando, Rocío; Figuerola, Jordi; Gangoso, Laura; Hooijmeijer, Jos C E W; Loonstra, A. H Jelle; Robin, Frédéric; Sarasa, Mathieu; Senner, Nathan; Valkema, Haije; Verhoeven, Mo A.; Piersma, Theunis

2017-01-01

Migrating long distances requires time and energy, and may interact with an individual's performance during breeding. These seasonal interactions in migratory animals are best described in populations with disjunct nonbreeding distributions. The black-tailed godwit (Limosa limosa limosa), which

Grassland bird productivity in warm season grass fields in southwest Wisconsin

Science.gov (United States)

Byers, Carolyn M.; Ribic, Christine; Sample, David W.; Dadisman, John D.; Guttery, Michael

2017-01-01

Surrogate grasslands established through federal set-aside programs, such as U.S. Department of Agriculture's Conservation Reserve Program (CRP), provide important habitat for grassland birds. Warm season grass CRP fields as a group have the potential for providing a continuum of habitat structure for breeding birds, depending on how the fields are managed and their floristic composition. We studied the nesting activity of four obligate grassland bird species, Bobolink (Dolichonyx oryzivorus), Eastern Meadowlark (Sturnella magna), Grasshopper Sparrow (Ammodramus savannarum), and Henslow's Sparrow (A. henslowii), in relation to vegetative composition and fire management in warm season CRP fields in southwest Wisconsin during 2009–2011. Intraspecific variation in apparent nest density was related to the number of years since the field was burned. Apparent Grasshopper Sparrow nest density was highest in the breeding season immediately following spring burns, apparent Henslow's Sparrow nest density was highest 1 y post burn, and apparent Bobolink and Eastern Meadowlark nest densities were higher in post fire years one to three. Grasshopper Sparrow nest density was highest on sites with more diverse vegetation, specifically prairie forbs, and on sites with shorter less dense vegetation. Bobolink, Eastern Meadowlark, and Henslow's Sparrow apparent nest densities were higher on sites with deeper litter; litter was the vegetative component that was most affected by spring burns. Overall nest success was 0.487 for Bobolink (22 d nesting period), 0.478 for Eastern Meadowlark (25 d nesting period), 0.507 for Grasshopper Sparrow (22 d nesting period), and 0.151 for Henslow's Sparrow (21 d nesting period). The major nest predators were grassland-associated species: thirteen-lined ground squirrel (Ictidomys tridecemlineatus), striped skunk (Mephitis mephitis), milk snake (Lampropeltis triangulum), American badger (Taxidea taxus), and western fox snake (Elaphe vulpina). Overall

Development of breeding objectives for beef cattle breeding ...

African Journals Online (AJOL)

Mnr J F Kluyts

However, to solve the simultaneous equations the ... The aggregate breeding value represents a fundamental concept, the breeding objective, which is ..... Two properties characterise a linear programming problem. The first is additivity, ...

Mobbing call experiment suggests the enhancement of forest bird movement by tree cover in urban landscapes across seasons

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Atsushi Shimazaki

2017-06-01

Full Text Available Local scale movement behavior is an important basis to predict large-scale bird movements in heterogeneous landscapes. Here we conducted playback experiments using mobbing calls to estimate the probability that forest birds would cross a 50-m urban area during three seasons (breeding, dispersal, and wintering seasons with varying amounts of tree cover, building area, and electric wire density. We examined the responses of four forest resident species: Marsh Tit (Poecile palustris, Varied Tit (Sittiparus varius, Japanese Tit (P. minor, and Eurasian Nuthatch (Sitta europaea in central Hokkaido, northern Japan. We carried out and analyzed 250 playback experiments that attracted 618 individuals. Our results showed that tree cover increased the crossing probability of three species other than Varied Tit. Building area and electric wire density had no detectable effect on crossing probability for four species. Seasonal difference in the crossing probability was found only for Varied Tit, and the probability was the highest in the breeding season. These results suggest that the positive effect of tree cover on the crossing probability would be consistent across seasons. We therefore conclude that planting trees would be an effective way to promote forest bird movement within an urban landscape.

Rock coasts and seabird breeding sites : a common optimization

Science.gov (United States)

Marie, Eveillard-Buchoux

2014-05-01

The North-West coasts of Europe support a lot of part of Northern hemisphere breeding seabirds. In that context, Scotland has a preponderant place and Brittany has southernmost limit of these species areas, for most of them. Outside the breeding season these species live mainly on the open sea and when they do visit the land to breed, they nest on a specific sites : almost all the time they breed on the rock coasts, often on seacliffs. This specific habitat are defines by geomorphological characteristics which offer special forms of the coast. The forms of rock coasts are originally and different because of several proprieties of geology, of lithology, of structures. Breeding seabird, occupying these sites, reveals, in a new light, the richness of these forms and the originals geographic location of the coastline : seabirds prefer nest in exposed coastline like rock caps, rocky points or islands. Seabirds and rock coasts are research topics in environmental geography since several years. However, these combination studies is a new approach in this field and enlargement in the heritage field allows supplement scientific approach. For example, it show that in most important touristic sites, environmental protection measures focused on landscape, habitat or bird, but much more rarely on rock coasts for these intrinsic values. Indeed, in Brittany or in Scotland, seabirds are often stars species in lot of coastal nature reserves, where they're considered like greater ecological heritage. We could see it in touristic promotion field : bird is everywhere, cliff is mostly kept in the dark, as well in leaflets as in speech visitor's guides - without, for example, as a part of this landscape. In all cases, combination of these two heritages is extremely rare. Yet, this current research illustrates the interest and the issue of development of this comparative approach seabirds / rock coasts for optimization of nature tourism and geotourism.

The effect of season on aspects of in vitro embryo production in sub ...

African Journals Online (AJOL)

The effect of season on aspects of in vitro embryo production in sub-fertile beef cows. ... Forty beef (40) cows of different breeds and parities were used in a trial ... in follicular populations could be established for different months of the year.

Recurrent selection as breeding strategy for heat tolerance in wheat

OpenAIRE

Juarez Campolina Machado; Moacil Alves de Souza; Davi Melo de Oliveira; Adeliano Cargnin; Aderico Júnior Badaró Pimentel; Josiane Cristina de Assis

2010-01-01

The development of heat-tolerant varieties is an important goal of wheat breeding programs, requiringefficient selection methods. In the present study the use of recurrent selection was evaluated as a strategy to improve heatstress tolerance in wheat. Two cycles of recurrent selection were performed in experiments conducted in research areas of theUniversidade Federal de Viçosa, located in Coimbra-MG and Viçosa-MG, in 2004 and 2007, in two growing seasons (summerand winter). The genetic gain ...

Breeding period in the mangrove crab Goniopsis cruentata (Decapoda: Grapsidae) in Northeast Brazil.

Science.gov (United States)

de Lira, José Jonathas Pereira Rodrigues; Calado, Tereza Cristina dos Santos; de Araújo, Marina de Sá Leitão Câmara

2013-03-01

The brachyuran crabs are iteroparous species which present a high diversification of reproduction patterns, which may have evolved as a species-specific response to environmental conditions. Tropical species commonly present a year-round reproduction due to stable environment conditions. Goniopsis cruentata is a crab species widely distributed along the Western Atlantic, inhabiting practically every microhabitat in the mangrove ecosystem. The aim of the present study is to determine the breeding period of the crab Goniopsis cruentata in Northeastern Brazil and also to evaluate the influence of water salinity, rainfall and air and water temperature on it. A total of 71 ovigerous females, captured from August-2007 to July-2008, were used to assess the breeding period of this species. It was analyzed by the monthly proportion of ovigerous females. A correlation was applied to verify the influence of the abiotic factors on the breeding period. The present population bred seasonal-continuously with peaks in the dry period, which was not associated with monthly variations of salinity, rainfall and air and water temperatures. Therefore, according to statistical analyses, our hypothesis was refuted. However, breeding was intensified in the dry period, when salinity and temperatures were higher and rainfall was lower. We conclude that, even though breeding is not related to monthly variation of environmental factors, it occurs in periods of higher salinity and temperatures and lower rainfall.

Breeding period in the mangrove crab Goniopsis cruentata (Decapoda: Grapsidae in Northeast Brazil

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José Jonathas Pereira Rodrigues de Lira

2013-03-01

Full Text Available The brachyuran crabs are iteroparous species which present a high diversification of reproduction patterns, which may have evolved as a species-specific response to environmental conditions. Tropical species commonly present a year-round reproduction due to stable environment conditions. Goniopsis cruentata is a crab species widely distributed along the Western Atlantic, inhabiting practically every microhabitat in the mangrove ecosystem. The aim of the present study is to determine the breeding period of the crab Goniopsis cruentata in Northeastern Brazil and also to evaluate the influence of water salinity, rainfall and air and water temperature on it. A total of 71 ovigerous females, captured from August-2007 to July-2008, were used to assess the breeding period of this species. It was analyzed by the monthly proportion of ovigerous females. A correlation was applied to verify the influence of the abiotic factors on the breeding period. The present population bred seasonal-continuously with peaks in the dry period, which was not associated with monthly variations of salinity, rainfall and air and water temperatures. Therefore, according to statistical analyses, our hypothesis was refuted. However, breeding was intensified in the dry period, when salinity and temperatures were higher and rainfall was lower. We conclude that, even though breeding is not related to monthly variation of environmental factors, it occurs in periods of higher salinity and temperatures and lower rainfall.

Some ecological factors influencing the breeding success of the Brenton Blue butterfly, Orachrysops niobe (Trimen (Lepidoptera: Lycaenidae

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D.A. Edge

2002-12-01

Full Text Available The Brenton Blue butterfly, Orachrysops niobe (Trimen, 1862 (Lepidoptera:Lycaenidae, is endemic to the southern Cape and is currently listed as Endangered. This study looks at some of the key ecological factors influencing the breeding success of the species—host plant abundance and condition, nectar sources, climate/ microclimate, and vegetation management techniques. The adult butterfly population was monitored over an entire breeding season; host plants were identified and individually monitored; and egg counts were done. This enabled the effects of a number of different management techniques to be evaluated (burning, cutting, physical removal of invasive elements, and combinations thereof. A fivefold increase in the population of O. niobe was observed over the breeding season. This increase was positively correlated to a similar increase in host plant abundance in the areas where cutting and physical removal of invasive elements was practiced. Burning, by contrast, appeared to have a negative impact on host plant and butterfly abundance over the same period. Impacts of other factors such as climate, nectar sources and the natural strength of the second brood are discussed. A hypothesis, of megaherbivore activity as the principal historical disturbance mechanism promoting locally favourable conditions for O. niobe to establish and maintain colonies, is proposed. Recommendations for reserve management and future research are made.

Body live weight and milk production parameters in the Majorera and Palmera goat breeds from the Canary Islands: influence of weight loss.

Science.gov (United States)

Lérias, Joana R; Hernández-Castellano, Lorenzo E; Morales-Delanuez, Antonio; Araújo, Susana S; Castro, Noemí; Argüello, Anastasio; Capote, Juan; Almeida, André M

2013-11-01

Seasonal weight loss (SWL), caused by poor quality pastures during the dry season, is the major limitation to animal production in the tropics. One of the ways to counter this problem is to breed animals that show tolerance to SWL. The objective of this study was to understand the effect of feed restriction in milk production and live weight (LW) evolution in two goat breeds, with different levels of adaptation to nutritional stress: the Majorera (considered to be tolerant) and the Palmera (considered to be susceptible). A total of ten animals per breed were used. Animals were divided in four groups (two for each breed): a restricted group (restricted diet) and a control group. LW and milk yield parameters were recorded through a trial that lasted 23 days in total. Overall, there were no significant differences between both restricted groups, regarding neither LW nor milk yield reductions (LW reduction 13 % and milk yield reduction of 87 % for both restricted groups). In what concerns control groups, there were no significant differences between breeds, thought there were different increments at the end of the trial for both breeds regarding LW (6 and 4 %, for Majorera and Palmera, respectively) and milk yield (28 and 8 %, respectively for Majorera and Palmera). The lack of statistically significant differences between Palmera and Majorera LW and milk yields in restricted groups may be due to the fact that the controlled trial does not replicate harsh field conditions, in which Majorera would excel, and the stress induced by those differences.

Breeding biology and the evolution of dynamic sexual dichromatism in frogs.

Science.gov (United States)

Bell, R C; Webster, G N; Whiting, M J

2017-12-01

Dynamic sexual dichromatism is a temporary colour change between the sexes and has evolved independently in a wide range of anurans, many of which are explosive breeders wherein males physically compete for access to females. Behavioural studies in a few species indicate that dynamic dichromatism functions as a visual signal in large breeding aggregations; however, the prevalence of this trait and the social and environmental factors underlying its expression are poorly understood. We compiled a database of 178 anurans with dynamic dichromatism that include representatives from 15 families and subfamilies. Dynamic dichromatism is common in two of the three subfamilies of hylid treefrogs. Phylogenetic comparative analyses of 355 hylid species (of which 95 display dynamic dichromatism) reveal high transition rates between dynamic dichromatism, ontogenetic (permanent) dichromatism and monochromatism reflecting the high evolutionary lability of this trait. Correlated evolution in hylids between dynamic dichromatism and forming large breeding aggregations indicates that the evolution of large breeding aggregations precedes the evolution of dynamic dichromatism. Multivariate phylogenetic logistic regression recovers the interaction between biogeographic distribution and forming breeding aggregations as a significant predictor of dynamic dichromatism in hylids. Accounting for macroecological differences between temperate and tropical regions, such as seasonality and the availability of breeding sites, may improve our understanding of ecological contexts in which dynamic dichromatism is likely to arise in tropical lineages and why it is retained in some temperate species and lost in others. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Low Impact of Avian Pox on Captive-Bred Houbara Bustard Breeding Performance.

Science.gov (United States)

Le Loc'h, Guillaume; Souley, Mam-Noury Amadou; Bertagnoli, Stéphane; Paul, Mathilde C

2017-01-01

Avian pox, a disease caused by avipoxviruses, is a major cause of decline of some endangered bird species. While its impact has been assessed in several species in the wild, effects of the disease in conservation breeding have never been studied. Houbara bustard species ( Chlamydotis undulata and Chlamydotis macqueenii ), whose populations declined in the last decades, have been captive bred for conservation purposes for more than 20 years. While mortality and morbidity induced by avipoxviruses can be controlled by appropriate management, the disease might still affect bird breeding performance and jeopardize the production objectives of conservation programs. Impacts of the disease was studied during two outbreaks in captive-bred juvenile Houbara bustards in Morocco in 2009-2010 and 2010-2011, by modeling the effect of the disease on individual breeding performance (male display and female egg production) of 2,797 birds during their first breeding season. Results showed that the impact of avian pox on the ability of birds to reproduce and on the count of displays or eggs is low and mainly non-significant. The absence of strong impact compared to what could be observed in other species in the wild may be explained by the controlled conditions provided by captivity, especially the close veterinary monitoring of each bird. Those results emphasize the importance of individual management to prevent major disease emergence and their effects in captive breeding of endangered species.

[Floral syndrome and breeding system of Corydalis edulis].

Science.gov (United States)

Xia, Qing; Zhou, Shoubiao; Zhang, Dong; Chao, Tiancai

2012-05-01

A field investigation was conducted on the floral syndrome and breeding system of Corydalis edulis located in natural populations in campus of Anhui Normal University by out-crossing index, pollen-ovule ratio, artificial pollination and bagging experiment. The results showed that the plant was in bloom from March to May and flowering span among populations was 72 days. The flowering span for a raceme was 14-24 days. The life span of one single flower was approximately 5-10 days. Spatial positioning of stigma and anthers were spatially desperation on the day of anthesis. The filaments were shorter than the styles through pollen vitality and stigma receptivity experiments. A self-pollination breeding system was reflected by OCI 3, pollinators were required sometimes; A complex cross bred was indicated by P/O = 857.14, combined with the results of the bagging and artificial pollination experiment, the breeding system of C. edulis was mixed with self-pollination and outcrossing. The special floral structure and pests destroying may have a certain impact on seed-set rate.

Different Ultimate Factors Define Timing of Breeding in Two Related Species.

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Veli-Matti Pakanen

Full Text Available Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony. Alternatively, time-dependent breeding success (the date hypothesis can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence, in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major and the willow tit (Poecile montanus by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider

Slave Breeding

OpenAIRE

Sutch, Richard

1986-01-01

This paper reviews the historical work on slave breeding in the ante-bellum United States. Slave breeding consisted of interference in the sexual life of slaves by their owners with the intent and result of increasing the number of slave children born. The weight of evidence suggests that slave breeding occurred in sufficient force to raise the rate of growth of the American slave population despite evidence that only a minority of slave-owners engaged in such practices.

Information theory and the neuropeptidergic regulation of seasonal reproduction in mammals and birds.

Science.gov (United States)

Stevenson, Tyler J; Ball, Gregory F

2011-08-22

Seasonal breeding in the temperate zone is a dramatic example of a naturally occurring change in physiology and behaviour. Cues that predict periods of environmental amelioration favourable for breeding must be processed by the brain so that the appropriate responses in reproductive physiology can be implemented. The neural integration of several environmental cues converges on discrete hypothalamic neurons in order to regulate reproductive physiology. Gonadotrophin-releasing hormone-1 (GnRH1) and Kisspeptin (Kiss1) neurons in avian and mammalian species, respectively, show marked variation in expression that is positively associated with breeding state. We applied the constancy/contingency model of predictability to investigate how GnRH1 and Kiss1 integrate different environmental cues to regulate reproduction. We show that variation in GnRH1 from a highly seasonal avian species exhibits a predictive change that is primarily based on contingency information. Opportunistic species have low measures of predictability and exhibit a greater contribution of constancy information that is sex-dependent. In hamsters, Kiss1 exhibited a predictive change in expression that was predominantly contingency information and is anatomically localized. The model applied here provides a framework for studies geared towards determining the impact of variation in climate patterns to reproductive success in vertebrate species.

CASSAVA BREEDING I: THE VALUE OF BREEDING VALUE

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Hernán Ceballos

2016-08-01

Full Text Available Breeding cassava relies on several selection stages (single row trial-SRT; preliminary; advanced; and uniform yield trials - UYT. This study uses data from 14 years of evaluations. From more than 20,000 genotypes initially evaluated only 114 reached the last stage. The objective was to assess how the data at SRT could be used to predict the probabilities of genotypes reaching the UYT. Phenotypic data from each genotype at SRT was integrated into the selection index (SIN used by the cassava breeding program. Average SIN from all the progenies derived from each progenitor was then obtained. Average SIN is an approximation of the breeding value of each progenitor. Data clearly suggested that some genotypes were better progenitors than others (e.g. high number of their progenies reaching the UYT, suggesting important variation in breeding values of progenitors. However, regression of average SIN of each parental genotype on the number of their respective progenies reaching UYT resulted in a negligible coefficient of determination (r2 = 0.05. Breeding value (e.g. average SIN at SRT was not efficient predicting which genotypes were more likely to reach the UYT stage. Number of families and progenies derived from a given progenitor were more efficient predicting the probabilities of the progeny from a given parent reaching the UYT stage. Large within-family genetic variation tends to mask the true breeding value of each progenitor. The use of partially inbred progenitors (e.g. S1 or S2 genotypes would reduce the within-family genetic variation thus making the assessment of breeding value more accurate. Moreover, partial inbreeding of progenitors can improve the breeding value of the original (S0 parental material and sharply accelerate genetic gains. For instance, homozygous S1 genotypes for the dominant resistance to cassava mosaic disease could be generated and selected. All gametes from these selected S1 genotypes would carry the desirable allele

Seasonal variations of the particle flux in the Peru-Chile current at 30°S under `normal' and El Niño conditions

Science.gov (United States)

Hebbeln, Dierk; Marchant, Margarita; Wefer, Gerold

Time-series sediment traps were deployed 180 km off the Chilean coast at 30°S in the Peru-Chile Current during the El Niño period 1991/1992 (6 months) and during the 'normal' period 1993/1994 (12 months). Under normal conditions in 1993/1994 the particle fluxes display a pronounced seasonal cycle marked by a settling phytoplankton bloom in September, intermediate fluxes until January, and low fluxes between January and July. This seasonal pattern is also reflected in stable isotope data, measured on the planktic foraminifera species Neogloboquadrina pachyderma (dex.) and Globigerina bulloides, which indicate persistent upwelling conditions between August and February followed by a stratified water column between March and July. The total flux under normal conditions amounts to 65.1 g m -2 a-1, with the main flux constituents contributing 47.6% (carbonate), 26.4% (lithogenic matter), 17.4% (biogenic opal), and 8.6% (organic matter), respectively. Based on these particle flux data the export production has been estimated to be 42 gC m -2 a-1. Although the main flux event in September was not sampled in the El Niño period 1991/1992, the available record from November 1991 to April 1992 allows an interesting comparison with the fluxes of the normal year. The total amount of fluxes and the timing of minor flux events are very similar under normal and under El Niño conditions. However, increased proportions of organic carbon and lithogenic matter under El Niño conditions are interpreted to reflect faster sedimentation and preferred scavenging of organic matter by elevated lithogenic fluxes rather than increased productivity. The higher lithogenic fluxes under El Niño conditions are probably due to increased precipitation and terrestial runoff in the arid to semiarid northern part of Chile.

Ornamental Plant Breeding

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Flávia Barbosa Silva Botelho

2015-04-01

Full Text Available World’s ornamental plant market, including domestic market of several countries and its exports, is currently evaluated in 107 billion dollars yearly. Such estimate highlights the importance of the sector in the economy of the countries, as well as its important social role, as it represents one of the main activities, which contributes to income and employment. Therefore a well-structured plant breeding program, which is connected with consumers’ demands, is required in order to fulfill these market needs globally. Activities related to pre-breeding, conventional breeding, and breeding by biotechnological techniques constitute the basis for the successful development of new ornamental plant cultivars. Techniques that involve tissue culture, protoplast fusion and genetic engineering greatly aid conventional breeding (germplasm introduction, plant selection and hybridization, aiming the obtention of superior genotypes. Therefore it makes evident, in the literature, the successful employment of genetic breeding, since it aims to develop plants with commercial value that are also competitive with the ones available in the market.

Multi-annual and seasonal patterns of waterbird assemblages in a Mediterranean coastal lagoon (El Mellah lagoon of Northeastern Algeria

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Telailia Salah

2017-06-01

Full Text Available Recently, Mediterranean coastal lagoons have raised considerable environmental concerns. Long-term studies of seasonal changes in waterbird assemblages are therefore extremely important in terms of ecological relevance and conservation of these sensitive ecosystems. An ornithological survey of four years was carried out in a typical costal wetland (El Mellah lagoon of Northeastern Algeria. Intra-seasonal comparison of waterbird assemblages (diversity indices demonstrates clear changes between the wintering and the breeding periods. It seems that the first one was rich in term of species number than the second season (43 against 24. In contrast, the breeding seasons were more equilibrate (high values of Simpson, Shannon and evenness index. Additionally, curves in the diversity/dominance diagram revealed that both wintering and breeding assemblages share the same characteristics of community structure, few dominant species (with intermediate relative abundance and many rare species with the relative abundance lower than 0.1. Invertebrates (25 species and piscivorous (11 species are the most abundant guilds over the four years of study (no significant differences among years have been calculated. The marked decline in bird species diversity recorded in this study (in comparison with previous studies is mainly due to salinity oscillations (due to aquaculture activities and may be of concern to wetland managers and it might be useful to provide some guidelines about the characteristics that coastal lagoons have to follow in the construction process to enhance the biodiversity.

Seasonal Changes in Serum Testosterone, LDH Concentration and Semen Characteristics in Markhoz Goats

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A. Farshad

2012-02-01

Full Text Available This experiment was conducted to study variations of serum testosterone and seminal characteristics of Markhoz male goats. Blood samples were obtained via jugular vein, and semen was collected by using an artificial vagina from 14 fertile male goats (2–3 years of age, at 15-day intervals starting on 15 July and ending on 30 October 2010 (during breeding and non-breeding season. Semen volume, total sperm (volume×concentration, live sperm (%, abnormal sperm (% and semen pH were significantly superior during the late summer and early autumn (breeding season. Variation of sperm density, motility and progressive motility was not significant during the sampling period. The results presented show that the lowest and highest levels of lactate dehydrogenase in the seminal plasma were recorded in late October (2.82 U/ml and in late August (4.81 U/ml, respectively. Moreover, the study indicated that the serum testosterone concentration was higher during late summer and early autumn (p<0.05 than at any other of sampling period. There were negative correlations between volume and sperm density (−0.135, p<0.05, and positive correlations between volume and percentage live sperm (0.224 and percentage progressive motility (0.194, p<0.01. Sperm density was correlated with live sperm (0.200, p<0.05 and progressive motility (0.202, p<0.01. The correlation between live sperm and progressive motility was 0.554 (p<0.01. Furthermore, the results in this study indicated a significant positive correlation between live sperm and LDH (0.450 and a negative correlation between sperm density and LDH concentration (−0.272 (p<0.01. Significant, but positive correlations were found between sperm motility and LDH (0.542 and testosterone concentration (0.522, respectively (p<0.05. In conclusion, this study demonstrated that the best obtained semen was collected in late summer (during decreasing photoperiod and early autumn (September and October. This also coincides with

A simple language to script and simulate breeding schemes: the breeding scheme language

Science.gov (United States)

It is difficult for plant breeders to determine an optimal breeding strategy given that the problem involves many factors, such as target trait genetic architecture and breeding resource availability. There are many possible breeding schemes for each breeding program. Although simulation study may b...

Wetland selection by breeding and foraging black terns in the Prairie Pothole Region of the United States

Science.gov (United States)

Steen, Valerie A.; Powell, Abby N.

2012-01-01

We examined wetland selection by the Black Tern (Chlidonias niger), a species that breeds primarily in the prairie pothole region, has experienced population declines, and is difficult to manage because of low site fidelity. To characterize its selection of wetlands in this region, we surveyed 589 wetlands throughout North and South Dakota. We documented breeding at 5% and foraging at 17% of wetlands. We created predictive habitat models with a machine-learning algorithm, Random Forests, to explore the relative role of local wetland characteristics and those of the surrounding landscape and to evaluate which characteristics were important to predicting breeding versus foraging. We also examined area-dependent wetland selection while addressing the passive sampling bias by replacing occurrence of terns in the models with an index of density. Local wetland variables were more important than landscape variables in predictions of occurrence of breeding and foraging. Wetland size was more important to prediction of foraging than of breeding locations, while floating matted vegetation was more important to prediction of breeding than of foraging locations. The amount of seasonal wetland in the landscape was the only landscape variable important to prediction of both foraging and breeding. Models based on a density index indicated that wetland selection by foraging terns may be more area dependent than that by breeding terns. Our study provides some of the first evidence for differential breeding and foraging wetland selection by Black Terns and for a more limited role of landscape effects and area sensitivity than has been previously shown.

To breed or not to breed: a seabird's response to extreme climatic events

OpenAIRE

Cubaynes, Sarah; Doherty, Paul F.; Schreiber, E. A.; Gimenez, Olivier

2010-01-01

Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), usin...

Climate factors affecting fertility after cervical insemination during the first months of the breeding season in Rasa Aragonesa ewes

Science.gov (United States)

Santolaria, P.; Yániz, J.; Fantova, E.; Vicente-Fiel, S.; Palacín, I.

2014-09-01

This study was carried out to examine the impact of several climate variables on the pregnancy rate after cervical artificial insemination (AI) of Rasa Aragonesa ewes. Data were derived from 8,977 inseminations in 76 well-managed flocks performed during the first month of the breeding season (July to October). The following data were recorded for each animal: farm, year, month of AI, parity, lambing-treatment interval, inseminating ram, AI technician, and climatic variables such as mean, maximum and minimum temperature, mean and maximum relative humidity, rainfall, and mean and maximum temperature-humidity index (THI) for each day from day 12 before AI to day 14 post-AI. Means were furthermore calculated for the following periods around AI (day 0): -12 to 0, -2 to 0, AI day, 0 to 2, and 0 to 14. Logistic regression analysis indicated that the likelihood of pregnancy decreased when maximum temperature in the 2 days prior to AI was higher than 30 °C (by a factor of 0.81). Fertility was also lower for primiparous ewes and in multiparous ewes with more than five previous parturitions. Other factors with significant impact on fertility were flock, technician, inseminating ram, and a lambing-AI interval longer than 240 days. It was concluded that the 2 days prior to AI seems to be the period when heat stress had the greatest impact on pregnancy rate in Rasa Aragonesa ewes.

Tritium breeding blanket

International Nuclear Information System (INIS)

Smith, D.; Billone, M.; Gohar, Y.; Baker, C.; Mori, S.; Kuroda, T.; Maki, K.; Takatsu, H.; Yoshida, H.; Raffray, A.; Sviatoslavsky, I.; Simbolotti, G.; Shatalov, G.

1991-01-01

The terms of reference for ITER provide for incorporation of a tritium breeding blanket with a breeding ratio as close to unity as practical. A breeding blanket is required to assure an adequate supply of tritium to meet the program objectives. Based on specified design criteria, a ceramic breeder concept with water coolant and an austenitic steel structure has been selected as the first option and lithium-lead blanket concept has been chosen as an alternate option. The first wall, blanket, and shield are integrated into a single unit with separate cooling systems. The design makes extensive use of beryllium to enhance the tritium breeding ratio. The design goals with a tritium breeding ratio of 0.8--0.9 have been achieved and the R ampersand D requirements to qualify the design have been identified. 4 refs., 8 figs., 2 tabs

Breeding value of the second generation of soybean populations for «growing season» trait

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О. З. Щербина

2016-02-01

Full Text Available Purpose. Studying the inheritance of such trait of soybean (Glucine max (L. Merrill as growing season length in F2 and assessing hybrid combinations to identify more quick-ripening phenotypes as compared to parents. Methods. Laboratory test, mathematico-statistical evaluation. Results. In most crossbreeding combinations, when parents differed by growing season length, late ripeness was dominated in F2, in one combination – early ripeness, in two combinations, when parents scarcely differed by growing season length, complementary effect was observed for this index. It was found that ‘Anzhelika’/‘Mageva’ combination generated the highest number of more quick-ripening forms than any of the parents (13.1%, a smaller number was identified in ‘Legenda’/‘Vizhion’ (6.4% and ‘Anzhelika’/‘Gentleman’ (4.0%, and barely noticeable number was observed in ‘Legenda’/‘Yelena’ combination (1.3%. Conclusions. In the following crossbreeding combinations as ‘Legenda’/‘Vizhion’, Legenda’/‘Korado’, ‘Legenda’/‘Ustia’, ‘Legenda’/‘Yelena’, ‘Yug-30’/‘Gentleman’, ‘No. 894’/‘Vizhion’, ‘Anzhelika’/‘Annushka’, ‘No. 894’/‘Annushka’, ‘Legenda’/‘Annushka’, ‘No. 441’/‘Gentleman’, ‘No. 441’/‘Vizhion’, ‘No. 441’/‘Annushka’, ‘Anzheli­ka’/‘Gentleman’ and ‘Anzhelika’/‘Prypiat’ when parents considerably and insignificantly differ by growing season length, late ripeness was dominated in F2. ‘Ustia’/‘Vizhion’ and ‘Yug-30’/‘ Vizhion’ crossbreeding combinations in which parents hardly differ by growing season, complementary effect was observed in F2 for this index.

Impact of seasonality and storage of semen on epigenetics in swine placenta and fetal livers

Science.gov (United States)

Epigenetics includes the study of external factors that can influence the expression of genes by altering accessibility of DNA through methylation and histone modification. To investigate the influence of: season (semen collection and breeding), absolute sperm head-shape change, and semen storage on...

Kelp gulls, Larus dominicanus (Aves: Laridae, breeding in Keller Peninsula, King George Island, Antarctic Peninsula

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Joaquim O. Branco

2009-09-01

Full Text Available We examined the distribution, abundance and density of the Kelp Gull, Larus dominicanus (Lichtenstein, 1823, at Keller Peninsula on two occasions during the breeding season of 2007-2008 (once for incubation and once for chick stages and compared our results with previously published data. We present information on the number of eggs, incubation success, and initial development of L. dominicanus chicks in the studied sites. The abundance and density of the species has remained statistically similar in Keller Peninsula over the last 30 years (since 1978-1979. Although the abundance and density were almost unchanged, we recorded alterations in the occupation of the breeding areas by L. dominicanus, mainly the abandonment of breeding sites in the eastern portion of Keller Peninsula. The results of the present study compared with similar previous investigations on the abundance of L. dominicanus indicate that the populations have been in equilibrium over the years.

Population dynamics and breeding patterns of multimammate mouse, Mastomys natalensis (Smith 1834), in irrigated rice fields in eastern Tanzania.

Science.gov (United States)

Mulungu, Loth S; Ngowo, Victoria; Mdangi, Mashaka; Katakweba, Abdul S; Tesha, Protas; Mrosso, Furaha P; Mchomvu, Mary; Sheyo, Paul M; Kilonzo, Bukhet S

2013-03-01

Multimammate mice are the most important vertebrate pests in Sub-Saharan Africa and are also reservoirs of many zoonotic diseases, including sylvan plague. This study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern Tanzania. The multimammate mouse, Mastomys natalensis, population varied with habitat and months. Fallow land had a more abundant population than rice fields. The highest population peak was observed during the dry season from July to October. Mastomys natalensis is sexually active throughout the year in the study area, although it reaches the highest level in June and December when rice is at the maturity stage. This suggests that breeding is highly influenced by the presence of a rice crop in both seasons. More juvenile individuals were recorded in August and September, indicating that they were produced in the previous breeding months. The sex ratio of M. natalensis was not skewed to either males or females, indicating that it was at parity. Rodent population dynamics during the study periods in all habitats indicated that high birth rates accounted for the rapid population growth and turnover. Regular control and sustainable operations are thus essential if rodent pest populations are to be kept within tolerable limits. Copyright © 2012 Society of Chemical Industry.

Dynamics of food availability, body condition and physiological stress response in breeding Black-legged Kittiwakes

Science.gov (United States)

Kitaysky, A.S.; Wingfield, J.C.; Piatt, John F.

1999-01-01

1. The seasonal dynamics of body condition (BC), circulating corticosterone levels (baseline, BL) and the adrenocortical response to acute stress (SR) were examined in long-lived Black-legged Kittiwakes, Rissa tridactyla, breeding at Duck (food-poor colony) and Gull (food-rich colony) Islands in lower Cook Inlet, Alaska. It was tested whether the dynamics of corticosterone levels reflect a seasonal change in bird physiological condition due to reproduction and/or variation in foraging conditions. 2. BC declined seasonally, and the decline was more pronounced in birds at the food-poor colony. BL and SR levels of corticosterone rose steadily through the reproductive season, and BL levels were significantly higher in birds on Duck island compared with those on Gull Island. During the egg-laying and chick-rearing stages, birds had lower SR on Duck Island than on Gull Island. 3. The results suggest that, in addition to a seasonal change in bird physiology during reproduction, local ecological factors such as food availability affect circulating levels of corticosterone and adrenal response to acute stress.

A deterministic, dynamic systems model of cow-calf production: The effects of breeding replacement heifers before mature cows over a 10-year horizon.

Science.gov (United States)

Shane, D D; Larson, R L; Sanderson, M W; Miesner, M; White, B J

2017-10-01

Some cattle production experts believe that cow-calf producers should breed replacement heifers (nulliparous cows) before cows (primiparous and multiparous cows), sometimes referred to as providing a heifer lead time (tHL). Our objective was to model the effects different durations of tHL may have on measures of herd productivity, including the percent of the herd cycling before the end of the first 21 d of the breeding season (%C21), the percent of the herd pregnant at pregnancy diagnosis (%PPD), the distribution of pregnancy by 21-d breeding intervals, the kilograms of calf weaned per cow exposed (KPC), and the replacement percentage (%RH), using a deterministic, dynamic systems model of cow-calf production over a 10-yr horizon. We also wished to examine differences in the effect of tHL related to the primiparous duration of postpartum anestrus (dPPA). The study model examined 6 different dPPA for primiparous cows (60, 70, 80, 90, 100, or 110 d). The multiparous cow duration of postpartum anestrus was set to 60 d. The breeding season length for nulliparous cows was 63 d, as was the breeding season length for primiparous and multiparous cows. Nulliparous cows were modeled with a tHL of 0, 7, 14, 21, 28, 35, or 42 d. Results are reported for the final breeding season of the 10-yr horizon. Increasing tHL resulted in a greater %C21 for the herd and for primiparous cows. Length of tHL had minimal impact on the %PPD unless the dPPA was 80 d or greater. For a dPPA of 110 d, a 0 d tHL resulted in the herd having 88.1 %PPD. When tHL was 21 d, the %PPD increased to 93.0%. The KPC was 161.2 kg when the dPPA was 110 d and tHL was 0 d and improved to 183.2 kg when tHL was increased to 42 d. The %RH did not vary much unless the dPPA was 90 d or greater, but increasing tHL resulted in decreased %RH. Based on the model results, increasing tHL improves the production outcomes included in the analysis, but herds with dPPA of 90 d or greater had the greatest degree of improvement

Introduction and Breeding of Rhododendrons in Latvia

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Kondratovičs Rihards

2017-06-01

Full Text Available Rhododendrons are relatively new beautiful ornamental plants in Latvia forming an essential part of public and private gardens, although they were introduced in Latvian territory already during the first half of 19th century. Rhododendrons deserve their immense popularity due to the diversity of their habitat, size and type of blossoms and leaves and their flowering season. There are about 1000 rhododendron species in the wild up to now whereas breeders in various countries have created more than 30 000 cultivars. Intensive rhododendrons introduction and acclimatization in Latvia started in 1957 when Rihards Kondratovičs, at the time director of the Botanical Garden, University of Latvia, started his research on the introduction and acclimatization of rhododendrons. Winterhardiness of about 400 wild species in Latvia was tested and 76 species were found to be suitable. Following the development of an extensive collection of wild rhododendron species and cultivars, the Rhododendron Breeding and Experimental Nursery “Babīte”, University of Latvia, was established at 1980 and the active breeding of new winterhardy cultivars was started. In 2017, the collection of outdoor rhododendrons of the University of Latvia consists of 76 species and 265 cultivars, including 109 cultivars bred in Latvia by Professor Rihards Kondratovičs.

Development of two new sesame lines (Inshas 11 and Inshas 12) using Irradiation Induced Mutations in cross Breeding

International Nuclear Information System (INIS)

Ragab, A.I.; Kassem, M.; Battah, N.S.

2001-01-01

Genetic improvement of sesame (Sesamum indicum, L). using gamma ray Induced mutations in cross breeding has been in progress. From prior studies a cross between two induced mutants mut 1 and Mut 2 and the exotic line N.A.121, two true breeding lines designated as Inshas 11 and Inshas 12 were established in F6 generation with morphological changes and desired characters i.e. three capsules / leaf axll, long capsule seed size increased and non-branched and branched types. In the present study evaluation of the two ne lines for agronomic characters including seed yield and oil content, field experiments were conducted at Nucl. Res, Center, Inshas during three successive seasons (1994,1995 and 1996). In each season, the experiment included two new lines and the best local variety Giza 32 using randomized complete block design with three replicates. The obtained results over the three seasons indicated that flowering date was earlier 13 and 6 days for inshas 11 and inshas 12, respectively, as compared to Giza 32. First capsule height was 34 cm and 17 cm lower than Giza 32 for inshas 11 and inshas 12, respectively. Marked reduction for plant height was only obtained for inshas 12. However, a considerable increase for fruiting zone length was only found for inshas 11

Dark-bellied Brent Geese Branta bernicla bernicla forego breeding when Arctic Foxes Alopex lagopus are present during nest initiation

NARCIS (Netherlands)

Spaans, B.; Blijleven, H.J.; Popov, I.U.; Rykhlikova, M.E.; Ebbinge, B.S.

1998-01-01

In an area north of the Pyasina delta in Taimyr (Russia), nest distribution, nest initiation and breeding success of Brent Geese Branta bernicla bernicla were studied in six successive summer seasons from 1990-1995 in relation to lemming and Arctic Fox Alopex lagopus abundance. Lemming abundance

Seasonal trends in nesting leatherback turtle (Dermochelys coriacea) serum proteins further verify capital breeding hypothesis

Science.gov (United States)

Perrault, Justin R.; Wyneken, Jeanette; Page-Karjian, Annie; Merrill, Anita; Miller, Debra L.

2014-01-01

Serum protein concentrations provide insight into the nutritional and immune status of organisms. It has been suggested that some marine turtles are capital breeders that fast during the nesting season. In this study, we documented serum proteins in neophyte and remigrant nesting leatherback sea turtles (Dermochelys coriacea). This allowed us to establish trends across the nesting season to determine whether these physiological parameters indicate if leatherbacks forage or fast while on nesting grounds. Using the biuret method and agarose gel electrophoresis, total serum protein (median = 5.0 g/dl) and protein fractions were quantified and include pre-albumin (median = 0.0 g/dl), albumin (median = 1.81 g/dl), α1-globulin (median = 0.90 g/dl), α2-globulin (median = 0.74 g/dl), total α-globulin (median = 1.64 g/dl), β-globulin (median = 0.56 g/dl), γ-globulin (median = 0.81 g/dl) and total globulin (median = 3.12 g/dl). The albumin:globulin ratio (median = 0.59) was also calculated. Confidence intervals (90%) were used to establish reference intervals. Total protein, albumin and total globulin concentrations declined in successive nesting events. Protein fractions declined at less significant rates or remained relatively constant during the nesting season. Here, we show that leatherbacks are most likely fasting during the nesting season. A minimal threshold of total serum protein concentrations of around 3.5–4.5 g/dl may physiologically signal the end of the season's nesting for individual leatherbacks. The results presented here lend further insight into the interaction between reproduction, fasting and energy reserves and will potentially improve the conservation and management of this imperiled species. PMID:27293623

Textbook animal breeding : animal breeding andgenetics for BSc students

NARCIS (Netherlands)

Oldenbroek, Kor; Waaij, van der Liesbeth

2014-01-01

This textbook contains teaching material on animal breeding and genetics for BSc students. The text book started as an initiative of the Dutch Universities for Applied (Agricultural) Sciences. The textbook is made available by the Animal Breeding and Genomics Centre (ABGC) of Wageningen UR

Tritium breeding in fusion reactors

International Nuclear Information System (INIS)

Abdou, M.A.

1982-10-01

Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements

Impact of mutation breeding in rice. A review

Energy Technology Data Exchange (ETDEWEB)

Rutger, J N [Department of Agriculture, Stoneville, MS (United States). Agricultural Research Service

1992-07-01

More cultivars have been developed in rice through the use of mutation breeding than in any other crop. Direct releases of mutants as cultivars began some 30 years ago, and now total 198 cultivars. During the last 20 years, increasing use has been made of induced mutants in cross-breeding programs, leading to 80 additional cultivars. Principal improvements through mutation breeding have been earlier maturity, short stature, and grain character modifications. Rice has been a popular subject of mutagenesis because it is the world`s leading food crop, has diploid inheritance, and is highly self-pollinated. In recent years induced mutation has been exploited to develop breeding tool mutants, which are defined as mutants that in themselves may not have direct agronomic application but may be useful genetic tools for crop improvement. Examples include the eui gene, hull colour mutants, normal genetic male steriles, and environmentally sensitive genetic male steriles. The environmentally sensitive genetic male steriles, especially those in which male sterility can be turned on or off by different photoperiod lengths, show promise for simplifying hybrid rice seed production both in China and the USA. Future applications of mutation in rice include induction of unusual endosperm starch types, plant types with fewer but more productive tillers, dominant dwarfs, dominant genetic male steriles, extremely early maturing mutants, nutritional mutants, and in vitro-derived mutants for tolerance to herbicides or other growth stresses. Refs, 4 figs, 2 tabs.

Differences in Voluntary Cow Traffic between Holstein and Illawarra Breeds of Dairy Cattle in a Pasture-based Automatic Milking System.

Science.gov (United States)

Clark, C E F; Kwinten, N B P; van Gastel, D A J M; Kerrisk, K L; Lyons, N A; Garcia, S C

2014-04-01

Automatic milking systems (AMS) rely upon voluntary cow traffic (the voluntary movement of cattle around a farm) for milk harvesting and feed consumption. Previous research on conventional milking systems has shown differences between dairy cow breeds for intake and milk production, however, the ability to manipulate voluntary cow traffic and milking frequency on AMS farms through breed selection is unknown. This study investigated the effect of breed (Holstein Friesian versus Illawarra) on voluntary cow traffic as determined by gate passes at the Camden AMS research farm dairy facility. Daily data on days in milk, milk yield, gate passes and milking frequency for 158 Holstein Friesian cows and 24 Illawarra cows were collated by month for the 2007 and 2008 years. Illawarra cows had 9% more gate passes/day than Holstein cows over the duration of the study; however, the milking frequency and milk yield of both breeds were similar. Gate passes were greatest for both breeds in early lactation and in the winter (June to August) and summer (December to February) seasons. These findings highlight an opportunity to translate increased voluntary cow movement associated with breed selection into increased milking frequencies, milk production and overall pasture-based AMS performance.

Meat physical quality and muscle fibre properties of rabbit meat as affected by the sire breed, season, parity order and gender in an organic production system

Directory of Open Access Journals (Sweden)

A. Dalle Zotte

2016-06-01

Full Text Available The aim of the study was to evaluate some meat physical quality and muscle fibre properties of rabbit meat when considering 2 sire breeds (SB: Vienna Blue [VB]; Burgundy Fawn [BF]; both coloured and slow-growing breeds, several parity orders (P: 1, 2, ≥3, gender (G, and 2 slaughter seasons (SS: spring, summer in an organic production system. The effect of storage time (ST at frozen state (2 mo at –20°C of Longissimus lumborum (LL meat was also evaluated. Animals were slaughtered when they reached 2.8 kg of live weight. Then, pH and L*a*b* colour values of Biceps femoris (BF and LL muscles, water loss and Warner-Bratzler shear force of LL and hind leg (HL meat, and the fibre typing and enzymatic activity of LL muscle were analysed. LL meat from females showed higher b* values than males (0.04 vs. –1.25; P<0.05. Significant (P<0.05 SB×P, SB×G and P×G interactions were observed for the b* value of LL: VB and BF crossbreds presented a higher b* value when born as P≥3 and P2 respectively, VB females showed higher b* value than VB males, and P2 and P≥3 produced males with a significantly lower b* value. HL thawing losses were significantly (P<0.05 higher in rabbits slaughtered in summer than in those slaughtered in spring, whereas the opposite result was obtained for LL meat (P<0.01. Cooking loss of LL meat was significantly lower in P2 group than P≥3 group (P<0.05. The lactate dehydrogenase activity in LL muscle was higher in VB than in BF crossbreds (930 vs. 830 IU; P<0.05, albeit not supported by differences in fibre type distribution. The ST significantly (P<0.01 reduced pH, a* and b* colour values, and increased lightness of LL meat. It was concluded that the crossbreeds derived from VB and BF genotypes and farmed organically did not show remarkable sexual dimorphism, considering their elder slaughter age than rabbits reared under intensive conditions. Physical quality of meat was mainly affected by slaughter season, indicating

Breeding biology of Mottled Ducks on agricultural lands in southwestern Louisiana

Science.gov (United States)

Durham, R.S.; Afton, A.D.

2006-01-01

Breeding biology of Anas fulvigula maculosa (Mottled Ducks) has been described in coastal marsh and associated habitats, but little information is available for agricultural habitats in Louisiana. We located nests to determine nest-initiation dates and clutch sizes during the primary breeding season (February-May) in 1999 (n = 29) and 2000 (n = 37) on agricultural lands in southwestern Louisiana. In 1999, 60% of located nests were initiated between 22 March and 10 April, whereas in 2000, only 22% of nests were initiated during the same time period. Average clutch size was 0.9 eggs smaller in 2000 than in 1999. Annual differences in reproductive parameters corresponded with extremely dry conditions caused by low rainfall before the laying period in 2000. Flooded rice fields appear to be important loafing and feeding habitat of Mottled Ducks nesting in agricultural lands, especially during drought periods when other wetland types are not available or where natural wetlands have been eliminated.

Influence of sexually transmitted infections in a horse breeding

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Kosec Marjan

2015-01-01

Full Text Available The most frequent problems in horses reproduction are generally divided into those of infectious and non infectious etiology. Common causes of infectious diseases are usual­ly viruses and bacteria, and less frequently protozoa, mykoplasma and fungi. In this work there are presented the most important fact about sexually transmitted diseases, their clinical picture, risk factors, preventive measures as well as measures to prevent and eradicate the diseases. The biggest risk factor for sexually transmitted diseases in horses are breeding stallions, both in natural mating and in artificial insemination. Therefore, in order to prevent genital infections in horses, it is essential that the stallions used for breeding are healthy (non-infected. That can be determined with certainty only if the stallions are examined (tested just before the breeding season on most frequent sexually transmitted diseases (CEM,EAV. It is well known that in most cases the clinical picture of sexually transmitted diseses is not manifested on genitals. As well, variations in clinical picture can be expected also in mares, depending on the stage of the disease and its etiology. Harms arising from sexually transmitted diseases can be divided into direct and indirect. Direct damage occurs in the form of endometritis, miscarriage, stillbirths and births of weak foals, and indirect in restricting the traffic of infected and suspicios animals, isolation of the infected ones as well as medical treatment and interrupting mating.

Failure to detect seasonal changes in the song system nuclei of the black-capped chickadee (Poecile atricapillus).

Science.gov (United States)

Smulders, T V; Lisi, M D; Tricomi, E; Otter, K A; Chruszcz, B; Ratcliffe, L M; DeVoogd, T J

2006-08-01

Most temperate songbird species sing seasonally, and the brain areas involved in producing song (the song system) vary in size alongside the changes in behavior. Black-capped chickadees (Poecile atricapillus) also sing seasonally, and we find that there are changes in the stereotypy and the length of the fee-bee song from the nonbreeding to the breeding season. Yet despite these changes, we fail to find any evidence of seasonal changes in the song system. The song system of males is larger than that of females, as is typical in songbirds, but the ratio between the sexes is small compared to other species. We suggest three hypotheses to explain our failure to find seasonal variation in the chickadee song system.

An ordination of life histories using morphological proxies: capital vs. income breeding in insects.

Science.gov (United States)

Davis, Robert B; Javoiš, Juhan; Kaasik, Ants; Õunap, Erki; Tammaru, Toomas

2016-08-01

Predictive classifications of life histories are essential for evolutionary ecology. While attempts to apply a single approach to all organisms may be overambitious, recent advances suggest that more narrow ordination schemes can be useful. However, these schemes mostly lack easily observable proxies of the position of a species on respective axes. It has been proposed that, in insects, the degree of capital (vs. income) breeding, reflecting the importance of adult feeding for reproduction, correlates with various ecological traits at the level of among-species comparison. We sought to prove these ideas via rigorous phylogenetic comparative analyses. We used experimentally derived life-history data for 57 species of European Geometridae (Lepidoptera), and an original phylogenetic reconstruction. The degree of capital breeding was estimated based on morphological proxies, including relative abdomen size of females. Applying Brownian-motion-based comparative analyses (with an original update to include error estimates), we demonstrated the associations between the degree of capital breeding and larval diet breadth, sexual size dimorphism, and reproductive season. Ornstein-Uhlenbeck model based phylogenetic analysis suggested a causal relationship between the degree of capital breeding and diet breadth. Our study indicates that the gradation from capital to income breeding is an informative axis to ordinate life-history strategies in flying insects which are affected by the fecundity vs. mobility trade off, with the availability of easy to record proxies contributing to its predictive power in practical contexts. © 2016 by the Ecological Society of America.

Seasonal ovulatory activity exists in tropical Creole female goats and Black Belly ewes subjected to a temperate photoperiod.

Science.gov (United States)

Chemineau, Philippe; Daveau, Agnès; Cognié, Yves; Aumont, Gilles; Chesneau, Didier

2004-08-27

Seasonality of ovulatory activity is observed in European sheep and goat breeds, whereas tropical breeds show almost continuous ovulatory activity. It is not known if these tropical breeds are sensitive or not to temperate photoperiod. This study was therefore designed to determine whether tropical Creole goats and Black-Belly ewes are sensitive to temperate photoperiod. Two groups of adult females in each species, either progeny or directly born from imported embryos, were used and maintained in light-proof rooms under simulated temperate (8 to 16 h of light per day) or tropical (11 - 13 h) photoperiods. Ovulatory activity was determined by blood progesterone assays for more than two years. The experiment lasted 33 months in goats and 25 months in ewes. Marked seasonality of ovulatory activity appeared in the temperate group of Creole female goats. The percentage of female goats experiencing at least one ovulation per month dramatically decreased from May to September for the three years (0%, 27% and 0%, respectively). Tropical female goats demonstrated much less seasonality, as the percentage of goats experiencing at least one ovulation per month never went below 56%. These differences were significant. Both groups of temperate and tropical Black-Belly ewes experienced a marked seasonality in their ovulatory activity, with only a slightly significant difference between groups. The percentage of ewes experiencing at least one ovulation per month dropped dramatically in April and rose again in August (tropical ewes) or September (temperate ewes). The percentage of ewes experiencing at least one ovulation per month never went below 8% and 17% (for tropical and temperate ewes respectively) during the spring and summer months. An important seasonality in ovulatory activity of tropical Creole goats was observed when females were exposed to a simulated temperate photoperiod. An unexpected finding was that Black-Belly ewes and, to a lesser extent, Creole goats exposed to

Energetic Physiology Mediates Individual Optimization of Breeding Phenology in a Migratory Arctic Seabird.

Science.gov (United States)

Hennin, Holly L; Bêty, Jöel; Legagneux, Pierre; Gilchrist, H Grant; Williams, Tony D; Love, Oliver P

2016-10-01

The influence of variation in individual state on key reproductive decisions impacting fitness is well appreciated in evolutionary ecology. Rowe et al. (1994) developed a condition-dependent individual optimization model predicting that three key factors impact the ability of migratory female birds to individually optimize breeding phenology to maximize fitness in seasonal environments: arrival condition, arrival date, and ability to gain in condition on the breeding grounds. While empirical studies have confirmed that greater arrival body mass and earlier arrival dates result in earlier laying, no study has assessed whether individual variation in energetic management of condition gain effects this key fitness-related decision. Using an 8-year data set from over 350 prebreeding female Arctic common eiders (Somateria mollissima), we tested this component of the model by examining whether individual variation in two physiological traits influencing energetic management (plasma triglycerides: physiological fattening rate; baseline corticosterone: energetic demand) predicted individual variation in breeding phenology after controlling for arrival date and body mass. As predicted by the optimization model, individuals with higher fattening rates and lower energetic demand had the earliest breeding phenology (shortest delays between arrival and laying; earliest laying dates). Our results are the first to empirically determine that individual flexibility in prebreeding energetic management influences key fitness-related reproductive decisions, suggesting that individuals have the capacity to optimally manage reproductive investment.

The direct response of the gonads to cues of stress in a temperate songbird species is season-dependent

Directory of Open Access Journals (Sweden)

Nicolette L. McGuire

2013-08-01

Full Text Available The gonadotropin releasing hormone (GnRH system in the hypothalamus is often considered the final point in integration of environmental cues as they pertain to the reproductive axis. However, cues such as stress and food availability are detectable in the plasma (as glucocorticoid and metabolic fuel fluctuations. Vertebrate gonads express glucocorticoid receptor, therefore we hypothesized that the gonads can detect and respond directly to cues of stress. We provide evidence here that, in addition to regulation by the brain, the gonads of European starlings (Sturnus vulgaris respond directly to fluctuations in corticosterone and metabolic fuels by modulating sex steroid secretion. Using a 4-h gonad culture, we show that physiologically-relevant concentrations of corticosterone and metabolic stress (via use of the glucose utilization inhibitor 2-deoxy-D-glucose and the fatty acid oxidation inhibitor ethyl 2-mercaptoacetate (2DG/MA can directly decrease testosterone and estradiol secretion from luteinizing hormone and follicle-stimulating hormone (LH/FSH-stimulated testes and ovaries. This effect is regulated seasonally. Prior to the breeding season, testes and ovaries respond to corticosterone and 2DG/MA by significantly decreasing gonadal steroid release. Within the breeding season, the testes do not respond to these cues of stress, while the ovaries respond only to corticosterone. This seasonal difference in response may be due in part to the influence of these cues of stress on gonadal neuropeptide expression: corticosterone upregulates GnIH expression in the testes while metabolic stress upregulates GnIH in the ovaries. Thus the gonads can directly respond to fluctuations in corticosterone and metabolic fuels during a time of critical importance to the onset of breeding.

To breed or not to breed: a seabird's response to extreme climatic events.

Science.gov (United States)

Cubaynes, Sarah; Doherty, Paul F; Schreiber, E A; Gimenez, Olivier

2011-04-23

Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), using a 19 year mark-recapture dataset involving more than 11,000 birds. We showed that skipping breeding was more likely in El-Niño years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niño years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities.

Influence of breed type and age on spermatological traits of Nigerian ...

African Journals Online (AJOL)

This study evaluated semen quality traits of 36 roosters, comprising 18 roosters each of normal feather and naked neck Nigerian local chicken (NLC) breeds at different ages. The abdominal massage technique was used to collect semen samples from individual roosters at 28, 32, 36 and 40 weeks of age. Individual ...

The breeding biology, nest success, habitat and behavior of the endangered Saffron-cowled Blackbird, Xanthopsar flavus (Aves: Icteridae, at an Important Bird Area (IBA in Rio Grande do Sul, Brazil

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Luciane R. da Silva Mohr

2017-10-01

Full Text Available ABSTRACT The Saffron-cowled Blackbird, Xanthopsar flavus (Gmelin, 1788, is a globally vulnerable icterid endemic to grasslands and open areas, and a priority species for research and conservation programs. This contribution provides information on the population size, habitat, behavior, breeding biology and nest success of X. flavus in two conservation units (CUs in Viamão, state of Rio Grande do Sul, Brazil: the Environmental Protection Area Banhado Grande, and the Wildlife Refuge Banhado dos Pachecos, classified as an “Important Bird Area”. Searches for X. flavus were carried out mainly in open areas, the type of habitat favored by the species. Outside the breeding season individual behavior was recorded by the ad libitum method; during the breeding season, selected X. flavus pairs were observed following the sequence sampling method. The research areas were visited once a month, totaling approximately 530 hours of observations (September 2014 to June 2016 over 84 days, which included two breeding seasons. The species was observed across all months (not necessarily within the same year and several X. flavus flocks were encountered, some with more than one hundred individuals (range = 2-137. Additionally, the behavior and feeding aspects, habitat use and breeding information on X. flavus were recorded. Two breeding colonies were found, and eleven nests were monitored. The estimated nesting success was 10% in Colony 1, but zero in Colony 2, where all eggs and nestlings were predated. Saffron-cowled Blackbirds were recorded in mixed flocks, mostly with Pseudoleistes guirahuro (Vieillot, 1819, P. virescens (Vieillot, 1819 and Xolmis dominicanus (Vieillot, 1823, the last also a globally endangered species. The collected information highlights the importance of CUs for the maintenance of X. flavus populations in the region. Maintenance of proper areas for feeding and breeding is necessary and urgent. Information from current research is being

Seasonal variation in food supply and breeding success in European Coots Fulica atra

NARCIS (Netherlands)

Brinkhof, M.W.G.

1997-01-01

Chick survival in the European Coot typically shows a convex seasonal pattern. Previous experiments revealed that this pattern is directly linked to hatching date and that food supply within the first ten days after hatching is a causal factor in this relationship. However, the precise mechanism

Breed-specific hematological phenotypes in the dog: a natural resource for the genetic dissection of hematological parameters in a mammalian species.

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Jennifer Lawrence

Full Text Available Remarkably little has been published on hematological phenotypes of the domestic dog, the most polymorphic species on the planet. Information on the signalment and complete blood cell count of all dogs with normal red and white blood cell parameters judged by existing reference intervals was extracted from a veterinary database. Normal hematological profiles were available for 6046 dogs, 5447 of which also had machine platelet concentrations within the reference interval. Seventy-five pure breeds plus a mixed breed control group were represented by 10 or more dogs. All measured parameters except mean corpuscular hemoglobin concentration (MCHC varied with age. Concentrations of white blood cells (WBCs, neutrophils, monocytes, lymphocytes, eosinophils and platelets, but not red blood cell parameters, all varied with sex. Neutering status had an impact on hemoglobin concentration, mean corpuscular hemoglobin (MCH, MCHC, and concentrations of WBCs, neutrophils, monocytes, lymphocytes and platelets. Principal component analysis of hematological data revealed 37 pure breeds with distinctive phenotypes. Furthermore, all hematological parameters except MCHC showed significant differences between specific individual breeds and the mixed breed group. Twenty-nine breeds had distinctive phenotypes when assessed in this way, of which 19 had already been identified by principal component analysis. Tentative breed-specific reference intervals were generated for breeds with a distinctive phenotype identified by comparative analysis. This study represents the first large-scale analysis of hematological phenotypes in the dog and underlines the important potential of this species in the elucidation of genetic determinants of hematological traits, triangulating phenotype, breed and genetic predisposition.

Intra-seasonal variation in foraging behavior among Adélie penguins (Pygocelis adeliae) breeding at Cape Hallett, Ross Sea, Antarctica

Science.gov (United States)

Lyver, P.O.B.; MacLeod, C.J.; Ballard, G.; Karl, B.J.; Barton, K.J.; Adams, J.; Ainley, D.G.; Wilson, P.R.

2011-01-01

We investigated intra-seasonal variation in foraging behavior of chick-rearing Adélie penguins, Pygoscelis adeliae, during two consecutive summers at Cape Hallett, northwestern Ross Sea. Although foraging behavior of this species has been extensively studied throughout the broad continental shelf region of the Ross Sea, this is the first study to report foraging behaviors and habitat affiliations among birds occupying continental slope waters. Continental slope habitat supports the greatest abundances of this species throughout its range, but we lack information about how intra-specific competition for prey might affect foraging and at-sea distribution and how these attributes compare with previous Ross Sea studies. Foraging trips increased in both distance and duration as breeding advanced from guard to crèche stage, but foraging dive depth, dive rates, and vertical dive distances travelled per hour decreased. Consistent with previous studies within slope habitats elsewhere in Antarctic waters, Antarctic krill (Euphausia superba) dominated chick meal composition, but fish increased four-fold from guard to crèche stages. Foraging-, focal-, and core areas all doubled during the crèche stage as individuals shifted distribution in a southeasterly direction away from the coast while simultaneously becoming more widely dispersed (i.e., less spatial overlap among individuals). Intra-specific competition for prey among Adélie penguins appears to influence foraging behavior of this species, even in food webs dominated by Antarctic krill.

Comparative studies on testicular and epididymal morphology, and serum hormone concentrations in foxes and the hybrids during the breeding season.

Science.gov (United States)

Yang, T A; Yang, Y H; Peng, Y H; Cong, B; Diao, Y F; Bao, K; Hu, P F; Song, X C; Liu, L L; Yang, Y F; Xing, X M; Yang, F H

2016-05-01

The silver fox and the blue fox belong to different genera, and the hybrid males are fully or partially sterile. In the present study, the objective was to evaluate the causes of hybrid male sterility, and therefore analyze the differences in testicular, and epididymal morphology and serum hormone concentrations among silver foxes, blue foxes, and the hybrids during the breeding season. Samples were collected from 20 male silver foxes, 20 male blue foxes, 15 male HSBs (silver fox female × blue fox male hybrids) and 14 male HBSs (blue fox male × silver fox female hybrids), respectively. Seminal evaluation showed large numbers of sperm present in the semen of blue foxes and silver foxes, but no sperm present in the hybrids. Mean testicular volume and the diameter of seminiferous tubules in silver foxes and blue foxes were greater than in the hybrids; and there were many Sertoli cells, spermatogenic cells, and sperm in silver foxes and blue foxes, while spermatogenic cells decreased with no sperm in the hybrids. Mean serum LH and prolactin concentrations in silver foxes and blue foxes were less and testosterone was greater than in the hybrids (P<0.05). The results indicate that germ cell meioses in the hybrids were arrested at the prophase stage of meiosis, and that lesser concentrations of testosterone and greater concentrations of LH and prolactin can inhibit the completion of spermatogenesis. Copyright © 2016 Elsevier B.V. All rights reserved.

Measurements of Neuronal Soma Size and Estimated Peptide Concentrations in Addition to Cell Abundance Offer a Higher Resolution of Seasonal and Reproductive Influences of GnRH-I and GnIH in European Starlings.

Science.gov (United States)

Amorin, Nelson; Calisi, Rebecca M

2015-08-01

Hypothalamic neuropeptides involved in vertebrate reproduction, gonadotropin releasing hormone (GnRH-I) and gonadotropin-inhibitory hormone (GnIH), can vary in the abundance of immunoreactive cells as a function of the reproductive status and nest box occupation of European starlings (Sturnus vulgaris). While using the abundance of cells as an indicator of the activity of neurohormones is informative, incorporating information on cell size (readily observed using immunohistochemistry) can offer a more detailed understanding of environmentally-mediated changes in hormonal dynamics. In this study, we tested the hypothesis that the size of cells' somas and the estimated concentration of peptides in cells immunoreactive (ir) for GnRH-I and GnIH would vary throughout the breeding season and as a function of nest-box status (resident or not). In the absence of a direct assay of protein, we estimated an index of the concentration of hypothalamic peptides via the relative optical density (i.e., the difference between the mean optical density and the optical density of background staining). In support of our hypothesis, we found that GnRH-I- and GnIH-ir soma size and peptide concentration changed both in males and females throughout the breeding season. Somas were largest and estimated peptide concentration was highest mid-season when compared with earlier in the season or to the non-breeding period. For nest-box residents, GnIH-ir soma size and peptide concentration were higher during the middle of the breeding season than earlier in the breeding season, although residence in the nest box was not related to GnRH-I-ir variables. Our results confirm that previously reported changes in cell abundance mimic changes we see in GnRH-I and GnIH-ir soma size and our proxy for peptide concentration. However, investigating changes in the soma of GnRH-I-ir cells revealed a peak in size during the middle of the breeding season, a change not evident when solely examining data on the

RFRP neurons - the doorway to understanding seasonal reproduction in mammals

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Jo Beldring Henningsen

2016-05-01

Full Text Available Seasonal control of reproduction is critical for the perpetuation of species living in temperate zones that display major changes in climatic environment and availability of food resources. In mammals, seasonal cues are mainly provided by the annual change in the 24h light/dark ratio (i.e. photoperiod, which is translated into the nocturnal production of the pineal hormone melatonin. The annual rhythm in this melatonin signal acts as a synchronizer ensuring that breeding occurs when environmental conditions favor survival of the offspring. Although specific mechanisms might vary among seasonal species, the hypothalamic RF (Arg-Phe amide-related peptides (RFRP-1 and -3 are believed to play a critical role in the central control of seasonal reproduction and in all seasonal species investigated, the RFRP system is persistently inhibited in short photoperiod. Central chronic administration of RFRP-3 in short day-adapted male Syrian hamsters fully reactivates the reproductive axis despite photoinhibitory conditions, which highlights the importance of the seasonal changes in RFRP expression for proper regulation of the reproductive axis. The acute effects of RFRP peptides, however, depend on species, photoperiod and recent studies point towards a different role of RFRP in regulating female reproductive activity. In this review we summarize the recent advances made to understand the role and underlying mechanisms of RFRP in the seasonal control of reproduction, primarily focusing on mammalian species.

A Study of the Effects of Gas Well Compressor Noise on Breeding Bird Populations of the Rattlesnake Canyon Habitat Management Area, San Juan County, New Mexico

Energy Technology Data Exchange (ETDEWEB)

LaGory, K.E.; Chang, Young-Soo; Chun, K.C.; Reeves, T.; Liebich, R.; Smith, K.

2001-06-04

This report, conducted from May through July 2000, addressed the potential effect of compressor noise on breeding birds in gas-production areas administered by the FFO, specifically in the Rattlesnake Canyon Habitat Management Area northeast of Farmington, New Mexico. The study was designed to quantify and characterize noise output from these compressors and to determine if compressor noise affected bird populations in adjacent habitat during the breeding season.

ITER breeding blanket module design and analysis

Energy Technology Data Exchange (ETDEWEB)

Kuroda, Toshimasa; Enoeda, Mikio; Kikuchi, Shigeto [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

1998-11-01

The ITER breeding blanket employs a ceramic breeder and Be neutron multiplier both in small spherical pebble form. Radial-poloidal cooling panels are arranged in the blanket box to remove the nuclear heating in these materials and to reinforce the blanket structure. At the first wall, Be armor is bonded onto the stainless steel (SS) structure to provide a low Z plasma-compatible surface and to protect the first wall/blanket structure from the direct contact with the plasma during off-normal events. Thermo-mechanical analyses and investigation of fabrication procedure have been performed for this breeding blanket. To evaluate thermo-mechanical behavior of the pebble beds including the dependency of the effective thermal conductivity on stress, analysis methods have been preliminary established by the use of special calculation option of ABAQUS code, which are briefly summarized in this report. The structural response of the breeding blanket module under internal pressure of 4 MPa (in case of in-blanket LOCA) resulted in rather high stress in the blanket side (toroidal end) wall, thus addition of a stiffening rib or increase of the wall thickness will be needed. Two-dimensional elasto-plastic analyses have been performed for the Be/SS bonded interface at the first wall taking a fabrication process based on HIP bonding and thermal cycle due to pulsed plasma operation into account. The stress-strain hysteresis during these process and operation was clarified, and a procedure to assess and/or confirm the bonding integrity was also proposed. Fabrication sequence of the breeding blanket module was preliminarily developed based on the procedure to fabricate part by part and to assemble them one by one. (author)

Influence of melatonin receptor 1A gene polymorphisms on seasonal reproduction in Sarda ewes with different body condition scores and ages.

Science.gov (United States)

Mura, M C; Luridiana, S; Bodano, S; Daga, C; Cosso, G; Diaz, M L; Bini, P P; Carcangiu, V

2014-10-01

In several species, circadian changes in melatonin concentrations play a key role in the photoperiodic control of seasonality. In sheep, two silent mutations in the melatonin receptor 1A gene (MTNR1A) at positions 606 and 612 of the exon II are associated with seasonal reproduction. However, in some sheep breeds, no relationships have been found between MTNR1A polymorphisms and reproductive seasonality. This lack of relationship could be due to effects of breed, body condition, age, and/or environmental conditions. Thus, the present study was conducted with the Sarda sheep breed with the aim of documenting the effect of MTNR1A gene polymorphisms on reproductive resumption and to evaluate whether such this effect was modified by differences in body condition score (BCS) and age. Six hundred three- to six-year-old multiparous ewes with BCSs between 2.5 and 3.5 were selected. Genomic DNA was extracted and subjected to PCR to amplify the ovine exon II of the MTNR1A gene. The amplicons were subjected to digestion with the restriction enzymes RsaI and MnlI to detect the T606C and A612G polymorphisms, respectively. Ewes carrying the G/G, G/A, C/C, and C/T genotypes exhibited higher fertility rates (Preproductive resumption in the Sarda sheep breed. Moreover, the data also indicated that, over the limited ranges evaluated in this study, BCS and age had no significant influence on reproductive activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Legume breeding for rust resistance: Lessons to learn from the model Medicago truncatula

OpenAIRE

Rubiales, Diego; Castillejo Sánchez, M. Ángeles; Madrid, Eva; Barilli, Eleonora; Rispail, Nicolas

2011-01-01

Rusts are major biotic constraints of legumes worldwide. Breeding for rust resistance is regarded as the most cost efficient method for rust control. However, in contrast to common bean for which complete monogenic resistance exists and is efficiently used, most of the rust resistance reactions described so far in cool season food legumes are incomplete and of complex inheritance. Incomplete resistance has been described in faba bean, pea, chickpea and lentil and several of their associated Q...

Recurrent selection as breeding strategy for heat tolerance in wheat

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Juarez Campolina Machado

2010-01-01

Full Text Available The development of heat-tolerant varieties is an important goal of wheat breeding programs, requiringefficient selection methods. In the present study the use of recurrent selection was evaluated as a strategy to improve heatstress tolerance in wheat. Two cycles of recurrent selection were performed in experiments conducted in research areas of theUniversidade Federal de Viçosa, located in Coimbra-MG and Viçosa-MG, in 2004 and 2007, in two growing seasons (summerand winter. The genetic gain and the existence of variability show the possibility of successful recurrent selection for heattolerancein wheat.

Analysis of Genome-Wide Copy Number Variations in Chinese Indigenous and Western Pig Breeds by 60 K SNP Genotyping Arrays

Science.gov (United States)

Sun, Yaqi; Wang, Hongyang; Wang, Chao; Yu, Shaobo; Liu, Jing; Zhang, Yu; Fan, Bin; Li, Kui; Liu, Bang

2014-01-01

Copy number variations (CNVs) represent a substantial source of structural variants in mammals and contribute to both normal phenotypic variability and disease susceptibility. Although low-resolution CNV maps are produced in many domestic animals, and several reports have been published about the CNVs of porcine genome, the differences between Chinese and western pigs still remain to be elucidated. In this study, we used Porcine SNP60 BeadChip and PennCNV algorithm to perform a genome-wide CNV detection in 302 individuals from six Chinese indigenous breeds (Tongcheng, Laiwu, Luchuan, Bama, Wuzhishan and Ningxiang pigs), three western breeds (Yorkshire, Landrace and Duroc) and one hybrid (Tongcheng×Duroc). A total of 348 CNV Regions (CNVRs) across genome were identified, covering 150.49 Mb of the pig genome or 6.14% of the autosomal genome sequence. In these CNVRs, 213 CNVRs were found to exist only in the six Chinese indigenous breeds, and 60 CNVRs only in the three western breeds. The characters of CNVs in four Chinese normal size breeds (Luchuan, Tongcheng and Laiwu pigs) and two minipig breeds (Bama and Wuzhishan pigs) were also analyzed in this study. Functional annotation suggested that these CNVRs possess a great variety of molecular function and may play important roles in phenotypic and production traits between Chinese and western breeds. Our results are important complementary to the CNV map in pig genome, which provide new information about the diversity of Chinese and western pig breeds, and facilitate further research on porcine genome CNVs. PMID:25198154

Foraging decisions, patch use, and seasonality in egrets (Aves: ciconiiformes)

Science.gov (United States)

Erwin, R.M.

1985-01-01

Feeding snowy (Egretta thula) and great (Casmerodius albus) egrets were observed during 2 breeding seasons in coastal New Jersey and 2 brief winter periods in northeast Florida (USA). A number of tests based on assumptions of foraging models, predictions from foraging theory, and earlier empirical tests concerning time allocation and movement in foraging patches was made. Few of the expectations based on foraging theory and/or assumptions were supported by the empirical evidence. Snowy egrets fed with greater intensity and efficiency during the breeding season (when young were being fed) than during winter. They also showed some tendency to leave patches when their capture rate declined, and they spent more time foraging in patches when other birds were present nearby. Great egrets showed few of these tendencies, although they did leave patches when their intercapture intervals increased. Satiation differences had some influence on feeding rates in snowy egrets, but only at the end of feeding bouts. Some individuals of both species revisited areas in patches that had recently been exploited, and success rates were usually higher after the 2nd visit. Apparently, for predators of active prey, short-term changes in resource availability ('resource depression') may be more important than resource depletion, a common assumption in most optimal foraging theory models.

First record of the Woolly-necked Stork Ciconia episcopus Boddaert, 1783 (Aves: Ciconiiformes: Ciconiidae breeding in the lowland wet zone of Sri Lanka

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Hemachandra Kularatne

2017-01-01

Full Text Available The Woolly-necked Stork Ciconia episcopus is a resident bird species commonly found breeding in the dry lowlands of Sri Lanka, preferably nesting in remote areas with minimal disturbance, although the breeding and nesting behavior has not yet been adequately documented.  Here we report its nesting behavior, for the first time in lowland wet zone Sri Lanka, from Thalagolla, Beddawela in Kegalle District.  Although its usual breeding season is in the dry zone from February to March with a second breeding cycle from November to early January, here we report breeding in the lowland wet zone from July–October in 2013–2014.  Further, it was interesting to note presumably the same couple of birds used the same nest in 2014 with minimum renovation.  In 2015 the nest had disintegrated and fallen due to continuous heavy rain and there have been no records till June 2016.  Breeding was again recorded from June–September in 2016 with a new nest in a different platform of twigs in the same tree.  

Testicular Morphohistology of Hypsiboas pulchellus (Amphibia, Hylidae During the Breeding Season

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Fernando José CAREZZANO

2015-01-01

Full Text Available In this study, data concerning to the morphological testicular features of Hypsiboas pulchel-lus during the breeding season is provided, in order to know aspects of their reproductive biology. The testis, ovoid and yellowish with 4.64 ± 0.48 mm length and 2.05 ± 0.23 mm wide, are surrounded by the tunica albuginea which measures 5.60 ± 0.82 µm. The seminif-erous locules, placed internally, measure 257.47 ± 58.25 µm in diameter, and cysts with spermatogenic cells associated with Sertoli cells are distinguished in them. The interstitial tissue is scarce. The biggest cells of the germinal series are the spermatogonia I (14.34 ± 1.74 µm, from which spermatogonia II (10.14 ± 1.33 µm originate. Spermatocytes I measure 9.34 ± 0.32 µm and have slightly condensed chromatin. The spermatocytes II are 8.12 ± 1.07 µm long. The spermatids I are spherical, grouped in rounded cysts, and measure 7.61 ± 1.45 µm. On the other hand, spermatids II are elongated (4.09 ± 0.51 µm and not within the cysts. Towards the center of the loculus, the free, lengthened and flagellated spermatozoids are located. The morphohistology of the analyzed testicles show similarities with those observed in other neotropical amphibians, being all the cells of the spermatogenic lineage in the same locule MORFOHISTOLOGÍA TESTICULAR DE Hypsiboas pulchellus (AMPHIBIA, HYLIDAE. En este estudio se aportan datos sobre la morfohistología testicular de Hypsiboas pulchellus para conocer aspectos de su biología reproductiva. Las gónadas se procesaron empleando técnicas histológicas básicas, cortándose a 8 µm y tiñéndose con hematoxilina-eosina y tricrómico de Masson. Los testículos, ovoides y amarillentos de 4,64 ± 0,48 mm de largo por 2,05 ± 0,23 mm de ancho, están rodeados por la túnica albugínea que mide 5,60 ± 0,82 µm. Internamente presentan lóculos seminíferos de 257,47 ± 58,25 µm de diámetro, distinguiéndose en ellos cistos con células espermatog

Breed, sex, and litter effects in 2-month old puppies' behaviour in a standardised open-field test.

Science.gov (United States)

Barnard, Shanis; Marshall-Pescini, Sarah; Pelosi, Annalisa; Passalacqua, Chiara; Prato-Previde, Emanuela; Valsecchi, Paola

2017-05-11

A considerable number of studies have reported differences among dog breeds with respect to their genetic profile, cognitive abilities or personality traits. Each dog breed is normally treated as a homogeneous group, however, researchers have recently questioned whether the behavioural profile of modern breeds still reflects their historical function or if the intense divergent selective pressures and geographical barriers have created a more fragmented picture. The majority of studies attempting to assess and compare modern breeds' personality focused on the evaluation of adult dogs where the potential effects of environmental/human factors on the dogs' behaviour are hard to discern from their genetic heritage. In the following study, we aimed at investigating between- and within-breed differences in the personality of two-months-old puppies by direct behavioural observation of 377 puppies from 12 breeds. Results showed that there was no effect of sex, however both breed and litter, significantly affected all personality traits. Breed on average explained 10% of the variance, whereas the effect of litter was noticeably higher, explaining on average 23% of the variance. Taken together, our results suggest that breed does have some influence on personality traits, but they also highlight the importance of taking litter effects into account.

Seasonal dynamics of butterfly population in DAE Campus, Kalpakkam, Tamil Nadu, India

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K.J. Hussain

2011-01-01

Full Text Available Seasonal population trends of butterflies inhabiting the campus of Department of Atomic Energy (DAE at Kalpakkam were recorded by setting a permanent line transect of 300m and recording all species of butterflies observed within a 5m distance. The survey yielded 2177 individuals of 56 butterfly species, belonging to the families Nymphalidae, Pieridae, Lycaenidae, Papilionidae and Hesperiidae. Nymphalidae were found to be the dominant family during all seasons. Species richness and abundance were highest during the northeast monsoon and winter periods, indicating that in the southern plains of India butterflies prefer cool seasons for breeding and emergence. The taxonomic structure of the butterflies sampled resembles that of the Western Ghats and other regions of India in two ways: (a dominance of nymphalids and (b peak abundance during wet seasons. A detailed study of ecologically important local butterfly fauna and their host plants is in progress, to construct a butterfly garden in Kalpakkam to attract and support butterflies.

U.S. Annual/Seasonal Climate Normals (1981-2010)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Annual Climate Normals for 1981 to 2010 are 30-year averages of meteorological parameters that provide users with many tools to understand typical climate...

RESEARCH STUDY ON THE BREEDING AVIFAUNA OF THE BASCOV RESERVOIR

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Maria Denisa Conete

2015-12-01

considered an important argument for the real protection of the respective area. We consider that the informational stress (the persistent noise pollution as well as chemical pollution (chemical fertilizers, pesticides, detergents, etc. affect in a certain measure not only the success rate of bird breeding but also the normal development of their offspring, at least in those species that are sensitive to the presence of humans. Under these circumstances, there may be unfortunate consequences on the orientation of birds during migration, in spite of the fact that they showed a considerable plasticity of the avian magnetic compass.

Seasonal productivity and nest survival of Golden-cheeked Warblers vary with forest type and edge density

Science.gov (United States)

Rebecca G. Peak; Frank R., III Thompson

2014-01-01

Knowledge of the demography and habitat requirements of the endangered Golden-cheeked Warbler (Setophaga chrysoparia) is needed for its recovery, including measures of productivity instead of reproductive indices. We report on breeding phenology and demography, calculate model-based estimates of nest survival and seasonal productivity and evaluate...

Differences in Voluntary Cow Traffic between Holstein and Illawarra Breeds of Dairy Cattle in a Pasture-based Automatic Milking System

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C. E. F. Clark

2014-04-01

Full Text Available Automatic milking systems (AMS rely upon voluntary cow traffic (the voluntary movement of cattle around a farm for milk harvesting and feed consumption. Previous research on conventional milking systems has shown differences between dairy cow breeds for intake and milk production, however, the ability to manipulate voluntary cow traffic and milking frequency on AMS farms through breed selection is unknown. This study investigated the effect of breed (Holstein Friesian versus Illawarra on voluntary cow traffic as determined by gate passes at the Camden AMS research farm dairy facility. Daily data on days in milk, milk yield, gate passes and milking frequency for 158 Holstein Friesian cows and 24 Illawarra cows were collated by month for the 2007 and 2008 years. Illawarra cows had 9% more gate passes/day than Holstein cows over the duration of the study; however, the milking frequency and milk yield of both breeds were similar. Gate passes were greatest for both breeds in early lactation and in the winter (June to August and summer (December to February seasons. These findings highlight an opportunity to translate increased voluntary cow movement associated with breed selection into increased milking frequencies, milk production and overall pasture-based AMS performance.

Effect of crude protein levels and organic selenium supplementation in the diets fed during the breeding season on reproductive parameters of red-winged tinamous (Rhynchotus rufescens

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L Felipe

2010-03-01

Full Text Available There is little information on the nutrition of red-winged tinamous (Rhynchotus rufescens reared in captivity, and their nutritional requirements still need to be determined. This study aimed at determining dietary crude protein requirements and testing four organic selenium supplementation levels in the diet of red-winged tinamous during the breeding season. Birds were housed in a conventional broiler house divided in 16 boxes with one male and three females each. Iso-energy (2800kcal ME/kg pelleted feeds, based on corn and soybean meal, were supplied in tube feeders. In the first experiment, treatments consisted of four different diets containing different crude protein (CP contents (15, 18, 21, or 24% and in the second experiment, the four diets contained equal protein level (22.5% and four different organic selenium levels (0, 0.2, 0.4, or 0.8ppm. Data were analyzed by the least square method. The best egg weight and eggshell thickness were obtained with 22.5% dietary CP. Organic selenium did not influence the studied reproductive traits of red-winged tinamous (Rhynchotus rufescens males or females.

Establishment of the biochemical and endocrine blood profiles in the Majorera and Palmera dairy goat breeds: the effect of feed restriction

DEFF Research Database (Denmark)

Lérias, Joana R; Peña, Raquel; Hernandez Castellano, Lorenzo E

2015-01-01

Feed restriction, and seasonal weight loss (SWL), are major setbacks for animal production in the tropics and the Mediterranean. They may be solved through the use of autochthonous breeds particularly well adapted to SWL. It is therefore of major importance to determine markers of tolerance to fe...

Analysis of breed effects on semen traits in light horse, warmblood, and draught horse breeds.

Science.gov (United States)

Gottschalk, Maren; Sieme, Harald; Martinsson, Gunilla; Distl, Ottmar

2016-05-01

In the present study, systematic effects on semen quality traits were investigated in 381 stallions representing 22 breeds. All stallions were used for AI either at the Lower Saxon National Stud Celle or the North Rhine-Westphalian National Stud Warendorf. A total of 71,078 fresh semen reports of the years 2001 to 2014 were edited for analysis of gel-free volume, sperm concentration, total number of sperm, progressive motility, and total number of progressively motile sperm. Breed differences were studied for warmblood and light horse breeds of both national studs (model I) and for warmblood breeds and the draught horse breed Rhenish German Coldblood from the North Rhine-Westphalian National stud (model II) using mixed model procedures. The fixed effects of age class, year, and month of semen collection had significant influences on all semen traits in both analyses. A significant influence of the horse breed was found for all semen traits but gel-free volume in both statistical models. Comparing warmblood and light horse stallions of both national studs, we observed highest sperm concentrations, total numbers of sperm, and total numbers of progressively motile sperm in Anglo-Arabian stallions. The draught horse breed Rhenish German Coldblood had the highest least squares means for gel-free volume, whereas all other investigated semen traits were significantly lower in this breed compared to the warmblood stallions under study. The variance components among stallions within breeds were significant for all semen traits and accounted for 40% to 59% of the total variance. The between-breed-variance among stallions was not significant underlining the similar size of the random stallion effect in each of the horse breeds analyzed here. In conclusion, breed and stallion are accounting for a significant proportion of the variation in semen quality. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors affecting the fertility of ewes after intrauterine insemination with frozen-thawed semen during the non-breeding season.

Science.gov (United States)

Fukui, Yutaka; Kohno, Hirohide; Okabe, Kentaro; Katsuki, Sara; Yoshizawa, Masahiro; Togari, Tetsuro; Watanabe, Hiroyuki

2010-08-01

In this study, two successive field trials were conducted during the non-breeding season to investigate various factors affecting on fertility of Suffolk ewes after intrauterine insemination with frozen-thawed semen. In the first year (Experiment 1), three sperm numbers per insemination dose (0.25, 0.5 and 1 million sperm) and five sheep farms were used, and in the second year (Experiment 2), parity, age, body weight, body condition score (BCS) and postpartum days were investigated to compare pregnancy and lambing rates. High pregnancy and lambing rates (70.6 and 70.6%, respectively) were obtained with 0.25 million sperm per dose. There were no significant differences in the pregnancy and lambing rates among the five farms, but there was a tendency for one farm to have higher pregnancy (75.8%, P=0.065) and lambing (72.7%, P=0.077) rates than those (46.7-53.3% and 45.2-53.3% for the pregnancy and lambing rates, respectively) of the other farms. In Experiment 2, ewe age significantly affected both the pregnancy and lambing rates. Nulliparous ewes had a higher lambing rate (72.0%) than that (44.2%) of multiparous ewes, but a significant difference was not revealed. Regardless of body weight, BCS tended to be an important factor influencing on fertility of ewes. Body weight and the postpartum days did not affect the fertility of ewes. It was concluded from these results that the fertility of Suffolk ewes after intrauterine insemination with frozen semen was significantly influenced by sperm number per dose and ewe age. Nulliparous ewes at less than three years of age and with a BCS of more than 3.0 are expected to have higher fertility than other ewes.

Selection problems and objectives in mutation breeding

International Nuclear Information System (INIS)

Mac Key, J.

1984-01-01

In plant breeding, major genes are preferably handled by inbreeding, back-crosses and selection through the family/pedigree method. Polygenic systems need gene accumulation, i.e. handling in bulk allowing natural/recurrent selection to operate. The two types of genetic control normally occur together irrespective of whether the variation is created by crossing or by mutagenesis. Cross-breeding can conveniently work with both types of variation and offers a range of genetic backgrounds. Problems are the often enormous recombination potential risking the break-down of already accomplished genic constellations or undesirable linkages. Mutation induction implies a scattered mono- to oligo-factorial variation mostly functioning as a negative load. As a result, it will be difficult and unrealistic to try to explore micromutations, as defined by Gaul, in vegetatively propagated and autogamous crop plants. Quantitative analyses have not been able to give guidance since the induced variation includes disturbed vitality and main or side-effects of events that are possible to define as macro-mutations. The possibility of better exhausting the variation induced will mainly depend on the precision in selection techniques, i.e. by dividing complex traits into their components, by improving environmental conditions for selection, and/or by sharpening the screening technique. Contrary to recombination breeding, mutation-induced variation does not fit a plan encompassing overall agronomic traits simultaneously. The progress has to go step by step. Thus, even more than in cross-breeding, it is important that accurately outlined objectives be set. Some characters, such as flower colour, can easily be defined while others, such as yield, may be more interdependent, calling for compromises difficult to foresee. The complexity of the latter category of traits is illustrated by the interaction pattern in relation to grain yield in cereals where both shoot and root are considered

Habitat use and movements of breeding male Boreal Owls (Aegolius funereus) in northeast Minnesota as determined by radio telemetry

Science.gov (United States)

William H. Lane; David E. Andersen; Thomas H. Nicholls

1997-01-01

To determine habitat use and movements of male Boreal Owls (Aegolius funereus) in northeast Minnesota, we monitored 10 radio-equipped owls from 1990-1992. We used mist nets, bal-chartris, and the taped playback recording of the primary song of the male Boreal Owl to trap territorial male owls during the springtime breeding season.

Breeding of proanthocyanidin free malting barley

International Nuclear Information System (INIS)

Andersen, Anna Maria

1990-01-01

Full text: Haze formation in stored beer is due to colloidal precipitation of proteins with polyphenols of which proanthocyanidins are the most important group. 70-80% of proanthocyanidin in beer are from barley malt. Today breweries attain haze stability by using enzymes, additives or adsorbents. A better solution would be to remove proanthocyanidins. Carlsberg Plant Breeding uses induced mutations to breed proanthocyanidin-free malting barley. After mutagen treatment with sodium azide M1 seeds are planted in the field and M2 seeds are harvested in bulk. A single seed, non-destructive method has been developed to identify mutant kernels lacking proanthocyanidins in the testa. The method involves the inclusion of M2 seeds - 50 at a time - in semisolid clay blocks, whereafter a small part of the endosperm, testa and pericarp are exposed by sanding the seeds. The clay block is then placed in a vanillin-HCI solution so that the uncovered tissues can react with the solution. A red colour will develop in the testa of normal seeds, whereas the testa layers of proanthocyanid-free seeds remain colourless. So far, more than 600 mutants have been induced in over 100 barley varieties, spring as well as winter-types, from barley producing areas around the world. The mutants can be assigned to at least 7 loci, all of which can block the biosynthetic pathway for the proanthocyanidins. Mutants in the ant-18 and ant-19 loci show poor kernel development. Only a few mutants are known in the ant-12, ant-22 and ant-25 loci. Breeding work is focussed on mutants belonging to the ant-13 and ant-17 loci. Whereas the malting quality of ant-17 lines suffer from apparent abnormal enzyme development in the aleurone layer, this defect does not exist in ant-13 lines. Brewing trials with proanthocyanidin-free malt have shown excellent haze stability without changes in beer flavour. Breeding work based on the ant-13 lines led to disease resistant lines with good malting quality, while grain yield

Machine Learning Model Analysis of Breeding Habitats for the Black-necked Crane in Central Asian Uplands under Anthropogenic Pressures.

Science.gov (United States)

Han, Xuesong; Guo, Yumin; Mi, Chunrong; Huettmann, Falk; Wen, Lijia

2017-07-21

The black-necked crane (Grus nigricollis) is the only alpine crane species and is endemic to the Tibetan Plateau. The breeding habitats of this species are poorly understood, which greatly hampers practical research and conservation work. Using machine learning methods and the best-available data from our 7,000-kilometer mega-transect survey and open access data, we built the first species distribution model (SDM) to analyze the black-necked crane's breeding habitats. Our model showed that current conservation gaps account for 26.7% of its predicted breeding habitats. Specifically, the northern parts of the Hengduan Mountains and the southeastern Tibet Valley, the northern side of the middle Kunlun Mountains, parts of the Pamir Plateau, the northern Pakistan Highlands and the western Hindu Kush should be considered as its main potential breeding areas. Additionally, our model suggested that the crane prefers to breed in alpine meadows at an elevation over 2,800 m, a maximum temperature of the warmest month below 20.5 °C, and a temperature seasonality above 7,800 units. The identified conservation gaps and potential breeding areas can aid in clearly prioritizing future conservation and research, but more attention and study should be directed to the unassessed Western Development of China to secure this endangered crane lineage and other wildlife on the Tibetan Plateau.

Oestrous behaviour and ovarian activity in D'man and Sardi breeds of Moroccan sheep under normal and experimental photoperiods

International Nuclear Information System (INIS)

Lahlou-Kassi, A.; Boukhliq, R.

1988-01-01

The effect of photoperiod on sexual activity was investigated in Sardi and D'man ewes. Twenty ewes from each breed were subjected to an experimental photoperiod corresponding to latitude 56 deg. N. Control ewes (12 per breed) were maintained under natural photoperiod (32 deg. N). Behavioural oestrus and ovarian activity were monitored using penis deviated rams and plasma progesterone levels. Preliminary results from this study show that an increase in amplitude of photoperiod variations causes a decrease in the expression of oestrous behaviour in D'man ewes during the period of decreasing daylight. Ovarian activity remained unchanged. Sardi ewes were not markedly affected by change in photoperiod. (author). 13 refs, 3 figs, 1 tab

Breeding behavior and reproductive life history of the Neosho Madtom, Noturus placidus (Teleostei: Ictaluridae)

Science.gov (United States)

Bulger, Angela G.; Wilkinson, Christopher D.; Edds, David R.; Wildhaber, Mark L.

2002-01-01

The Neosho madtom, Noturus placidus, is a small catfish listed by the U. S. Fish and Wildlife Service as threatened. Little is known of its breeding biology and behavior because high turbidity and flow during its spawning season prevent direct observation in the field, and captive propagation has met with limited success. We held Neosho madtoms in laboratory aquaria in 1996 and 1998 to study sexual dimorphism during breeding season, courtship and nesting behavior, egg and clutch size, and embryological and larval development. We also attempted to induce spawning. Courtship behaviors were recorded on videotape, including “carousel” and “tail curl” displays in which the fish spun in circles, head to tail, then quivered, with the male's tail wrapped around the female's head. Three clutches were observed, all in nest cavities that had been excavated by the fish under a structure; one clutch (1996) consisted of approximately 60 eggs, with a mean chorion diameter of 3.1 mm, and two (1998) consisted of approximately 30 eggs, with mean diameter of 3.7 mm. In all situations, eggs hatched after eight or nine days, and yolk-sacs were fully depleted seven days later. One spawn (1998) occurred after two days of injection with synthetic hormone. Male parental care of eggs and larvae was observed in 1996. Larvae remained in the nest until yolk-sacs were absorbed, after which they dispersed throughout the tank. Dissection of two females that laid clutches in this study revealed previtellogenic eggs in the lumen of ovaries, with a mean chorion diameter of 0.9 mm. Swollen lips of males, distended abdomen of females, and differences in head shape, premaxillary tooth patch coloring, and genital papillae of breeding males and females were documented during spawning periods.

Regional variation in diets of breeding Red-shouldered hawks

Science.gov (United States)

Strobel, Bradley N.; Boal, Clint W.

2010-01-01

We collected data on breeding season diet composition of Red-shouldered Hawks (Buteo lineatus) in south Texas and compared these data, and those reported from studies elsewhere to examine large scale spatial variation in prey use in eastern North America. Red-shouldered Hawk diets aligned into two significantly different groups, which appear to correlate with latitude. The diets of Red-shouldered Hawks in group 1, which are of more northern latitudes, had significantly more mammalian prey and significantly less amphibian prey than those in group 2, which are at more southerly latitudes. Our meta-analysis demonstrated the dietary flexibility of Red-shouldered Hawks, which likely accounts for their broad distribution by exploiting regional variations in taxon-specific prey availability.

What drives cooperative breeding?

Directory of Open Access Journals (Sweden)

Walter D Koenig

2017-06-01

Full Text Available Cooperative breeding, in which more than a pair of conspecifics cooperate to raise young at a single nest or brood, is widespread among vertebrates but highly variable in its geographic distribution. Particularly vexing has been identifying the ecological correlates of this phenomenon, which has been suggested to be favored in populations inhabiting both relatively stable, productive environments and in populations living under highly variable and unpredictable conditions. Griesser et al. provide a novel approach to this problem, performing a phylogenetic analysis indicating that family living is an intermediate step between nonsocial and cooperative breeding birds. They then examine the ecological and climatic conditions associated with these different social systems, concluding that cooperative breeding emerges when family living is favored in highly productive environments, followed secondarily by selection for cooperative breeding when environmental conditions deteriorate and within-year variability increases. Combined with recent work addressing the fitness consequences of cooperative breeding, Griesser et al.'s contribution stands to move the field forward by demonstrating that the evolution of complex adaptations such as cooperative breeding may only be understood when each of the steps leading to it are identified and carefully integrated.

The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes

Institute of Scientific and Technical Information of China (English)

Emmanuel ZUFIAURRE; Mariano CODESIDO; Agustín M.ABBA; David BILENCA

2017-01-01

In temperate agroecosystems,avian responses in abundance and distribution to landscape attributes may be exacerbated by the coupling of natural seasons and farming practices.We assessed the seasonal roles of field WPe,field use in the surroundings,and distance from a field to the nearest woodlot on the abundance of seed-eating birds in a 225,000 km2 study area in the Pampas of central Argentina.During spring-summer and autumn of 2011-2013,we randomly selected 392 fields and used transect samples to collect data on abundance and presence of seed-eating bird species.We recorded a total of 11,579 individuals belonging to 15 seed-eating bird species.We used generalized lineal mixed models to relate bird abundance to field type,field use in the surroundings,and distance to the nearest woodlot.In spring-summer (breeding season) most bird responses were associated with their nesting requirements.Species that build their nests in trees,such as eared doves Zenaida auriculata,picazuro pigeons Patagioenas picazuro,and monk parakeets Myiopsitta monachus,were more abundant in fields closer to woodlots,whereas grassland yellow-finches Sicalis luteola,which nest at areas with tall grasses,were more abundant in fields with livestock use patches in the field surroundings.In autumn (non-breeding season),most bird responses were associated with foraging and refuge needs.The high abundance of eared doves in crop stubbles and the association of pigeons at field surroundings dominated by croplands or at crop stubbles surrounded by livestock use fields revealed the intimate association of these species to sites with high availability of food resources.In addition,both picazuro pigeons and spot-winged pigeons Patagioenas maculosa were associated with woodlots,which provide suitable roosting sites.Our results show that in temperate agroecosystems,the relationships between field characteristics and seed-eating bird abundances vary with season.

The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes

Science.gov (United States)

Codesido, Mariano; Abba, Agustín M.; Bilenca, David

2017-01-01

Abstract In temperate agroecosystems, avian responses in abundance and distribution to landscape attributes may be exacerbated by the coupling of natural seasons and farming practices. We assessed the seasonal roles of field type, field use in the surroundings, and distance from a field to the nearest woodlot on the abundance of seed-eating birds in a 225,000 km2 study area in the Pampas of central Argentina. During spring-summer and autumn of 2011–2013, we randomly selected 392 fields and used transect samples to collect data on abundance and presence of seed-eating bird species. We recorded a total of 11,579 individuals belonging to 15 seed-eating bird species. We used generalized lineal mixed models to relate bird abundance to field type, field use in the surroundings, and distance to the nearest woodlot. In spring-summer (breeding season) most bird responses were associated with their nesting requirements. Species that build their nests in trees, such as eared doves Zenaida auriculata, picazuro pigeons Patagioenas picazuro, and monk parakeets Myiopsitta monachus, were more abundant in fields closer to woodlots, whereas grassland yellow-finches Sicalis luteola, which nest at areas with tall grasses, were more abundant in fields with livestock use patches in the field surroundings. In autumn (non-breeding season), most bird responses were associated with foraging and refuge needs. The high abundance of eared doves in crop stubbles and the association of pigeons at field surroundings dominated by croplands or at crop stubbles surrounded by livestock use fields revealed the intimate association of these species to sites with high availability of food resources. In addition, both picazuro pigeons and spot-winged pigeons Patagioenas maculosa were associated with woodlots, which provide suitable roosting sites. Our results show that in temperate agroecosystems, the relationships between field characteristics and seed-eating bird abundances vary with season. PMID

indigenous cattle breeds

African Journals Online (AJOL)

Received 31 August 1996; accepted 20 March /998. Mitochondrial DNA cleavage patterns from representative animals of the Afrikaner and Nguni sanga cattle breeds, indigenous to Southern Africa, were compared to the mitochondrial DNA cleavage patterns of the Brahman (zebu) and the Jersey. (taurine) cattle breeds.

Genomic dairy cattle breeding

DEFF Research Database (Denmark)

Mark, Thomas; Sandøe, Peter

2010-01-01

the thoughts of breeders and other stakeholders on how to best make use of genomic breeding in the future. Intensive breeding has played a major role in securing dramatic increases in milk yield since the Second World War. Until recently, the main focus in dairy cattle breeding was on production traits...... it less accountable to the concern of private farmers for the welfare of their animals. It is argued that there is a need to mobilise a wide range of stakeholders to monitor developments and maintain pressure on breeding companies so that they are aware of the need to take precautionary measures to avoid...

Across Breed QTL Detection and Genomic Prediction in French and Danish Dairy Cattle Breeds

DEFF Research Database (Denmark)

van den Berg, Irene; Guldbrandtsen, Bernt; Hozé, C

Our objective was to investigate the potential benefits of using sequence data to improve across breed genomic prediction, using data from five French and Danish dairy cattle breeds. First, QTL for protein yield were detected using high density genotypes. Part of the QTL detected within breed was...

Male endocrine response to seasonally varying environmental and social factors in a neotropical primate, Cebus capucinus.

Science.gov (United States)

Schoof, Valérie A M; Bonnell, Tyler R; Jack, Katharine M; Ziegler, Toni E; Melin, Amanda D; Fedigan, Linda M

2016-04-01

Circannual variation in reproduction is pervasive in birds and mammals. In primates, breeding seasonality is variable, with seasonal birth peaks occurring even in year-round breeders. Environmental seasonality is reportedly an important contributor to the observed variation in reproductive seasonality. Given that food availability is the primary factor constraining female reproduction, predictions concerning responsiveness to environmental seasonality focus on females, with studies of males focusing primarily on social factors. We examined the influence of both environmental and social factors on male fecal testosterone (fT) and glucocorticoids (fGC) in moderately seasonally breeding white-faced capuchin monkeys (Cebus capucinus) in Costa Rica. Over 17 months, we collected 993 fecal samples from 14 males in three groups. We used LMM to simultaneously examine the relative effects of photoperiod, fruit biomass, rainfall, temperature, female reproductive status (i.e., number of periovulatory periods, POPs), and male age and dominance rank on monthly fT and fGC levels. Male age and rank had large effects on fT and fGC. Additionally, some hormone variation was explained by environmental factors: photoperiod in the previous month (i.e., lagged photoperiod) was the best environmental predictor of monthly fT levels, whereas fGC levels were best explained by lagged photoperiod, fruit biomass, and rainfall. POPs predicted monthly fT and fGC, but this effect was reduced when all variables were considered simultaneously, possibly because lagged photoperiod and POP were highly correlated. Males may use photoperiod as a cue predicting circannual trends in the temporal distribution of fertile females, while also fine-tuning short-term hormone increases to the actual presence of ovulatory females, which may occur at any time during the year. © 2016 Wiley Periodicals, Inc.

Tritium breeding materials

International Nuclear Information System (INIS)

Hollenberg, G.W.; Johnson, C.E.; Abdou, M.

1984-03-01

Tritium breeding materials are essential to the operation of D-T fusion facilities. Both of the present options - solid ceramic breeding materials and liquid metal materials are reviewed with emphasis not only on their attractive features but also on critical materials issues which must be resolved

Tritium breeding materials

International Nuclear Information System (INIS)

Hollenberg, G.W.; Johnson, C.E.; Abdou, M.A.

1984-01-01

Tritium breeding materials are essential to the operation of D-T fusion facilities. Both of the present options - solid ceramic breeding materials and liquid metal materials are reviewed with emphasis not only on their attractive features but also on critical materials issues which must be resolved

Estimating occurrence and detection probabilities for stream-breeding salamanders in the Gulf Coastal Plain

Science.gov (United States)

Lamb, Jennifer Y.; Waddle, J. Hardin; Qualls, Carl P.

2017-01-01

Large gaps exist in our knowledge of the ecology of stream-breeding plethodontid salamanders in the Gulf Coastal Plain. Data describing where these salamanders are likely to occur along environmental gradients, as well as their likelihood of detection, are important for the prevention and management of amphibian declines. We used presence/absence data from leaf litter bag surveys and a hierarchical Bayesian multispecies single-season occupancy model to estimate the occurrence of five species of plethodontids across reaches in headwater streams in the Gulf Coastal Plain. Average detection probabilities were high (range = 0.432–0.942) and unaffected by sampling covariates specific to the use of litter bags (i.e., bag submergence, sampling season, in-stream cover). Estimates of occurrence probabilities differed substantially between species (range = 0.092–0.703) and were influenced by the size of the upstream drainage area and by the maximum proportion of the reach that dried. The effects of these two factors were not equivalent across species. Our results demonstrate that hierarchical multispecies models successfully estimate occurrence parameters for both rare and common stream-breeding plethodontids. The resulting models clarify how species are distributed within stream networks, and they provide baseline values that will be useful in evaluating the conservation statuses of plethodontid species within lotic systems in the Gulf Coastal Plain.

The influence of cross-breeding Zlotnicka Spotted native breed sows ...

African Journals Online (AJOL)

To sum up, it is possible to say that the raw meat of Zlotnicka Spotted pigs and their cross-breeds with Duroc and Polish Large White breeds is characterised by good quality and because of its considerable intramuscular fat content, it has a high culinary and processing value, especially for ripening products. Key words: Pigs ...

Home in the heat: Dramatic seasonal variation in home range of desert golden eagles informs management for renewable energy development

Science.gov (United States)

Braham, Melissa A.; Miller, Tricia A.; Duerr, Adam E.; Lanzone, Michael J.; Fesnock, Amy; LaPre, Larry; Driscoll, Daniel; Katzner, Todd E.

2015-01-01

Renewable energy is expanding quickly with sometimes dramatic impacts to species and ecosystems. To understand the degree to which sensitive species may be impacted by renewable energy projects, it is informative to know how much space individuals use and how that space may overlap with planned development. We used global positioning system–global system for mobile communications (GPS-GSM) telemetry to measure year-round movements of golden eagles (Aquila chrysaetos) from the Mojave Desert of California, USA. We estimated monthly space use with adaptive local convex hulls to identify the temporal and spatial scales at which eagles may encounter renewable energy projects in the Desert Renewable Energy Conservation Plan area. Mean size of home ranges was lowest and least variable from November through January and greatest in February–March and May–August. These monthly home range patterns coincided with seasonal variation in breeding ecology, habitat associations, and temperature. The expanded home ranges in hot summer months included movements to cooler, prey-dense, mountainous areas characterized by forest, grasslands, and scrublands. Breeding-season home ranges (October–May) included more lowland semi-desert and rock vegetation. Overlap of eagle home ranges and focus areas for renewable energy development was greatest when eagle home ranges were smallest, during the breeding season. Golden eagles in the Mojave Desert used more space and a wider range of habitat types than expected and renewable energy projects could affect a larger section of the regional population than was previously thought.

Predation risk determines breeding territory choice in a Mediterranean cavity-nesting bird community.

Science.gov (United States)

Parejo, Deseada; Avilés, Jesús M

2011-01-01

Non-direct effects of predation can be an important component of the total effect of predation, modulating animal population and community dynamics. The isolated effects of predation risk on the spatial organisation of the breeding bird community, however, remains poorly studied. We investigated whether an experimentally increased predation risk prior to reproduction affected breeding territory selection and subsequent reproductive strategies in three Mediterranean cavity-nesting birds, i.e., the little owl Athene noctua, European roller Coracias garrulus and scops owl Otus scops. We found that territories used the previous year were more likely to be re-occupied when they belonged to the safe treatment rather than to the risky treatment. The first choice of breeders of all three species was for safe territories over risky ones. When all breeding attempts in the season (i.e., final occupation) were considered, breeders also preferred safe to risky sites. In addition, little owls laid larger eggs in risky territories than in safe territories. Our study provides experimental evidence of a rapid preventive response of the three most abundant species in a cavity-nesting bird community to a short-term manipulation of predation risk. This response highlights the key role of the non-direct effects of predation in modulating avian community organisation.

Genetic diversity of dog breeds: within-breed diversity comparing genealogical and molecular data.

Science.gov (United States)

Leroy, G; Verrier, E; Meriaux, J C; Rognon, X

2009-06-01

The genetic diversity of 61 dog breeds raised in France was investigated. Genealogical analyses were performed on the pedigree file of the French kennel club. A total of 1514 dogs were also genotyped using 21 microsatellite markers. For animals born from 2001 to 2005, the average coefficient of inbreeding ranged from 0.2% to 8.8% and the effective number of ancestors ranged from 9 to 209, according to the breed. The mean value of heterozygosity was 0.62 over all breeds (range 0.37-0.77). At the breed level, few correlations were found between genealogical and molecular parameters. Kinship coefficients and individual similarity estimators were, however, significantly correlated, with the best mean correlation being found for the Lynch & Ritland estimator (r = 0.43). According to both approaches, it was concluded that special efforts should be made to maintain diversity for three breeds, namely the Berger des Pyrénées, Braque Saint-Germain and Bull Terrier.

Blood gas and electrolyte values of (Capra hircus Canindé breed goats raised in the northeastern semiarid

Directory of Open Access Journals (Sweden)

Talyta Lins Nunes

2014-09-01

Full Text Available ABSTRACT. Nunes T.L., Oliveira M.G.C., Paiva A.L.C., Bezerra T.C.G., Barrêto Júnior R.A. & Paula V.V. [Blood gas and electrolyte values of (Capra hircus Canindé breed goats raised in the northeastern semiarid.] Valores hemogasométricos de caprinos (Capra hircus da raça Canindé criados no semiárido nordestino. Revista Brasileira de Medicina Veterinária, 36(3:255-260, 2014. Departamento de Ciências Animais, Universidade Federal Rural do Semi-Árido, BR 110, Km 47, Bairro Presidente Costa e Silva, Mossoró, RN 59625-900, Brasil. E-mail: talyta_lins@hotmail.com Canindé goat breed is native of northeastern Brazil and is in danger of extinction. The objective of this research was to determine blood gas and electrolytes values in Canindé goat breed reared in the state of Rio Grande do Norte, establishing baseline data for the breed in the semi-arid conditions. Blood samples from 83 clinically healthy animals were collected and distributed in four groups: Group I comprised of 32 pregnant females, Group II, 29 non-pregnant, Group III, 10 males, and group IV consisted of 12 pups. The blood sample was submitted for blood gas analysis, determining the concentration of sodium, potassium, chloride, total carbon dioxide, pH, carbon dioxide partial pressure, sodium bicarbonate, excess base, and anion gap. Data with normal distribution were analyzed by ANOVA and Tukey test; those which did not have a normal distribution were analyzed by Kruskal-Wallis, Mann-Whitney and Spearman. The results were expressed as mean and standard deviation. The values obtained were similar to those found in other studies with different goat and sheep breeds, and thus may serve as reference for the Canindé breed. The data suggest an influence of age, sex and reproductive status in the variables analyzed.

Breeds in danger of extintion and biodiversity

OpenAIRE

A. Blasco

2008-01-01

Some arguments currently used to support breed conservation are examined. The central point is that we cannot conserve all breeds because we do not have financial resources enough to keep everything (mainly in developing countries) and in many cases we do not have special reasons to conserve breeds. A breed is a human product and it should not be confused with specie. A breed can be generated or transformed. We can create synthetic breeds with the best characteristics of several breeds. Selec...

Effects of testosterone on contractile properties of sexually dimorphic forelimb muscles in male bullfrogs (Rana catesbeiana, Shaw 1802

Directory of Open Access Journals (Sweden)

Aaron R. Kampe

2013-07-01

This study examined the effects of testosterone (T on the contractile properties of two sexually dimorphic forelimb muscles and one non-dimorphic muscle in male bullfrogs (Rana catesbeiana, Shaw 1802. The dimorphic muscles in castrated males with testosterone replacement (T+ achieved higher forces and lower fatigability than did castrated males without replaced testosterone (T0 males, but the magnitude of the differences was low and many of the pair-wise comparisons of each muscle property were not statistically significant. However, when taken as a whole, the means of seven contractile properties varied in the directions expected of masculine values in T+ animals in the sexually dimorphic muscles. Moreover, these data, compared with previous data on male and female bullfrogs, show that values for T+ males are similar to normal males and are significantly different from females. The T0 males tended to be intermediate in character between T+ males and females, generally retaining masculine values. This suggests that the exposure of young males to T in their first breeding season produces a masculinizing effect on the sexually dimorphic muscles that is not reversed between breeding seasons when T levels are low. The relatively minor differences in contractile properties between T+ and T0 males may indicate that as circulating T levels rise during breeding season in normal males, contractile properties can be enhanced rapidly to maximal functional levels for breeding success.

Genomics-assisted breeding in fruit trees.

Science.gov (United States)

Iwata, Hiroyoshi; Minamikawa, Mai F; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

2016-01-01

Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the plant to assess the marketable product (fruit). In this article, we describe the potential of genomics-assisted breeding, which uses these novel genomics-based approaches, to break through these barriers in conventional fruit tree breeding. We first introduce the molecular marker systems and whole-genome sequence data that are available for fruit tree breeding. Next we introduce the statistical methods for biparental linkage and quantitative trait locus (QTL) mapping as well as GWAS and GS. We then review QTL mapping, GWAS, and GS studies conducted on fruit trees. We also review novel technologies for rapid generation advancement. Finally, we note the future prospects of genomics-assisted fruit tree breeding and problems that need to be overcome in the breeding.

Seasonal migrations, body temperature fluctuations, and infection dynamics in adult amphibians

Directory of Open Access Journals (Sweden)

David R. Daversa

2018-05-01

Full Text Available Risks of parasitism vary over time, with infection prevalence often fluctuating with seasonal changes in the annual cycle. Identifying the biological mechanisms underlying seasonality in infection can enable better prediction and prevention of future infection peaks. Obtaining longitudinal data on individual infections and traits across seasons throughout the annual cycle is perhaps the most effective means of achieving this aim, yet few studies have obtained such information for wildlife. Here, we tracked spiny common toads (Bufo spinosus within and across annual cycles to assess seasonal variation in movement, body temperatures and infection from the fungal parasite, Batrachochytrium dendrobatidis (Bd. Across annual cycles, toads did not consistently sustain infections but instead gained and lost infections from year to year. Radio-tracking showed that infected toads lose infections during post-breeding migrations, and no toads contracted infection following migration, which may be one explanation for the inter-annual variability in Bd infections. We also found pronounced seasonal variation in toad body temperatures. Body temperatures approached 0 °C during winter hibernation but remained largely within the thermal tolerance range of Bd. These findings provide direct documentation of migratory recovery (i.e., loss of infection during migration and escape in a wild population. The body temperature reductions that we observed during hibernation warrant further consideration into the role that this period plays in seasonal Bd dynamics.

Differences in size between first and replacement clutches match the seasonal decline in single clutches in Tree Swallows

NARCIS (Netherlands)

Karagicheva, J.; Liebers, M.; Rakhimberdiev, E.; Hallinger, K.; Saveliev, A.; Winkler, D.W.

2016-01-01

The seasonal decline in clutch size in birds can be a response to the environmentallyconditioned decrease in prospects for offspring or a consequence of a lower physical abilityof late-breeding females. To find out which of the explanations apply in Tree SwallowsTachycineta bicolor, we assessed

Seasonal changes in the physiology of male Virginia opossums (Didelphis virginiana): signs of the Dasyurid semelparity syndrome?

Science.gov (United States)

Woods, Henri A; Hellgren, Eric C

2003-01-01

Semelparity, which is multiplying once in a lifetime, is a rare reproductive strategy among mammals. Several species of the marsupial family Dasyuridae experience 100% male mortality following an intense mating period. We investigated seasonal physiological changes that may be associated with early mortality in the male Virginia opossum (Didelphis virginiana; Didelphidae) and compared these changes with those of semelparous, male dasyurids. Free-ranging male Virginia opossums (n=36) were collected during 2001 at the Oklahoma State University Cross Timbers Experimental Range. Seasonal data were collected on hematological, morphological, and helminth parameters of these individuals. We used one-way ANOVA to determine whether there were seasonal differences among means for each parameter. It appeared that male Virginia opossums experienced some physiological changes similar to those of male dasyurids exhibiting semelparity. All males collected in summer (August) were juveniles of the year. Lack of adult males in August suggests high mortality of this cohort during the breeding season. Opossum characteristics exhibiting the dasyurid semelparity syndrome included packed cell volume, adrenal mass, and helminth numbers. Minor lymphocytopenia, neutrophilia, and testosterone concentrations also were similar to semelparous dasyurids. However, a lack of change in serum cortisol concentration and body mass and dynamics in immunoglobulin protein, serum protein, and testes mass were not consistent with previous reports of semelparous dasyurid physiology. Evolutionary divergence and differences in breeding behavior between dasyurids and didelphids may be responsible for the lack of consistency between the taxa.

The effect of breeding facility and sexual stimulation on plasma cortisol in boars.

Science.gov (United States)

Levis, D G; Barnett, J L; Hemsworth, P H; Jongman, E

1995-12-01

Nine boars were used to evaluate effects of breeding facility design and sexual activity on plasma cortisol concentrations . In one breeding facility (conventional), boars were housed individually in small pens, and female pigs were mated in those boar pens. In another breeding facility (Detection-Mating Area [DMA] system), boars were housed individually in stalls, and female pigs were mated in a specific mating pen adjacent to the front of stalls where boars were housed. After 51 d of housing treatment, a catheter was surgically implanted in the cephalic vein for collection of blood samples. Daytime profiles (hourly collections from 0900 to 1700) of cortisol did not differ among boars in the two treatment groups. Cortisol was greater (P cortisol in boars, but breeding facility did not affect the ACTH-induced changes in cortisol concentrations. There was a treatment x time interaction (P cortisol after sexual stimulation, and the magnitude and duration of increase in cortisol were greater (P Cortisol was greater (P cortisol concentration in boars seems to be a normal biological response to sexual activity. However, magnitude and duration of the increase in cortisol may be influenced by breeding facility design and mating procedure. There is no evidence, based on physiological data, that housing boars in stalls in the DMA system has any adverse effects on their welfare.

Mutation breeding on dueruem wheat (Triticum durum Desf.) by nuclear techniques

International Nuclear Information System (INIS)

2011-01-01

Cereals provide 50 % of protein and calorie essential for nutrition. Cereals contribution to total daily food consumption can go up to 3/4, if their role in animal feeding has also been considered. Of the 41 % of crop plants are cereals and their share in food production is as high as 98 %. Combination of high yielding cultivars and adequate management techniques is primary to increase yield in unit area. Crossing is the most common breeding method to develop new cultivars. Mutation has been important as a direct or complemental technique to crossing in plant breeding. Mutation is an effective method to expand existent gene pools for breeding purposes. It has been proved as a successful and effectual method by widely grown mutant cereal varieties. Considering these successful examples, Saraykoey Nuclear Research and Training Center started a durum wheat mutation breeding program in 2002. Main goal of the program is to develop durum wheat lines/varieties with high adaptation to drought and cold, high yield and quality, and short length. Kunduru 1149 has been used as parent cultivar. Kunduru 1149 had 11 % seed moisture content and 98 % germination rate. Seeds were irradiated with 50, 150, 250 Gy of gamma rays from a 6 0Co source and 0,002-0,004 EMS doses of individual and bulk applications for growth rooms and field experiments, respectfully. M1 plants of field experiment had been transplanted to the several field days after the treatment. M2 generation seeds were harvested from fertile spikes of M1 plants and planted to field in the next growing season in 2003. Selections based on the program goals were made throughout M3-M6 generations in 2004-2008. Preliminary field yield trials have been in progress with selected mutant lines of M6 generation based on their quality analysis.

Genomic analyses of modern dog breeds.

Science.gov (United States)

Parker, Heidi G

2012-02-01

A rose may be a rose by any other name, but when you call a dog a poodle it becomes a very different animal than if you call it a bulldog. Both the poodle and the bulldog are examples of dog breeds of which there are >400 recognized worldwide. Breed creation has played a significant role in shaping the modern dog from the length of his leg to the cadence of his bark. The selection and line-breeding required to maintain a breed has also reshaped the genome of the dog, resulting in a unique genetic pattern for each breed. The breed-based population structure combined with extensive morphologic variation and shared human environments have made the dog a popular model for mapping both simple and complex traits and diseases. In order to obtain the most benefit from the dog as a genetic system, it is necessary to understand the effect structured breeding has had on the genome of the species. That is best achieved by looking at genomic analyses of the breeds, their histories, and their relationships to each other.

Investigation of the seasonal microbiome of Anopheles coluzzii mosquitoes in Mali.

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Benjamin J Krajacich

Full Text Available The poorly understood mechanisms of dry season persistence of Anopheles spp. mosquitoes through the dry season in Africa remain a critical gap in our knowledge of Plasmodium disease transmission. While it is thought that adult mosquitoes remain in a dormant state throughout this seven-month dry season, the nature of this state remains unknown and has largely not been recapitulated in laboratory settings. To elucidate possible connections of this state with microbial composition, the whole body microbiomes of adult mosquitoes in the dry and wet seasons in two locations of Mali with varying water availability were compared by sequencing the 16S ribosomal RNA gene. These locations were a village near the Niger River with year-round water sources (N'Gabakoro, "riparian", and a typical Sahelian area with highly seasonal breeding sites (Thierola Area, "Sahelian". The 16S bacterial data consisted of 2057 sequence variants in 426 genera across 184 families. From these data, we found several compositional differences that were seasonally and spatially linked. Counter to our initial hypothesis, there were more pronounced seasonal differences in the bacterial microbiome of riparian, rather than Sahelian areas. These seasonal shifts were primarily in Ralstonia, Sphingorhabdus, and Duganella spp. bacteria that are usually soil and water-associated, indicating these changes may be from bacteria acquired in the larval environment, rather than adulthood. In Sahelian dry season mosquitoes, there was a unique intracellular bacteria, Anaplasma, which likely was acquired through non-human blood feeding. Cytochrome B analysis of blood meals showed greater heterogeneity in host choice of An. coluzzii independent of season in the Thierola area compared to N'Gabakoro (77.5% vs. 94.6% human-origin blood meal, respectively, indicating a relaxation of anthropophily. Overall, this exploratory study provides valuable indications of spatial and seasonal differences in

Sire breed and breed genotype of dam effects in crossbreeding beef ...

African Journals Online (AJOL)

Cows bred to Afrikaner bulls were less (P < 0.05) productive than cows bred to other Bos taurus sires. An increase in proportion Afrikaner breeding in dam resulted in longer calving intervals and a decline in cow productivity, but these differences were not always significant. A breeding strategy for the retainment of superior ...

Development of new techniques of using irradiation in the genetic improvement of warm season grasses and an assessment of the genetic and cytogenetic effects. Progress report, November 1, 1977--October 31, 1978

International Nuclear Information System (INIS)

Hanna, W.W.; Burton, G.W.

1978-05-01

Progress is reported on plant breeding programs for the genetic improvement of warm season grasses using irradiation as a tool. Data are included from studies on alteration of the protein quantity and quality in pearl millet grain by irradiation and mutation breeding; the effects of nitrogen and genotype on pearl millet grain; the effects of seed size on quality in pearl millet; irradiation breeding of sterile triploid turf Bermuda grasses; irradiation breeding of sterile coastcross-1, a forage grass, to increase winter hardiness; use of irradiation to induce resistance to rust disease; and an economic assessment of irradiation-induced mutants for plant breeding programs

The influence of age, breed, rearing intensity and exercise on the incidence of spavin in Swedish dairy cattle: a clinical and morphological investigation

International Nuclear Information System (INIS)

Holmberg, T.; Reiland, S.

1984-01-01

The hocks of tied cows of a Swedish dairy herd of different breeds were radiographed. Osteoarthrosis of the arthrodial joints (spavin) was found in 37% of the animals. Changes were seen before the cows were 2 yr old, and they increased in severity with increasing age. Macroscopic and histologic examination revealed that there was osteoarthrosis also in many radiologically normal hocks. The frequency of spavin in tied dairy cows is higher than clinical signs indicate. Only cows with fusion of the arthrodial joints show the stiff hind leg movements considered typical of spavin. Differences in the incidence of spavin were found between the different breeds. Cows of the Swedish Friesian breed had the lowest (20%) and cows of the Jersey breed had the highest (50%) incidence of spavin. As regards the Jersey breed this was due to the high incidence (71%) found in cows raised on a high intensity feeding during the young stock period. Among the SJB [Swedish Jersey] cows raised on a normal intensity feeding the incidence of spavin was 25%. Such a relationship between high young stock feeding intensity and the incidence of spavin was not seen within the other breeds. The cows in another herd with loose housing had a lower frequency of spavin than the tied cows. Offspring of animals with spavin had a higher incidence of spavin than the offspring of animals without spavin. (author)

The influence of age, breed, rearing intensity and exercise on the incidence of spavin in Swedish dairy cattle: a clinical and morphological investigation

Energy Technology Data Exchange (ETDEWEB)

Holmberg, T.; Reiland, S. [Sveriges Lantbruksuniversitet, Uppsala (Sweden)

1984-07-01

The hocks of tied cows of a Swedish dairy herd of different breeds were radiographed. Osteoarthrosis of the arthrodial joints (spavin) was found in 37% of the animals. Changes were seen before the cows were 2 yr old, and they increased in severity with increasing age. Macroscopic and histologic examination revealed that there was osteoarthrosis also in many radiologically normal hocks. The frequency of spavin in tied dairy cows is higher than clinical signs indicate. Only cows with fusion of the arthrodial joints show the stiff hind leg movements considered typical of spavin. Differences in the incidence of spavin were found between the different breeds. Cows of the Swedish Friesian breed had the lowest (20%) and cows of the Jersey breed had the highest (50%) incidence of spavin. As regards the Jersey breed this was due to the high incidence (71%) found in cows raised on a high intensity feeding during the young stock period. Among the SJB [Swedish Jersey] cows raised on a normal intensity feeding the incidence of spavin was 25%. Such a relationship between high young stock feeding intensity and the incidence of spavin was not seen within the other breeds. The cows in another herd with loose housing had a lower frequency of spavin than the tied cows. Offspring of animals with spavin had a higher incidence of spavin than the offspring of animals without spavin. (author)

Influence of cross-breeding of native breed sows of Zlotnicka spotted ...

African Journals Online (AJOL)

The aim of this study was the estimation of the cross-breeding influence of Zlotnicka spotted sows with boars of polish large white and Duroc breeds on carcass traits of fatteners. 50 pigs were divided into four groups: Zlotnicka spotted (ZS), Zlotnicka spotted x polish large white (ZS x PLW), Zlotnicka spotted x Duroc (ZS x D) ...

Spatial and temporal distribution patterns of Anopheles arabiensis breeding sites in La Reunion Island - multi-year trend analysis of historical records from 1996-2009

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Lempérière Guy

2011-06-01

Full Text Available Abstract Background An often confounding facet of the dynamics of malaria vectors is the aquatic larval habitat availability and suitable conditions under which they can thrive. Here, we investigated the impact of environmental factors on the temporal and spatial distribution of larval habitats of Anopheles arabiensis in different locations on La Reunion Island. Methods A retrospective examination was made from archival data which provided the complete enumeration of An. arabiensis breeding habitats in three distinct geographic zones - extending North-east, West and South of the island over 14 years, from January 1996 to December 2009. Data on the occurrence and the number of active larval habitats at each of a total of 4376 adjacent ellipsoid grid cells (216,506 square meters each were used (1 to provide the geographic extent of breeding site availability from year to year and (2 to analyze associations with prevailing environmental factors, habitat types, and locations. Results Anopheles arabiensis utilized a spectrum of man-made and natural aquatic habitats, most of which were concentrated primarily in the rock pools located in ravines and river fringes, and also in the large littoral marshes and within the irrigated agricultural zones. The numbers of breeding site per sampling grid differed significantly in different parts of the island. In contrast to an originally more widespread distribution across the island in the 1950s, detailed geographic analyses of the data obtained in the period extending from 1996-2009 showed an intriguing clustered distribution of active breeding sites in three discontinuous geographic zones, in which aquatic habitats availability fluctuates with the season and year. Seasonality in the prevalence of anopheles breeding sites suggests significant responsiveness to climatic factors. Conclusions The observed retreat of An. arabiensis distribution range to lower altitudinal zones (

ROOT VEGETABLES, BREEDING TRENDS, RESULTS