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Sample records for anestrus

  1. Risk factors for postpartum anestrus in crossbred cows in Bangladesh

    International Nuclear Information System (INIS)

    Full text: Ultrasonography and a structured questionnaire were used in a cross-sectional study to gather data on the prevalence and risk factors for anestrus in crossbred cows at ≥60 days postpartum in 273 smallholder farms. The prevalence of anestruc was 18%. The odds ratio (OR) for true anestrus was 17.52 and 2.81 times higher (P < 0.05) in cows with poor (≤2.0) and excessive (>3.5) body condition score (BCS), respectively, compared to those with optimal BCS (2.5-3.5), 2.82 times higher in suckled than in nonsuckled cows (P = 0.03), and 2.53 times higher in cows that calved during the cold season than in those that calved during the hot season (P = 0.03). The OR for anestrus was 1.62 times higher (P = 0.017) in cows managed by an employee than in those managed by the farmers themselves (P = 0.001), and 2.66 times higher (P = 0.003) in small farms (≤5 cows) than in large farms (≥11 cows). The OR was 0.71 to 0.46 times lower in farms having a guaranteed market to sell milk than those with an uncertain traditional milk market (P < 0.05). Maintaining optimal BCS of cows, farmers' training on management of cattle reproduction, and development of a market linkage to sell milk would improve the number of cows for breeding by 60 days postpartum. (author)

  2. Strategies to overcome seasonal anestrus in water buffalo.

    Science.gov (United States)

    de Carvalho, Nelcio Antonio Tonizza; Soares, Julia Gleyci; Baruselli, Pietro Sampaio

    2016-07-01

    Reproductive seasonality in buffalo (Bubalus bubalis) is characterized by behavioral, endocrine, and reproductive changes that occur over distinct periods of the year. During the nonbreeding season (spring and summer), the greater light-dark ratio (long days) suppresses estrus behavior and the occurrence of ovulation. Anestrous buffaloes have insufficient pulsatile of LH to support the final stages of follicular development, and subsequently, estrus behavior and ovulation do not occur, limiting reproductive efficiency, especially in artificial insemination (AI) programs. A number of therapeutic strategies designed to synchronize follicular wave emergence and ovulation have allowed for the use of AI throughout the year, overcoming seasonal anestrus in buffalo. These therapies also improve reproductive performance by increasing the service rate and pregnancy per AI in buffalo herds, regardless of reproductive seasonality. PMID:27157389

  3. Ultrasonographic reproductive tract measures and pelvis measures as predictors of pregnancy failure and anestrus in restricted bred beef heifers.

    Science.gov (United States)

    Holm, Dietmar E; Nielen, Mirjam; Jorritsma, Ruurd; Irons, Peter C; Thompson, Peter N

    2016-02-01

    Previous reports have shown that reproductive tract score (RTS) can predict reproduction outcomes in seasonally bred beef heifers, although the accuracy can vary. Some ultrasonographic measures of the female reproductive tract and pelvis area have also been associated with reproductive outcome in young heifers. The objectives of this study were to determine which transrectal ultrasound or pelvis measures taken at a single examination are independent predictors of reproductive failure and whether the RTS system can be optimized with this information. In this observational study, year-old beef heifers (n = 488) in 2 birth cohorts were followed from just before the first breeding until confirmation of pregnancy. A single pre-breeding examination included body condition score, RTS, ultrasound measures of the reproductive tract (length and diameter of the left and right ovaries, presence and diameter of a CL, largest follicle diameter and left uterus horn diameter) and transverse and vertical diameters of the pelvis. Additional farm records including dam parity, sire, birth weight and birth date, weaning weight, weaning date, prebreeding body weight, AI dates, and semen used were available. Breeding consisted of 50 days of AI, followed 5 to 7 days later by a 42-day bull breeding period. Pregnancy failure was defined as the failure to become pregnant after the AI and bull breeding periods, while anestrus was defined as the failure to be detected in estrus during the 50-day AI period. From the prebreeding data and farm records, independent predictors of pregnancy failure and anestrus were identified using stepwise reduction in multiple logistic regression models. Age at the onset of breeding was the only consistent independent predictor of pregnancy failure and anestrus in both cohorts of this study (P heifers as a result of their association with anestrus, and that smaller PA has additional prognostic value for poorly performing heifers. PMID:26589700

  4. Comparative efficacy of different estrus synchronization protocols on estrus induction response, fertility and plasma progesterone and biochemical profile in crossbred anestrus cows

    Directory of Open Access Journals (Sweden)

    A. J. Dhami

    2015-11-01

    Full Text Available Aim: To evaluate estrus induction response and fertility including plasma progesterone and biochemical profile following use of three standard hormonal protocols in anestrus crossbred cows. Materials and Methods: The study was carried out on 40 true anestrus and 10 normal cyclic cows. 10 anestrus cows each were treated with standard intravaginal controlled internal drug release (CIDR device, Ovsynch (GPG protocol, and Norgestomet ear implant with fixed-time artificial insemination (FTAI. 10 anestrus cows were kept as untreated control while 10 cows exhibiting the first estrus within 90 days postpartum without any treatment served as normal cyclic control. Blood samples were obtained from treated cows on day 0, 7, 9 (AI of treatment and day 21 post-AI, and from control groups on the day of AI and day 21 post-AI for estimation of plasma progesterone, protein, cholesterol, calcium, and inorganic phosphorus profile. Results: The use of CIDR, Ovsynch, and Norgestomet ear implant protocols resulted in 100% estrus induction with conception rates at induced estrus of 60%, 50%, and 50%, and the overall of three cycles as 80%, 80%, and 70%. In untreated anestrus control (n=10, only three cows exhibited spontaneous estrus within 90 days of follow-up and conceived giving the first service and overall conception rates of 66.66% and 30.00%, respectively. In normal cyclic control (n=10, the conception rates at first and overall of three cycles were 50% and 80%. The overall mean plasma progesterone (P4 concentrations in anestrus cows studied on day 0 (initiation, 7 (prostaglandin injection and/or removal of implant, 9 (FTAI of treatment and on day 21 post-AI revealed that the values on day 7 and 21 were significantly (p<0.01 higher than other two periods in all three groups. The concentrations were significantly (p<0.05 higher in conceived than non-conceived group on day 21 post-AI in CIDR (4.36±0.12 vs. 1.65±0.82 ng/ml and Ovsynch (4.85±0.62 vs. 1.59±0

  5. Reproductive outcomes of Alpine goats primed with progesterone and treated with human chorionic gonadotropin during the anestrus-to-estrus transition season.

    Science.gov (United States)

    Alvarado-Espino, A S; Meza-Herrera, C A; Carrillo, E; González-Álvarez, V H; Guillen-Muñoz, J M; Ángel-García, O; Mellado, M; Véliz-Deras, F G

    2016-04-01

    This study aimed to determine the possible effects of a single injection of human chorionic gonadotropin (hCG) as a means for estrus induction in acyclic French-Alpine goats during the reproductive transition period at 25°N, 103°W. The potential effects of hCG upon ovarian function and reproductive performance of goats were also assessed. Multiparous acyclic French-Alpine goats (n = 39; 37.4 ± 8 .5 kg) were primed with 20mg progesterone (P4) 1 day prior to hCG administration. Thereafter, does were treated either with saline (hCG-0; n = 10), 50 (hCG-50; n = 9), 100 (hCG-100; n = 10), or 300 IU of hCG (hCG-300; n = 10). Ovarian structures and pregnancy were monitored by transrectal ultrasonography. In addition, after hCG application, goats were monitored twice daily (0800 and 1800 h) to detect estrus signs, with the use of aproned, sexually active bucks treated with testosterone. Goats were bred 12h after the onset of estrus. Two days after hCG administration, the number of large follicles was higher (P 0.05), being always accompanied by ovulation. Pregnancy rate (67, 100, and 70%), kidding rate (55%, 80%, and 70%), and litter size (1.6 ± 0.5, 1.5 ± 0.5, and 1.5 ± 0.5) for hCG-50, hCG-100, and hCG-300, respectively, did not differ among the hCG-treated does. Therefore, the combined use of P4-priming plus a 100-IU hCG injection is an effective protocol for inducing estrus in non-cycling Alpine goats during the anestrus-to-estrus transition period, which is of key importance for both goat producers and industrializers. PMID:26944772

  6. Estudo histomorfométrico do músculo esquelético de ratos em anestro Skeletal muscle histomorphometric study of rats in anestrus

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    Manoel de Almeida Moreira

    2005-08-01

    Full Text Available A castração, assim como a menopausa, representa estágio de supressão endócrina em que prevalece o hipoestrogenismo e sua conseqüência maior sobre o músculo esquelético é provocar sarcopenia. OBJETIVOS: estudar as alterações histomorfológicas do músculo esquelético de ratos fêmeas castrados. MÉTODOS: vinte e seis ratos Wistar, distribuídos em dois grupos, A e B, submetidos inicialmente à pesagem, citologia vaginal, ovariectomia e biópsia do músculo rectus femoris das patas traseiras, grupo A na direita e B na esquerda. Decorridos 20 dias foi colhido citologia vaginal para comprovar o estado de anestro. Após 70 dias os animais foram pesados e passaram por biópsia muscular, grupo A na pata E e grupo B na D. A histomorfometria foi realizada com o auxílio de uma lente gradiculada de 1cm², com retículo de Weibel de 1mm²; contou-se as miofibrilas com seis leituras na vertical e cinco na horizontal em cada lamina, obtendo-se um número múltiplo que aplicado sobre uma formula especifica para calcular o Coeficiente de Densidade Muscular. RESULTADOS: em A a densidade muscular variou de 60.0 para 52.33 (pCastration, as well as the menopause, represents endocrine suppression that prevails the hipoestrogenism and their larger consequence on the skeletal muscle is to provoke sarcopenia. OBJETIVE: To study the morphometric alteration of striated muscle of castrated female rats. METHODS: Twenty six female rats Wistar , distributed in two sub-groups, A and B, submitted initially to weigh-in place, vaginal cytology, ovariectomy, and biopsy of the muscle rectus femoris on the back paws, A group on right paw, and B on the left. Elapsed 20 days it was collected vaginal cytology to prove the anestrus status. After 70 days the animals went through weigh-in place, and new muscle biopsy, A group in left paw and B in right paw. The morphometric study was accomplished with the aids of a graduated lens, with reticules of 100 mm², it was counted

  7. Variations of Reproductive Hormones of Female Swamp Buffalos from Guangxi Region in Anestrus%广西沼泽型母水牛发情淡季生殖激素的变化规律研究

    Institute of Scientific and Technical Information of China (English)

    祝晓丽; 许惠艳; 刘晓华; 谭世俭; 卢克焕; 石德顺

    2012-01-01

    [ Objective] The aim of the paper is to find the change law of reproductive hormones of female swamp buffalos in anestrus and to investigate the relationship between various hormones. [ Method ] The concentrations of follicle stimulating hormone ( FSH) , luteinizing hormone (LH), inhibin (INH), estradiol (E2) and progesterone (P4) were determined by the enzyme-linked immunosorbent assay (EL1SA) in anestrus. The changes of follicles in the estrous cycle were examined using B-mode ultrasonography. [ Result ] In anestrus of female swamp buffalos from Guangxi region, the blood concentration of E2 and P4 varied fluctuantly. The concentration of E2 had two peaks, respectively 3 d before ovu-lation and after 13 d post ovulation. The concentration of P4 increased slowly from the first day after ovulation, increased rapidly from 5 to 13 d, peaked on Day 16 and decreased to the baseline 3 d before ovulation. The concentrations of FSH, LH and INH reached a peak respectively after 10 d post ovulation, 2 d before ovulation, and after 4 d post ovulation. The changes of the hormones had correlations. The concentrations of FSH, LH and INH had highly significant correlations with each other, while the concentration of INH had highly significant correlations with that of E2 or P4. The concentration of E2 also had a highly significant correlation with that of P4. [ Conclusion] The study can guide the breeding of swamp buffalos from Guangxi region and also help to improve their reproduction performance.%[目的]研究发情淡季母水牛生殖激素的变化规律及各激素之间的相互关系.[方法]采用酶联免疫分析方法( ELISA)测定了发情淡季广西沼泽母水牛血样中促卵泡素(FSH)、促黄体素(LH)、抑制素(INH)、雌二醇(E2)和孕酮(P4)的浓度变化,并结合B超技术检测了母水牛卵泡在发情周期中的变化.[结果]广西沼泽型母水牛血样中E2和P4浓度呈波动式变化.其中,E2分别在排卵后第13天及排卵前3d

  8. Reason Analysis on Butcher Cow Anestrus Infertility and Countermeasures on Prophylaxis and Treatment%张掖市肉用母牛乏情不育原因分析与防治对策

    Institute of Scientific and Technical Information of China (English)

    卢汝学; 朱跃明

    2012-01-01

    With the current institution of increase of butcher cow lacking affection infertility rate in re cent years,this article randomly investigated the cow feeding management, the type, constituent and ori gin,artificial insemination status in Shajing, Linze and other six towns in Zhangye city. Combined with and analyzed the reproductive disorders and systemic change of cows,it could reached the nutritional anestrus infertility conclusion. And the prophylaxis and treatment countermeasures were put forward.%文章根据张掖市近年来户养肉用母牛乏情不育发病率上升现状,随机调查了甘州区沙井镇、临泽县倪家营乡等6个乡镇母牛饲养管理、饲料的种类、成分及来源和人工授精状况,结合母牛生殖机能紊乱和全身变化等情况进行研究分析,得出母牛营养性乏情不育结论并提出防治对策。

  9. Reproductive activity after induced anestrus using altrenogest in Tursiops truncatus females in captivity in marine environment

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    J. A. Herrera

    2015-01-01

    Full Text Available i nterest to reproduce Bottlenose dolphin ( Tursiops truncatus in captivity has increased due to the international restrictions for its commercialization and the risks and logistical difficulties for transporting specimens. Therefore, it has become important to study its reproductive biology in captivity. The objective of the present study was to determine altrenogest ( r egumate ® post-treatment indicators of vaginal cytology, estradiol levels and restarting of reproductive activity of T. truncatus females in captivity in marine environment. Twelve females received altrenogest at a daily dose of 0.07mg kg -1 for a year. a total 420 slides of vaginal cytology of each female were performed to determine the percentage of cornified cells. a lso, 60 blood samples of each animal were analyzed to determine estradiol levels. r egarding the vaginal cytology; percentage of cornified cells increased between 60 and 70% from day 4 to day 9 after removing the altrenogest treatment and between 70 and 80% from day 12 to day 19. e stradiol levels were in the range of 16 to 114pg ml -1 during the entire monitoring period. a positive correlation (r = 0.7062; P<0.05 was found between these indicators. Therefore, we conclude that treatment with altrenogest and monitoring the estrous cycle with simple techniques such as vaginal cytology might be used for designing protocols for assisted reproduction for groups of T truncatus in captivity.

  10. Medicinal Product Use Reglandin D-(+ - Cloprostenol, Synthetic Analogue of Prostaglandins F2α Natural Body in Fighting with Anestrus Lute (CL in Cattle

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    George Florea Tobă

    2011-05-01

    Full Text Available The studies made by us are based on fundamental biological role of prostaglandin modulator of hormonal actions, influxs nerve transmission and cellular ionic exchange. One of the main actions of PGF2α is luteolyse, a process that includes the secretion of progesterone and regression yellow body. PGF2α is a luteolitic for almost species: cow, buffalo, sow, mare, sheep, rabbits, guinea pigs, hamsters and rats, except primates. At present it is considered that PGF2α have their specific receptors, which are fixed and through their model would enable guanidine monophosphate or cyclic GMP's Goldberg. The effect of ocitocic luteolitic and pharmacodynamics basis of PGF2α, used in breeding biotechnologies and hormonal therapy. In medicine veterinary prostaglandines are used after 1973. Were injected with 2 ml Reglandin (150 mg D-(+ - cloprostenol 24 women diagnosed with corpus luteum anestris and 22 females (87.5% came in to oestrus at a mean of 59 hours, and after an average interval of 70 hours.şi were artificially inseminated (AI a total of 20 female (83.33%.

  11. 超细品系羊非发情季节同期发情实用技术研究--配种公羊对同期发情效果的对比分析%Research of super-fine Sheep applied estrus synchronization technology in anestrus Season-Contrasted and analysed effects of estrus synchronization on ram breeding

    Institute of Scientific and Technical Information of China (English)

    杨林; 张富强; 沙木好; 马春萍; 库木斯汗; 王建华; 魏荣安; 张永胜; 王惠; 王宏伟; 刘正山; 何其宏; 毛路山

    2006-01-01

    对中国美利奴羊(新疆军垦型)超细品系乏情季节不同配种公羊对同期发情效果的影响作了对比分析.结果证明,成年公羊配种比周岁公羊好,1060、1063、1073号公羊的效果比1068、1069、1070、3021号公羊好.

  12. 超细品系羊非发情季节同期发情实用技术研究--氟孕酮海绵栓阴道栓塞法的应用效果分析%Research of Super-fine-wool Breed of Chinese Merino Fine-wool Sheep Applied Estrus Synchronization Technology in Anestrus Season--Analysed Effect of Method Used Controlled Interal Drug Release

    Institute of Scientific and Technical Information of China (English)

    王建华; 张富强; 沙木好; 马春萍; 库木斯汗; 魏荣安; 王惠; 张永胜; 刘正山; 何其宏; 王宏伟; 毛路山; 丁志坤

    2005-01-01

    本文对中国美利奴(新疆军垦型)羊超细品系采用CIDR同期发情的效果做了分析,证明不同年份的自然环境因素对同期发情效果有明显影响.成年母羊同期发情的效果明显好于周岁母羊.

  13. 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 (P<0.01), and OOS ewes were intermediate to, and tended to differ from (P<0.10), the other two breeds. We conclude that OOS ewes developed by selection for fertility in spring matings had an abbreviated seasonal anestrus that is one of the shortest ever reported for temperate breeds, and that tropical St. Croix sheep did not have a shorter seasonal anestrus than Suffolk sheep under temperate conditions and ram isolation. PMID:23528712

  14. Hormonal induction of estrous cycles in anestrous Bos taurus beef cows.

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    Day, M L

    2004-07-01

    A significant proportion of postpartum beef cows are anestrus at the onset of the breeding season. Much progress has been made in understanding anestrus and the changes that lead to spontaneous resumption of reproductive function. Likewise, knowledge regarding the impact of hormonal interventions on the endocrine and ovarian changes normally associated with spontaneous resumption of estrous cycles continue to accumulate. A wide range of hormonal treatment programs designed to induce estrous cycles in anestrous cows to coincide with the start of the breeding season have been developed. Programs structured to provide for increased progesterone, estradiol and LH concentrations at the appropriate times during the period leading to the first ovulation, and an induced preovulatory gonadotropin surge when the dominant ovarian follicle is of appropriate maturity have been demonstrated to induce estrous cycles of normal duration and acceptable fertility in a majority of anestrous, Bos taurus beef cows.

  15. Nutrition and fertility in dairy cow

    OpenAIRE

    Rossi, Federico

    2012-01-01

    Nutrition has an important impact on the reproductive performance of dairy cattle. Energy is the major nutrient required by adult cattle and inadequate energy intake has a detrimental impact on reproductive activity of bovine. Cows under negative energy balance have extended periods of anovulation. Postpartum anestrus, as well as infertility, is magnified by losses of body condition during the early postpartum period. Resumption of ovulatory cycles is associated with energy balance, but s...

  16. Ovarian reaction and estrus manifestation in delayed puberty gilts after treatment with equine chorionic gonadotropin

    OpenAIRE

    Stančić Ivan B; Bošnjak Darko V; Radović Ivan B; Stančić Blagoje L.; Harvey Roger B; Anderson Robin C

    2012-01-01

    Abstract Background Prolonged pre-insemination anestrus (i.e. delayed puberty) is a major contributing factor for culling up to 30% of the replacement gilts at large breeding farm units in Vojvodina. It is imperative to determine if these gilts are acyclic (prepubertal) or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG) can increase the diestrous phase duration in sexually mature gilts. Based on the...

  17. Induction and Synchronization of Estrus in Gilts with P.G.600

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    Ion Valeriu Caraba

    2014-11-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Recent developments in understanding the physiological mechanisms of reproduction control can be adapted to swine reproductive management. This article points out the procedures that can be used to induce estrus, in pre-pubescent and anestrus gilts, and heat synchronization. For estrus induction and heat synchronization, we used P.G. 600 commercial product (400 IU of PMSG and 200 IU of hCG, Intervet, Millsboro, DE. A total of 36 gilts, from Large White breed, were used, divided in two lots: pre-pubescent gilts (5months of age, no = 19 and gilts in anestrus (8 months of age, no = 17. The efficacy of hormonal P.G. 600 product was different for the two lots. Estrus manifestation rate was different between lots 73.68% of pre-pubescent gilts compared with 76.47% of anestrus gilts. The use of P.G. 600 hormonal product is effective in inducing and synchronizing estrus in gilts. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  18. Collagen and glycosaminoglycan profiles in the canine cervix during different stages of the estrous cycle and in open- and closed-cervix pyometra.

    Science.gov (United States)

    Linharattanaruksa, Pichanun; Srisuwatanasagul, Sayamon; Ponglowhapan, Suppawiwat; Khalid, Muhammad; Chatdarong, Kaywalee

    2014-03-01

    The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyometra. Cervices were collected after ovariohysterectomy. The proportion of collagen to smooth muscle was determined using Masson's trichrome staining. Alcian blue staining was used to evaluate the relative distribution of cervical GAGs. The proportion of cervical collagen relative to smooth muscle was higher at estrus compared to anestrus (P≤0.05). It was also higher (P≤0.05) in bitches with open- compared to those with closed-cervix pyometra. Overall, hyaluronan (HA) was the predominant GAG in the canine cervix. In the luminal epithelium, the staining intensity for HA was stronger in estrus than in anestrus (P≤0.05), but not in diestrus (P>0.05). On the contrary, the intensity for the combined keratan sulfate (KS) and heparan sulfate (HS) was stronger in anestrus than in estrus and diestrus (P≤0.05). In bitches with pyometra, the staining intensity of the stroma for KS and HS was weaker in open- compared to closed-cervix pyometra (P≤0.05). Collectively, the different profiles of collagen and GAG suggest that the metabolism of both collagen and GAGs in the canine cervix is associated with hormonal statuses during the estrous cycle and cervical patency of bitches with pathological uterine conditions, such as pyometra. PMID:24152876

  19. Reproductive disorders in dairy cattle under semi-intensive system of rearing in North-Eastern India

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    M. H. Khan

    2016-05-01

    Full Text Available Aim: This study was conducted to determine the incidence of major reproductive problems of dairy cattle reared under a semi-intensive system by small and marginal farmers in Meghalaya province of North-Eastern India. Materials and Methods: In a 3 years study, a total of 576 crossbred dairy cattle (212 Holstein Friesian cross and 364 Jersey cross from all districts (n=11 of Meghalaya were assessed with the survey, clinical examination, and personal observations. Results: Out of the total animal assessed, 33.85% (n=195 were found to be affected with one or more of the clinical reproductive problems. Repeat breeding (RB, anestrus, retention of fetal membrane, and abortion were found to be the major clinical reproductive problems. Out of the total animal affected with reproductive disorders, the incidence of anestrus, RB, retention of fetal membrane, and abortion was found to be 31.79% (n=62, 24.61% (n=48, 14.35% (n=28, and 11.25% (n=22, respectively. In addition, dystocia (5.12%, prolapse (1.53%, endometritis (4.61%, and pyometra (6.66% were minor clinical reproductive problems. There was a significant difference in the incidence of reproductive disorders with respect to breed, age, and parity. Conclusion: It was revealed from this study that RB, anestrus, retention of fetal membrane, and dystocia are the major clinical reproductive problems in Meghalaya. Results indicated unsatisfactory feeding, housing, and health management practices are the main cause of low fertility of dairy cows. Lack of scientific knowledge, low access to breeding, and health services further contributed to low productivity and fertility.

  20. Immunolocalization of Prostaglandin E2 Receptor Subtype 4 (EP4 in the Cervix of Cyclic Bitches and Those with Pyometra

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    P Linharattanaruksa1, K Chatdarong1, S Ponglowhapan1, M Khalid3 and S Srisuwatanasagul2*

    2013-07-01

    Full Text Available Cervix is an important part of the reproductive tract; in non-pregnant animals it remains closed during anestrus and diestrus and is open only during estrus. In pathological conditions like pyometra, the cervix may be open or closed but the control mechanism is not clearly known. Prostaglandin E2 (PGE2 is considered to be involved in changes of extracellular matrix via coupling to prostaglandin E receptor subtype 4 (EP4. This study investigated the expression of EP4 in the cervices of bitches during different stages of estrous cycle and those with pyometra. After ovariohysterectomy, cervices were collected from anestrus (n=6, estrus (n=12 and diestrus (n=6, open- (n=10 and closed-cervix pyometra (n=10 bitches. Cervical EP4 expression was observed at all the layers and the stages but the differences in EP4 expression either among bitches in different stages of the estrous cycle and between open- and closed-cervix pyometra were limited to only surface epithelium (SE. In cyclic bitches during estrus and in open-cervix pyometra bitches, significantly higher (P<0.05 EP4 expression was found in SE of uterine part than vaginal part. In SE of the uterine part, the expression was higher in the bitches during estrus than in anestrus and diestrus, and in the bitches affected by open-cervix than those with closed-cervix pyometra. The results suggest that regulation of cervical dilation appeared in the uterine part of the cervix. Moreover, EP4 may be involved in stimulating dilation of the cervix in both estrus and open-cervix pyometra bitches.

  1. Reproductive cycle of dogs and artificial insemination

    OpenAIRE

    Zvolská, Helena

    2012-01-01

    The first sexual cycle of a bitch begins in the period of pubescence, approximately between 6th and 24th month of life. Considering breed and individuality, estrus is repeated mostly twice a year. The whole cycle is divided into 4 stadiums: proestrus (5 – 20 days), estrus (3 – 21 days), metestrus (diestrus, 50-80 days) and anestrus (80 – 240 days). The cycle is initiated due to the evaluation of inner and extinor impulses by the central nervous system. In the first stadium of the cycle, ...

  2. Immunolocalization of Prostaglandin E2 Receptor Subtype 4 (EP4) in the Cervix of Cyclic Bitches and Those with Pyometra

    OpenAIRE

    P Linharattanaruksa1, K Chatdarong1, S Ponglowhapan1, M Khalid3 and S Srisuwatanasagul2*

    2013-01-01

    Cervix is an important part of the reproductive tract; in non-pregnant animals it remains closed during anestrus and diestrus and is open only during estrus. In pathological conditions like pyometra, the cervix may be open or closed but the control mechanism is not clearly known. Prostaglandin E2 (PGE2) is considered to be involved in changes of extracellular matrix via coupling to prostaglandin E receptor subtype 4 (EP4). This study investigated the expression of EP4 in the cervices of bitch...

  3. Pathologies of the puerperium in the cow

    OpenAIRE

    Hanzen, Christian; Rao, Anne-Sophie; Theron, Léonard; Siewruk, Katarzyna; Gajewski, Zdzislaw

    2015-01-01

    Conférence donnée le 10 octobre 2015 à la faculté de Médecine vétérinaire de Varsovie .Les questions suivantes ont été développées 1. In which context are we working ? 1 2. Is puerperium important for cow reproductive performances ? 2 3. How to define these pathologies ? 3 1.1. Dystocia 3 1.2. Placental retention 3 1.3. Uterine involution and uterine involution delay. 4 1.4. Uterine infections 4 1.5. The postpartum anestrus 5 4. What’s the prevalence of these pathol...

  4. Major reproductive health problems of indigenous Borena cows in Ethiopia

    Directory of Open Access Journals (Sweden)

    Ararsa Duguma Benti

    2014-12-01

    Full Text Available The study was conducted to identify the major reproductive health problems and its associated risk factors in indigenous Borena breed cows in Borena zone in Southern Ethiopia between September 2013 and February 2014. Out of the total 409 cows examined, 195 (47.7% were having at least one of the reproductive problems identified by either questionnaire interview (n=329 or regular follow up (n=80 of individual cows. The major reproductive health problems identified in the present study were mastitis (21.3%; n=87/409, abortion (12.2%; n=50/409, repeat breeder (10.3%; n=42/409, anestrus (10.3%; n=42/409 and retained fetal membrane (RFM; 7.6%; n=31/409. The rate of abortion increased significantly (p=0.001 with the increase in the stage of gestation. Laboratory findings indicated that brucellosis and mastitis had great roles in reproductive health problems of dairy cows in the study area with prevalence rates of 2.91% and 68.41%, respectively. In conclusion, the study revealed that several reproductive health problems such as mastitis, abortion, repeat breeder, anestrus and RFM are mostly prevalent in dairy cows in Borena zone in southern Ethiopia.

  5. Estrus cycle effect on muscle tyrosine kinase activity in bitches.

    Science.gov (United States)

    Gomes Pöppl, Álan; Costa Valle, Sandra; Hilário Díaz González, Félix; de Castro Beck, Carlos Afonso; Kucharski, Luiz Carlos; Silveira Martins Da Silva, Roselis

    2012-03-01

    Estrus cycle is a well recognized cause of insulin resistance in bitches. The insulin receptor (IR) as well as the insulin-like growth factor-I receptor belong to the same subfamily of tyrosine kinase (TK) receptors. The objective of this study was to evaluate basal TK activity in muscle tissue of bitches during the estrus cycle. Twenty-four bitches were used in the study (7 in anestrus, 7 in estrus, and 10 in diestrus). Muscle samples, taken after spaying surgery to determine TK activity, were immediately frozen in liquid nitrogen and then stored at -80°C until the membranes were prepared by sequential centrifugation after being homogenized. TK activity was determined by Poly (Glu 4:Tyr 1) phosphorylation and expressed in cpm/μg of protein. TK activity was significantly lower (P < 0.001) in the animals in estrus (104.5 ± 11.9 cpm/μg of protein) and diestrus (94.5 ± 16.9 cpm/μg of protein) when compared with bitches in anestrus (183.2 ± 39.2 cpm/μg of protein). These results demonstrate, for the first time, lower basal TK activity in the muscle tissue of female dogs during estrus and diestrus, which may represent lower insulin signaling capacity, opening a new field of investigation into the molecular mechanisms of insulin resistance in dogs. PMID:22139063

  6. Prostaglandin release by cultured endometrial tissues after challenge with lipopolysaccharide and tumor necrosis factor α, in relation to the estrous cycle, treatment with medroxyprogesterone acetate, and pyometra.

    Science.gov (United States)

    Jursza-Piotrowska, Ewelina; Socha, Piotr; Skarzynski, Dariusz Jan; Siemieniuch, Marta Jolanta

    2016-04-01

    To better understand the pathogenesis of endometrial changes in cats associated with administration of progestagen contraceptives and with pyometra, we examined local variability of the prostaglandin synthesis system after challenge with either tumor necrosis factor α (TNF-α) or lipopolysaccharide (LPS) in organ cultures of endometrial tissues derived from cyclic cats, cats treated with medroxyprogesterone acetate (MPA), or cats with pyometra, as well as in cultured endometrial epithelial and stromal cells. In addition, spontaneous prostaglandin secretion was compared in endometria from different experimental groups. Data gathered in the present study show that the concentration of PGE2 in supernatants was increased only in endometrial organ cultures from cats with pyometra (P < 0.001) compared with other groups. This was also true for PGF2α in pyometra, compared with cats treated either short- or long-term with MPA and cats during late diestrus (P < 0.001), anestrus (P < 0.01), and estrus and middiestrus (P < 0.05). Treatment with LPS and TNF-α combined stimulated PGE2 secretion in all groups compared with the control (P < 0.001 for endometria of cats during anestrus or middiestrus, cats treated short-term with MPA, and those with pyometra; P < 0.01 for endometria of cats treated long-term with MPA; and P < 0.05 for the endometria of cats during estrus and late diestrus). The combined treatment with LPS and TNF-α increased PGF2α secretion in the endometria of cats treated short-term with MPA (P < 0.001), during anestrus and pyometra (P < 0.01 for both), and estrus and middiestrus (P < 0.05 for both), compared with the control. Spontaneous secretion of prostaglandins was several times greater in the endometria of queens with pyometra, compared with other groups, which may further regulate the local inflammatory response. Data gathered from endometrial cell culture and endometrial organ culture lead to the conclusion that disturbances in prostaglandin release

  7. Continuous exposure to sexually active rams extends estrous activity in ewes in spring.

    Science.gov (United States)

    Abecia, J A; Chemineau, P; Flores, J A; Keller, M; Duarte, G; Forcada, F; Delgadillo, J A

    2015-12-01

    Sexual activity in sheep is under photoperiodic control, which is the main environmental factor responsible for the seasonality of reproduction. However, other natural environmental factors such as presence of conspecifics can slightly influence the timing of onset and offset of the breeding season. In goats, we have found that the continuous presence of bucks that were rendered sexually active out of season by previous exposure to long days, prevented goats from displaying seasonal anestrus, which suggests that the relative contribution of photoperiod in controlling seasonal anestrus should be reevaluated in small ruminant species. The aim of this study was to assess whether the presence of sexually active rams that had been stimulated by artificial photoperiod and melatonin implants, reduces seasonal anestrus in sheep, by prolonging ovulatory activity in spring. Ewes were assigned to one of two groups (n = 16 and 15), which were housed in two separate barns, and kept in contact, either with the treated or the control rams between March and July. Vasectomized rams were either exposed to 2 months of long days followed by the insertion of three subcutaneous melatonin implants (treated rams, n = 8), or exposed to natural light conditions (control rams, n = 2). Estrus was monitored daily, and weekly plasma progesterone analyses indicated ovulatory activity. Ewes that were exposed to treated rams exhibited a higher proportion of monthly estrus than ewes exposed to the control rams (P rams exhibited estrous behavior in a cyclic manner. In contrast, all ewes exposed to control rams stopped estrous activity for a period of time during the study, such that this group exhibited a significantly longer anestrous season (mean ± standard error of the mean 89 ± 9 days) than did the ewes housed with treated rams (26 ± 10 days; P rams, 13 of them exhibited continuous ovulatory activity between March and July, whereas one stopped in June and two in July. All

  8. Test accuracy of metabolic indicators in predicting decreased fertility in dairy cows

    DEFF Research Database (Denmark)

    Lomander, H; Gustafsson, H; Svensson, C;

    2012-01-01

    from 241 cows in 7 of the participating herds were analyzed for progesterone concentration to define the first day of luteal activity. The diagnostic sensitivity (Se) and specificity (Sp) at different cut-off concentrations of NEFA, BHBA, or IGF-1 were calculated and related to individual cow fertility...... status, measured as anestrus (ANEST), delayed first artificial insemination (DFAI), or delayed conception. Positive and negative predictive values (PV+; PV−) were calculated considering different levels of (within-herd) prevalence. Strata (i.e., subgroup)-specific Se and Sp and associations between test...... results and fertility parameters were investigated using logistic regression. The NEFA and BHBA tests for ANEST and DFAI had the highest combined Se and Sp and were thus evaluated further. Cut-off values with Sp around 80% were used in this step to provide a reasonable number of test-positive cows...

  9. Effect of dexamethasone on the estrous cycle length in Black Bengal goats (Capra hircus ).

    Science.gov (United States)

    Alam, M G; Ahmed, J U; Jahan, S

    1989-04-01

    In an experiment to examine the relationships between adrenals and reproductive cycle, 10 mg dexamethasone (a synthetic glucocorticoid) were injected intramuscularly twice daily for 10 d to four Black Bengal goats, beginning on Day 11 of the synchronized estrous cycle. The extended length of the sexual cycle was monitored by the clinical signs of anestrus. Laparotomy was performed to examine the status of the ovary of an 8, 9, 10 and 8 d extended cycle, respectively. The length of the next cycle was normal. Endogenous cortisol values were suppressed for 11, 13, 20 and 24 d, respectively. It is thought that dexamethasone caused prolonged luteal function either by the suppression of prostaglandin F(2)alpha synthesis or by the suppression of pituitary stimulation of follicular growth. PMID:16726609

  10. 4-Vinylcyclohexene diepoxide reduces fertility in female Siberian hamsters when treated during their reproductively active and quiescent states.

    Science.gov (United States)

    Roosa, Kristen A; Mukai, Motoko; Place, Ned J

    2015-01-01

    The industrial compound 4-vinylcyclohexene diepoxide (VCD) destroys ovarian follicles and reduces fertility in rodents, but to date VCD has not been tested in species that experience seasonal anestrus. To determine if VCD destroys follicles when administered during reproductive quiescence, Siberian hamsters were treated with VCD (240mg/kg i.p. daily for 10 days) during short days, and outcomes were compared with reproductively active females that were maintained and treated in long days. Primordial follicle numbers were significantly reduced by VCD under both day lengths, and reproductive quiescence in short days did not appear to render the ovaries less susceptible to VCD-induced follicle depletion. Independent of day length and reproductive state, VCD-treated hamsters weaned substantially fewer offspring than controls. These results suggest that time of year may not be an important consideration for optimizing use of VCD in the field when the target pest species is a seasonally breeding rodent.

  11. Identifying diagnostic endocrine markers and changes in endometrial gene expressions during pyometra in cats.

    Science.gov (United States)

    Jursza-Piotrowska, Ewelina; Siemieniuch, Marta J

    2016-06-01

    Pyometra is a significant reproductive problem in cats. The aims of this study were to evaluate (i) the immunological profile of queens by studying plasma concentrations of metabolites of prostacyclin I2 (6-keto-PGF1α), leukotriene B4 (LTB4) and leukotriene C4 (LTC4); and (ii) the gene transcription profiles of Toll-like receptors (TLRs) 2 and 4 (TLR2/4), PGE2-synthase (PGES), PGF2α-synthase (PGFS) and prostaglandin-endoperoxide synthase 2 (PTGS2) in the feline endometrium throughout the estrous cycle, after medroxyprogesterone acetate (MPA) treatment and during pyometra. The concentration of plasma 6-keto-PGF1α in pyometra was increased in comparison to other groups studied (p<0.01). Endometrial mRNA coding for TLR2 was up-regulated in cats suffering from pyometra compared to other groups (p<0.001). Expression of mRNA for TLR4 was up-regulated in endometria originating from MPA-treated cats, pyometra and late diestrus cats, compared with tissues from cats during estrus and anestrus (p<0.05). As expected, endometrial mRNA for PTGS2 was up-regulated only in pyometra, compared with other groups (p<0.001). Similarly, endometrial mRNA for PGFS was up-regulated in pyometra, compared with endometria from anestrus, late diestrus and from MPA-treated cats (p<0.05), or from cats during estrus (p<0.01). Overall, these results indicate that plasma concentrations of LTB4 and LTC4 are not useful diagnostic markers since they were not increased in queens with pyometra, in contrast to 6-keto-PGF1α. In addition, treatment with MPA evoked neither endocrine nor molecular changes in endometria of cats. PMID:27288342

  12. Sexual odor discrimination and physiological profiles in adult male rats after a neonatal, short term, reversible nasal obstruction.

    Science.gov (United States)

    Thornton, S N; Padzys, G S; Trabalon, M

    2014-05-01

    The present study was designed to examine behavioral responses (interpreted as preferences) to olfactory cues (nest bedding odor and odors of estrous and anestrus females) in adult male rats after they had a short term reversible, bilateral, nasal obstruction (RbNO) as developing rat pups. These results were compared to behavior of control (untreated) and sham operated male littermates. Behavioral tests and physiological parameters were analyzed 90 days after recovery of nasal breathing. Experiments investigated the time spent in arms or the center of a maze of male rats in response to odors from the nest bedding or from adult females. There were no differences in responses between untreated, sham and RbNO adult male rats to fresh and nest bedding odors. RbNO males spent more time in the center of the maze when given a choice of estrus or anestrus female odors, or bedding odors from untreated or sham operated female rats. In contrast untreated and sham male rats preferred the odors of estrous females and of untreated or sham females. Plasma corticosterone levels in the males increased during the behavioral tests. Plasma testosterone levels were significantly lower in RbNO males compared to untreated males and did not increase during the behavioral tests compared to sham operated males. Males from all groups had similar preferences for the odor of bedding from adult RbNO females. Plasma levels of cholesterol and triglycerides were increased in RbNO adults. In conclusion, short term nasal obstruction in males while juvenile has long term consequences on hormones and behavioral preferences, thus potential partner selection when adult. PMID:24769524

  13. Seasonal variation in the gonadotropin-releasing hormone response to kisspeptin in sheep: possible kisspeptin regulation of the kisspeptin receptor.

    Science.gov (United States)

    Li, Qun; Roa, Alexandra; Clarke, Iain J; Smith, Jeremy T

    2012-01-01

    Kisspeptin signaling in the hypothalamus appears critical for the onset of puberty and driving the reproductive axis. In sheep, reproduction is seasonal, being activated by short days and inhibited by long days. During the non-breeding (anestrous) season, gonadotropin-releasing hormone (GnRH) and gonadotropin secretion is reduced, as is the expression of Kiss1 mRNA in the brain. Conversely, the luteinizing hormone response to kisspeptin during this time is greater. To determine whether the GnRH response to kisspeptin is increased during anestrus, we utilized hypophysial portal blood sampling. In anestrus ewes, the GnRH and LH responses to kisspeptin were greater compared to the breeding season (luteal phase). To ascertain whether this difference reflects a change in Kiss1r, we measured its expression on GnRH neurons using in situ hybridization. The level of Kiss1r was greater during the non-breeding season compared to the breeding season. To further examine the mechanism underlying this change in Kiss1r, we examined Kiss1r/GnRH expression in ovariectomized ewes (controlling for sex steroids) during the breeding and non-breeding seasons, and also ovariectomized non-breeding season ewes with or without estradiol replacement. In both experiments, Kiss1r expression on GnRH neurons was unchanged. Finally, we examined the effect of kisspeptin treatment on Kiss1r. Kiss1r expression on GnRH neurons was reduced by kisspeptin infusion. These studies indicate the kisspeptin response is indeed greater during the non-breeding season and this may be due in part to increased Kiss1r expression on GnRH neurons. We also show that kisspeptin may regulate the expression of its own receptor.

  14. The "ram effect": new insights into neural modulation of the gonadotropic axis by male odors and socio-sexual interactions.

    Science.gov (United States)

    Fabre-Nys, Claude; Kendrick, Keith M; Scaramuzzi, Rex J

    2015-01-01

    Reproduction in mammals is controlled by the hypothalamo-pituitary-gonadal (HPG) axis under the influence of external and internal factors such as photoperiod, stress, nutrition, and social interactions. Sheep are seasonal breeders and stop mating when day length is increasing (anestrus). However, interactions with a sexually active ram during this period can override the steroid negative feedback responsible for the anoestrus state, stimulate luteinizing hormone (LH) secretion and eventually reinstate cyclicity. This is known as the "ram effect" and research into the mechanisms underlying it is shedding new light on HPG axis regulation. The first step in the ram effect is increased LH pulsatile secretion in anestrus ewes exposed to a sexually active male or only to its fleece, the latter finding indicating a "pheromone-like" effect. Estradiol secretion increases in all ewes and this eventually induces a LH surge and ovulation, just as during the breeding season. An exception is a minority of ewes that exhibit a precocious LH surge (within 4 h) with no prior increase in estradiol. The main olfactory system and the cortical nucleus of the amygdala are critical brain structures in mediating the ram effect since it is blocked by their inactivation. Sexual experience is also important since activation (increased c-fos expression) in these and other regions is greatly reduced in sexually naïve ewes. In adult ewes kisspeptin neurons in both arcuate and preoptic regions and some preoptic GnRH neurons are activated 2 h after exposure to a ram. Exposure to rams also activates noradrenergic neurons in the locus coeruleus and A1 nucleus and increased noradrenalin release occurs in the posterior preoptic area. Pharmacological modulation of this system modifies LH secretion in response to the male or his odor. Together these results show that the ram effect can be a fruitful model to promote both a better understanding of the neural and hormonal regulation of the HPG axis in

  15. Effect of suckling restriction with nose plates and premature weaning on postpartum anestrous interval in primiparous cows under range conditions.

    Science.gov (United States)

    Quintans, G; Vázquez, A I; Weigel, K A

    2009-11-01

    Suckling and nutrition are generally recognized as two major factors controlling the duration of the postpartum anovulatory period. In the present study, the effect of premature weaning and suckling restriction with nose plates (NPs) on cow and calf performance was evaluated. The study was conducted over 2 years; primiparous Hereford cows, weighing (mean+/-S.E.M.) 344+/-3.5kg and with 4.1+/-0.05 units of body condition score (BCS) (scale 1-8 [Vizcarra, J.A., Ibañez, W., Orcasberro, R., 1986. Repetibilidad y reproductibilidad de dos escalas para estimar la condición corporal de vacas Hereford. Investigaciones Agronómicas 7 (1), 45-47]) at calving, remained with their calves until 72.5+/-1.2 days postpartum (day 0). They were then assigned to one of three treatments: (i) calves with free access to their dams and ad libitum suckling (S, n=29); (ii) calves fitted with NPs for 14 days, but remained with their dams (NP, n=29), and (iii) calves that were weaned from their dams (W, n=28). All cows were anestrus at the time treatments commenced (day 0). All cows were blood sampled twice weekly from 1 week before the beginning of the experiment until the end of the mating period (day 74) for progesterone analysis. The mating period began on day 14. Cows in W treatment had ovulations earlier (P<0.05) than those in NP and S groups. Cows in the NP group had longer (P<0.05) intervals between the first progesterone increase and normal luteal phase than cows in the other two treatments groups (23.3+/-3.2 vs. 6.5+/-3.2 and 5.2+/-3.3 days for NP, S and W cows, respectively). Fifty per cent of the cows with NP had a short cycle (7 days) but there was a group of cows that had longer (P<0.05) intervals (66 days) between first progesterone increase and normal estrous activity. In the NP group, 8 of 29 cows had a short luteal phase and then a normal one; for 9 of these 29 cows progesterone concentrations remained low for 6 weeks from the beginning of the treatment; and for 12 of these

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

    Directory of Open Access Journals (Sweden)

    Rubianes E

    2005-03-01

    levels than ewes that did not ovulate, none of which had an LH surge. We conclude that (a the effect of ram introduction in cyclic ewes treated with MAP may vary depending on the time of the breeding season at which teasing is performed; (b patterns of FSH, and estradiol-17β concentrations, as indicators of activity of the reproductive axis, may be used to classify depth of anestrus; and (c the endocrine pattern of the induced follicular phase, which is related to the depth of anestrus, may be reflected in the behavioral responses to MAP priming and the ram effect.

  17. Distribution of superoxide dismutase 1 and glutathione peroxidase 1 in the cyclic canine endometrium.

    Science.gov (United States)

    Santos, Celso; Pires, Maria Dos Anjos; Santos, Dario; Payan-Carreira, Rita

    2016-08-01

    Superoxide dismutase (SOD) and glutathione peroxidase (GPx) are two important antioxidant enzymes involved in tissue homeostasis by protecting cells and tissues from an accumulation of reactive oxygen species. Information concerning antioxidant enzymes in the canine uterus is almost inexistent. This work intends to establish the pattern of distribution of SOD1 and GPx1 immunoreaction in canine endometrium throughout the estrous cycle, using 46 endometrium samples of healthy dogs representing different cycle stages (anestrus-10, proestrus-10, estrus-10, early diestrus-7, and diestrus-9). SOD1 distribution in canine endometrium showed cyclic variations (P ≤ 0.001), with higher immunoscores in the progesterone-associated stages. Changing immunoreaction also concerned the different epithelial structures considered (surface epithelium, superficial glandular epithelium, and deep glandular epithelium) (P ≤ 0.001), but it was always higher than in the stroma (P ≤ 0.001). Deep glandular epithelial cells usually showed higher scores of immunoreaction compared with the other epithelial cells. Interestingly, in epithelial cells, distinct subcellular patterns for SOD1 were seen: the nuclear labeling was observed in estrus and early diestrus (P ≤ 0.001), whereas an apical reinforcement was observed in estrus (P = 0.011) in the glandular epithelia but not in the surface epithelia. In general, GPx1 distribution in canine endometrium remained relatively unchanged throughout the estrous cycle (P = 0.169) despite the slight decrease observed from proestrus to early diestrus. The highest scores were found in anestrus and diestrus (P < 0.05), varying with of the structure considered. An apical reinforcement pattern was also found for this molecule, which peaked in proestrus and estrus (P < 0.005). In summary, the present study showed that SOD1 and GPx1 are consistently distributed in the canine endometrium. The cyclic changes registered for both molecules

  18. Effects of prolonged nutrient restriction on baseline and periprandial plasma ghrelin concentrations of postpubertal Holstein heifers.

    Science.gov (United States)

    Field, M E; Deaver, S E; Rhoads, R P; Collier, R J; Rhoads, M L

    2013-10-01

    Objectives of this study were to measure both daily and periprandial plasma ghrelin concentrations of postpubertal Holstein heifers during prolonged undernutrition. Following an acclimation period, Holstein heifers [n=10; 339.5 ± 8.6 kg of body weight (BW)] were fed ad libitum [well fed (WF); n=5] or restricted to 50% of ad libitum intake [underfed (UF); n=5) for 8 wk. Body condition scores (BCS) were recorded at the beginning and end of the treatment period, and weekly measurements of BW, plasma ghrelin, progesterone, and nonesterified fatty acids (NEFA) concentrations were obtained. Ovarian follicular and luteal structures were measured twice weekly via transrectal ultrasonography. Plasma ghrelin concentrations were also measured during a periprandial window bleed conducted at the end of the experiment. During the window bleed, samples were collected every 15 min between 0500 and 0900 h, with feed offered at 0700 h. Underfed heifers lost BW and BCS, whereas WF heifers gained weight and either increased or maintained BCS. Chronic underfeeding increased circulating ghrelin and NEFA concentrations. By wk 4 of the treatment period, circulating ghrelin concentrations of the UF heifers reached a plateau. Periprandial fluctuations in ghrelin concentrations were apparent as plasma ghrelin concentrations changed over time. Overall differences in periprandial plasma ghrelin concentrations were primarily due to prefeeding effects of plane of nutrition. Plasma ghrelin concentrations and change in BCS were negatively correlated such that heifers that lost the most BCS had the highest concentrations of circulating ghrelin. Two of the 5 UF heifers became anestrus by wk 3 of the treatment period. Despite being of similar age, the heifers that became anestrus had lower BW and plasma ghrelin concentrations than the UF heifers that continued to ovulate. In the current experiment, long-term undernutrition elicited ghrelin responses similar to those reported for shorter durations of

  19. Diagnosis of post-partum anoestrus in dairy cattle

    International Nuclear Information System (INIS)

    A study was carried out to establish the incidence of anoestrus in dairy cattle in Southern Chile. Cows that had not been seen in oestrus up to 60 days after parturition were considered in anoestrus and were clinically examined. Cows without corpora lutea were designated clinically anoestrus and a milk sample was taken for progesterone radioimmunoassay. Cows with progesterone concentration below 9.5 nmol/L were considered to be in true anoestrus. A total of 1831 post-partum cows from 10 farms were studied. Based on the reproductive records, 208 cows were in anoestrus (11.3% with a range from 4.3 to 33.3%). The clinical examination revealed that only 66 out of the 208 cows were in clinical anoestrus reducing the anoestrus percentage to 36% (range 1.9 - 10.8%). The progesterone concentration in skim milk showed that only 41 cows had low values compatible with anoestrus. Thus the true incidence of anestrus was 2.2% with a range of 0.8 to 7.0% between farms. In conclusion, the figures from the different methods of diagnosis of anoestrus (records, clinical and endocrine status) seem to be within the range of reported data in countries with high standards for livestock production. This study identified true reproductive problems, such as deficient oestrus detection and failures in clinical diagnosis of active CLs. Also, it confirmed that progesterone RIA is a valuable tool to monitor ovarian activity. (author). 18 refs, 1 tab

  20. Resumption of cyclic ovarian activity in postpartum ewes: a review

    Directory of Open Access Journals (Sweden)

    Ivan Júnior Ascari

    2016-04-01

    Full Text Available The reproduction rate is considered a crucial factor that affects the ability of producers to meet the growing demand for ovines meat, and optimizing this factor will maximize the production rate and increase the efficiency of livestock. A reduction in the length of the postpartum anestrus period results in a shorter interval between lambing and conception and enables more lambs to be produced throughout the life of a ewe. This review discusses the current knowledge of several factors associated with the resumption of cyclic ovarian function in postpartum ewes and how the suckling management of ewes may affect this process. Factors that influence the resumption of cyclic ovarian activity include uterine involution, follicular development, occurrence of silent ovulation and short estrous cycles, breed, reproductive seasonality, nutrition and lactation. Controlled suckling and early weaning are management practices that may be used to obtain three lambings in a 24-month period. In the majority of the studies the interval between lambing and first estrus was reduced when a controlled suckling management strategy was used, therefore the controlled suckling appears to be the best alternative because it has produced good results and is easy to implement. Currently, however, this practice is still not widely used.

  1. Treatments to Optimize the Use of Artificial Insemination and Reproductive Efficiency in Beef Cattle under Tropical Environments

    Directory of Open Access Journals (Sweden)

    Ocilon Gomes de Sá Filho

    2011-01-01

    Full Text Available Bos indicus cattle, the preferred genetic group in tropical climates, are characterized by having a lower reproductive efficiency than Bos taurus. The reasons for the poorer reproductive efficiency of the Bos indicus cows include longer lengths of gestation and postpartum anestrus, a short length of estrous behavior with a high incidence of estrus occurring during the dark hours, and puberty at older age and at a higher percentage of body weight relative to mature body weight. Moreover, geography, environment, economics, and social traditions are factors contributing for a lower use of reproductive biotechnologies in tropical environments. Hormonal protocols have been developed to resolve some of the reproductive challenges of the Bos indicus cattle and allow artificial insemination, which is the main strategy to hasten genetic improvement in commercial beef ranches. Most of these treatments use exogenous sources of progesterone associated with strategies to improve the final maturation of the dominant follicle, such as temporary weaning and exogenous gonadotropins. These treatments have caused large impacts on reproductive performance of beef cattle reared under tropical areas.

  2. Genome-wide association for the outcome of fixed-time artificial insemination of Brahman heifers in northern Australia.

    Science.gov (United States)

    Porto-Neto, L R; Edwards, S; Fortes, M R S; Lehnert, S A; Reverter, A; McGowan, M

    2015-11-01

    Fixed-time AI (FTAI) is a powerful tool for genetic improvement of extensively managed beef cattle. A genomewide association study (GWAS) was conducted to investigate genes and genetic markers associated with the outcome (pregnant or not pregnant) of FTAI in 614 commercial Brahman heifers genotyped for 18,895 SNP and imputed to 51,588 SNP. The likelihood of Brahman heifers becoming pregnant after hormonal treatment to synchronize ovulation followed by FTAI was influenced by the content of their genomes, as determined by a principal component analysis. The principal component analysis involved comparisons between the studied heifers and populations of known and ancestry. The heritability of FTAI outcome was = 0.18, which is higher than for most other reproductive outcome traits. The number of SNP associated with FTAI outcome was 101 ( heifer puberty and postpartum anestrus interval, 3 genomic regions emerge as important for overall Brahman heifer fertility, which mapped to chromosomes 1, 7, and 9. Further analyses, including improved genome annotation, are required to elucidate the link between these regions and heifer fertility. Additional studies are needed to confirm SNP and gene associations reported herein and further elucidate the genetics of FTAI outcome. Future GWAS should target other Braham populations and additional cattle breeds with FTAI records, including breeds with higher ancestry. PMID:26641032

  3. Plasma Nesfatin-1 and Leptin in pubertal and non-pubertal Murrah buffalo heifers (Bubalus bubalis

    Directory of Open Access Journals (Sweden)

    Gorakh Nath Prajapati

    2015-12-01

    Full Text Available Buffaloes mostly suffer from delayed puberty, anestrus, sub–estrus, summer infertility, prolonged inter-calving interval and postpartum uterine disorders. Nesfatin-1 and Leptin are directly or indirectly related with body weight (BW, feed parameters and regulation of puberty. The objective of this study was to investigate the influence of Nesfatin-1 and Leptin in pubertal and non-pubertal Murrah buffalo heifers. The Murrah buffalo heifers (n=13 were randomly selected and divided into two groups; pubertal group (PG and non-pubertal group (NG. Heifers with plasma progesterone (P4 level of ≥1 ng/mL were classified as PG. Blood samples were collected at fortnight intervals for analysis of plasma Nesfatin-1, Leptin, P4, glucose and non-esterified fatty acids. Body weight, dry matter intake and feed conversion efficiency were recorded at fortnight intervals. The mean (±SEM plasma Nesfatin-1, Leptin, P4, BW and feed conversion efficiency (% were significantly (P<0.01 higher in PG as compared to NG. Dry matter intake by the heifers was also significantly (P<0.001 higher in PG than NG. Plasma metabolites (glucose and NEFA did not differ significantly between the groups. The findings of this study suggest that Nesfatin-1 and Leptin have indispensable role in the onset of puberty in buffalo heifers by affecting BW and feed parameters.

  4. Estrous behavior, progesterone in peripheral plasma and milk in dairy goats at onset of breeding season.

    Science.gov (United States)

    Thibier, M; Pothelet, D; Jeanguyot, N; De Montigny, G

    1981-03-01

    Two large flocks of 60 and 120 French Alpine dairy does were studied beginning in late June. Estrous behavior was checked daily in the presence of bucks, and numerous blood and milk samples were collected. The end of the anestrus was characterized by consistent low progesterone around .1 ng/ml in plasma and 2 to 4 ng/ml in milk. Cyclic activity was detected in early July in one flock and in early August in the other. Individual patterns of plasma and milk progesterone in cyclic females were correlated greater than .5. Estrus was short (4 to 5 days) in 3 to 10 goats sampled daily following first estrus, and a small and transient rise of concentrations of progesterone was concomitant. Mean plasma and milk progesterone increased from about .1 to .5 and 2 to 4 ng/ml at the time of estrus to 6 to 8 in plasma and 6 to 10 ng/ml in milk 10 days later (midluteal phase). Twenty-one days after mating, concentrations in plasma and milk of pregnant animals were of the same magnitude as during the midluteal phase and higher than those in nonpregnant does (.1 to .7 and 2 to 3 ng/ml in plasma and milk). PMID:7196414

  5. Recovery rate, morphological quality and nuclear maturity of canine cumulus-oocyte complexes collected from anestrous or diestrous bitches of different ages.

    Science.gov (United States)

    Lopes, G; Sousa, M; Luvoni, G Cecilia; Rocha, A

    2007-10-01

    Canine cumulus-oocyte complexes (COC) were recovered from ovaries of post-pubertal animals (1-3, 4-6 and 7-10 years old) at different ovarian estrous phases (anestrus and diestrus). The number of COCs, and the number and nuclear maturity of high-quality (grade-1) oocytes were assessed. For all animals, no significant differences were found between the two reproductive phases relatively to the total number of COCs and grade-1 oocytes recovered. However, significant higher numbers of COCs were recovered from young than from elderly animals, and the proportion of grade-1 oocytes was also significantly higher in the younger group than in the other two age-groups. Of 226 grade-1 oocytes, 73% were at the germinal vesicle stage (GV), 10% had resumed meiosis (9% at germinal vesicle breakdown; 1% at metaphase-I) and 17% were degenerated. A significant effect of the reproductive phase on oocyte nuclear maturity was found only for adult animals, with a higher number of GV oocytes being found at anestrous (79%) due to higher rates of meiosis resumption (34%) at diestrous. The high number of grade-1 oocytes with meiosis resumption and fragmented or unidentified nuclear contents, indicates that current criteria for the selection of viable canine COCs are not optimized and need a new definition. PMID:17714773

  6. Sustained delivery of exogenous melatonin influences biomarkers of oxidative stress and total antioxidant capacity in summer-stressed anestrous water buffalo (Bubalus bubalis).

    Science.gov (United States)

    Kumar, Ashok; Mehrotra, S; Singh, G; Narayanan, K; Das, G K; Soni, Y K; Singh, Mahak; Mahla, A S; Srivastava, N; Verma, M R

    2015-06-01

    High ambient temperature during summer in tropical and subtropical countries predisposes water buffaloes (Bubalus bubalis) to develop oxidative stress having antigonadotropic and antisteroidogenic actions. Melatonin is a regulator of seasonal reproduction in photoperiodic species and highly effective antioxidant and free radical scavenger. Therefore, a study was designed to evaluate the effect of sustained-release melatonin on biomarkers of oxidative stress i.e., the serum malondialdehyde (MDA) and nitric oxide (NO), and the total antioxidant capacity (TAC). For the study, postpartum buffaloes diagnosed as summer anestrus (absence of overt signs of estrus, concurrent rectal examination, and RIA for serum progesterone) were grouped as treated (single subcutaneous injection of melatonin at 18 mg/50 kg body weight dissolved in sterilized corn oil as vehicle, n = 20) and untreated (subcutaneous sterilized corn oil, n = 8). Blood sampling for estimation of serum TAC and MDA (mmol/L) and NO (μmol/L) was carried out at 4 days of interval from 8 days before treatment till 28 days after treatment or for the ensuing entire cycle length. Results showed serum TAC concentration was higher in the treatment group with a significant (P stress resulting in the induction of cyclicity in summer-stressed anestrous buffaloes. PMID:25805692

  7. Fertility in Gyr Cows (Bos indicus) with Fixed Time Artificial Insemination and Visual Estrus Detection Using a Classification Table

    Science.gov (United States)

    Ramírez-Iglesia, Lilido Nelson; Roman Bravo, Rafael María; Díaz de Ramirez, Adelina; Torres, Leandro J.

    2014-01-01

    The aim of this research was to compare two artificial insemination protocols (AIP): hormonal synchronization with fixed time artificial insemination (SC-FTAI) and the use of a table based on visual observation of estrus signs (VO) in order to identify cows in natural or spontaneous estrus being assigned to AI (NSE-IA). Two groups were formed: in the first group 109 cows were assigned to SC-FTAI, in which a commercial protocol is used; the second one included 108 randomly chosen cows, which were assigned to NSE-AI and in this group a modified table was used. Response variable was first service fertility rate (FSF), which was coded 1 for pregnant and 0 for empty. Predictor variables were AIP, postpartum anestrus, daily milk yield, body condition score at AI and calving number. Statistical analyses included association chi-square tests and logistic regression. Results showed an overall 41.94% FSF and a significant association was detected (P 0.05). The odds ratio for the effect of AIP was only 1.050, suggesting no differences in FSF between groups. The NSE-AI protocol can enhance both the technique of VO and reproductive efficiency. Further validation of the table is required. PMID:26464929

  8. The role of toll-like receptors 2 and 4 in the pathogenesis of feline pyometra.

    Science.gov (United States)

    Jursza, E; Kowalewski, M P; Boos, A; Skarzynski, D J; Socha, P; Siemieniuch, M J

    2015-03-01

    Pyometra is the most common uterine disease in queens. To protect itself from infection, the female reproductive tract possesses several immune mechanisms that are based on germline-encoded pattern recognition receptors (toll-like receptors [TLRs]). The aim of our study was to examine endometrial immunolocalization of TLR2/4, study the influence of lipopolysaccharide (LPS) and tumor necrosis factor (TNF) α on messenger RNA expression of both receptors in pyometric queens, and compare these patterns between estrous cycling queens and those hormonally treated with medroxyprogesterone acetate (MPA). Thirty-six queens, ranging in age from 7 months to 11 years, were allocated into seven groups (anestrus, estrus, mid-diestrus and late diestrus, short-term and long-term hormonally treated queens, and pyometric queens). At the messenger RNA level, the real-time polymerase chain reaction was applied, whereas at the TLR2/4 protein level, the expression was tested by immunohistochemistry. In queens at estrus, gene expression of TLR2 was upregulated after stimulation of endometrial explants by TNF (P glandular epithelia. These data show that short-term and especially long-term administration of progesterone derivatives impairs TLRs in the endometrial epithelium, presumably enabling pathogens to break through this first natural barrier and thereby increase the risk of pyometra development. PMID:25481489

  9. A cow-level association of ruminal pH on body condition score, serum beta-hydroxybutyrate and postpartum disorders in Thai dairy cattle.

    Science.gov (United States)

    Chaidate, Inchaisri; Somchai, Chanpongsang; Jos, Noordhuizen; Henk, Hogeveen

    2014-09-01

    Subacute ruminal acidosis in dairy cows occurs when ruminal pH is below about 5.5. However, the exact threshold level of ruminal pH affecting cow health is still in debate. This investigation was carried out in 505 cows within 31 farms. The postpartum disorders, including dystocia, retained placenta, anestrus, cystic ovary, metritis, clinical mastitis and lameness, were analyzed. Ruminal pH, serum beta-hydroxy butyrate (SBHB), serum urea nitrogen and body condition score (BCS) were measured once during the 3 to 6 weeks postpartum, while BCS was determined once more at 1 week before calving. Ruminal pH was determined by ruminocentesis technique. The ruminal pH was evaluated to study the association with BCS, SBHB and postpartum disorders using linear regression in a generalized linear mixed model with farm as a random effect. The results show that low ruminal pH was associated with dystocia, metritis and lameness. Moreover, a low ruminal pH can be found in cows with a high loss of BCS after calving and also in cows with low SBHB postpartum. These findings confirmed the feasibility of the ruminocentesis technique and the association of low ruminal pH on various postpartum disorders at the individual cow level. However, the consequences of low ruminal pH on dairy cow health still needs more exploration for a better understanding of the physiological mechanisms.

  10. The enhanced reproduction of cow parent brahman cross post partum with feed supplement multinutrient block medicated

    International Nuclear Information System (INIS)

    One of the problems in breeding Brahman Cross cattle reproduction efficiency is low due to the length of postpartum anestrus and the high number of services per conception is partly due to the low nutrient content of rations. This study aims to improve the performance of reproductive cows parent Brahman Cross post partum through feeding strategy supplement Multi nutrient Block plus Medicated (MBPM) which starts with the correct parent condition score so that it can accelerate the process appear oestrus post partum then increasing conception rate to minimize the number of service per conception as well as to improve the growth calf produced. This research uses 16 cows parent Brahman Cross post partum not exceeding 90 days comprising 9 tails were given feed supplements MBPM compared with 7 tail not given feed supplements MBPM as control. Research results show that feeding supplements MBPM can enhanced reproductive cow parent Brahman Cross post partum i.e. : maintain parent condition score in early post partum until the occurrence of pregnant, accelerating day 24,8 appear oestrus post partum, number service per conception = 1 and conception rate can reach 60%, maintaining the levels of urea plasma of blood and blood glucose levels within normal limits either at the time of post partum and oestrus post partum. Feeding supplements MBPM on cows parent Brahman Cross post partum can give added daily gain 0,51 kg on calf is suckling. (author)

  11. The effect of environmental mycotoxins on selected ovarian tissue fragments of multiparous female wild boars at the beginning of astronomical winter.

    Science.gov (United States)

    Zielonka, Łukasz; Gajęcka, Magdalena; Rozicka, Anna; Dąbrowski, Michał; Żmudzki, Jan; Gajęcki, Maciej

    2014-10-01

    The contamination of plant material with mycotoxins, in particular of the genus Fusarium, is common in the natural environment. Multiparous female wild boars are exposed to feed contaminated with zearalenone (ZEN) and deoxynivalenol throughout the year. The aim of this study was to determine the concentrations of the above mycotoxins in multiparous female wild boars and to describe their effect on the histological structure of the ovaries at the beginning of astronomical winter. Toxicological examinations revealed 0.291 ng/ml of ZEN, 0.406 ng/ml of α-zearalenol (α-ZEL), 0.392 ng/ml β-zearalenol (β-ZEL) and an absence of deoxynivalenol (values below the sensitivity of the method) in the blood plasma of multiparous female wild boars. Numerous ovarian follicles at various stages of development, characterized by different degree of damage, were observed. Numerous deformed resting ovarian follicles were noted directly under the epithelium, and signs of follicular atresia and hyalinization were observed. Blood vessels in the medulla of the ovary were dilated, which probably improved the distribution of ZEN in the ovaries. Higher substrate (ZEN) concentrations in the ovaries led to an insignificant increase in the staining intensity of 3β-HSD and 17β-HSD clusters. The observed changes could contribute to prolonging the initial stage of late anestrus in multiparous female wild boars.

  12. Metabolic profiles using (1)H-nuclear magnetic resonance spectroscopy in postpartum dairy cows with ovarian inactivity.

    Science.gov (United States)

    Xu, Chuchu; Xia, Cheng; Sun, Yuhang; Xiao, Xinhuan; Wang, Gang; Fan, Ziling; Shu, Shi; Zhang, Hongyou; Xu, Chuang; Yang, Wei

    2016-10-01

    To understand the differences in metabolic changes between cows with ovarian inactivity and estrus cows, we selected cows at 60-90 days postpartum from an intensive dairy farm. According to clinical manifestations, B-ultrasound scan, rectal examination, 10 cows were assigned to the estrus group (A) and 10 to the ovarian inactivity group (B). All plasma samples were analyzed by (1)H-nuclear magnetic resonance spectroscopy to compare plasma metabolomic profiles between the groups. We used multivariate pattern recognition to screen for different metabolites in plasma of anestrus cows. Compared with normal estrous cows, there were abnormalities in 12 kinds of metabolites in postpartum cows with ovarian inactivity (|r|> 0.602), including an increase in acetic acid (r = -0.817), citric acid (r = -0.767), and tyrosine (r = -0.714), and a decrease in low-density lipoprotein (r = 0.820), very low-density lipoprotein (r = 0.828), lipids (r = 0.769), alanine (r = 0.816), pyruvate (r = 0.721), creatine (r = 0.801), choline (r = 0.639), phosphorylcholine (r = 0.741), and glycerophosphorylcholine (r = 0.881). These metabolites were closely related to abnormality of glucose, amino acid, lipoprotein and choline metabolism, which may disturb the normal estrus. The decrease in plasma creatine and the increase in tyrosine were new changes for ovarian inactivity of postpartum cows. The decrease in plasma creatine and choline and the increase in tyrosine and p-hydroxyphenylalanine in cows with ovarian inactivity provide new directions for research on the mechanism of ovarian inactivity in cows. PMID:27291083

  13. Metabolic profiles using (1)H-nuclear magnetic resonance spectroscopy in postpartum dairy cows with ovarian inactivity.

    Science.gov (United States)

    Xu, Chuchu; Xia, Cheng; Sun, Yuhang; Xiao, Xinhuan; Wang, Gang; Fan, Ziling; Shu, Shi; Zhang, Hongyou; Xu, Chuang; Yang, Wei

    2016-10-01

    To understand the differences in metabolic changes between cows with ovarian inactivity and estrus cows, we selected cows at 60-90 days postpartum from an intensive dairy farm. According to clinical manifestations, B-ultrasound scan, rectal examination, 10 cows were assigned to the estrus group (A) and 10 to the ovarian inactivity group (B). All plasma samples were analyzed by (1)H-nuclear magnetic resonance spectroscopy to compare plasma metabolomic profiles between the groups. We used multivariate pattern recognition to screen for different metabolites in plasma of anestrus cows. Compared with normal estrous cows, there were abnormalities in 12 kinds of metabolites in postpartum cows with ovarian inactivity (|r|> 0.602), including an increase in acetic acid (r = -0.817), citric acid (r = -0.767), and tyrosine (r = -0.714), and a decrease in low-density lipoprotein (r = 0.820), very low-density lipoprotein (r = 0.828), lipids (r = 0.769), alanine (r = 0.816), pyruvate (r = 0.721), creatine (r = 0.801), choline (r = 0.639), phosphorylcholine (r = 0.741), and glycerophosphorylcholine (r = 0.881). These metabolites were closely related to abnormality of glucose, amino acid, lipoprotein and choline metabolism, which may disturb the normal estrus. The decrease in plasma creatine and the increase in tyrosine were new changes for ovarian inactivity of postpartum cows. The decrease in plasma creatine and choline and the increase in tyrosine and p-hydroxyphenylalanine in cows with ovarian inactivity provide new directions for research on the mechanism of ovarian inactivity in cows.

  14. Progesterone status, parity, body condition, and days postpartum before estrus or ovulation synchronization in suckled beef cattle influence artificial insemination pregnancy outcomes.

    Science.gov (United States)

    Stevenson, J S; Hill, S L; Bridges, G A; Larson, J E; Lamb, G C

    2015-05-01

    Our objective was to assess the effects of progesterone before initiating an estrus- or ovulation-synchronization program in addition to the influence of parity, BCS, and days postpartum on resulting pregnancy rates per AI. Experimental data were combined from 73 herd-year studies consisting of more than 8,500 suckled beef cows exposed to variants of the CO-Synch program. Blood was harvested from samples collected at 10 and 0 d before the onset of CO-Synch, and progesterone concentrations of the samples were determined. The progesterone environment preceding synchronization was assessed in 3 ways on the basis of progesterone concentrations measured in the 2 defined blood samples. All binomial logistic regression models used procedure GLIMMIX in SAS and included the fixed effects of program duration, inclusion of progesterone via an intravaginal insert, parity, days postpartum at AI, BCS, and appropriate interactions. In addition, model 1 included 3 categories of progesterone concentrations (low [BCS, days postpartum, and progesterone status assessed in 3 ways were consistent in nearly all models. Progesterone status at the onset of synchronization was not important to pregnancy outcomes in multiparous cows, whereas pregnancy rate per AI was suppressed in primiparous cows that began in a low-progesterone environment (proestrus, estrus, metestrus, or anestrus). A significant 3-way interaction of parity, BCS, and days postpartum in 2 models reinforced the importance of these factors to AI pregnancy outcomes. Ancillary analyses identified the significant effects of cycling status and BCS as well as days postpartum on luteolytic response to PGF(2α). Pregnancy loss of 2.7% to 4.2% was detected to occur between a positive pregnancy diagnosis at 35 d post-AI and later stages of pregnancy. We concluded that progesterone status at the onset of the synchronization program is critical to pregnancy outcomes in primiparous but not multiparous cows.

  15. Saliva ferning, an unorthodox estrus detection method in water buffaloes (Bubalus bubalis).

    Science.gov (United States)

    Ravinder, R; Kaipa, Onnureddy; Baddela, Vijay Simha; Singhal Sinha, Eshu; Singh, Prashant; Nayan, Varij; Velagala, Chandra Sekhar Naidu; Baithalu, Rubina Kumari; Onteru, Suneel Kumar; Singh, Dheer

    2016-09-15

    Estrus detection is a major problem in buffalo husbandry because of inconsistent expression of estrous signs at different seasons, and a high prevalence of the silent heat and postpartum anestrus in this species. Around 50% of the estrus events in buffaloes are currently undetected in the field conditions, resulting in a huge economic loss. Although the cervicovaginal fluid fern patterns confirm the estrus for a breeding decision, the fluid discharge is absent during the silent-heat condition. Therefore, the present study focused on the crystallization patterns of the saliva as an alternative method for estrus detection in buffaloes. Saliva is a body fluid available regularly, and its ferning ability before ovulation was established in women. In this study, eight female nonpregnant Murrah buffaloes (Bubalus bubalis) were considered during two experimental periods of 3 months each. One period was in summer with five animals, and another period was in rainy season with three animals. Estrus was determined by the estrus symptoms, ovarian ultrasonography, and salivary estradiol (E2) to progesterone (P4) ratio. A total of 450 saliva samples were collected from these animals on the daily basis. The salivary smear was prepared with 20 μL of the cell-free saliva on a clean glass slide, and its microscopic images were captured at a magnification of × 200. The images were used for fractal analysis as the salivary crystallization or fern patterns follow the fractal geometry. Saliva at estrus showed a typical symmetrical fern-like crystallization patterns with significantly (P buffaloes on the basis of distinct salivary crystallization patterns. The proportion of estrus detection by the salivary fern patterns was very significantly (P buffaloes. PMID:27181055

  16. Morphometric Study of the Mare Oviductal Mucosa at Different Reproductive Stages.

    Science.gov (United States)

    Mouguelar, Horacio; Díaz, Tomás; Borghi, Damiana; Quinteros, Rolando; Bonino, Facundo; Apichela, Silvana Andrea; Aguilar, José Javier

    2015-11-01

    The objectives of this work were to describe some morphometric characteristics and to establish quantitative parameters of different regions of the equine oviductal mucosa from the isthmus, ampullary-isthmic junction (AIJ), and ampulla. Twenty-one mixed-bred mares were used for this study. Mares were selected in the following reproductive phases: anestrus, estrus, and diestrus. The left oviducts were examined with light microscopy, and rights ones were studied through the intraoviductal molds. The isthmus showed the smallest luminal area, mucosal area, epithelial perimeter, and luminal diameter. On the molds surfaces, some grooves extended as longitudinal canals, reducing their depth as they approached to the AIJ. Several small height projections, some obliquely positioned towards utero-tubal junction, were observed in all reproductive phases. These formations may represent pockets or cul-de-sacs in the basal areas of the epithelial folds. The AIJ mucosa gradually changed from the smooth isthmic region toward highly folded ampulla. The number and complexity of epithelial folds showed moderate increase in the same way that many of the morphometric parameters. Multiple curves were observed on the molds of the AIJ, creating a zigzag path in the oviductal lumen. In the ampulla, the high branched epithelial folds occupied most of the lumen, leaving a small luminal area free. A linear relationship between epithelial perimeter and mucosal area was found. The presence of glandular-like structures was observed in all the reproductive stages studied. The equine endosalpinx reveals a highly complex tridimensional arrangement where each region shows very particular and specific designs.

  17. Haemato-biochemical and endocrine profiling of north western Himalayan Gaddi sheep during various physiological/reproductive phases

    Directory of Open Access Journals (Sweden)

    A. Sharma

    2015-08-01

    Full Text Available The study was aimed to provide baseline data regarding haemato-biochemical and endocrine profiling of Gaddi sheep found in north western Himalayan region of Himachal Pradesh, India. Each random sample was collected from 45 Gaddi sheep reared in government sheep breeding farm Tal, Hamirpur, India, during various reproductive phases viz. anestrus, breeding season and post partum period. Haematology revealed significantly higher (P<0.05 RBC as well as haematocrit values in pregnant animals (n=23 during breeding season than during other reproductive phases. The number of platelets were significantly lower (P<0.05 and MCH, MCHC values were statistically higher (P<0.05 during postpartum period than during other reproductive phases. Blood biochemistry revealed significantly higher (P<0.05 concentrations of plasma cholesterol (83.98±3.68 mg/dl, plasma calcium (71.06±1.52 mg/l, magnesium (18.21±0.53 mg/l, potassium (5.10±0.13 mEq/l and significantly lower (P<0.05 concentrations of plasma total protein (5.75±0.31 gm/dl, globulin (3.04±0.29 gm/dl and sodium (138.83±1.83 mEq/l during postpartum period in comparison to other reproductive phases. Endocrine profile revealed significantly higher (P<0.05 serum estrogen (60.97±1.24 pg/ml and T4 (6.0±0.27 μg/ml concentrations during postpartum phase. Similarly, significantly higher (P<0.05 serum progesterone (5.16±0.76 ng/ml as well as TSH (0.70±0.14 μg/ml concentration were recorded during pregnancy. From the study it can be concluded that physiological status significantly affects the blood metabolic and endocrine profile in Gaddi sheep.

  18. Kisspeptin signaling is required for the luteinizing hormone response in anestrous ewes following the introduction of males.

    Directory of Open Access Journals (Sweden)

    Julie-Ann P De Bond

    Full Text Available The introduction of a novel male stimulates the hypothalamic-pituitary-gonadal axis of female sheep during seasonal anestrus, leading to the resumption of follicle maturation and ovulation. How this pheromone cue activates pulsatile secretion of gonadotropin releasing hormone (GnRH/luteinizing hormone (LH is unknown. We hypothesised that pheromones activate kisspeptin neurons, the product of which is critical for the stimulation of GnRH neurons and fertility. During the non-breeding season, female sheep were exposed to novel males and blood samples collected for analysis of plasma LH profiles. Females without exposure to males served as controls. In addition, one hour before male exposure, a kisspeptin antagonist (P-271 or vehicle was infused into the lateral ventricle and continued for the entire period of male exposure. Introduction of a male led to elevated mean LH levels, due to increased LH pulse amplitude and pulse frequency in females, when compared to females not exposed to a male. Infusion of P-271 abolished this effect of male exposure. Brains were collected after the male effect stimulus and we observed an increase in the percentage of kisspeptin neurons co-expressing Fos, by immunohistochemistry. In addition, the per-cell expression of Kiss1 mRNA was increased in the rostral and mid (but not the caudal arcuate nucleus (ARC after male exposure in both aCSF and P-271 treated ewes, but the per-cell content of neurokinin B mRNA was decreased. There was also a generalized increase in Fos positive cells in the rostral and mid ARC as well as the ventromedial hypothalamus of females exposed to males. We conclude that introduction of male sheep to seasonally anestrous female sheep activates kisspeptin neurons and other cells in the hypothalamus, leading to increased GnRH/LH secretion.

  19. Using UHF proximity loggers to quantify male-female interactions: a scoping study of estrous activity in cattle.

    Science.gov (United States)

    O'Neill, C J; Bishop-Hurley, G J; Williams, P J; Reid, D J; Swain, D L

    2014-12-10

    Reproductive efficiency is an important determinant of profitable cattle breeding systems and the success of assisted reproductive techniques (ART) in wildlife conservation programs. Methods of estrous detection used in intensive beef and dairy cattle systems lack accuracy and remain the single biggest issue for improvement of reproductive rates and such methods are not practical for either large-scale extensive beef cattle enterprises or free-living mammalian species. Recent developments in UHF (ultra high frequency) proximity logger telemetry devices have been used to provide a continuous pair-wise measure of associations between individual animals for both livestock and wildlife. The objective of this study was to explore the potential of using UHF telemetry to identify the reproductive cycle phenotype in terms of intensity and duration of estrus. The study was conducted using Belmont Red (interbred Africander Brahman Hereford-Shorthorn) cattle grazing irrigated pasture on Belmont Research Station, northeastern Australia. The cow-bull associations from three groups of cows each with one bull were recorded over a 7-week breeding season and the stage of estrus was identified using ultrasonography. Telemetry data from bull and cows, collected over 4 8-day logger deployments, were log transformed and analyzed by ANOVA. Both the number and duration of bull-cow affiliations were significantly (P<0.001) greater in estrous cows compared to anestrus cows. These results support the development of the UHF technology as a hands-off and noninvasive means of gathering socio-sexual information on both wildlife and livestock for reproductive management. PMID:25449547

  20. Effect of some management and nutritional factors on the fertility of milking cows under traditional husbandry system in Sudan

    International Nuclear Information System (INIS)

    Six farms (A, B, C, D, E and F) of the intensive system type were selected. They were located 50 km south of Khartoum. Nutritional parameters with respect to metabolizable energy intake (MEI)and crude protein (CP) concentration of the diet were investigated . Other managerial practices were also closely examined. Cows that recently calved were monitored throughout the study period (300 days) for days to first progesterone (P4) rise and days to conception using radioimmunoassay (RIA) technique and rectal palpation. The above fertility parameters were correlated with either body condition score (BCS) or body weight (Bwt) at calving, 30, 60 and 90 days from calving. Similar correlations were done after pooling all farms together excluding farm E which consisted of the pure exotic breed. Likewise same correlations were done for the cows grouped according to calving during wet and dry summer. Milk yield at 30, 60 and 90 days from calving were also correlated with days to first P4 rise and days to conception. Regression analysis were carried out for correlations which showed high or moderate relationships. The interval from caving to ovulation or conception varied within and between farms. Farm E showed the shortest (17) days to first P4 rise while farm C showed the longest days. Likewise farm E showed the shortest (56) days to conception while farm F showed the longest (161) days. However farm F, showed the lowest conception rate and highest percentage of anestrus cows. Best conception rates within 90 days postpartum were observed in farm C followed by farm E, B, A, D and F. Days to conception was negatively correlated (P4 rise was negatively correlated (P<0.004, r=0.99) with body score at calving (BCS.Calv), but positively correlated with Bwt.Calv. (P<0.08, r=0.91), body weight change at 30 days from calving (P<0.13, r=0.86), and body weight change at 60 days from calving (P<0.08, r=0.91). No significant difference (P=0.29) between wet and dry summer for days to

  1. Exposure of sexually inactive males to estrogenized females increased the investigative and consummatory sexual behavior.

    Science.gov (United States)

    Guillén-Muñoz, J M; Meza-Herrera, C A; Santos-Jimenez, Z; Rivas-Muñoz, R; Luna-Orozco, J R; Mellado, M; Véliz-Deras, F G

    2016-10-01

    been anestrus (P<0.05). PMID:27609358

  2. Blood metabolites and hormone-based programmed breeding treatments in anovular lactating dairy cows.

    Science.gov (United States)

    El-Zarkouny, S Z; Shaaban, M M; Stevenson, J S

    2011-12-01

    The objectives were to (1) compare blood metabolites and reproductive outcomes in lactating dairy cows not inseminated before (early) and after (late) 100 d in milk (DIM) because of prolonged anovulation or anestrus; and (2) evaluate reproductive responses of cows ≤100 DIM to GnRH+PGF(2α) treatments after a fixed-time artificial insemination (AI; Ovsynch) or after induced estrus (Select Synch). In blood samples collected before initiating hormone-based breeding programs, anovular cows ≤ 100 DIM had the greatest serum total protein and globulin concentrations and the lowest tri-iodothyronine concentrations. Anovular and ovular cows >100 DIM had the greatest serum urea concentrations. Ovaries in cows (n=40) >100 DIM were examined by transrectal ultrasonography, and those without a detectable corpus luteum (CL; anovular) were given GnRH and then PGF(2α) 7 d later (Select Synch), whereas cows with a CL (ovular) were given 2 PGF(2α) injections 12 d apart. Cows were inseminated at observed estrus after the second or only PGF(2α) injection. More ovular (79%; 15/19) than anovular cows (24%; 5/21) were detected in estrus. No differences were detected between ovular and anovular cows in DIM at first AI, conception rate to first AI, cumulative pregnancy rates, number of services per conception, or days open. Cows (n=93) ≤100 DIM were assigned randomly to 3 treatments: (1) control (n=20) AI at estrus; (2) GnRH and then PGF(2α) on 7d (Select Synch; n=42) and monitored for signs of estrus for 5d and AI accordingly; or (3) 2 GnRH injections 9 d apart with PGF(2α) given 48 h before second GnRH injection and AI at 16h after the second GnRH injection (Ovsynch; n=31). Among cows ≤100 DIM, controls had more days to first service (149±16 d) than Select Synch cows (117±7 d). Ovsynch cows had the fewest days to first service (84±10 d) compared with control (149±16 d) and Select Synch (117±7 d) cows. Conception rates in control (25%) and Select Synch (26.2%) cows did

  3. Validation of a noninvasive diagnostic tool to verify neuter status in dogs: The urinary FSH to creatinine ratio.

    Science.gov (United States)

    Albers-Wolthers, C H J; de Gier, J; Oei, C H Y; Schaefers-Okkens, A C; Kooistra, H S

    2016-09-15

    Determining the presence of functional gonadal tissue in dogs can be challenging, especially in bitches during anestrus or not known to have been ovariectomized, or in male dogs with nonscrotal testes. Furthermore, in male dogs treated with deslorelin, a slow-release GnRH agonist implant for reversible chemical castration, the verification of complete downregulation of the hypothalamic-pituitary-gonadal (HPG) axis can be difficult, especially if pretreatment parameters such as the size of the testes or prostate gland are not available. The aims of this study were to validate an immunoradiometric assay for measurement of FSH in canine urine, to determine if the urinary FSH to creatinine ratio can be used to verify the neuter status in bitches and male dogs, as an alternative to the plasma FSH concentration, and to determine if downregulation of the HPG axis is achieved in male dogs during deslorelin treatment. Recovery of added canine FSH and serial dilutions of urine reported that the immunoradiometric assay measures urinary FSH concentration accurately and with high precision. Plasma FSH concentrations (the mean of two samples, taken 40 minutes apart) and the urinary FSH to creatinine ratio were determined before gonadectomy and 140 days (median, range 121-225 days) and 206 days (median, range 158-294 days) after gonadectomy of 13 bitches and five male dogs, respectively, and in 13 male dogs before and 132 days (median, range 117-174 days) after administration of a deslorelin implant. In both bitches and male dogs, the plasma FSH concentration and the urinary FSH to creatinine ratio were significantly higher after gonadectomy, with no overlapping of their ranges. Receiver operating characteristic analysis of the urinary FSH to creatinine ratio revealed a cut-off value of 2.9 in bitches and 6.5 in males to verify the presence or absence of functional gonadal tissue. In male dogs treated with deslorelin, the plasma FSH concentrations and urinary FSH to

  4. Ovarian reaction and estrus manifestation in delayed puberty gilts after treatment with equine chorionic gonadotropin

    Directory of Open Access Journals (Sweden)

    Stančić Ivan B

    2012-08-01

    Full Text Available Abstract Background Prolonged pre-insemination anestrus (i.e. delayed puberty is a major contributing factor for culling up to 30% of the replacement gilts at large breeding farm units in Vojvodina. It is imperative to determine if these gilts are acyclic (prepubertal or cyclic, but just fail to exhibit behavioural estrus. Recent investigations demonstrate that treatment with equine chorionic gonadotropin (eCG can increase the diestrous phase duration in sexually mature gilts. Based on these finding, the aim of the present studies was to determine the reproductive status of delayed puberty gilts following injection with eCG. Methods Two experiments were conducted on a swine breeding farm in Vojvodina. In Exp. 1, 20 prepubertal (acyclic gilts, and 120 sexually mature (cyclic gilts were injected with a single injection of 400 IU eCG + 200 IU human chorionic gonadotropin (hCG or with 1000 IU eCG (cyclic gilts, at d5, d11 or d17 after spontaneous estrus detection, to determine their ovarian reaction and induced estrus manifestation. In Exp. 2, sixty delayed puberty gilts (estrus not detected until 8 month of age, av. 258 days were culled from breeding herd and slaughtered to determine their reproductive status based on ovarian anatomical features. The second group of gilts (n = 60 was treated with a single 1000 IU eCG injection to determine their reproductive status, based on the interval between eCG injection to estrus detection and duration. The data were analyzed by descriptive statistics, t-test, analysis of variance and Duncan’s test in the software package Statistics 10th. Results Ovulations were induced in 90% of acyclic (sexually immature and, on average, 93.3% of cyclic (sexually mature gilts after the eCG injection. On average, 4 days after the eCG injection, estrus was detected in 85% of the treated acyclic (sexually immature gilts and in 95% (19/20 of the cyclic (sexually mature gilts, treated with eCG on day 17

  5. New concepts of the central control of reproduction, integrating influence of stress, metabolic state, and season.

    Science.gov (United States)

    Clarke, I J; Arbabi, L

    2016-07-01

    Gonadotropin releasing hormone is the primary driver of reproductive function and pulsatile GnRH secretion from the brain causes the synthesis and secretion of LH and FSH from the pituitary gland. Recent work has revealed that the secretion of GnRH is controlled at the level of the GnRH secretory terminals in the median eminence. At this level, projections of kisspeptin cells from the arcuate nucleus of the hypothalamus are seen to be closely associated with fibers and terminals of GnRH cells. Direct application of kisspeptin into the median eminence causes release of GnRH. The kisspeptin cells are activated at the time of a natural "pulse" secretion of GnRH, as reflected in the secretion of LH. This appears to be due to input to the kisspeptin cells from glutamatergic cells in the basal hypothalamus, indicating that more than 1 neural element is involved in the secretion of GnRH. Because the GnRH secretory terminals are outside the blood-brain barrier, factors such as kisspeptin may be administered systemically to cause GnRH secretion; this offers opportunities for manipulation of the reproductive axis using factors that do not cross the blood-brain barrier. In particular, kisspeptin or analogs of the same may be used to activate reproduction in the nonbreeding season of domestic animals. Another brain peptide that influences reproductive function is gonadotropin inhibitory hormone (GnIH). Work in sheep shows that this peptide acts on GnRH neuronal perikarya, but projections to the median eminence also allow secretion into the hypophysial portal blood and action of GnIH on pituitary gonadotropes. GnIH cells are upregulated in anestrus, and infusion of GnIH can block the ovulatory surge in GnRH and/or LH secretion. Metabolic status may also affect the secretion of reproduction, and this could involve action of gut peptides and leptin. Neuropeptide Y and Y-receptor ligands have a negative impact on reproduction, and Neuropeptide Y production is markedly increased in

  6. Desenvolvimento folicular no pós-parto de vacas da raça Gir tratadas com acetato de buserelina (GnRH ou gonadotrofina coriônica humana (hCG Follicular development in Gir breed cows (Bos indicus treated with buserelin acetate or human chorionic gonadotrophin during the postpartum period

    Directory of Open Access Journals (Sweden)

    Álan Maia Borges

    2004-12-01

    Full Text Available Foram utilizadas 22 vacas da raça Gir (Bos indicus em anestro pós-parto, amamentando e mantidas sob regime de pastejo. O padrão de crescimento folicular foi estudado em 15 animais, enquanto os outros sete foram utilizados somente no acompanhamento da resposta aos tratamentos hormonais. Ultra-sonografia em tempo real foi realizada diariamente, do quarto ao qüinquagésimo dia de lactação, por meio de aparelho equipado com probe de 5MHz. Nenhum animal apresentou estro, ovulação ou luteinização folicular durante o período de avaliação. Verificaram-se quatro a oito ondas foliculares surgindo em intervalos de seis a sete dias, cujo diâmetro máximo dos folículos dominantes e subordinados foi de 8,9±0,6 e 6,3±0,7mm, respectivamente. Aos 56 dias pós-parto, as 22 vacas foram divididas em dois grupos: 11 tratadas com 4,2 mig de acetato de buserelina e 11 com 3.000UI de hCG. A ovulação, regressão e luteinização folicular foram verificadas em animais dos dois tratamentos e uma nova onda folicular surgiu dentro de dois a três dias após a terapia hormonal. Corpos lúteos de menor tamanho e concentrações de progesterona abaixo de 1ng/mL indicaram baixa atividade luteal.This experiment was carried out with 22 anestrus Gir cows (Bos indicus, with the postpartum follicular growth studied in 15 of these suckling and kept on pasture, while the seven others were used only for hormonal treatments. Daily real time ultrasonography was done from 4th to the 50th day, using B-mode ultrasound scanner equipped with a linear array 5.0MHz probe. No animal showed estrus, ovulation or follicular luteinization during de experimental period. Four to eight follicular waves emerged each six or seven days and maximum diameter of dominant and subordinate follicles were 8.9±0.6mm and 6.3±0.7mm, respectively. On day 56 of postpartum all cows were separated in two groups: 11 cows were treated either with 4.2 mug of buserelin acetate and 11 with 3,000UI of h

  7. The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle Aplicação da inseminação artificial e transferência de embrião em tempo fixo no manejo reprodutivo de vacas leiteiras

    Directory of Open Access Journals (Sweden)

    Divakar Justus Ambrose

    2010-07-01

    Full Text Available Fertility of dairy cattle is generally decreasing. Overall estrus detection efficiency in lactating dairy cattle is low, as expression of estrus is often compromised. Consequently, undetected estrus, low AI-submission rates, and long inter-breeding intervals are the main contributors to poor reproductive efficiency. Although failure to become pregnant is the most common reason for culling dairy cattle, pregnancy rates could be improved by increasing the AI-submission rate through increased estrus detection efficiency, timed insemination (Timed-AI, or timed embryo transfer (Timed-ET. In these protocols, ovarian follicular development and luteolysis are controlled, culminating in synchronous ovulation in most cows. There are several modifications to improve pregnancy rates in Timed-AI protocols, e.g. presynchronization with 2 doses of PGF2a 14 d apart, and starting the Ovsynch protocol 12 d after the 2nd PGF2a. Timed-AI programs ensure a timely first breeding; this should be followed with early pregnancy diagnosis to identify nonpregnant cows, and prompt re-insemination. However, in a recent field study involving 23 dairy herds, the mean interval between 1st and 2nd breeding was 42 d; only 28% of the cows were rebred within 24 d after 1st breeding. Fortunately, there are several resynchronization protocols to reduce inter-breeding intervals. Anestrus cows, or those with cystic ovarian follicles, have a good chance of conceiving when subjected to synchronization of ovulation and Timed-AI. Furthermore, Timed-ET is a practical and viable option for synchronizing and selecting recipient cattle for embryo transfers. In summary, systematic and judicious use of Timed-AI and Timed-ET protocols can greatly enhance reproductive performance, and improve herd productivity.A fertilidade em vacas de leite está em decréscimo e, de modo geral, a detecção eficiente do estro em vacas lactantes é baixa, já que a expressão do estro é frequentemente