Root Characteristics of Perennial Warm-Season Grasslands Managed for Grazing and Biomass Production

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Rattan Lal

2013-07-01

Full Text Available Minirhizotrons were used to study root growth characteristics in recently established fields dominated by perennial C4-grasses that were managed either for cattle grazing or biomass production for bioenergy in Virginia, USA. Measurements over a 13-month period showed that grazing resulted in smaller total root volumes and root diameters. Under biomass management, root volume was 40% higher (49 vs. 35 mm3 and diameters were 20% larger (0.29 vs. 0.24 mm compared to grazing. While total root length did not differ between grazed and biomass treatments, root distribution was shallower under grazed areas, with 50% of total root length in the top 7 cm of soil, compared to 41% in ungrazed exclosures. These changes (i.e., longer roots and greater root volume in the top 10 cm of soil under grazing but the reverse at 17–28 cm soil depths were likely caused by a shift in plant species composition as grazing reduced C4 grass biomass and allowed invasion of annual unsown species. The data suggest that management of perennial C4 grasslands for either grazing or biomass production can affect root growth in different ways and this, in turn, may have implications for the subsequent carbon sequestration potential of these grasslands.

Using Ecophysiology to Improve Farm Efficiency: Application in Temperate Dairy Grazing Systems

Directory of Open Access Journals (Sweden)

David F. Chapman

2016-04-01

Full Text Available Information on the physiological ecology of grass-dominant pastures has made a substantial contribution to the development of practices that optimise the amount of feed harvested by grazing animals in temperate livestock systems. However, the contribution of ecophysiology is often under-stated, and the need for further research in this field is sometimes questioned. The challenge for ecophysiolgists, therefore, is to demonstrate how ecophysiological knowledge can help solve significant problems looming for grassland farming in temperate regions while also removing constraints to improved productivity from grazed pastures. To do this, ecophysiological research needs to align more closely with related disciplines, particularly genetics/genomics, agronomy, and farming systems, including systems modelling. This review considers how ecophysiological information has contributed to the development of grazing management practices in the New Zealand dairy industry, an industry that is generally regarded as a world leader in the efficiency with which pasture is grown and utilised for animal production. Even so, there are clear opportunities for further gains in pasture utilisation through the refinement of grazing management practices and the harnessing of those practices to improved pasture plant cultivars with phenotypes that facilitate greater grazing efficiency. Meanwhile, sub-optimal persistence of new pastures continues to constrain productivity in some environments. The underlying plant and population processes associated with this have not been clearly defined. Ecophysiological information, placed in the context of trait identification, grounded in well-designed agronomic studies and linked to plant improvements programmes, is required to address this.

Variability in carbon dioxide fluxes among six winter wheat paddocks managed under different tillage and grazing practices

Science.gov (United States)

Carbon dioxide (CO2) fluxes from six winter wheat (Triticum aestivum L.) paddocks (grain only, graze-grain, and graze-out) managed under conventional till (CT) and no-till (NT) systems were synthesized for the 2016-2017 growing season to compare the magnitudes and seasonal dynamics of CO2 fluxes and...

Annual methane budgets of sheep grazing systems were regulated by grazing intensities in the temperate continental steppe: A two-year case study

Science.gov (United States)

Ma, Lei; Zhong, Mengying; Zhu, Yuhao; Yang, Helong; Johnson, Douglas A.; Rong, Yuping

2018-02-01

Methane (CH4) emission from animal husbandry accounts for a large percentage of anthropogenic contributions to CH4 emissions. Fully understanding of grazing management effects on the CH4 budget is essential for mitigating CH4 emissions in the temperate grazing steppe systems. Annual CH4 budgets for the sheep grazed steppes at various grazing intensities, un-grazing (UG, 0 sheep ha-1year-1), defer grazing (DG, 1.0 sheep ha-1 year-1), moderate grazing (MG, 1.43 sheep ha-1year-1), and heavy grazing (HG, 2.43 sheep ha-1year-1) were assessed across 2012-2014 in the agro-pastoral region of northern China. Annual soil CH4 uptake averaged across 2012-2014 were 1.1 ± 0.1, 2.4 ± 0.2, 2.2 ± 0.2, and 1.3 ± 0.1 kg CH4-C ha-1 for UG, DG (only 2013-2014), MG and HG sites. Non-growing season CH4 uptake comprised 50.0 ± 4.3% of annual CH4 uptake in 2012-2013 and 37.7 ± 2.0% in 2013-2014. DG and MG significantly promoted annual soil CH4 uptake (P 0.05). Bell-shaped relationship was presented between stocking rates and soil CH4 uptake (r2 = 0.59, P budgets for the grazed grasslands were -1.1 ± 0.1, 5.7 ± 0.6, 11.5 ± 1.5 and 15.5 ± 1.3 kg CH4-C ha-1 year-1 in UG, DG (only 2013-2014), MG and HG across 2012-2014. Soil CH4 uptake could offset 29.7 ± 5.6, 15.9 ± 4.3 and 6.8 ± 1.0% of total annual CH4 emissions from sheep, sheepfold and faeces in DG, MG, and HG. All grazed steppes are sources for atmospheric CH4 and the magnitude is regulated by grazing intensities. Sheep CH4 emissions for 1-g liveweight gain were 0.21, 0.32 and 0.37 g CH4-C in DG, MG and HG, respectively. DG is the recommended grazing management in this region to achieve greater herbage mass, higher sheep performance and lower CH4 emissions simultaneously.

Prescribed grazing for management of invasive vegetation in a hardwood forest understory

Science.gov (United States)

Ronald A. Rathfon; Songlin Fei; Jason Tower; Kenneth Andries; Michael. Neary

2014-01-01

Land managers considering prescribed grazing (PG) face a lack of information on animal stocking rates, timing of grazing, and duration of grazing to achieve desired conditions in natural ecosystems under invasion stress from a variety of nonnative invasive plant (NNIP) species. In this study we tested PG treatments using goats for reducing NNIP brush species and...

Grazing management for Nordic organic dairy farming

OpenAIRE

Kuusela, Eeva

2005-01-01

The aims of this study were to identify limiting factors and to develop adjusted grazing management for Nordic organic dairy farming conditions. The focus was to combine the aspects of plant, animal and organic production, as they are all involved in organic dairy pastures.

Rotation grazing as a conservation management tool : Vegetation changes after six years of application in a salt marsh ecosystem

NARCIS (Netherlands)

Lagendijk, D. D. Georgette; Howison, Ruth A.; Esselink, Peter; Ubels, Richard; Smit, Christian

2017-01-01

Grazing is commonly used in conservation to promote biodiversity, but the search for a grazing management regime that optimises biodiversity is still ongoing. Rotation grazing, where grazing is followed by a relatively long period of non-grazing, is a relative new tool in conservation management,

Cyanobacterial crusts linked to soil productivity under different grazing management practices in Northern Australia

Science.gov (United States)

Alchin, Bruce; Williams, Wendy

2015-04-01

In arid and semi-arid Australia, the central role of healthy soil ecosystems in broad-acre grazing lands may be attributed to the widespread presence of cyanobacterial crusts. In terms of soil nutrient cycling and stability their role is particularly crucial in a climate dominated by annual dry seasons and variable wet seasons. In this study, we aimed to measure the contribution of cyanobacteria to soil nutrient cycling under contrasting levels of disturbance associated with grazing management. Field sampling was carried out on six paired sites (twelve properties) located across an east-west 3,000 km transect that covered different rangeland types on grazing properties in northern Australia (Queensland, Northern Territory and Western Australia). At each location paired sites were established and two different management systems were assessed, cell-paddock rotations (25-400 ha) and continuous grazing (200-2,000 ha). Cyanobacterial soil crusts were recorded from all of the twelve sites and cyanobacteria with the capacity to fix nitrogen were found at ten of the twelve sites. The overall diversity of cyanobacteria varied from three to ten species under any type of grazing system. As field work was conducted in the dry season, it is likely that the diversity may be greater in the wet season than the initial data may indicate. The average cyanobacterial soil crust cover across soil surfaces, between grass tussocks, during the dry season was estimated to be 50.9% and, 42.6% in the early wet season. This reflected longer established crust cover (dry season) versus newly established crusts. There was a high level of variability in the biomass of cyanobacteria however; the grazing system did not have any marked effect on the biomass for any one rangeland type. The grazing system differences did not appear to significantly influence the diversity at any location except on a floodplain in the Pilbara (WA). Biological nitrogen fixation by cyanobacteria was recorded at all

Long-term effects of grazing management and buffer strips on soil erosion from pastures

Science.gov (United States)

High grazing pressure can lead to soil erosion in pastures by compacting soil and increasing runoff and sediment delivery to waterways. Limited information exists on the effects of grazing management and best management practices (BMPs), such as buffer strips, on soil erosion from pastures. The obje...

Towards evenly distributed grazing patterns: including social context in sheep management strategies

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Agustina di Virgilio

2016-06-01

Full Text Available Background. A large proportion of natural grasslands around the world is exposed to overgrazing resulting in land degradation and biodiversity loss. Although there is an increasing effort in the promotion of sustainable livestock management, rangeland degradation still occurs because animals’ foraging behaviour is highly selective at different spatial scales. The assessment of the ecological mechanisms modulating the spatial distribution of grazing and how to control it has critical implications for long term conservation of resources and the sustainability of livestock production. Considering the relevance of social interactions on animals’ space use patterns, our aim was to explore the potential effects of including animals’ social context into management strategies using domestic sheep grazing in rangelands as case study. Methods. We used GPS data from 19 Merino sheep (approximately 10% of the flock grazing on three different paddocks (with sizes from 80 to 1000 Ha during a year, to estimate resource selection functions of sheep grazing in flocks of different levels of heterogeneity. We assessed the effects of sheep class (i.e., ewes, wethers, and hoggets, age, body condition and time since release on habitat selection patterns. Results. We found that social rank was reflected on sheep habitat use, where dominant individuals (i.e., reproductive females used more intensively the most preferred areas and low-ranked (i.e., yearlings used less preferred areas. Our results showed that when sheep grazed on more heterogeneous flocks, grazing patterns were more evenly distributed at all the paddocks considered in this study. On the other hand, when high-ranked individuals were removed from the flock, low-ranked sheep shifted their selection patterns by increasing the use of the most preferred areas and strongly avoided to use less preferred sites (i.e., a highly selective grazing behaviour. Discussion. Although homogenization and segregation of

Towards evenly distributed grazing patterns: including social context in sheep management strategies.

Science.gov (United States)

di Virgilio, Agustina; Morales, Juan Manuel

2016-01-01

Background. A large proportion of natural grasslands around the world is exposed to overgrazing resulting in land degradation and biodiversity loss. Although there is an increasing effort in the promotion of sustainable livestock management, rangeland degradation still occurs because animals' foraging behaviour is highly selective at different spatial scales. The assessment of the ecological mechanisms modulating the spatial distribution of grazing and how to control it has critical implications for long term conservation of resources and the sustainability of livestock production. Considering the relevance of social interactions on animals' space use patterns, our aim was to explore the potential effects of including animals' social context into management strategies using domestic sheep grazing in rangelands as case study. Methods. We used GPS data from 19 Merino sheep (approximately 10% of the flock) grazing on three different paddocks (with sizes from 80 to 1000 Ha) during a year, to estimate resource selection functions of sheep grazing in flocks of different levels of heterogeneity. We assessed the effects of sheep class (i.e., ewes, wethers, and hoggets), age, body condition and time since release on habitat selection patterns. Results. We found that social rank was reflected on sheep habitat use, where dominant individuals (i.e., reproductive females) used more intensively the most preferred areas and low-ranked (i.e., yearlings) used less preferred areas. Our results showed that when sheep grazed on more heterogeneous flocks, grazing patterns were more evenly distributed at all the paddocks considered in this study. On the other hand, when high-ranked individuals were removed from the flock, low-ranked sheep shifted their selection patterns by increasing the use of the most preferred areas and strongly avoided to use less preferred sites (i.e., a highly selective grazing behaviour). Discussion. Although homogenization and segregation of flocks by classes

Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

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Antonio Rigueiro-Rodríguez

2012-02-01

Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

Equine Grazing in Managed Subalpine Wetlands: Effects on Arthropods and Plant Structure as a Function of Habitat

Science.gov (United States)

Holmquist, Jeffrey G.; Schmidt-Gengenbach, Jutta; Haultain, Sylvia A.

2013-12-01

Grazing management necessarily emphasizes the most spatially extensive vegetation assemblages, but landscapes are mosaics, often with more mesic vegetation types embedded within a matrix of drier vegetation. Our primary objective was to contrast effects of equine grazing on both subalpine vegetation structure and associated arthropods in a drier reed grass ( Calamagrostis muiriana) dominated habitat versus a wetter, more productive sedge habitat ( Carex utriculata). A second objective was to compare reed grass and sedge as habitats for fauna, irrespective of grazing. All work was done in Sequoia National Park (CA, USA), where detailed, long-term records of stock management were available. We sampled paired grazed and control wet meadows that contained both habitats. There were moderate negative effects of grazing on vegetation, and effects were greater in sedge than in reed grass. Conversely, negative grazing effects on arthropods, albeit limited, were greater in the drier reed grass, possibly due to microhabitat differences. The differing effects on plants and animals as a function of habitat emphasize the importance of considering both flora and fauna, as well as multiple habitat types, when making management decisions. Sedge supported twice the overall arthropod abundance of reed grass as well as greater diversity; hemipteran and dipteran taxa were particularly abundant in sedge. Given the greater grazing effects on sedge vegetation, greater habitat provision for terrestrial arthropods, and value as aquatic arthropod habitat, the wetter sedge assemblage is worthy of additional consideration by managers when planning for grazing and other aspects of land usage.

Animal health management practices in zero grazing dairy units in ...

African Journals Online (AJOL)

Animal health management practices in zero grazing dairy units in Arusha City, Tanzania. ... African Journal of Food, Agriculture, Nutrition and Development ... findings, majority (84.6%) of the cow's enclosures were of poor hygiene.

An agent-based model of cattle grazing toxic Geyer's larkspur.

Science.gov (United States)

Jablonski, Kevin E; Boone, Randall B; Meiman, Paul J

2018-01-01

By killing cattle and otherwise complicating management, the many species of larkspur (Delphinium spp.) present a serious, intractable, and complex challenge to livestock grazing management in the western United States. Among the many obstacles to improving our understanding of cattle-larkspur dynamics has been the difficulty of testing different grazing management strategies in the field, as the risk of dead animals is too great. Agent-based models (ABMs) provide an effective method of testing alternate management strategies without risk to livestock. ABMs are especially useful for modeling complex systems such as livestock grazing management, and allow for realistic bottom-up encoding of cattle behavior. Here, we introduce a spatially-explicit, behavior-based ABM of cattle grazing in a pasture with a dangerous amount of Geyer's larkspur (D. geyeri). This model tests the role of herd cohesion and stocking density in larkspur intake, finds that both are key drivers of larkspur-induced toxicosis, and indicates that alteration of these factors within realistic bounds can mitigate risk. Crucially, the model points to herd cohesion, which has received little attention in the discipline, as playing an important role in lethal acute toxicosis. As the first ABM to model grazing behavior at realistic scales, this study also demonstrates the tremendous potential of ABMs to illuminate grazing management dynamics, including fundamental aspects of livestock behavior amidst ecological heterogeneity.

A 100-Year Review: A century of change in temperate grazing dairy systems.

Science.gov (United States)

Roche, J R; Berry, D P; Bryant, A M; Burke, C R; Butler, S T; Dillon, P G; Donaghy, D J; Horan, B; Macdonald, K A; Macmillan, K L

2017-12-01

reduction in pasture intake associated with the provision of supplementary feed (i.e., substitution rate) is accounted for. A unique feature of grazing systems research over the last 70 yr has been the use of multi-year farm systems experimentation. These studies have allowed the evaluation of strategic changes to a component of the system on all the interacting features of the system. This technique has allowed excellent component research to be "systemized" and is an essential part of the development of the intensive grazing production system that exists today. Future challenges include the provision of skilled labor or specifically designed automation to optimize farm management and both environmental sustainability and animal welfare concerns, particularly relating to the concentration of nitrogen in each urine patch and the associated risk of nitrate leaching, as well as concerns regarding exposure of animals to harsh climatic conditions. These combined challenges could affect farmers' "social license" to farm in the future. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of grazing management and buffer strips on metal runoff from pastures fertilized with poultry litter

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Metal runoff from fields fertilized with poultry litter may pose a threat to aquatic systems. Buffer strips have been added to fields to reduce nutrients and solids runoff. However, scant information exists on the effects of buffer strips combined with grazing management strategies on metal runoff f...

The effect of grazing on cow mortality in Danish dairy herds

DEFF Research Database (Denmark)

Burow, Elke; Thomsen, Peter Thorup; Sørensen, Jan Tind

2011-01-01

The effect of summer grazing in large Danish dairy herds and certain management characteristics of grazing were studied for their impact on dairy cow mortality. Mortality data (from the Danish Cattle Database) from 391 Danish dairy herds (>100 cows) were combined with information from...... a questionnaire survey of grazing procedures on these herds in 2008. In all, 131 of the herds were identified as summer grazing and 260 as zero-grazing herds. The mortality was affected by an interaction of summer grazing and milking system. The risk of a cow dying was reduced to 46% in a grazing compared...... and pasture was associated with increased cow mortality....

Modelling parasite transmission in a grazing system: the importance of host behaviour and immunity.

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Naomi J Fox

Full Text Available Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts' immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites' free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes

Grazing winter rye cover crop in a cotton no-till system: yield and economics

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Winter cover crop adoption in conservation management systems continues to be limited in the US but could be encouraged if establishment costs could be offset. A 4-yr field experiment was conducted near Watkinsville, Georgia in which a rye (Secale cereale L.) cover crop was either grazed by catt...

Western land managers will need all available tools for adapting to climate change, including grazing: a critique of Beschta et al.

Science.gov (United States)

Svejcar, Tony; Boyd, Chad; Davies, Kirk; Madsen, Matthew; Bates, Jon; Sheley, Roger; Marlow, Clayton; Bohnert, David; Borman, Mike; Mata-Gonzàlez, Ricardo; Buckhouse, John; Stringham, Tamzen; Perryman, Barry; Swanson, Sherman; Tate, Kenneth; George, Mel; Ruyle, George; Roundy, Bruce; Call, Chris; Jensen, Kevin; Launchbaugh, Karen; Gearhart, Amanda; Vermeire, Lance; Tanaka, John; Derner, Justin; Frasier, Gary; Havstad, Kris

2014-06-01

In a previous article, Beschta et al. (Environ Manag 51(2):474-491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO₂ and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20-50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing.

Livestock grazing, wildlife habitat, and rangeland values

Science.gov (United States)

Paul R. Krausman; David E. Naugle; Michael R. Frisina; Rick Northrup; Vernon C. Bleich; William M. Block; Mark C. Wallace; Jeffrey D. Wright

2009-01-01

Livestock managers make and implement grazing management decisions to achieve a variety of objectives including livestock production, sustainable grazing, and wildlife habitat enhancement. Assessed values of grazing lands and ranches are often based on aesthetics and wildlife habitat or recreational values, which can exceed agricultural values, thus providing...

Vegetation patterns and nutrients in relation to grazing pressure and ...

African Journals Online (AJOL)

A major challenge confronting managers of extensive grazing systems is uneven use of erbaceous forage plants by livestock. The concentration of grazing in preferred areas or around foci points (e.g. water points) eventually results in adverse impacts in soil nutrients, vegetation structure, production and composition.

Emergy analysis of cropping-grazing system in Inner Mongolia Autonomous Region, China

International Nuclear Information System (INIS)

Zhang, L.X.; Yang, Z.F.; Chen, G.Q.

2007-01-01

An ecological energetic evaluation is presented in this paper as a complement to economic account for the cropping-grazing system in the Inner Mongolia Autonomous Region in China in the year 2000. Based on Odum's well-known concept of emergy in terms of embodied solar energy as a unified measure for environmental resources, human or animal labors and industrial products, a systems diagram is developed for the crop and livestock productions with arms and sub-arms for free renewable natural resource input, purchased economic investment, yields of and interactive fluxes between the cropping and grazing sub-industries. In addition to conventional systems indices of the emergy yield ratio (EYR), emergy investment ratio (EIR), environmental load ratio (ELR) and environmental sustainability index (ESI) introduced for congregated systems ecological assessment with essential implication for sustainability, new indicators of soil emergy cost (SEC), self-support intensity (SSI) and self-support orientation (SSO) are defined to characterize the desertification and internal recycling associated with the special agricultural system. Extensive emergy accounting is made for the cropping-grazing system as a whole as well as for the cropping and grazing subsystems. The overall cropping-grazing system is shown with outstanding production competence compared with agricultural systems in some other provinces and the national average in China, though confronted with severe desertification associated with soil loss. The production of crops has higher emergy density and yield rate per unit area as well as higher rate of soil loss than grazing system. The soil emergy cost defined as the soil loss emergy divided by the yield emergy is estimated to be of the same value for both of the subsystems, but the grazing activity is with less extraction intensity, leaving rangeland to rest and rehabilitate. Suggestions with regard to the local sustainability and national ecological security in

Transitions and coexistence along a grazing gradient in the Eurasian steppe

Science.gov (United States)

Ren, Haiyan; Taube, Friedelm; Zhang, Yingjun; Bai, Yongfei; Hu, Shuijin

2017-04-01

Ecological resilience theory has often been applied to explain species coexistence and range condition assessment of various community states and to explicate the dynamics of ecosystems. Grazing is a primary disturbance that can alter rangeland resilience by causing hard-to-reverse transitions in grasslands. Yet, how grazing affects the coexistence of plant functional group (PFG) and transition remains unclear. We conducted a six-year grazing experiment in a typical steppe of Inner Mongolia, using seven grazing intensities (0, 1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 sheep/ hectare) and two grazing systems (i.e. a continuous annual grazing as in the traditional grazing system, and a mixed grazing system combining grazing and haymaking), to examine grazing effects on plant functional group shifts and species coexistence in the semi-arid grassland system. Our results indicate that the relative richness of dominant bunchgrasses and forbs had a compensatory coexistence at all grazing intensities, and the richness of rhizomatous grasses fluctuated but was persistent. The relative productivity of dominant bunchgrasses and rhizomatous grasses had compensatory interactions with grazing intensity and grazing system. Dominant bunchgrasses and rhizomatous grasses resist grazing effects by using their dominant species functional traits: high specific leaf area and low leaf nitrogen content. Our results suggest that: 1. Stabilizing mechanisms beyond grazing management are more important in determining plant functional group coexistence and ecological resilience. 2. Plant functional group composition is more important in influencing ecosystem functioning than diversity. 3. Ecosystem resilience at a given level is related to the biomass of dominant PFG, which is determined by a balanced shift between dominant species biomass. The relatively even ecosystem resilience along the grazing gradient is attributed to the compensatory interactions of dominant species in their biomass variations

Possibilities and constraints for grazing in high output dairy systems

NARCIS (Netherlands)

Hennessy, D.; Delaby, L.; Pol, van den A.; Shalloo, L.

2015-01-01

In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of

Grazing effects on species composition in different vegetation types (La Palma, Canary Islands)

Science.gov (United States)

Arévalo, J. R.; de Nascimento, L.; Fernández-Lugo, S.; Mata, J.; Bermejo, L.

2011-05-01

Grazing management is probably one of the most extensive land uses, but its effects on plant communities have in many cases been revealed to be contradictory. Some authors have related these contradictions to the stochastic character of grazing systems. Because of that, it is necessary to implement specific analyses of grazing effects on each community, especially in natural protected areas, in order to provide the best information to managers. We studied the effects of grazing on the species composition of the main vegetation types where it takes place (grasslands, shrublands and pine forests) on the island of La Palma, Canary Islands. We used the point-quadrat intersect method to study the species composition of grazed and ungrazed areas, which also were characterized by their altitude, distance to farms, distance to settlements, year of sampling, herbaceous aboveground biomass and soil organic matter. The variables organic matter, productivity and species richness were not significantly affected by grazing. The species composition of the analyzed plant communities was affected more by variables such as altitude or distance to farms than by extensive grazing that has been traditionally carried out on the island of La Palma involving certain practices such as continuous monitoring of animals by goat keepers, medium stocking rates adjusted to the availability of natural pastures, supplementation during the dry season using local forage shrubs or mown pastures and rotating animals within grazing areas Although some studies have shown a negative effect of grazing on endangered plant species, these results cannot be freely extrapolated to the traditional grazing systems that exert a low pressure on plant communities (as has been found in this study). We consider extensive grazing as a viable way of ensuring sustainable management of the studied ecosystems.

36 CFR 222.3 - Issuance of grazing and livestock use permits.

Science.gov (United States)

2010-07-01

... livestock use permits. 222.3 Section 222.3 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE RANGE MANAGEMENT Grazing and Livestock Use on the National Forest System § 222.3 Issuance of grazing and livestock use permits. (a) Unless otherwise specified by the Chief, Forest Service, all...

Arbuscular mycorrhizal fungi associated with vegetation and soil parameters under rest grazing management in a desert steppe ecosystem.

Science.gov (United States)

Bai, Gegenbaoleer; Bao, Yuying; Du, Guoxin; Qi, Yunlong

2013-05-01

The impact of rest grazing on arbuscular mycorrhizal fungi (AMF) and the interactions of AMF with vegetation and soil parameters under rest grazing condition were investigated between spring and late summer in a desert steppe ecosystem with different grazing managements (rest grazing with different lengths of resting period, banned or continuous grazing) in Inner Mongolia, China. AMF diversity and colonization, vegetation biomass, soil properties and soil phosphatase activity were examined. In rest grazing areas of 60 days, AMF spore number and diversity index at a 0-10 cm soil depth as well as vesicular and hyphal colonization rates were higher compared with other grazing treatments. In addition, soil organic matter and total N contents were highest and soil alkaline phosphatase was most active under 60-day rest grazing. In August and September, these areas also had the highest amount of aboveground vegetation. The results indicated that resting grazing for an appropriate period of time in spring has a positive effect on AMF sporulation, colonization and diversity, and that under rest grazing conditions, AMF parameters are positively correlated with some soil characteristics.

Invariant polygons in systems with grazing-sliding.

Science.gov (United States)

Szalai, R; Osinga, H M

2008-06-01

The paper investigates generic three-dimensional nonsmooth systems with a periodic orbit near grazing-sliding. We assume that the periodic orbit is unstable with complex multipliers so that two dominant frequencies are present in the system. Because grazing-sliding induces a dimension loss and the instability drives every trajectory into sliding, the system has an attractor that consists of forward sliding orbits. We analyze this attractor in a suitably chosen Poincare section using a three-parameter generalized map that can be viewed as a normal form. We show that in this normal form the attractor must be contained in a finite number of lines that intersect in the vertices of a polygon. However the attractor is typically larger than the associated polygon. We classify the number of lines involved in forming the attractor as a function of the parameters. Furthermore, for fixed values of parameters we investigate the one-dimensional dynamics on the attractor.

Knowledge and tools to enhance resilience of beef grazing systems for sustainable animal protein production.

Science.gov (United States)

Steiner, Jean L; Engle, David M; Xiao, Xiangming; Saleh, Ali; Tomlinson, Peter; Rice, Charles W; Cole, N Andy; Coleman, Samuel W; Osei, Edward; Basara, Jeffrey; Middendorf, Gerad; Gowda, Prasanna; Todd, Richard; Moffet, Corey; Anandhi, Aavudai; Starks, Patrick J; Ocshner, Tyson; Reuter, Ryan; Devlin, Daniel

2014-11-01

Ruminant livestock provides meat and dairy products that sustain health and livelihood for much of the world's population. Grazing lands that support ruminant livestock provide numerous ecosystem services, including provision of food, water, and genetic resources; climate and water regulation; support of soil formation; nutrient cycling; and cultural services. In the U.S. southern Great Plains, beef production on pastures, rangelands, and hay is a major economic activity. The region's climate is characterized by extremes of heat and cold and extremes of drought and flooding. Grazing lands occupy a large portion of the region's land, significantly affecting carbon, nitrogen, and water budgets. To understand vulnerabilities and enhance resilience of beef production, a multi-institutional Coordinated Agricultural Project (CAP), the "grazing CAP," was established. Integrative research and extension spanning biophysical, socioeconomic, and agricultural disciplines address management effects on productivity and environmental footprints of production systems. Knowledge and tools being developed will allow farmers and ranchers to evaluate risks and increase resilience to dynamic conditions. The knowledge and tools developed will also have relevance to grazing lands in semiarid and subhumid regions of the world. © 2014 New York Academy of Sciences.

Modeling the grazing effect on dry grassland carbon cycling with modified Biome-BGC grazing model

Science.gov (United States)

Luo, Geping; Han, Qifei; Li, Chaofan; Yang, Liao

2014-05-01

Identifying the factors that determine the carbon source/sink strength of ecosystems is important for reducing uncertainty in the global carbon cycle. Arid grassland ecosystems are a widely distributed biome type in Xinjiang, Northwest China, covering approximately one-fourth the country's land surface. These grasslands are the habitat for many endemic and rare plant and animal species and are also used as pastoral land for livestock. Using the modified Biome-BGC grazing model, we modeled carbon dynamics in Xinjiang for grasslands that varied in grazing intensity. In general, this regional simulation estimated that the grassland ecosystems in Xinjiang acted as a net carbon source, with a value of 0.38 Pg C over the period 1979-2007. There were significant effects of grazing on carbon dynamics. An over-compensatory effect in net primary productivity (NPP) and vegetation carbon (C) stock was observed when grazing intensity was lower than 0.40 head/ha. Grazing resulted in a net carbon source of 23.45 g C m-2 yr-1, which equaled 0.37 Pg in Xinjiang in the last 29 years. In general, grazing decreased vegetation C stock, while an increasing trend was observed with low grazing intensity. The soil C increased significantly (17%) with long-term grazing, while the soil C stock exhibited a steady trend without grazing. These findings have implications for grassland ecosystem management as it relates to carbon sequestration and climate change mitigation, e.g., removal of grazing should be considered in strategies that aim to increase terrestrial carbon sequestrations at local and regional scales. One of the greatest limitations in quantifying the effects of herbivores on carbon cycling is identifying the grazing systems and intensities within a given region. We hope our study emphasizes the need for large-scale assessments of how grazing impacts carbon cycling. Most terrestrial ecosystems in Xinjiang have been affected by disturbances to a greater or lesser extent in the past

Non-traditional Forages in a Managed Grazing System for Control of Gastrointestinal Parasites in Sheep: Preliminary Work

Science.gov (United States)

This project compared lambs grazing forage chicory (Cichorium intybus L.) with lambs grazing brown mid-rib forage sorghum (Sorghum bicolor (L.) Moench.) x sudangrass (Sorghum sudanense Piper) hybrid (BMR) to determine if anti-parasitic effects of chicory could be demonstrated. Lambs grazed these fo...

Carbon sequestration potential of grazed pasture depends on prior management history

Science.gov (United States)

Grazed pastures are often assumed to be net sinks for removing carbon dioxide from the atmosphere and thus, are promoted as a management practice that can help mitigate climate change. The ability to serve as a C sink is especially pronounced following a history of tillage and row crop production. I...

Relationships among rotational and conventional grazing systems, stream channels, and macroinvertebrates

Science.gov (United States)

Raymond, K.L.; Vondracek, B.

2011-01-01

Cattle grazing in riparian areas can reduce water quality, alter stream channel characteristics, and alter fish and macroinvertebrate assemblage structure. The U.S. Department of Agriculture, Natural Resources Conservation Services has recommended Rotational Grazing (RG) as an alternative management method on livestock and dairy operations to protect riparian areas and water quality. We evaluated 13 stream channel characteristics, benthic macroinvertebrate larvae (BML), and chironomid pupal exuviae (CPE) from 18 sites in the Upper Midwest of the United States in relation to RG and conventional grazing (CG). A Biotic Composite Score comprised of several macroinvertebrate metrics was developed for both the BML assemblage and the CPE assemblage. Multi-Response Permutation Procedures (MRPP) indicated a significant difference in stream channel characteristics between RG and CG. Nonmetric Multidimensional Scaling indicated that RG sites were associated with more stable stream banks, higher quality aquatic habitat, lower soil compaction, and larger particles in the streambed. However, neither MRPP nor Mann-Whitney U tests demonstrated a difference in Biotic Composite Scores for BML or CPE along RG and CG sites. The BML and CPE metrics were significantly correlated, indicating that they were likely responding to similar variables among the study sites. Although stream channel characteristics appeared to respond to grazing management, BML and CPE may have responded to land use throughout the watershed, as well as local land use. ?? 2011 Springer Science+Business Media B.V. (outside the USA).

Response of mountain meadows to grazing by recreational pack stock

Science.gov (United States)

Cole, David N.; Van Wagtendonk, Jan W.; McClaran, Mitchel P.; Moore, Peggy E.; McDougald, Neil K.

2004-01-01

Effects of recreational pack stock grazing on mountain meadows in Yosemite National Park were assessed in a 5-year study. Yosemite is a designated wilderness, to be managed such that its natural conditions are preserved. Studies were conducted in 3 characteristic meadow types: shorthair sedge (Carex filifolia Nutt.), Brewer's reed grass (Calamagrostis breweri Thurber), and tufted hairgrass [Deschampsia cespitosa (L.) Beauv.]. Horses and mules grazed experimental plots at intensities of 15 to 69% utilization for 4 seasons. In all 3 meadows, grazing caused decreases in productivity. The mean reduction after 4 years of grazing was 18% in the shorthair sedge meadow, 17% in the Brewer's reed grass meadow, and 22% in the tufted hairgrass meadow. Grazing also caused shifts in basal groundcover (usually a reduction in vegetation cover and increase in bare soil cover), and changes in species composition. Productivity and vegetation cover decreased as percent utilization increased, while bare soil cover increased as utilization increased. Changes in species composition were less predictably related to differences in grazing intensity. Passive management of grazing is insufficient in wilderness areas that are regularly used by groups with recreational stock. Wilderness managers need to monitor meadow conditions and the grazing intensities that occur. Our study suggests that biomass and ground cover are more sensitive indicators of grazing impact than species composition. Managers must make decisions about maximum acceptable levels of grazing impact and then develop guidelines for maximum use levels, based on data such as ours that relates grazing intensity to meadow response.

Bayesian estimation of shrubs diversity in rangelands under two management systems in northern Syria

NARCIS (Netherlands)

Niane, A.A.; Singh, M.; Struik, P.C.

2014-01-01

The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the

Landscape management of fire and grazing regimes alters the fine-scale habitat utilisation by feral cats.

Science.gov (United States)

McGregor, Hugh W; Legge, Sarah; Jones, Menna E; Johnson, Christopher N

2014-01-01

Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been documented. To test for such an interaction, we investigated fine-scale habitat selection by feral cats in relation to fire, grazing and small-mammal abundance. Our study was conducted in north-western Australia, where small mammal populations are sensitive to changes in fire and grazing management. We deployed GPS collars on 32 cats in landscapes with contrasting fire and grazing treatments. Fine-scale habitat selection was determined using discrete choice modelling of cat movements. We found that cats selected areas with open grass cover, including heavily-grazed areas. They strongly selected for areas recently burnt by intense fires, but only in habitats that typically support high abundance of small mammals. Intense fires and grazing by introduced herbivores created conditions that are favoured by cats, probably because their hunting success is improved. This mechanism could explain why, in northern Australia, impacts of feral cats on small mammals might have increased. Our results suggest the impact of feral cats could be reduced in most ecosystems by maximising grass cover, minimising the incidence of intense fires, and reducing grazing by large herbivores.

Landscape management of fire and grazing regimes alters the fine-scale habitat utilisation by feral cats.

Directory of Open Access Journals (Sweden)

Hugh W McGregor

Full Text Available Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been documented. To test for such an interaction, we investigated fine-scale habitat selection by feral cats in relation to fire, grazing and small-mammal abundance. Our study was conducted in north-western Australia, where small mammal populations are sensitive to changes in fire and grazing management. We deployed GPS collars on 32 cats in landscapes with contrasting fire and grazing treatments. Fine-scale habitat selection was determined using discrete choice modelling of cat movements. We found that cats selected areas with open grass cover, including heavily-grazed areas. They strongly selected for areas recently burnt by intense fires, but only in habitats that typically support high abundance of small mammals. Intense fires and grazing by introduced herbivores created conditions that are favoured by cats, probably because their hunting success is improved. This mechanism could explain why, in northern Australia, impacts of feral cats on small mammals might have increased. Our results suggest the impact of feral cats could be reduced in most ecosystems by maximising grass cover, minimising the incidence of intense fires, and reducing grazing by large herbivores.

Dynamics of production and forage utilization on elephant grass pastures managed with different post-grazing heights

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Braulio Maia de Lana Sousa

2012-08-01

Full Text Available This study was conducted to evaluate the daily production of forage and its morphological components, as well as the potential of forage utilization in pastures of Pennisetum purpureum cv. Napier managed with three post-grazing heights (30, 50 and 70 cm. Two experiments were carried out: one from February to May 2009 and another from December 2009 to May 2010, characterizing months of summer and fall. The experimental design was of completely randomized blocks with three replicates. The grazing was performed by crossbred heifers of approximately 270 kg body weight, when the sward intercepted 95% of the incoming light. In both experiments, the pastures managed with post-grazing height of 30 cm, in the summer months (December to March, presented lower daily production of leaves and stems, as well as less daily leaf senescence, which resulted in lower daily forage production and accumulation in comparison with those managed at 70 and 50 cm. In the period from February to March 2009 (experiment 1 and December 2009 to March 2010 (experiment 2, pastures presented greater daily production of leaves and forage, greater daily forage accumulation and more daily leaf senescence in relation to the months of April and May 2009 and 2010. On the other hand, the daily production of stems was higher in the fall, in comparison with the summer. Therefore, elevation in the post-grazing height, especially in the summer, increases the regrowth vigor of elephant grass cv. Napier.

Lucerne varieties for continuous grazing

DEFF Research Database (Denmark)

Søegaard, Karen

2012-01-01

severe grazing with heifers in two cutting/grazing managements. Two new varieties, Verbena and Camporegio, and an older variety Luzelle were established in 2009 in pure stands and in two different mixtures with perennial ryegrass (Lolium perenne). Camporegio had the lowest yield, the lowest competitive...... strength, the lowest plant density in spring, and the density was most reduced during grazing. The results could not confirm significant differences between the new and the older varieties. The results for Luzelle were generally between Verbena and Camporegio. The varieties did not differ in herbage...

Species Diversity and Botanical Composition of Permanent Grassland as a Response to Different Grazing Management Practices

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Marie Štýbnarová

2015-01-01

Full Text Available The effects of different levels of grazing utilization (two, three and four grazing cycles per year and mineral fertilization (nil-fertilization; N100P30K60 on the botanical composition of permanent grasslands were studied in the locality of Rapotín (Czech Republic, 332 m a.s.l. from 2003–2010. The vegetation of the experimental pasture was classified as Cynosurion. It was found that moderate treatment (three grazing cycles per year without mineral fertilization showed the highest value of diversity index (DI = 6.08, and maximum dominance of legumes (Dmax = 9.1%, particularly Trifolium repens. The highest dominance of grasses (Dmax = 77.7%, mainly Dactylis glomerata and Elytrigia repens, was achieved with the fertilized treatment utilized in two grazing cycles per year. Based on RDA results, tested management treatments explained 26% of species composition variability, where effect of number of grazing cycles per year was five-times higher than effect of fertilization. We recommend grassland utilization in three grazing cycles per year as the most suitable way from the objective of both species diversity and botanical composition of pastures in similar site conditions. Pasture fertilization should be more controlled by careful consideration of individual pasture goals, actual nutrient status of the soil and possible environmental risks.

Seasonality constraints to livestock grazing intensity.

Science.gov (United States)

Fetzel, Tamara; Havlik, Petr; Herrero, Mario; Erb, Karl-Heinz

2017-04-01

Increasing food production is essential to meet the future food demand of a growing world population. In light of pressing sustainability challenges such as climate change and the importance of the global livestock system for food security as well as GHG emissions, finding ways to increasing food production sustainably and without increasing competition for food crops is essential. Yet, many unknowns relate to livestock grazing, in particular grazing intensity, an essential variable to assess the sustainability of livestock systems. Here, we explore ecological limits to grazing intensity (GI; i.e. the fraction of net primary production consumed by grazing animals) by analysing the role of seasonality in natural grasslands. We estimate seasonal limitations to GI by combining monthly net primary production data and a map of global livestock distribution with assumptions on the length of nonfavourable periods that can be bridged by livestock (e.g. by browsing dead standing biomass, storage systems or biomass conservation). This allows us to derive a seasonality-limited potential GI, which we compare with the GI prevailing in 2000. We find that GI in 2000 lies below its potential on 39% of the total global natural grasslands, which has a potential for increasing biomass extraction of up to 181 MtC/yr. In contrast, on 61% of the area GI exceeds the potential, made possible by management. Mobilizing this potential could increase milk production by 5%, meat production by 4% or contribute to free up to 2.8 Mio km² of grassland area at the global scale if the numerous socio-ecological constraints can be overcome. We discuss socio-ecological trade-offs, which may reduce the estimated potential considerably and require the establishment of sound monitoring systems and an improved understanding of livestock system's role in the Earth system. © 2017 John Wiley & Sons Ltd.

The grazing pattern of Muturu cattle under range system | Nweze ...

African Journals Online (AJOL)

Eighty Muturu cattle were grazed on rangeland, twice daily for two years to determine their grazing pattern. Twenty bulls and cows each between two to four years and forty calves between one to three months were used. The field grazing time (FGT), active grazing time (GT) and grazing travel time (GTT) were monitored.

How Does “Hunger” Level Impact Grazing Behavior?

Science.gov (United States)

Grazing behavior can be influenced through feeding and grazing management decisions. Research at our USDA-ARS lab showed that ruminal fill, or how ‘hungry’ the cow is, can affect grazing behavior. Cows that had less ruminal fill took a bigger bite that was shallow and wide, compared to a ‘full’ cow ...

Mixed grazing systems of goats with cattle in tropical conditions: an alternative to improving animal production in the pasture.

Science.gov (United States)

d'Alexis, S; Periacarpin, F; Jackson, F; Boval, M

2014-08-01

Mixed grazing systems combining sheep and cattle have shown better growth performance for one or both species. This observation has been attributed to their complementary feeding behaviour and the reduced host infection by gastrointestinal nematodes. Less attention has been paid to mixed grazing systems combining goats and cattle. Here, continuously grazing goats mixed with cattle (M) were compared with control goats reared alone (C) under tropical conditions. The comparison was conducted with gastrointestinal nematode-infected (I) and non-infected (nI) goats. Thus, the four treatments were cattle with gastrointestinal nematode-infected goats (MI), gastrointestinal nematode-infected goats alone (CI), cattle with non-infected goats (MnI) and non-infected goats (CnI). Average daily gain (ADG, g/day) and grass production were measured for the four groups of animals (six goats and two heifers treated with MI or MnI) grazing for 3 months on 4 subplots. Monthly measurements were performed over 5-day periods. This pattern was replicated in space for a second set of four subplots and in time for six successive cohorts of animals (bands 1 to 6). The ADG of goats in mixed grazing conditions was higher than controls irrespective of the infection status (32.6 v. 18.4 g/day for MI v. CI; 44.2 v. 33.5 g/day for MnI v. CnI). Concomitantly, the average biomass was lower for mixed grazing animals compared with controls (174 v. 170 for MI and MnI; 235 v. 208 for CI and CnI, respectively), suggesting better use of the sward. For daily BW gain (g/kg DM), mixed grazing also yielded better results than the control (1.88 v. 0.52 g BW/kg DM per day for MI v. CI; 2.08 v. 1.47 g BW/kg DM per day for MnI and CnI). Mixed grazing of goats and heifers offers a promising alternative for increasing goat and overall animal production as well as improving the management of pastures.

Influence of sward characteristics on grazing behaviour and short ...

African Journals Online (AJOL)

Relative to temperate systems, there has been few reported detailed assessments of sward characteristics and associated grazing behavior from natural and ... in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria.

The effects of grazing intensity on soil processes in a Mediterranean protected area.

Science.gov (United States)

Panayiotou, Evaggelia; Dimou, Maria; Monokrousos, Nikolaos

2017-08-08

We investigated the temporal and among-site differentiation of soil functionality properties in fields under different grazing intensities (heavy and light) and compared them to those found in their adjacent hedgerows, consisting either of wooden shrubs (Rubus canescens) or of high trees (Populus sp.), during the cold and humid seasons of the year. We hypothesized that greater intensity of grazing would result in higher degradation of the soil system. The grazing factor had a significant effect on soil organic C and N, microbial biomass C, microbial biomass N, microbial activity, and β-glucosidase, while acid phosphatase and urease activity were not found to differ significantly among the management systems. The intensity of grazing affected mostly the chemical properties of soil (organic C and N) and altered significantly the composition of the soil microbial community, as lower C:N ratio of the microbial biomass indicates the dominance of bacteria over fungi in the heavily grazed fields. All estimated biological variables presented higher values in the humid period, although the pattern of differentiation was similar at both sampling times, revealing that site-specific variations were more pronounced than the time-specific ones. Our results indicate that not all C, N, and P dynamics were equally affected by grazing. Management plans applied to pastures, in order to improve soil quality properties and accelerate passive reforestation, should aim at the improvement of soil parameters related primarily to C and secondly to N cycle.

Productivity of grasslands under continuous and rotational grazing

NARCIS (Netherlands)

Lantinga, E.A.

1985-01-01

In the Netherlands, rotational grazing, with grazing periods of 2 to 5 days, is the most common grazing system at present. In contrast with other countries of North-western Europe, the continuous grazing system is used here only to a limited extent. However, the results of numerous

Effects of Grazing Management in Brachiaria grass-forage Peanut Pastures on Canopy Structure and Forage Intake.

Science.gov (United States)

Gomes, F K; Oliveira, M D B L; Homem, B G C; Boddey, R M; Bernardes, T F; Gionbelli, M P; Lara, M A S; Casagrande, D R

2018-06-13

Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A two-year experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 days (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at five points above the canopy for each paddock using a canopy analyzer. For all treatments, the post-grazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre-and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited neutral detergent fiber intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible organic matter (OM; P = 0.007) and the ratio of crude protein/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency

Improved grazing activity of dairy heifers in shaded tropical grasslands

Directory of Open Access Journals (Sweden)

Andréia Cristina Tavares de Mello

Full Text Available ABSTRACT: Trees in the production systems can effectively reduce hot weather-induced stress in the Brazilian Midwest. High temperatures cause changes in animals daily routine, and trees into pastures can promote benefits. The aim of this research was to evaluate the behavior of dairy heifers in silvopastoral systems in the state of Mato Grosso, Brazil. A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein/Zebu, 350kg average weight, was evaluated over three seasons. Piatã grass was managed under three shade levels: full-sun, moderate-shade, and intensive-shade provided by 10 to 12m high Eucalyptus trees. Behavior data were collected every 15 minutes from 8:30h to 16h. Shade availability significantly impacted heifer behavior, mainly affecting grazing frequency and time during the hottest hours. Grazing behavior was affected by shade levels during the different seasons. Heifers showed preferred grazing times. Heifers in the intensive-shade system visited shady areas during the hottest hours throughout the seasons. Heifers in the full sun-system avoided grazing during the warmer times, ceasing feeding activities. Our results from the Brazilian Midwest showed that shade availability causes breed heifers to change their daily routine.

Dynamics of forage accumulation in Elephant grass subjected to rotational grazing intensities

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Braulio Maia de Lana Sousa

2013-09-01

Full Text Available We assessed the accumulation dynamics of forage and its components in Elephant grass cv. Napier (Pennisetum purpureum Schum. that were subjected to three post-grazing height treatments (30, 50, and 70 cm from February through May 2009 (experiment one and December 2009 through May 2010 (experiment two. In experiment one, the grazing events started when the light interception by the canopy reached 95%. The same was adopted for experiment two, except for the first grazing event, which was based on the height of the apical meristems of basal tillers. The experimental design for both experiments was a randomized complete block with three replications. The pastures that were managed at a post-grazing height of 30 cm exhibited lower rates of leaf and stem growth, total growth and forage accumulation than those that were managed at 50 or 70 cm, indicating that post-grazing height affects Elephant grass. The pastures that were managed at 50 cm exhibited relatively stable accumulation rates and less stem accumulation. Pastures managed at 70 cm of pos-grazing height presented more leaf and stem accumulation. Most apical meristems of Elephant grass should be removed in the first grazing when they reach the post-grazing target height of 50 cm. The elevation in the residual post-grazing height, especially in the summer, raises the regrowth vigor in the Elephant grass cv. Napier pasture. The post-grazing height of 30 cm reduces the growth of the Elephant grass cv. Napier.

Tillering dynamics in pastures of guinea grass subjected to grazing severities under intermittent stocking

Directory of Open Access Journals (Sweden)

Denise Baptaglin Montagner

2012-03-01

Full Text Available This experiment was carried out to analyze the tillering dynamics of the species Panicum maximum cv. Mombaca subjected to three post-grazing heights: residue of 30 cm (30; residue of 50 cm (50; and residue of 50 cm during spring and summer, lowered to 40 cm in the first fall season grazing and to 30 cm in the following grazing cycle, resuming to 50 cm after the first grazing of the following spring season (50-30. Grazings were initiated whenever the swards intercepted 95% of the incident light. The post-grazing heights were allocated in the experimental units in a completely randomized block design with three replications. The density of basal tillers did not vary between the residual heights evaluated. Swards managed with variable residual height (50-30 presented higher rates of appearance and mortality of basal tillers during the summer of 2007, indicating high tiller renovation. Regardless of the post-grazing height evaluated, lower rates of appearance of basal tillers were found in the spring of 2006. The stability index of guinea grass cv. Mombaca was close to 1.0 throughout the experimental period. Swards managed with variable post-grazing present structural changes able to improve the regrowth vigor, which may be important to maximize the use of the forage species in the production system.

Progress Report: Stratton Ecological Research Site - An Experimental Approach to Assess Effects of Various Grazing Treatments on Vegetation and Wildlife Communities Across Managed Burns and Habitat Controls

Science.gov (United States)

Erickson, Heidi J.; Aldridge, Cameron L.; Hobbs, N. Thompson

2009-01-01

Understanding how management practices affect wildlife is fundamental to wise decisions for conservation of public lands. Prescribed fire and grazing timing are two management tools frequently used within publicly owned sagebrush ecosystems. We conducted a variety of surveys in order to assess the impacts of grazing timing strategies (early summer before peak green-up, mid-summer at peak green-up, and late summer after peak green-up) in conjunction with prescribed fire on avian and small mammal populations in a high-elevation sagebrush ecosystem. Avian surveys resulted in a large detection sample size for three bird species: Brewer's sparrow (Spizella breweri), horned lark (Eremophila alpestris), and vesper sparrow (Pooecetes gramineus). Brewer's sparrows had the lowest number of detections within the mid-summer grazing treatment compared to early and late summer grazing treatments, while horned larks and vesper sparrows had higher detection frequencies within the late summer grazing treatment. Summer and fall sage-grouse (Centrocercus urophasianus) pellet counts revealed that the greatest over-winter and over-summer use by sage-grouse occurred within the early summer grazing treatment with minimal use of burn treatment areas across all grazing treatments. Deer-mice (Peromyscus maniculatus) represented approximately 90 percent of small mammals captured and were most prevalent within the mid-summer grazing treatment. Sagebrush cover was greatest within the mid-summer grazing treatment. We monitored 50 and 103 nests in 2007 and 2008, respectively. The apparent success rate for shrub-obligate nesting species was 58 percent in 2007 and 63 percent in 2008. This research will support management of sagebrush ecosystems by providing public land managers with direct comparisons of wildlife response to management regimes.

Livestock grazing and the desert tortoise in the Mojave Desert

Science.gov (United States)

Oldemeyer, John L.

1994-01-01

A large part of the Mojave Desert is not in pristine condition, and some current conditions can be related to past grazing-management practices. No information could be found on densities of the desert tortoise (Gopherus agassizii) or on vegetative conditions of areas that had not been grazed to allow managers a comparison of range conditions with data on tortoises. Experimental information to assess the effect of livestock grazing on tortoises is lacking, and researchers have not yet examined whether the forage that remains after grazing is sufficient to meet the nutritional needs of desert tortoises.

78 FR 66064 - Notice of Intent To Prepare a Livestock Grazing Monument Management Plan Amendment and Associated...

Science.gov (United States)

2013-11-04

...-level decisions associated with livestock grazing, thereby amending the GSENM Management Plan. DATES..., archaeology, paleontology, wildlife and fisheries, hydrology, soils, sociology and economics, and public...

Grazing management effects on sediment, phosphorus, and pathogen loading of streams in cool-season grass pastures.

Science.gov (United States)

Schwarte, Kirk A; Russell, James R; Kovar, John L; Morrical, Daniel G; Ensley, Steven M; Yoon, Kyoung-Jin; Cornick, Nancy A; Cho, Yong Il

2011-01-01

Erosion and runoff from pastures may lead to degradation of surface water. A 2-yr grazing study was conducted to quantify the effects of grazing management on sediment, phosphorus (P), and pathogen loading of streams in cool-season grass pastures. Six adjoining 12.1-ha pastures bisected by a stream in central Iowa were divided into three treatments: continuous stocking with unrestricted stream access (CSU), continuous stocking with restricted stream access (CSR), and rotational stocking (RS). Rainfall simulations on stream banks resulted in greater ( CSR pastures. Bovine enterovirus was shed by an average of 24.3% of cows during the study period and was collected in the runoff of 8.3 and 16.7% of runoff simulations on bare sites in CSU pastures in June and October of 2008, respectively, and from 8.3% of runoff simulations on vegetated sites in CSU pastures in April 2009. Fecal pathogens (bovine coronavirus [BCV], bovine rotavirus group A, and O157:H7) shed or detected in runoff were almost nonexistent; only BCV was detected in feces of one cow in August of 2008. Erosion of cut-banks was the greatest contributor of sediment and P loading to the stream; contributions from surface runoff and grazing animals were considerably less and were minimized by grazing management practices that reduced congregation of cattle by pasture streams. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Floodplains as a source of fine sediment in grazed landscapes: Tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

Science.gov (United States)

Yu, Mingjing; Rhoads, Bruce L.

2018-05-01

The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five sources: croplands, forested floodplains, grasslands, upper grazed floodplains, and lower grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from the five sources to the suspended sediment loads. To account for possible effects of small sample sizes, the analysis was repeated with only two sources: grazed floodplains and croplands/grasslands/forested floodplains. Results based on mean values of tracers indicate that the vast majority of suspended sediment within the stream (>95%) is derived from erosion of channel banks and the soil surface within areas of grazed floodplains. Uncertainty analysis based on Monte Carlo simulations indicates that mean values of tracer properties, which do not account for sampling variability in these properties, probably overestimate contributions from the two major sources. Nevertheless, this analysis still supports the conclusion that floodplain erosion accounts for the largest percentage of instream sediment (≈55-75%). Although grazing occurs over only a small portion of the total watershed area, grazed floodplains, which lie in close proximity to the stream channel, are an important source of sediment in this headwater steam system. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should

External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates

International Nuclear Information System (INIS)

Roca-Fernández, A.I.; González-Rodríguez, A.

2017-01-01

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems.

External validation of the GrazeIn model of pasture dry matter intake and milk yield prediction for cows managed at different calving dates and stocking rates

Energy Technology Data Exchange (ETDEWEB)

Roca-Fernández, A.I.; González-Rodríguez, A.

2017-07-01

The aim was to evaluate the prediction accuracy of pasture dry matter intake (PDMI) and milk yield (MY) predicted by the GrazeIn model using a database representing 124 PDMI measurements at paddock level and 2232 MY measurements at cow level. External validation of the model was conducted using data collected from a trial carried out with Holstein-Friesian cows (n=72) while grazed 28 paddocks and were managed in a 2×2 factorial design by considering two calving dates (CD), with different number of days in milk (DIM), early (E, 29 DIM) vs. middle (M, 167 DIM), and two stocking rates (SR), medium (M, 3.9 cows ha-1) vs. high (H, 4.8 cows ha-1), under a rotational grazing system. Cows were randomly assigned to four grazing scenarios (EM, EH, MM and MH). The mean observed PDMI of the total database was 14.2 kg DM cow-1 day-1 while GrazeIn predicted a mean PDMI for the database of 13.8 kg DM cow-1 day-1. The mean bias was −0.4 kg DM cow-1 day-1. GrazeIn predicted PDMI for the total database with a relative prediction error (RPE) of 10.0% at paddock level. The mean observed MY of the database was 23.2 kg cow-1 day-1 while GrazeIn predicted a MY for the database of 23.1 kg cow-1 day-1. The mean bias was –0.1 kg cow-1 day-1. GrazeIn predicted MY for the total database with a mean RPE of 17.3% at cow level. For the scenarios investigated, GrazeIn predicted PDMI and MY with a low level of error which made it a suitable tool for decision support systems.

Morphogenesis in guinea grass pastures under rotational grazing strategies

Directory of Open Access Journals (Sweden)

Denise Baptaglin Montagner

2012-04-01

Full Text Available This study was conducted in order to evaluate the morphogenetic and structural characteristics of guinea grass cv. Mombasa under three post-grazing heights (intense - 30 cm, lenient - 50 cm and variable - 50 in spring-summer and 30 cm in autumn-winter when sward light interception reached 95% during regrowth. Post-grazing heights were allocated to experimental units (0.25 ha in a completely randomized block design with three replications. Post-grazing heights affected only leaf elongation rate and the number of live leaves. Pastures managed with variable post-grazing height showed higher leaf elongation rate in the summer of 2007. This management strategy also resulted in a higher number of live leaves. During the spring of 2006, plants showed lower leaf elongation rate, leaf appearance rate and number of live leaves, and greater phyllochron and leaf lifespan. In contrast, during the summer of 2007, the leaf appearance rate, leaf elongation rate, number of live leaves, and final leaf length were greater while phyllochron, stem elongation rate, and leaf senescence rate were lower. The management of the guinea grass cv. Mombasa with intense or variable post-grazing height throughout the year seems to represent an interesting management target, in terms of leaf appearance rate and number of live leaves.

Effect of yearling steer sequence grazing of perennial and annual forages in an integrated crop and livestock system on grazing performance, delayed feedlot entry, finishing performance, carcass measurements, and systems economics.

Science.gov (United States)

Sentürklü, Songul; Landblom, Douglas G; Maddock, Robert; Petry, Tim; Wachenheim, Cheryl J; Paisley, Steve I

2018-06-04

In a 2-yr study, spring-born yearling steers (n = 144), previously grown to gain <0.454 kg·steer-1·d-1, following weaning in the fall, were stratified by BW and randomly assigned to three retained ownership rearing systems (three replications) in early May. Systems were 1) feedlot (FLT), 2) steers that grazed perennial crested wheatgrass (CWG) and native range (NR) before FLT entry (PST), and 3) steers that grazed perennial CWG and NR, and then field pea-barley (PBLY) mix and unharvested corn (UC) before FLT entry (ANN). The PST and ANN steers grazed 181 d before FLT entry. During grazing, ADG of ANN steers (1.01 ± SE kg/d) and PST steers (0.77 ± SE kg/d) did not differ (P = 0.31). But even though grazing cost per steer was greater (P = 0.002) for ANN vs. PST, grazing cost per kg of gain did not differ (P = 0.82). The ANN forage treatment improved LM area (P = 0.03) and percent i.m. fat (P = 0.001). The length of the finishing period was greatest (P < 0.001) for FLT (142 d), intermediate for PST (91 d), and least for ANN (66 d). Steer starting (P = 0.015) and ending finishing BW (P = 0.022) of ANN and PST were greater than FLT steers. Total FLT BW gain was greater for FLT steers (P = 0.017), but there were no treatment differences for ADG, (P = 0.16), DMI (P = 0.21), G: F (P = 0.82), and feed cost per kg of gain (P = 0.61). However, feed cost per steer was greatest for FLT ($578.30), least for ANN ($276.12), and intermediate for PST ($381.18) (P = 0.043). There was a tendency for FLT steer HCW to be less than ANN and PST, which did not differ (P = 0.076). There was no difference between treatments for LM area (P = 0.094), backfat depth (P = 0.28), marbling score (P = 0.18), USDA yield grade (P = 0.44), and quality grade (P = 0.47). Grazing steer net return ranged from an ANN system high of $9.09/steer to a FLT control system net loss of -$298 and a PST system that was slightly less than the ANN system (-$30.10). Ten-year (2003 to 2012) hedging and net return

Regional Standards for Rangeland Health and Guidelines for Livestock Grazing Management ... A Progress Report

OpenAIRE

1996-01-01

In August 1995, new BLM regulations for rangeland administration went into effect. The new regulations require BLM to establish regional standards for rangeland health and guidelines for grazing management. This publication is a report on the alternatives being considered for the Montana/Dakotas Rangeland Health Standards and Guidelines process.

Effects of seasonal changes in feeding management under part-time grazing on the evolution of the composition and coagulation properties of raw milk from ewes.

Science.gov (United States)

Abilleira, E; Virto, M; Nájera, A I; Salmerón, J; Albisu, M; Pérez-Elortondo, F J; Ruiz de Gordoa, J C; de Renobales, M; Barron, L J R

2010-09-01

Ewe raw milk composition, rennet coagulation parameters, and curd texture were monitored throughout the milk production season in 11 commercial flocks reared under a part-time grazing system. Milking season lasted from February to July. During that period, the diet of the animals shifted from indoor feeding, consisting of concentrate and forage, to an outdoor grazing diet. Lean dry matter, fat, protein, calcium, and magnesium contents increased throughout the milking season, as did rennet coagulation time, curd firmness, and curd resistance to compression. However, lean dry matter, protein content, and curd resistance to compression stabilized when sheep started to graze. Principal component analysis correlated curd resistance to compression and proteins, whereas curd firmness was highly correlated with fat content and minerals. Discriminant analysis distributed milk samples according to the feeding management. Curd firmness, fat, and magnesium turned out to be discriminant variables. Those variables reflected the evolution of the composition and coagulation parameters when fresh pasture prevailed over other feeds in the diet of the flocks. The present study shows that seasonal changes associated with feeding management influence milk technological quality and that milk of good processing quality can be obtained under part-time grazing. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Grazing effects on forage production and botanical composition in a Quercus ithaburensis subs. macrolepis silvopastoral system

Science.gov (United States)

Pantera, A.; Papanastasis, V. P.

2009-04-01

Grazing is considered as a major factor affecting forage production as well as botanical composition of many silvopastoral systems. In order to study these effects, three pairs of grazed and protected plots were established in a Quercus ithaburensis subsp. macrolepis silvopastoral system. The experiment was carried out in western Greece, 15 km west of the city of Agrinion. Data were collected for two continuous years and included the determination of palatable and unpalatable to animals plant species as well as the botanical composition. The results suggest that heavy grazing decreased biomass production approximately threefold. Grazing also affected number of acorns, botanical composition as well as vegetation cover whereas had no effect on natural regeneration in the study period.

Nest survival of American Coots relative to grazing, burning, and water depths

Science.gov (United States)

Austin, Jane E.; Buhl, Deborah A.

2011-01-01

Water and emergent vegetation are key features influencing nest site selection and success for many marsh-nesting waterbirds. Wetland management practices such as grazing, burning, and water-level manipulations directly affect these features and can influence nest survival. We used model selection and before-after-control-impact approaches to evaluate the effects of water depth and four common land-management practices or treatments, i.e., summer grazing, fall grazing, fall burning, and idle (no active treatment) on nest survival of American coots (Fulica americana) nesting at Grays Lake, a large montane wetland in southeast Idaho. The best model included the variables year × treatment, and quadratic functions of date, water depth, and nest age; height of vegetation at the nest did not improve the best model. However, results from the before-after-control-impact analysis indicate that management practices affected nest success via vegetation and involved interactions of hydrology, residual vegetation, and habitat composition. Nest success in idled fields changed little between pre- and post-treatment periods, whereas nest success declined in fields that were grazed or burned, with the most dramatic declines the year following treatments. The importance of water depth may be amplified in this wetland system because of rapid water-level withdrawal during the nesting season. Water and land-use values for area ranchers, management for nesting waterbirds, and long-term wetland function are important considerations in management of water levels and vegetation.

Nest Survival of American Coots Relative to Grazing, Burning, and Water Depths

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Jane E. Austin

2011-12-01

Full Text Available Water and emergent vegetation are key features influencing nest site selection and success for many marsh-nesting waterbirds. Wetland management practices such as grazing, burning, and water-level manipulations directly affect these features and can influence nest survival. We used model selection and before-after-control-impact approaches to evaluate the effects of water depth and four common land-management practices or treatments, i.e., summer grazing, fall grazing, fall burning, and idle (no active treatment on nest survival of American coots (Fulica americana nesting at Grays Lake, a large montane wetland in southeast Idaho. The best model included the variables year × treatment, and quadratic functions of date, water depth, and nest age; height of vegetation at the nest did not improve the best model. However, results from the before-after-control-impact analysis indicate that management practices affected nest success via vegetation and involved interactions of hydrology, residual vegetation, and habitat composition. Nest success in idled fields changed little between pre- and post-treatment periods, whereas nest success declined in fields that were grazed or burned, with the most dramatic declines the year following treatments. The importance of water depth may be amplified in this wetland system because of rapid water-level withdrawal during the nesting season. Water and land-use values for area ranchers, management for nesting waterbirds, and long-term wetland function are important considerations in management of water levels and vegetation.

Linking remote-sensing and ecosystem services modeling to support and assess management for regenerative grazing in the South Gobi, Mongolia

Science.gov (United States)

Chaplin-Kramer, R.; Kowal, V. A.; Sharp, R.

2017-12-01

Managing and monitoring supply chain sustainability is a major challenge and opportunity for business, especially in rangelands, heavily managed and often degraded natural systems that provide significant resources and raw materials for production. One of the largest and most threatened rangeland systems in the world is in Mongolia, which has seen a rapid rise in grazing pressure due to increasing global demand for cashmere along with privatization of a formerly government-run livestock industry. A new opportunity is emerging for remote-sensing to improve the management decisions of the producers and their incentive-setters, leading to a more sustainable rangeland system and better outcomes for biodiversity and people in this unique and imperiled landscape. Oyu Tolgoi (OT), the Mongolian subsidiary of the mining company Rio Tinto, in cooperation with Kering, an apparel conglomerate that sources cashmere from the region, are providing financial incentives to improve grazing patterns through a Sustainable Cashmere program, in order to restore the degraded rangeland ecosystem in the Gobi desert region. We present a framework and approach for predicting the effect of changing grazing practices on biodiversity and ecosystem services, which we are developing into decision-support tools for OT, Kering, and their local partner Wildlife Conservation Society to quantify the impacts of their programs and where these interventions will have greatest benefit. Our approach integrates remote-sensing and ecosystem modeling to scale up field monitoring data and forecast future impacts. Our rangeland production model, based on the soil-vegetation model CENTURY and the livestock model GRAZPLAN, predicts biomass production and plant species composition changes, and can feed into ecosystem services models such as soil retention and water regulation in the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) software suite. This presents a significant advance in ecosystem

Nature conservation and grazing management. Free-ranging cattle as a driving force for cyclic vegetation seccession

NARCIS (Netherlands)

Bokdam, J.

2003-01-01

Key-words : biodiversity, herbivory, wilderness, non-linear dynamics, mosaic cycling, grassland, wood encroachment, forest, Bos taurus , Calluna vulgaris , Deschampsia flexuosa.This thesis examines the suitability of controlled and wilderness grazing as conservation management tool for open,

Forage patch use by grazing herbivores in a South African grazing ecosystem

NARCIS (Netherlands)

Venter, J.A.; Nabe-Nielsen, J.; Prins, H.H.T.; Slotow, R.

2014-01-01

Understanding how different herbivores make forage patch use choices explains how they maintain an adequate nutritional status, which is important for effective conservation management of grazing ecosystems. Using telemetry data, we investigated nonruminant zebra (Equus burchelli) and ruminant red

Soil quality parameters for row-crop and grazed pasture systems with agroforestry buffers

Science.gov (United States)

Incorporation of trees and establishment of buffers are practices that can improve soil quality. Soil enzyme activities and water stable aggregates are sensitive indices for assessing soil quality by detecting early changes in soil management. However, studies comparing grazed pasture and row crop...

Effects of seasonal changes in feeding management under part-time grazing on terpene concentrations of ewes' milk.

Science.gov (United States)

Abilleira, Eunate; Virto, Mailo; Nájera, Ana Isabel; Albisu, Marta; Pérez-Elortondo, Francisco José; Ruiz de Gordoa, Juan Carlos; de Renobales, Mertxe; Barron, Luis Javier R

2011-05-01

Terpene composition of ewes' raw milk from nine commercial flocks was analysed from February to July. Ewes' diet consisted of concentrate and conserved forage in winter (indoor feeding) and part-time grazing from spring (transition and outdoor feeding). Regardless of the feeding, limonene and β-phellandrene were the most abundant monoterpenes and β-caryophyllene showed the highest concentrations among sesquiterpenes. Terpene content increased in the milks of commercial flocks when animals were reared under grazing management. Monoterpenes were detected in the milks of all the commercial flocks throughout the season, whereas sesquiterpenes were only detected in the milks from flocks grazing on non-cultivated community-owned grasslands in which a higher biodiversity of plant species grew. These preliminary results indicated that β-caryophyllene could be a potential pasture-diet marker in the case of milks from animals grazing a higher biodiversity of plant species but in-depth studies including information on terpene composition of plants ingested by the animals are necessary to evaluate the suitability of β-caryophyllene or another terpenoid compound as pasture biomarker.

A critical analysis of the long-term impact (1936-2015) of grazing management on Land Degradation in a marginal, rural community of Southern Italy

Science.gov (United States)

Quaranta, Giovanni; Salvia, Rosanna; De Paola, Velia; Coluzzi, Rosa; Imbrenda, Vito; Simoniello, Tiziana

2017-04-01

Unsustainable grazing, one of the most diffused problem in land management at the global scale, is considered as a serious pressure on natural landscapes. Particularly in the Mediterranean agroforestry landscapes, unsustainable grazing is regarded as a key factor of degradation processes, mostly determined and exacerbated by evolving socioeconomic and environmental conditions at the local scale, revised agricultural policies and changing international market scenario. The Common Agricultural Policy set at the European level plays a powerful and twofold role in shaping the dynamics at local level. Measures adopted for Less Favoured Areas, for example, have stimulated grazing intensification based on financial supports whose effectiveness is shaped by the socioeconomic local context. At the same time, pasture-based livestock farming systems are considered priority habitats preserving traditional and high natural value farmlands in Mediterranean Europe. A sustainable management of pastures may also contribute to limit soil erosion and to mitigate land degradation. This paper critically analyses the drivers of change and the challenges facing a Mediterranean upland pastoralist systems in Southern Italy along a period of almost 80 years (1936-2015). The detailed case study highlights the linkages between the evolution of landscape, grazing management, locally adapted animal breeds and social capital. Historical forest maps, aerial imagery and satellite data at different spatial resolutions have been used to trace land use trajectories occurred during the investigated period within the study area. The integration in a GIS environment of the obtained results with diachronic detailed farm management surveys and semi-structured interviews, shows a strong link between land use changes and economic performances mainly connected to policy orientation. Along the time period considered, different adaptation strategies adopted by local actors are analysed leading to the present

Greenhouse Gas Emission from Beef Cattle Grazing Systems on Temperate Grasslands

Science.gov (United States)

Rice, C. W.; Rivera-Zayas, J.

2017-12-01

At a global scale, cattle production is responsible for 65% of GHG emissions. During 2014 cattle management was the largest emitters of methane (CH4) representing a 23.2% of the total CH4 from anthropogenic activities. Since 2014, gas samples have been gathered and analyzed for carbon dioxide (CO2), CH4 and nitrous oxide (N2O) from three grazing areas under three different burning regimes at the temperate grassland of Konza Prairie Biological Station in Kansas. Burning regimes included one site in annually burned, and two sites with patch burned every three years on offset years. Burning regimes showed no effect in N2O emissions (pconsumed on grazed grassland soils; with an increase in consumption with patch burning. Results quantify the role of temperate grasslands as a sink of CH4, and a possible sink of N2O. This experiment evidence CO2, CH4 and N2O emissions behavior as a consequence of burning regimes, and quantify the role of temperate grasslands as a sink of CH4 and N2O in order to understand best practice for resilience of beef cattle management.

Livestock grazing intensity affects abundance of Common shrews (Sorex araneus) in two meadows in Denmark

Science.gov (United States)

Schmidt, Niels M; Olsen, Henrik; Leirs, Herwig

2009-01-01

Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool. PMID:19152713

Livestock grazing intensity affects abundance of Common shrews (Sorex araneus in two meadows in Denmark

Directory of Open Access Journals (Sweden)

Olsen Henrik

2009-01-01

Full Text Available Abstract Background Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. Results High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. Conclusion No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool.

Performance and Grazing Pattern of West African Dwarf Sheep to ...

African Journals Online (AJOL)

Sixty (60) West African Dwarf sheep managed semi intensively and grazing on natural pastures were used in a study to determine the performance and grazing pattern to seasonal forage supply and quality. The animals were allowed to graze for about 6 hours daily for four months each in the dry and wet seasons, ...

Determining grazing capacity in Namibia with the aid of remote ...

African Journals Online (AJOL)

The Namibian rangelands consist of a mixture of herbaceous and woody components. The main source of income is from farming systems with grass production the predominant source of forage. For rangeland managers to utilise this source sustainably, the accurate determination of grazing capacity is vital since it allows ...

Ecological Effects of Grazing in the Northern Tianshan Mountains

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Xiaotao Huang

2017-11-01

Full Text Available Identifying the effects of grazing is critical for the conservation, protection and sustainable use of arid grassland ecosystems. However, research regarding the ecological effects of grazing along mountainous elevation gradients is limited in arid areas, particularly at the regional scale. Using the Biome-BGC grazing model, we explored the effects of grazing on grassland net primary productivity (NPP, evapotranspiration (ET and water use efficiency (WUE from 1979 to 2012 along an elevation gradient in the northern Tianshan Mountains. The NPP, ET and WUE values were generally lower under the grazing scenario than under the ungrazed scenario; the differences between the grazing and ungrazed scenarios showed increasing trends over time; and distinct spatial heterogeneity in these differences was observed. Distinct decreases in NPP and WUE under the grazing scenario mainly occurred in regions with high livestock consumption. The decrease in ET was greater in mountainous areas with high grazing intensity due to decreased transpiration and increased surface runoff. This study contributes to a better understanding of the ecological effects of grazing along an elevation gradient in the northern Tianshan Mountains and provides data to support the scientific management of grassland ecosystems.

A two reservoir model to predict Escherichia coli losses to water from pastures grazed by dairy cows.

Science.gov (United States)

Muirhead, R W; Monaghan, R M

2012-04-01

Animal agriculture has been identified as an important source of diffuse faecal microbial pollution of water. Our current understanding of the losses of faecal microbes from grazed pasture systems is however poor. To help synthesise our current knowledge, a simple two reservoir model was constructed to represent the faecal and environmental sources of Escherichia coli found in a grazed pastoral system. The size of the faecal reservoir was modelled on a daily basis with inputs from grazing animals, and losses due to die-off of E. coli and decomposition of the faecal material. Estimates were made of transport coefficients of E. coli losses from the two reservoirs. The concentration of E. coli measured in overland flow and artificial drainage from grazed plots, used for calibration of the model, showed a significant (Ppasture systems. Research is needed to understand the behaviour and impact of this environmental reservoir. Scenario analysis using the model indicated that rather than manipulating the faecal material itself post defecation, mitigation options should focus on manipulating grazing management. Copyright © 2011 Elsevier Ltd. All rights reserved.

Rangeland Brush Estimation Toolbox (RaBET): An Approach for Evaluating Brush Management Conservation Efforts in Western Grazing Lands

Science.gov (United States)

Holifield Collins, C.; Kautz, M. A.; Skirvin, S. M.; Metz, L. J.

2016-12-01

There are over 180 million hectares of rangelands and grazed forests in the central and western United States. Due to the loss of perennial grasses and subsequent increased runoff and erosion that can degrade the system, woody cover species cannot be allowed to proliferate unchecked. The USDA-Natural Resources Conservation Service (NRCS) has allocated extensive resources to employ brush management (removal) as a conservation practice to control woody species encroachment. The Rangeland-Conservation Effects Assessment Project (CEAP) has been tasked with determining how effective the practice has been, however their land managers lack a cost-effective means to conduct these assessments at the necessary scale. An ArcGIS toolbox for generating large-scale, Landsat-based, spatial maps of woody cover on grazing lands in the western United States was developed through a collaboration with NRCS Rangeland-CEAP. The toolbox contains two main components of operation, image generation and temporal analysis, and utilizes simple interfaces requiring minimum user inputs. The image generation tool utilizes geographically specific algorithms developed from combining moderate-resolution (30-m) Landsat imagery and high-resolution (1-m) National Agricultural Imagery Program (NAIP) aerial photography to produce the woody cover scenes at the Major Land Resource (MLRA) scale. The temporal analysis tool can be used on these scenes to assess treatment effectiveness and monitor woody cover reemergence. RaBET provides rangeland managers an operational, inexpensive decision support tool to aid in the application of brush removal treatments and assessing their effectiveness.

Impact of rotational grazing on management of gastrointestinal nematodes in weaned lambs.

Science.gov (United States)

Burke, J M; Miller, J E; Terrill, T H

2009-07-07

Gastrointestinal nematode (GIN) control for 'natural' or organic lamb production is needed, especially where Haemonchus contortus is prevalent. The objective was to determine the impact of rotational grazing on GIN infection of weaned lambs. In year 1, naturally infected Katahdin lambs (120 days of age) were randomly assigned to graze (1) continuous bermudagrass (CB; n=14), (2) rotational bermudagrass moved every 3.5 days and returned to original plot 35 days later for three rotations (RB; n=14), or (3) rotational bermudagrass rotated when forage height fell below 10 cm (RBH; n=7) where first day of grazing=Day 0. In late summer, all lambs were supplemented with 500 g corn/SBM because of poor condition. The following year, similar animals were used and included the CB (n=18) and the RB (n=36) groups only. In both years, fecal egg counts (FECs) and blood packed cell volume (PCV) were determined every 7-14 days and body weight every 28 days. Individuals were dewormed with 0.5 g copper oxide wire particles (COWP) when FAMACHA score increased to 3 or more. Between 0 and 3 deworming treatments per lamb were necessary and there tended to be fewer RB than CB lambs dewormed by Day 84 for both years combined (Pdays of grazing. Abomasal worm burden tended to be greater in RB than CB or RBH tracer lambs (P<0.10), but intestinal worm numbers were similar. Differences may be due to differences in grazing patterns among groups. Body weight gains were similar between CB and RB groups. Economic value between the CB and RB lambs was similar based on number of lambs that could have been marketed as organic. For both years, lambs relied exclusively on COWP for GIN control with the exception of one lamb. In summary, while there was a reduced incidence of deworming in the RB compared with the CB group of lambs, estimated economic value of these systems was similar.

Dry matter intake, performance and carcass characteristics of hair sheep reared under different grazing systems

Directory of Open Access Journals (Sweden)

Viviane Rodrigues Ventolin dos Santos

Full Text Available ABSTRACT The aim of this study was to evaluate the effect of three different grazing systems: isolated, alternate and simultaneous, on feed intake, performance and carcass characteristics of sheep. About 5.2 ha area of Tanzania grass (Panicum maximun Jacq cultivate Tanzania was divided into 13 paddocks. This area was used as a stocking rate of two animal units (AU per ha for 7 days’ occupation and 21 days rest. A total number of 58 animals were used consisting of 12 heifers and 30 Santa Ines lambs with the addition of 16 adult ewes that were used to stabilize grazing pressure in the isolated system. The sheep were fed on 200 g per head per day of concentrate and cattle 2 kg per head per day. The parameters determined were the following: weekly weight (WW, total live weight gain (LWG and mean daily weight gain (MDW. Also dry matter intake was estimated 84 days after the start of the experiment using external indicators (Purified and Enriched Lignin in addition to carcass traits and composition which were also estimated. The result obtained for carcass composition revealed that the muscle:bone ratio and bone percentage were better in the alternate system. Moreover, the simultaneous and isolated systems showed higher lamb performance than the alternate system, while there was no effect on dry matter intake. Furthermore, there was no difference of the different systems on carcass traits and feed intake of sheep. Nevertheless, the simultaneous grazing system showed better sheep performance than the alternate grazing system.

PRODUCTIVITY OF A SILVOPASTORAL SYSTEM UNDER INTENSIVE MIXED SPECIES GRAZING BY CATTLE AND SHEEP

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Leonor Yalid Manriquez-Mendoza

2011-11-01

Full Text Available The presence of forage trees in pastures enhances yield and nutritional quality of forage available for animal feeding. We assessed forage yield and nutritional quality, and weight gain of cattle and sheep foraging in a silvopastoral system containing Guazuma ulmifolia Lam. and the grasses Digitaria eriantha Stent (cv. Pangola, Brachiaria brizantha (Hochst. ex A. Rich. Stapf (cv. Insurgentes and Megathyrsus maximus (Jacq. B.K. Simon & S.W.L. Jacobs (cv. Tanzania, during three seasons (windy, dry and rainy in two grazing treatments: 1 mixed species grazing by four to five Criollo Lechero Tropical heifers and six female Pelibuey lambs, and 2 simple species grazing by 12 female Pelibuey lambs. Weight gain was greater (P

Response of soil methane uptake to simulated nitrogen deposition and grazing management across three types of steppe in Inner Mongolia, China.

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Li, Xianglan; He, Hong; Yuan, Wenping; Li, Linghao; Xu, Wenfang; Liu, Wei; Shi, Huiqiu; Hou, Longyu; Chen, Jiquan; Wang, Zhiping

2018-01-15

The response of soil methane (CH 4 ) uptake to increased nitrogen (N) deposition and grazing management was studied in three types of steppe (i.e., meadow steppe, typical steppe, and desert steppe) in Inner Mongolia, China. The experiment was designed with four simulated N deposition rates such as 0, 50, 100, and 200kgNha -1 , respectively, under grazed and fenced management treatments. Results showed that the investigated steppes were significant sinks for CH 4 , with an uptake flux of 1.12-3.36kgha -1 over the grass growing season and that the magnitude of CH 4 uptake significantly (Prates. The soil CH 4 uptake rates were highest in the desert steppe, moderate in the typical steppe, and lowest in the meadow steppe. Compared with grazed plots, fencing increased the CH 4 uptake by 4.7-40.2% with a mean value of 20.2% across the three different steppe types. The responses of soil CH 4 uptake to N deposition in the continental steppe varied depending on the N deposition rate, steppe type, and grazing management. A significantly positive correlation between CH 4 uptake and soil temperature was found in this study, whereas no significant relationship between soil moisture and CH 4 uptake occurred. Our results may contribute to the improvement of model parameterization for simulating biosphere-atmosphere CH 4 exchange processes and for evaluating the climate change feedback on CH 4 soil uptake. Copyright © 2017 Elsevier B.V. All rights reserved.

Patterns in Greater Sage-grouse population dynamics correspond with public grazing records at broad scales.

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Monroe, Adrian P; Aldridge, Cameron L; Assal, Timothy J; Veblen, Kari E; Pyke, David A; Casazza, Michael L

2017-06-01

Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) and timing across a gradient in vegetation productivity as measured by the Normalized Vegetation Difference Index (NDVI). We found grazing can have both positive and negative effects on Sage-grouse populations depending on the timing and level of grazing. Sage-grouse populations responded positively to higher grazing levels after peak vegetation productivity, but populations declined when similar grazing levels occurred earlier, likely reflecting the sensitivity of cool-season grasses to grazing during peak growth periods. We also found support for the hypothesis that effects of grazing management vary with local vegetation productivity. These results illustrate the importance of broad-scale analyses by revealing patterns in Sage-grouse population trends that may not be inferred from studies at finer scales, and could inform sustainable grazing management in these ecosystems. © 2017 by the Ecological Society of America.

Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

DEFF Research Database (Denmark)

Kristensen, Troels; Thamsborg, S.M.; Andersen, Refsgaard

2006-01-01

Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2x2 factorial, replicated experiment with two sexes (steers v. heifers) and two...

Trade patterns facilitating highly pathogenic avian influenza virus dissemination in the free-grazing layer duck system in Vietnam.

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Meyer, A; Dinh, T X; Han, T A; Do, D V; Nhu, T V; Pham, L T; Nguyen, T T T; Newman, S; Häsler, B; Pfeiffer, D U; Vergne, T

2018-04-01

Highly pathogenic avian influenza (HPAI) viruses continue to threaten smallholder poultry producers in several South-east Asian countries, including Vietnam. In particular, the free-grazing duck system has been repeatedly highlighted as a major risk factor for HPAI outbreaks. Free-grazing ducks, which scavenge on rice paddies after the harvest, account for a large proportion of the duck population in Vietnam and the wider South-east Asian region. However, the structure and dynamics of the free-grazing duck production from farm to consumption has not been described for Vietnam. In this study, we used a value chain approach to provide a complete picture of the actors involved in the production and marketing of free-grazing duck eggs and spent layer ducks, as well as to investigate the governance structure of this food system. Group interviews and key informant interviews were conducted in two provinces located in the Mekong River Delta (MRD) and the Red River Delta (RRD). The results presented here highlight similarities and differences in farming and trade practices between the two provinces. The trade of spent layer ducks involved large volumes of live ducks being sent to China and Cambodia for consumption, generating a substantial risk of transboundary spread of pathogens, including HPAI viruses. We describe the major role of "duck yards", which act as hubs in the northbound trade of spent layer ducks. These yards should be considered as essential links in the value chain of spent layer ducks when considering HPAI surveillance and control. The veterinary authorities are only marginally involved in the value chain activities, and their influence could be strengthened by increasing surveillance activities for instance in duck yards. Last, we discuss the dynamics of the duck value chain and further implications for future HPAI management policies. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

Grasshopper fecundity responses to grazing and fire in a tallgrass prairie.

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Laws, Angela N; Joern, Anthony

2011-10-01

Grasshopper abundance and diversity vary with management practices such as fire and grazing. Understanding how grasshopper life history traits such as fecundity respond to management practices is key to predicting grasshopper population dynamics in heterogeneous environments. Landscape-level experimental fire and bison grazing treatments at the Konza Prairie Biological Station (Manhattan, KS) provide an opportunity to examine how management affects grasshopper fecundity. Here we report on grasshopper fecundity for nine common species at Konza Prairie. From 2007 to 2009, adult female grasshoppers were collected every 3 wk from eight watersheds that varied in fire and grazing treatments. Fecundity was measured by examining female reproductive tracts, which contain a record of past and current reproductive activity. Body size was a poor predictor of fecundity for all species. Despite large differences in vegetation structure and composition with management regime (grazing and fire interval), we observed little effect of management on grasshopper fecundity. Habitat characteristics (grasshopper density, vegetation biomass, and vegetation quality; measured in 2008 and 2009) were better predictors of past fecundity than current fecundity, with species-specific responses. Fecundity increased throughout the summer, indicating that grasshoppers were able to acquire sufficient nutritional resources for egg production in the early fall when vegetation quality is generally low. Because fecundity did not vary across management treatments, population stage structure may be more important for determining population level reproduction than management regime at Konza Prairie.

Grazing intensity affects the environmental impact of dairy systems.

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Aguirre-Villegas, H A; Passos-Fonseca, T H; Reinemann, D J; Larson, R

2017-08-01

Dairy products are major components of the human diet but are also important contributors to global environmental impacts. This study evaluated greenhouse gas (GHG) emissions, net energy intensity (NEI), and land use of confined dairy systems with increasing levels of pasture in the diet. A Wisconsin farm was modeled to represent practices adopted by dairy operations in a humid continental climate typical in the Great Lakes region and other climates that have large differences in seasonal temperatures. Five grazing scenarios (all of which contained some portion of confinement) were modeled based on different concentrations of dry matter intake from pasture and feed supplementation from corn grain, corn silage, and soybean meal. Scenarios that incorporate grazing consisted of 5 mo of pasture feeding from May to September and 7 mo of confined feeding from October to April. Environmental impacts were compared within the 5 scenarios that incorporate grazing and across 2 entirely confined scenarios with and without on-farm electricity production through anaerobic digestion (AD). To conduct a fair comparison, all scenarios were evaluated based on the same total amount of milk produced per day where resource inputs were adjusted according to the characteristics of each scenario. A cradle-to-farm gate life cycle assessment evaluated the environmental burdens that were partitioned by allocation between milk and meat and by system expansion when biogas-based electricity was produced. Overall, results for all scenarios were comparable. Enteric methane was the greatest contributor to GHG emissions, and the production of crops was the most energy-intense process. For the confined scenario without AD, GHG emissions were 0.87 kg of CO 2 equivalents, NEI was 1.59 MJ, and land use was 1.59 m 2 /kg of fat- and protein-corrected milk (FPCM). Anaerobic digestion significantly reduced emissions to 0.28 kg of CO 2 equivalents/kg of FPCM and reduced NEI to -1.26 MJ/kg of FPCM, indicating

e-Dairy: a dynamic and stochastic whole-farm model that predicts biophysical and economic performance of grazing dairy systems.

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Baudracco, J; Lopez-Villalobos, N; Holmes, C W; Comeron, E A; Macdonald, K A; Barry, T N

2013-05-01

A whole-farm, stochastic and dynamic simulation model was developed to predict biophysical and economic performance of grazing dairy systems. Several whole-farm models simulate grazing dairy systems, but most of them work at a herd level. This model, named e-Dairy, differs from the few models that work at an animal level, because it allows stochastic behaviour of the genetic merit of individual cows for several traits, namely, yields of milk, fat and protein, live weight (LW) and body condition score (BCS) within a whole-farm model. This model accounts for genetic differences between cows, is sensitive to genotype × environment interactions at an animal level and allows pasture growth, milk and supplements price to behave stochastically. The model includes an energy-based animal module that predicts intake at grazing, mammary gland functioning and body lipid change. This whole-farm model simulates a 365-day period for individual cows within a herd, with cow parameters randomly generated on the basis of the mean parameter values, defined as input and variance and co-variances from experimental data sets. The main inputs of e-Dairy are farm area, use of land, type of pasture, type of crops, monthly pasture growth rate, supplements offered, nutritional quality of feeds, herd description including herd size, age structure, calving pattern, BCS and LW at calving, probabilities of pregnancy, average genetic merit and economic values for items of income and costs. The model allows to set management policies to define: dry-off cows (ceasing of lactation), target pre- and post-grazing herbage mass and feed supplementation. The main outputs are herbage dry matter intake, annual pasture utilisation, milk yield, changes in BCS and LW, economic farm profit and return on assets. The model showed satisfactory accuracy of prediction when validated against two data sets from farmlet system experiments. Relative prediction errors were <10% for all variables, and concordance

Efeito do sistema de manejo sobre o comportamento em pastejo, desempenho ponderal e infestação parasitária em ovinos Suffolk Effect of a management system on grazing behaviour, ponderal growth and parasitic infestation of Suffolk ewes

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Eduardo Antonio da Cunha

1997-07-01

Full Text Available Foi estudado o comportamento em pastejo, o desempenho ponderal e o nível de infestação parasitária em ovelhas da raça Suffolk, no período de 1994 a 1995, em Nova Odessa, SP. Comparou-se dois sistemas de manejo: pastejo restrito, onde os animais foram soltos às 9:50h e presos às 17:30h e pastejo em período integral, no qual os animais não eram recolhidos, tendo a disposição abrigo para passarem a noite. Foram utilizadas 34 fêmeas adultas no verão (17 em pastejo livre e 17 em pastejo restrito e 42 fêmeas adultas no inverno (21 em pastejo livre e 21 em pastejo restrito. Trabalhou-se ainda com 12 animais traçadores em cada estação do ano, sendo metade em cada sistema de manejo visando a contagem de nematódeos no trato digestivo dos animais. Durante 3 dias consecutivos nos meses de janeiro/fevereiro (verão e julho/agosto (inverno estudou-se, através da observação dos animais, a cada 30 minutos entre as 7:00 e 17:30h, o hábito de pastejo (pastando ou não; na sombra ou no sol. Acompanhou-se o nível de infestação parasitária dos animais em cada sistema, pela contagem do OPG do rebanho e dos traçadores e nematódeos recuperados nos traçadores. Concluiu-se que a restrição do horário de pastejo isoladamente não propiciou um controle efetivo da infestação parasitária nos animais mostrando. A restrição do tempo de pastejo é compensada pela maior atividade dos animais nas horas mais quentes do dia, todavia este comportamento afetou o desempenho, resultando em menor ganho de peso. A maior disponibilidade de forragem, em relação ao consumo estimado, pode explicar a similaridade entre os tempos de pastejo verificados nos dois sistemas de manejo, tanto no verão como no inverno.Grazing behaviour, ponderal growth and level of parasitic infestation were studied in Suffolk breed sheep, from 1994 to 1995, in Nova Odessa, São Paulo. Two management systems were compared: restricted grazing, where the animals were released to

Revealing livestock effects on bunchgrass vegetation with Landsat ETM+ data across a grazing season

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Jansen, Vincent S.

Remote sensing provides monitoring solutions for more informed grazing management. To investigate the ability to detect the effects of cattle grazing on bunchgrass vegetation with Landsat Enhanced Thematic Mapper Plus (ETM+) data, we conducted a study on the Zumwalt Prairie in northeastern Oregon across a gradient of grazing intensities. Biophysical vegetation data was collected on vertical structure, biomass, and cover at three different time periods during the grazing season: June, August, and October 2012. To relate these measures to the remotely sensed Landsat ETM+ data, Pearson's correlations and multiple regression models were computed. Using the best models, predicted vegetation metrics were then mapped across the study area. Results indicated that models using common vegetation indices had the ability to discern different levels of grazing across the study area. Results can be distributed to land managers to help guide grassland conservation by improving monitoring of bunchgrass vegetation for sustainable livestock management.

Floodplains as a source of fine sediment in grazed landscapes: tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

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Yu, M.; Rhoads, B. L.; Stumpf, A.

2017-12-01

The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five potential sources: streambanks, forested floodplain, grassland, and grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from five potential sources to the suspended sediment loads. Organic matter content, trace elements, and fallout radionuclides were used as potential tracers. Principal Component analysis was employed to complement the results and Monte Carlo random sampling routine was used to test the uncertainty in estimated contributions of sources to in-stream sediment loads. Results indicate that the majority of suspended sediment is derived from streambanks and grazed floodplains. Erosion of the floodplain both by surface runoff and by streambank erosion from lateral channel migration contributes to the production of fine sediment within the stream system. These results suggest that human activities, in this case grazing, have converted portions of floodplains, normally net depositional environments, into sources of fine sediments. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should focus on degraded floodplain surfaces and eroding channel banks within heavily grazed reaches of the stream.

Carbon and nitrogen cycling in an integrated soybean-beef cattle production system under different grazing intensities

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Joice Mari Assmann

2015-10-01

Full Text Available Abstract:The objective of this work was to evaluate the effect of grazing intensity on the decomposition of cover crop pasture, dung, and soybean residues, as well as the C and N release rates from these residues in a long-term integrated soybean-beef cattle system under no-tillage. The experiment was initiated in 2001, with soybean cultivated in summer and black oat + Italian ryegrass in winter. The treatments consisted of four sward heights (10, 20, 30, and 40 cm, plus an ungrazed area, as the control. In 2009-2011, residues from pasture, dung, and soybean stems and leaves were placed in nylon-mesh litter bags and allowed to decompose for up to 258 days. With increasing grazing intensity, residual dry matter of the pasture decreased and that of dung increased. Pasture and dung lignin concentrations and C release rates were lower with moderate grazing intensity. C and N release rates from soybean residues are not affected by grazing intensity. The moderate grazing intensity produces higher quality residues, both for pasture and dung. Total C and N release is influenced by the greater residual dry matter produced when pastures were either lightly grazed or ungrazed.

The capability of alfalfa grazing- and concentrate-based feeding systems to produce homogeneous carcass quality in light lambs over time

Energy Technology Data Exchange (ETDEWEB)

Ripoll, G.; Alvarez-Rodriguez, J.; Sanz, A.; Joy, M.

2014-06-01

The effects of grazing on the carcasses and meat of light lambs are unclear, mainly due to variations in weather conditions and pasture production, which affect the growth of lambs and the quality of their carcasses. The aim of this study was to evaluate the effect of feeding systems, which varied in intensification due to the use of concentrate, on the growth and carcass traits of light lambs and the capability of these feeding systems to produce homogeneous lamb carcasses over the course of several years. The average daily weight gain of grazing lambs, but not lambs fed indoors was affected over years. The colour of the Rectus abdominis muscle and the amount of fat were more variable in grazing lambs (from 2.7 to 6.3) than indoor lambs (from 4.5 to 5.1). Grazing feeding systems without concentrate supplementation are more dependent than indoor feeding systems on the year. This climatologic dependence could lead to slaughter of older grazing lambs (77 days) to achieve the target slaughter weight when temperatures are low or the rainfall great. All feeding systems evaluated produced light lambs carcasses with a conformation score from O to R that is required by the market. Even the potential change in fat colour found in both grazing treatments was not enough to change the subjective evaluation of fat colour. (Author)

Soil contamination of plant surfaces from grazing and rainfall interactions

International Nuclear Information System (INIS)

Hinton, T.G.; Stoll, J.M.; Tobler, L.

1995-01-01

Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings ( g soil kg -1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r 2 = 0.78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2.5 times to reduce soil loadings by 50%. (author)

Development of a portable system of grazing exit X-Ray fluorescence applied to environmental and biological studies

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Santos, Ramon S.; Oliveira, Davi F.; Anjos, Marcelino J. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Instituto de Fisica; Assis, Joaquim T., E-mail: ramonziosp@yahoo.com.br, E-mail: davi.oliveira@uerj.br, E-mail: marcelin@uerj.br, E-mail: joaquim.iprj@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politécnico

2017-07-01

In this study was developed a portable system of grazing exit X-ray fluorescence (geometric 90° - 0°) that will be applied in environmental studies (aerosol samples) and biological studies. GE-XRF portable system is formed by a mini X-ray tube of low power (anode of Au, maximum voltage and current of 50 kV and 200 μA, respectively) and a SiPIN detector (model XR-100CR of the Amptek). The reflectors used as sample support (sampler carrier) were quartz discs with 25.4 mm diameter and 3.0 mm thickness. The grazing exit angle was experimentally determined by measuring a cooper solution (10 μg.g{sup -1}). The system of GE-XRF proved to be quite stable and reproducible. It was calculated the sensibility curve of the system using multielement solutions. The accuracy of the system was checked using multielement reference solution as standard reference material. The relative errors between measured and certified values are in the range of 4 to 19%. The first results showed a background was drastically reduced at grazing exit angles, enabling trace elemental analysis. This paper shows that it is possible to produce a portable system of grazing exit X-ray fluorescence compact, efficient, low-cost and easy-to-handle instrumentation using a low-power X-ray tube and a SiPIN compact detector. (author)

Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture

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Hunt, John E.; Laubach, Johannes; Barthel, Matti; Fraser, Anitra; Phillips, Rebecca L.

2016-05-01

Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB = 103 ± 42 g C m-2 yr-1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = -13 ± 23 g C m-2 yr-1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m-2 yr-1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m-2 yr-1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

Dairy farmers using mob grazing in Pennsylvania and New York

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Proponents of ultra-high stocking density grazing emphasize increased forage use efficiency and soil improvement by grazing mature forage with stocking densities up to 500,000 lb per acre of beef cattle on small paddocks with rest periods up to 180 days. However, it is unclear if this management tec...

Concentrate Supplement Modifies the Feeding Behavior of Simmental Cows Grazing in Two High Mountain Pastures.

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Romanzin, Alberto; Corazzin, Mirco; Piasentier, Edi; Bovolenta, Stefano

2018-05-16

During grazing on Alpine pastures, the use of concentrates in dairy cows' diet leads to a reduction of the environmental sustainability of farms, and influences the selective pressure on some plant species. In order to minimize the use of concentrates, it is imperative to obtain data on the grazing behavior of cows. The aim of this study was to assess the effect of concentrate levels on the behavior of dairy cows during grazing. One hundred and ten lactating Italian Simmental cows, that sequentially grazed two pastures characterized by Poion alpinae (Poion) and Seslerion caeruleae (Seslerion) alliance, were considered. For each pasture, eight cows were selected and assigned to two groups: High and Low, supplemented with 4 kg/head/d, and 1 kg/head/d of concentrate respectively. Cows were equipped with a noseband pressure sensor and a pedometer (RumiWatch system, ITIN-HOCH GmbH) to assess grazing, ruminating, and walking behavior. In addition, the plant selection of the animals was assessed. On Poion, increased supplement intake caused a more intense selection of legumes, without affecting feeding and walking times. On Seslerion, grazing time was higher in Low than High. Grazing management in alpine region must take into account the great variability of pastures that largely differ from a floristic and nutritional point of view.

The effects of burning and grazing on soil carbon dynamics in managed Peruvian tropical montane grasslands

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Oliver, Viktoria; Oliveras, Imma; Kala, Jose; Lever, Rebecca; Arn Teh, Yit

2017-12-01

Montane tropical soils are a large carbon (C) reservoir, acting as both a source and a sink of CO2. Enhanced CO2 emissions originate, in large part, from the decomposition and losses of soil organic matter (SOM) following anthropogenic disturbances. Therefore, quantitative knowledge of the stabilization and decomposition of SOM is necessary in order to understand, assess and predict the impact of land management in the tropics. In particular, labile SOM is an early and sensitive indicator of how SOM responds to changes in land use and management practices, which could have major implications for long-term carbon storage and rising atmospheric CO2 concentrations. The aim of this study was to investigate the impacts of grazing and fire history on soil C dynamics in the Peruvian montane grasslands, an understudied ecosystem, which covers approximately a quarter of the land area in Peru. A density fractionation method was used to quantify the labile and stable organic matter pools, along with soil CO2 flux and decomposition measurements. Grazing and burning together significantly increased soil CO2 fluxes and decomposition rates and reduced temperature as a driver. Although there was no significant effect of land use on total soil C stocks, the combination of burning and grazing decreased the proportion of C in the free light fraction (LF), especially at the lower depths (10-20 and 20-30 cm). In the control soils, 20 % of the material recovered was in the free LF, which contained 30 % of the soil C content. In comparison, the burnt-grazed soil had the smallest recovery of the free LF (10 %) and a significantly lower C content (14 %). The burnt soils had a much higher proportion of C in the occluded LF (12 %) compared to the not-burnt soils (7 %) and there was no significant difference among the treatments in the heavy fraction (F) ( ˜ 70 %). The synergistic effect of burning and grazing caused changes to the soil C dynamics. CO2 fluxes were increased and the dominant

The effects of burning and grazing on soil carbon dynamics in managed Peruvian tropical montane grasslands

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V. Oliver

2017-12-01

Full Text Available Montane tropical soils are a large carbon (C reservoir, acting as both a source and a sink of CO2. Enhanced CO2 emissions originate, in large part, from the decomposition and losses of soil organic matter (SOM following anthropogenic disturbances. Therefore, quantitative knowledge of the stabilization and decomposition of SOM is necessary in order to understand, assess and predict the impact of land management in the tropics. In particular, labile SOM is an early and sensitive indicator of how SOM responds to changes in land use and management practices, which could have major implications for long-term carbon storage and rising atmospheric CO2 concentrations. The aim of this study was to investigate the impacts of grazing and fire history on soil C dynamics in the Peruvian montane grasslands, an understudied ecosystem, which covers approximately a quarter of the land area in Peru. A density fractionation method was used to quantify the labile and stable organic matter pools, along with soil CO2 flux and decomposition measurements. Grazing and burning together significantly increased soil CO2 fluxes and decomposition rates and reduced temperature as a driver. Although there was no significant effect of land use on total soil C stocks, the combination of burning and grazing decreased the proportion of C in the free light fraction (LF, especially at the lower depths (10–20 and 20–30 cm. In the control soils, 20 % of the material recovered was in the free LF, which contained 30 % of the soil C content. In comparison, the burnt–grazed soil had the smallest recovery of the free LF (10 % and a significantly lower C content (14 %. The burnt soils had a much higher proportion of C in the occluded LF (12 % compared to the not-burnt soils (7 % and there was no significant difference among the treatments in the heavy fraction (F ( ∼  70 %. The synergistic effect of burning and grazing caused changes to the soil C dynamics. CO2

The Effects of Timing of Grazing on Plant and Arthropod Communities in High-Elevation Grasslands

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Davis, Stacy C.; Burkle, Laura A.; Cross, Wyatt F.; Cutting, Kyle A.

2014-01-01

Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season. PMID:25338008

Woodlands Grazing Issues in Mediterranean Basin

Science.gov (United States)

Campos, P.

2009-04-01

In Mediterranean basin, woodlands grazing still continue to be important commercial owners' benefits. These owners manage woodlands vegetations as if they were not at risk of degradation and declining. Frequently, no temporally grazing set-aside is taken into account to avoid overgrazing of annual and perennial vegetations. Although less common, in the northern shore of Mediterranean basin undergrazing might increase the frequency and the number of catastrophic forest fires. This under/over grazing regime occurs in the Mediterranean basin woodlands with contrasted differences on land property rights, local economies and government livestock policy incentives. Spain and Tunisia are examples of these Mediterranean livestock contrasts. Most of Spanish Mediterranean woodlands and livestock herds are large private ownerships and owners could maintain their lands and livestock herds properties on the basis of moderate cash-income compensation against land revaluation and exclusive amenity self-consumption. The later is less tangible benefit and it could include family land legacy, nature enjoyment, country stile of life development, social status and so on. In public woodlands, social and environmental goals -as they are cultural heritage, biodiversity loss mitigation, soil conservation and employment- could maintain market unprofitable woodlands operations. Last three decades Spanish Mediterranean woodlands owners have increased the livestock herds incentivized by government subsidies. As result, grazing rent is pending on the level of European Union and Spanish government livestock subsidies. In this context, Spanish Mediterranean woodlands maintain a high extensive livestock stoking population, which economy could be called fragile and environmentally unsustainable because forest degradation and over/under grazing practices. Tunisian Mediterranean woodlands are state properties and livestock grazing is practice as a free private regimen. Livestock herds are small herd

Contrasting responses of insect communities to grazing intensity in lowland heathlands

NARCIS (Netherlands)

Wallis de Vries, Michiel; Noordijk, Jinze; Colijn, Ed O.; Smit, John T.; Veling, Kars

2016-01-01

Grazing at low stocking rates is often recommended for the preservation of the characteristic biodiversity of open landscapes. However, the fine-tuning of grazing management still lacks a good evidence base. This is particularly true for insect communities, as available evidence indicates that

Effects of Seasonal and Perennial Grazing on Soil Fauna Community and Microbial Biomass Carbon in the Subalpine Meadows of Yunnan, Southwest China

Institute of Scientific and Technical Information of China (English)

LIU Shengjie; YANG Xiaodong; Anthony R.IVES; FENG Zhili; SHA Liqing

2017-01-01

Grazing and over-grazing may drive changes in the diversity and functioning of below-ground meadow ecosystems.A field soil survey was conducted to compare microbial biomass carbon (Cmin) and soil fauna communities in the two main grassland management systems in subalpine regions of Yunnan Province,China:perennial grazing currently practiced due to increasing herd sizes and traditional seasonal grazing.A three-year exclosure experiment was then conducted to further compare the effects of different grazing practices,including treatments of no mowing,perennial grazing (NM + G),mowing followed by seasonal grazing (M + G),mowing and no grazing (M + NG),and no mowing or grazing (NM + NG).The comparative survey result revealed that Cmin and total density of soil fauna were significantly lower at a perennially grazed site than at a seasonally grazed site.The experiment results showed that in comparison to non-grazing treatments (M + NG and NM + NG),grazing (NM + G and M + G) reduced total fauna density (by 150 individuals m-2) and the number of taxonomic groups present (by 0.32 taxa m-2).Mowing decreased Cmin (by 0.31 mg g-1).Furthermore,the NM + G treatment (perennial grazing) had the lowest density of Collembola (16.24 individuals m-2),one of the two most common taxonomic groups,although other taxonomic groups responded differently to the treatments.Treatment effects on soil fauna were consistent with those on above-ground grasses,in which C:N ratios were greatly reduced by grazing,with this effect being the greatest for the NM + G treatment.In contrast,different grazing treatments had little effect on C:N ratio of soil.Furthermore,the traditional grazing method (mowing followed by seasonal grazing) may have less severe effects on some taxonomic groups than perennial grazing.Therefore,an appropriate management should aim to protect soil fauna and microbes in this area from over-grazing and against further degradation.

Nutritive value of Tanzania grass for dairy cows under rotational grazing

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Alberto Magno Fernandes

2014-08-01

Full Text Available A nutritional analysis of Tanzania grass (Megathyrsus maximus Jacquin cv. Tanzânia was conducted. Pasture was managed in a rotational grazing system with a 30-day resting period, three days of paddock occupation and two grazing cycles. Ten Holstein × Zebu crossbred cows were kept within a 2-ha area divided into 11 paddocks ha-1. Cows were fed 2 kg of corn meal daily and performance was evaluated by weighing the animals every 14 days and by recording milk production twice a day. Nutritional composition of the Tanzania grass was determined from forage (extrusa samples collected by esophageal fistulae from two animals. The nutritive value of Tanzania grass was estimated according to a modification of the CNCPS evaluation model. Tanzania grass supplemented with 2 kg of corn meal supplied 33.2% more net energy for lactation than required by the animals to produce 13.7 kg of milk day-1. Nevertheless, the amount of metabolizable protein met the daily protein requirement of the animals. Although the model used in the study requires adjustments, Tanzania grass has the potential to produce milk in a rotational grazing system.

Reaction of cocksfoot (Dactylis glomerata L. in grass-clover mixture on N fertilization and grazing

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Marcela Andreata-Koren

2009-09-01

Full Text Available Grazing is the most common way of using a hill and mountain areas because of their specific agro-ecological conditions. Cocksfoot is a grass with high productivity and quality, and it is very good for sowing in the sward for grazing. Because of its good adaptability to different growing conditions, especially in very dry and cold areas, it is excellent in relation to some other good grasses, which can not be raised in such areas. The aim of the experiment was to determine effect of N application (0-N0 and 150 kg ha-1 year-1-N150 and rotational grazing by cattle (C and sheep (S, and their interaction on the cocksfoot sown in a mixture of smooth-stalked meadow grass (Poa pratensis L. and white clover (Trifolium repens L. in hill mountain areas. In a three-year average, the application of 150 kg ha-1 N had significant impact on cocksfoot population density (number of tillers m-2, and it was 51.4 % higher than the recorded one before grazing (P<0.05 and 42.2 % higher after grazing (P<0.01 in comparison to N0. The application of 150 kg ha-1 N resulted in significantly higher cocksfoot dry matter (DM yield for 38.6 % (P<0.01 and 15.3 % higher cocksfoot share in the total mixture in relation to N0 (P<0.01. Grazing management and grazing management interaction with N rate did not significantly affect the population density of individual years. However, in the three-year average, grazing management significantly affected cocksfoot DM (P<0.01 and its percentage in the total DM mixture (P<0.01. Cattle grazing resulted in 9.9 % higher cocksfoot DM yield and 15.2 % higher cocksfoot percentage in pasture. Interaction of grazing management and N-level had significant influence on the percentage of cocksfoot DM in grass-clover mixture. On cattle grazed areas fertilized with 150 kg ha-1 N, the percentage of cocksfoot DM was the highest (74. 07%, while the lowest percentage of cocksfoot DM was recorded on the sheep grazed areas without N (55.12%.

Forage management to improve on-farm feed production, nitrogen fluxes and greenhouse gas emissions from dairy systems in a wet temperate region

DEFF Research Database (Denmark)

Doltra, J; Villar, A.; Moros, R

2018-01-01

characteristic forage systems according to field management based on grazing, zero-grazing, conserved forages and growth of maize. The semi-dynamic whole farm model FarmAC was used to characterize a model farm representing an average farm in each of the forage systems including field area and use, number of cows...

Grasshopper responses to fire and postfire grazing in the northern Great Plains vary among species

Science.gov (United States)

Rangeland management practices such as burning and grazing management may affect grasshopper populations by impacting development, survival and reproduction. Experiments are lacking in the northern Great Plains examining the effects of fire and grazing intensity on grasshoppers. As part of a larger ...

Nitrate leaching affected by management options with respect to urine-affected areas and groundwater levels for grazed grassland

NARCIS (Netherlands)

Hack-ten Broeke, M.J.D.; Putten, van der A.H.J.

1997-01-01

Simulations were performed to quantify the effects of management options on nitrate leaching to the groundwater in grazed pastures. At the experimental farm for sustainable dairy farming ‘De Marke’, experimental data on soil water and nitrates were gathered for two fields during the years 1991–1995.

Rotational Grazing System for Beef Cows on Dwarf Elephantgrass Pasture for Two Years after Establishment

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M Mukhtar

2011-01-01

Full Text Available An intensive rotational grazing system for dwarf and late heading (DL elephant grass (Pennisetum purpureum Schumach pasture was examined in a summer period for two years following establishment. Four 0.05 of DL elephant grass pastures (20×25 m were established on May 2003. They were rotationally grazed for 1 week, followed by a 3-week rest period by three breeding or raising beef cattle for three and six cycles during the first and second years of establishment respectively. Before grazing, the plant height, leaf area index and the ratio of leaf blade to stem were at the highest, while tiller number increased and herbage mass tended to increase, except for the first grazing cycle both two years and for one paddock in the second year. Herbage consumption, the rate of herbage consumption and dry matter intake tended to decrease in three paddocks from the first to the third cycle in the first year, but increase as grazing occurred in the second year. Dry matter intake averaged 10.2-14.5 and 15.4–23.2 g DM/kg/live weight (LW/day over the four paddocks in the first and second year, respectively, and average daily gains were 0.09 and 0.35 kg/head/day in the first and second year respectively. The carrying capacities were estimated at 1,016 and 208 cow-days (CD/ha (annual total 1,224 CD/ha in the first year and 1,355 and 207 CD/ha (annual total 1,562 CD/ha in the second year. Thus, DL elephant grass pasture can expand the grazing period for beef cows for the following two-year establishment. (Animal Production 13(1:10-17 (2011 Key Words: dwarf elephant grass, herbage mass, plant characters, rotational grazing

Concentrate Supplement Modifies the Feeding Behavior of Simmental Cows Grazing in Two High Mountain Pastures

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Alberto Romanzin

2018-05-01

Full Text Available During grazing on Alpine pastures, the use of concentrates in dairy cows’ diet leads to a reduction of the environmental sustainability of farms, and influences the selective pressure on some plant species. In order to minimize the use of concentrates, it is imperative to obtain data on the grazing behavior of cows. The aim of this study was to assess the effect of concentrate levels on the behavior of dairy cows during grazing. One hundred and ten lactating Italian Simmental cows, that sequentially grazed two pastures characterized by Poion alpinae (Poion and Seslerion caeruleae (Seslerion alliance, were considered. For each pasture, eight cows were selected and assigned to two groups: High and Low, supplemented with 4 kg/head/d, and 1 kg/head/d of concentrate respectively. Cows were equipped with a noseband pressure sensor and a pedometer (RumiWatch system, ITIN-HOCH GmbH to assess grazing, ruminating, and walking behavior. In addition, the plant selection of the animals was assessed. On Poion, increased supplement intake caused a more intense selection of legumes, without affecting feeding and walking times. On Seslerion, grazing time was higher in Low than High. Grazing management in alpine region must take into account the great variability of pastures that largely differ from a floristic and nutritional point of view.

Influence of grazing regimes on cattle nutrition and performance and vegetation dynamics in Sahelian rangelands

NARCIS (Netherlands)

Ayantunde, A.A.

1998-01-01

In the West African Sahel, common herd management practices such as night grazing and corralling influence time available for grazing. When animals are used to deposit manure in the cropping fields, conflicts often arise between the need for animals to graze long enough for adequate feed

Spatial Distribution of Nitrogen on Grazed Karst Landscapes

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Douglas G. Boyer

2001-01-01

Full Text Available The impact on water quality by agricultural activity in karst terrain is an important consideration for resource management within the Appalachian region. Karst areas comprise about 18% of the region’s land area. An estimated one-third of the region’s farms, cattle, and agricultural market value are located on karst terrain. Mean nitrate concentrations in several karst springs in southeastern West Virginia exhibit a strong linear relationship with the percentage of agriculture land cover. Development of best management practices for efficient nitrogen (N use and reduction of outflow of N to water from karst areas requires knowledge about N dynamics on those landscapes. Water extractable NO3-N and NH4-N were measured along transects at four soil depths in two grazed sinkholes and one wooded sinkhole. Distribution of soil NO3-N and NH4-N were related to frequency of animal presence and to topographic and hydrologic redistribution of soil and fecal matter in the grazed sinkholes. Karst pastures are characterized by under drainage and funneling of water and contaminants to the shallow aquifer. Control of NO3-N leaching from karst pasture may depend on management strategies that change livestock grazing behavior in sinkholes and reduce the opportunity for water and contaminants to quickly reach sinkhole drains.

Introducing cattle grazing to a noxious weed-dominated rangeland shifts plant communities

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Josh S. Davy

2015-10-01

Full Text Available Invasive weed species in California's rangelands can reduce herbaceous diversity, forage quality and wildlife habitat. Small-scale studies (5 acres or fewer have shown reductions of medusahead and yellow starthistle using prescribed grazing on rangelands, but little is published on the effects of pasture-scale (greater than 80 acres prescribed grazing on weed control and plant community responses. We report the results of a 6-year collaborative study of manager-applied prescribed grazing implemented on rangeland that had not been grazed for 4 years. Grazing reduced medusahead but did not alter yellow starthistle cover. Medusahead reductions were only seen in years that did not have significant late spring rainfall, suggesting that it is able to recover from heavy grazing if soil moisture is present. Later season grazing appears to have the potential to suppress medusahead in all years. In practice, however, such grazing is constrained by livestock drinking water availability and forage quality, which were limited even in years with late spring rainfall. Thus, we expect that grazing treatments under real-world constraints would reduce medusahead only in years with little late spring rainfall. After 10 years of grazing exclusion, the ungrazed plant communities began to shift, replacing medusahead with species that have little value, such as ripgut and red brome.

An experimental analysis of grasshopper community responses to fire and livestock grazing in a northern mixed-grass prairie.

Science.gov (United States)

Branson, David H; Sword, Gregory A

2010-10-01

The outcomes of grasshopper responses to both vertebrate grazing and fire vary across grassland ecosystems, and are strongly influenced by local climactic factors. Thus, the possible application of grazing and fire as components of an ecologically based grasshopper management strategy must be investigated in regional studies. In this study, we examined the effects of grazing and fire on grasshopper population density and community composition in a northern Great Plains mixed-grass prairie. We employed a large-scale, replicated, and fully-factorial manipulative experimental design across 4 yr to examine the separate and interactive effects of three grazing systems in burned and unburned habitats. Grasshopper densities were low throughout the 4-yr study and 1 yr of pretreatment sampling. There was a significant fire by grazing interaction effect on cumulative density and community composition, resulting from burned season long grazing pastures having higher densities than unburned pastures. Shannon diversity and grasshopper species richness were significantly higher with twice-over rotational livestock grazing. The ability to draw strong conclusions regarding the nature of species composition shifts and population changes in the presence of fire and grazing is complicated by the large site differences and low grasshopper densities. The results reinforce the importance of long-term research to examine the effects of habitat manipulation on grasshopper population dynamics.

Acoustic monitoring system to quantify ingestive behavior of free-grazing cattle

Science.gov (United States)

Methods to estimate intake in grazing livestock include using markers, visual observation, mechanical sensors that respond to jaw movement and acoustic recording. In most of the acoustic monitoring studies, the microphone is inverted on the forehead of the grazing livestock and the skull is utilize...

White clover regenerative ability under N fertilizing and grazing

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Josip Leto

2008-12-01

Full Text Available Recently, ecological and economic factors in milk and meat production stimulate use of legumes and grass-legumes mixtures, with zero or minimum mineral N as alternative to grass monoculture with high rate of mineral N. Research objective was to examine the effect of N application (0-N0 and 150 kg ha-1 year-1-N150 and rotational grazing by cattle (C and sheep (S on white clover: growing points number, stolon lenght, stolon dry weight, dry matter yield and clover contribution to total annual herbage production. N150 significantly reduced the growing points number, stolon length and stolon dry weight for more than 70 % compared to N0. Grazing treatment affected stolon population density only in interaction with N application because of N150 significantly reduced white clover population density only in sheep grazing. S-treatment had higher clover DM yield (0.21 t ha-1 than C-treatment (0.13 t ha-1. N0 had higher clover DM yield (0.25 t ha-1 than N150 (0.09 t ha-1. However, the interaction grazing management x N rate was significant for clover DM yield and clover contribution to total DM yield. N150 reduced both parameters for 80 % only in sheep grazing while difference in DM yield and clover contribution to total DM yield between grazing treatment was recorded only in N0 Sheep grazing increased DM yield for 150 % and clover contribution for 99 % compared to cattle grazing.

Effects of grazing intensity on small mammal population ecology in wet meadows

DEFF Research Database (Denmark)

Schmidt, Niels Martin; Olsen, Henrik; Bildsøe, Mogens

2005-01-01

Livestock grazing is common management practice in wet grasslands. However, knowledge of its effects on small mammals is limited. We studied the influence of grazing intensity on small mammals in general and field voles Microtus agrestis in particular in two Danish wet meadows, 1998-2000. General...

Herbage intake, methane emissions and animal performance of steers grazing dwarf elephant grass v. dwarf elephant grass and peanut pastures.

Science.gov (United States)

Andrade, E A; Almeida, E X; Raupp, G T; Miguel, M F; de Liz, D M; Carvalho, P C F; Bayer, C; Ribeiro-Filho, H M N

2016-10-01

Management strategies for increasing ruminant legume consumption and mitigating methane emissions from tropical livestock production systems require further study. The aim of this work was to evaluate the herbage intake, animal performance and enteric methane emissions of cattle grazing dwarf elephant grass (DEG) (Pennisetum purpureum cv. BRS Kurumi) alone or DEG with peanut (Arachis pintoi cv. Amarillo). The experimental treatments were the following: DEG pastures receiving nitrogen fertilization (150 kg N/ha as ammonium nitrate) and DEG intercropped with peanut plus an adjacent area of peanut that was accessible to grazing animals for 5 h/day (from 0700 to 1200 h). The animals grazing legume pastures showed greater average daily gain and herbage intake, and shorter morning and total grazing times. Daily methane emissions were greater from the animals grazing legume pastures, whereas methane emissions per unit of herbage intake did not differ between treatments. Allowing animals access to an exclusive area of legumes in a tropical grass-pasture-based system can improve animal performance without increasing methane production per kg of dry matter intake.

Effects of grazing management on biodiversity across trophic levels-The importance of livestock species and stocking density in salt marshes

NARCIS (Netherlands)

van Klink, Roel; Nolte, Stefanie; Mandema, Freek; Lagendijk, D. D. Georgette; WallisDeVries, Michiel F.; Bakker, Jan P.; Esselink, Peter; Smit, Christian

2016-01-01

European coastal salt marshes are important for the conservation of numerous species of specialist plants, invertebrates, breeding and migratory birds. When these marshes are managed for nature conservation purposes, livestock grazing is often used to counter the dominance of the tall grass

Grazing alters net ecosystem C fluxes and the global warming potential of a subtropical pasture.

Science.gov (United States)

Gomez-Casanovas, Nuria; DeLucia, Nicholas J; Bernacchi, Carl J; Boughton, Elizabeth H; Sparks, Jed P; Chamberlain, Samuel D; DeLucia, Evan H

2018-03-01

The impact of grazing on C fluxes from pastures in subtropical and tropical regions and on the environment is uncertain, although these systems account for a substantial portion of global C storage. We investigated how cattle grazing influences net ecosystem CO 2 and CH 4 exchange in subtropical pastures using the eddy covariance technique. Measurements were made over several wet-dry seasonal cycles in a grazed pasture, and in an adjacent pasture during the first three years of grazer exclusion. Grazing increased soil wetness but did not affect soil temperature. By removing aboveground biomass, grazing decreased ecosystem respiration (R eco ) and gross primary productivity (GPP). As the decrease in R eco was larger than the reduction in GPP, grazing consistently increased the net CO 2 sink strength of subtropical pastures (55, 219 and 187 more C/m 2 in 2013, 2014, and 2015). Enteric ruminant fermentation and increased soil wetness due to grazers, increased total net ecosystem CH 4 emissions in grazed relative to ungrazed pasture (27-80%). Unlike temperate, arid, and semiarid pastures, where differences in CH 4 emissions between grazed and ungrazed pastures are mainly driven by enteric ruminant fermentation, our results showed that the effect of grazing on soil CH 4 emissions can be greater than CH 4 produced by cattle. Thus, our results suggest that the interactions between grazers and soil hydrology affecting soil CH 4 emissions play an important role in determining the environmental impacts of this management practice in a subtropical pasture. Although grazing increased total net ecosystem CH 4 emissions and removed aboveground biomass, it increased the net storage of C and decreased the global warming potential associated with C fluxes of pasture by increasing its net CO 2 sink strength. © 2017 by the Ecological Society of America.

Impacts of fire and grazing management on South Africa’s moist highland grasslands: A case study of the Steenkampsberg Plateau, Mpumalanga, South Africa

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Ian T. Little

2015-11-01

Full Text Available Background: Grasslands are heavily utilised for livestock agriculture and the resultant degradation through mismanagement contributes to an estimated 60% of this biome being permanently transformed. This study focused on the impact of fire and grazing in moist highland grasslands. Objectives: To determine the contribution of burning frequency and grazing intensity combined (for domestic livestock and indigenous ungulates on vegetation structure heterogeneity and species diversity. Methods: Eight study sites under different management regimes were sampled over two summers. Vegetation structure characteristics and diversity data were collected monthly within multiple replicates in each study site. A disc pasture meter was used to assess standing biomass. Differences in vegetation structure characteristics, plant community composition and plant species assemblage structure across sites were statistically analysed using analyses of variance, indicator species analyses, multidimensional scaling ordinations and two-way cluster analyses. Results: The combination of heavy grazing and annual burning leads to a distinct plant community dominated by disturbance specialist species. Selective grazing by indigenous herbivores promotes a community of unpalatable species. This study illustrates that fenced indigenous herbivores, even at moderate stocking densities, have a greater detrimental impact on plant diversity and structure than do domestic livestock. Conclusion: Intensive grazing and burning have a detrimental impact on plant species diversity and structure. This also affects resultant palatability for grazing livestock and fenced game. To promote both grazing quality and ecological integrity we recommend a minimum sustainable ‘fodder capacity’ or standing phytomass of 5000 kg per large-animal unit per hectare for domestic livestock in moist highland grasslands.

Subclinical ketosis in dairy cows: prevalence and risk factors in grazing production system.

Science.gov (United States)

Garro, C J; Mian, L; Cobos Roldán, M

2014-10-01

The purpose of this study was to estimate the prevalence of Subclinical ketosis (SCK) between 4 and 19 days in milk (DIM) in a grazing production system and investigate the importance of potential risk factors for SCK. This cross-sectional study was conducted in dairy cows (n = 107), which had more of two parities. The concentration of β-hydroxybutyric (BHB) in blood was quantified through a hand-held meter. Potential risk factors evaluated were calving interval (CI), milk yield in previous lactation, metritis, dystocia, calf sex (male), parity (≤3 vs. ≥4) and pre-partum body condition score (BCS ≤ 3.5 vs. ≥3.75). Prevalence of SCK was 10.3% (95% CI 4.7-15) between 4 and 19 DIM. Risk factors identified were the occurrence of both metritis and pre-partum BCS ≥ 3.75. Cows with metritis had 4.9 (95% CI 1.17-20.98) times more risk of developing SCK than cows without metritis. And the cows with pre-partum BCS ≥ 3.75 had 5.25 (95% CI 1.32-21.11) times more risk of developing SCK than cows with pre-partum BCS ≤ 3.5. Metritis could induce a lower feed intake and promote the development of SCK. High pre-partum BCS could induce a greater mobilization of body reserves altering liver function and aggravating post-partum NEB. The results are indicative of the expected prevalence of SCK in grazing production system. Factors associated could help to identify cattle at risk of SCK and improve the management of strategies to limit the effects. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

A 4-year study on the effectiveness of alternate grazing of cattle and sheep in the control of bovine parasitic gastro-enteritis.

Science.gov (United States)

Bairden, K; Armour, J; Duncan, J L

1995-11-01

In many farming enterprises, animal management systems which could provide a practical and effective alternative to chemotherapy for the control of bovine helminthosis would be readily accepted. One system which has been proposed and shown to be effective in the short or medium term involves grazing different host species on a rotational basis. The study described here examined the effect of alternating cattle and sheep annually over an extended period of 4 years. Up to the second grazing season the system appeared to be successful, with a marked reduction in the cattle worm burdens. However, by the end of the study period the parasite burdens in calves grazed on the alternated pasture were equal to, or greater than, those of set-stocked control animals. It was thus clear that the alternate grazing strategy had failed. Data obtained from other parameters measured, i.e. faecal egg counts, pasture larval numbers and plasma pepsinogen levels, confirmed this observation.

Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures.

Science.gov (United States)

Dougherty, Warwick J; Nicholls, Paul J; Milham, Paul J; Havilah, Euie J; Lawrie, Roy A

2008-01-01

Fertilizer phosphorus (P) and grazing-related factors can influence runoff P concentrations from grazed pastures. To investigate these effects, we monitored the concentrations of P in surface runoff from grazed dairy pasture plots (50 x 25 m) treated with four fertilizer P rates (0, 20, 40, and 80 kg ha(-1) yr(-1)) for 3.5 yr at Camden, New South Wales. Total P concentrations in runoff were high (0.86-11.13 mg L(-1)) even from the control plot (average 1.94 mg L(-1)). Phosphorus fertilizer significantly (P pasture biomass (P dairy pastures should be the maintenance of soil P at or near the agronomic optimum by the use of appropriate rates of P fertilizer.

Bison grazing increases arthropod abundance and diversity in a tallgrass prairie.

Science.gov (United States)

Moran, Matthew D

2014-10-01

How grazing-induced ecosystem changes by ungulates indirectly affect other consumers is a question of great interest. I investigated the effect of grazing by American Bison (Bos bison L.) on an arthropod community in tallgrass prairie. Grazing increased the abundance of arthropods, an increase that was present in both herbivorous and carnivorous assemblages, but not in detritivores. The increase in herbivores and reduction in plant biomass from grazing resulted in an arthropod herbivore load almost three times higher in grazed plots compared with controls. Among herbivores, the sap-feeding insect guild was dramatically more abundant, while chewing herbivores were not affected. Herbivorous and carnivorous arthropod richness was higher in grazed plots, although the response was strongest among herbivores. Arthropod abundance on individual grasses and forbs was significantly higher in grazed areas, while plant type had no effect on abundance, indicating that the change was ecosystem-wide and not simply in response to a reduction in grass biomass from grazing. The response of arthropods to grazing was strongest in the early part of the growing season. Published research shows that ungulate grazing, although decreasing available biomass to other consumers, enhances plant quality by increasing nitrogen level in plants. The arthropod results of this study suggest higher plant quality outweighs the potential negative competitive effects of plant biomass removal, although other activities of bison could not be ruled out as the causative mechanism. Because arthropods are extremely abundant organisms in grasslands and a food source for other consumers, bison may represent valuable management tools for maintaining biodiversity.

Range-wide assessment of livestock grazing across the sagebrush biome

Science.gov (United States)

Veblen, Kari E.; Pyke, David A.; Jones, Christopher A.; Casazza, Michael L.; Assal, Timothy J.; Farinha, Melissa A.

2011-01-01

Domestic livestock grazing occurs in virtually all sagebrush habitats and is a prominent disturbance factor. By affecting habitat condition and trend, grazing influences the resources required by, and thus, the distribution and abundance of sagebrush-obligate wildlife species (for example, sage-grouse Centrocercus spp.). Yet, the risks that livestock grazing may pose to these species and their habitats are not always clear. Although livestock grazing intensity and associated habitat condition may be known in many places at the local level, we have not yet been able to answer questions about use, condition, and trend at the landscape scale or at the range-wide scale for wildlife species. A great deal of information about grazing use, management regimes, and ecological condition exists at the local level (for individual livestock management units) under the oversight of organizations such as the Bureau of Land Management (BLM). However, the extent, quality, and types of existing data are unknown, which hinders the compilation, mapping, or analysis of these data. Once compiled, these data may be helpful for drawing conclusions about rangeland status, and we may be able to identify relationships between those data and wildlife habitat at the landscape scale. The overall objective of our study was to perform a range-wide assessment of livestock grazing effects (and the relevant supporting data) in sagebrush ecosystems managed by the BLM. Our assessments and analyses focused primarily on local-level management and data collected at the scale of BLM grazing allotments (that is, individual livestock management units). Specific objectives included the following: 1. Identify and refine existing range-wide datasets to be used for analyses of livestock grazing effects on sagebrush ecosystems. 2. Assess the extent, quality, and types of livestock grazing-related natural resource data collected by BLM range-wide (i.e., across allotments, districts and regions). 3. Compile and

The role of grazing land on the buffalo population dynamics in Brebes regency

Science.gov (United States)

Sumanto

2017-04-01

Brebes District is one of the centre of grazing buffalo in Indonesia that involve thousands of rearers usually kept as a family savings. This paper highlighted the availability of land and the role of the grazing land for the durability of the maintenance of buffalo in Brebes Regency. The information obtained is from interviewed the livestock facilitators in the sub-district (primary data) and from statistic of agriculture in Brebes Regency 2014 (secondary data). Generally the buffalo kept semi-intensively and commonly the buffaloes graze in the fields that are not used from morning until evening and during nights buffaloes are placed in the stalls. Rearers chose the semi-intensive system in rearing the buffalo because it is considered easy to manage and they do not need to provide fresh money to prepare the roughage for feed, because commonly the grazing buffalo are shepherd by herdman that will receive buffalo as their payment. The population density is very high (1.056 heads/km2), the buffalo ownership is between 2-4 head/households; generally the location of the grazing land is in the forest, rice fields fallow, and sleeping land, and estimated that greenfeed stock is still available abunandtly, on the other hand the urban land is less capacity of feed. The spread of buffalo is only in 125 villages from 297 villages in Brebes. The acceptance of buffalo business is around IDR 3.5 million to IDR 7.5 million/family/year. The availability of grazing land strongly influence the maintaining of buffalo farming by rearers.

Use of n-alkanes and long-chain alcohols as faecal markers to estimate diet composition on small ruminants grazing/browsing mountain grasslands

OpenAIRE

Magalhães, Rui José Ribeiro Ferreira de

2018-01-01

Knowledge on the grazing/browsing behaviour, especially diet selection, of the different domestic herbivorous species under diverse vegetation communities is of particular importance for the development and application of appropriate grazing management strategies that increase the efficiency of the utilization of the existing vegetation and, consequently, the sustainability of the animal production system. Plant-wax components, namely alkanes and long-chain alcohols (LCOH), have been suggeste...

Sustainability, arid grasslands and grazing: New applications for technology

Energy Technology Data Exchange (ETDEWEB)

Pregenzer, A.L.; Parmenter, R.; Passell, H.D.; Budge, T.; Vande Caste, J.

1999-12-08

The study of ecology is taking on increasing global importance as the value of well-functioning ecosystems to human well-being becomes better understood. However, the use of technological systems for the study of ecology lags behind the use of technologies in the study of other disciplines important to human well-being, such as medicine, chemistry and physics. The authors outline four different kinds of large-scale data needs required by land managers for the development of sustainable land use strategies, and which can be obtained with current or future technological systems. They then outline a hypothetical resource management scenario in which data on all those needs are collected using remote and in situ technologies, transmitted to a central location, analyzed, and then disseminated for regional use in maintaining sustainable grazing systems. They conclude by highlighting various data-collection systems and data-sharing networks already in operation.

Effects of grazing management on biodiversity across trophic levels – The importance of livestock species and stocking density in salt marshes

NARCIS (Netherlands)

Klink, van Roel; Nolte, Stefanie; Mandema, Freek S.; Lagendijk, D.D.G.; Wallis de Vries, Michiel; Bakker, Jan P.; Esselink, Peter; Smit, Christian

2016-01-01

European coastal salt marshes are important for the conservation of numerous species of specialist plants, invertebrates, breeding and migratory birds. When these marshes are managed for nature conservation purposes, livestock grazing is often used to counter the dominance of the tall grass

Effect of grazing frequency and intensity on Lolium perenne L ...

African Journals Online (AJOL)

) system. Low frequency, low intensity grazing produced lower CDMD and herbage N levels than higher grazing frequencies and intensities. These differences were, however, generally small. Overall, levels of herbage digestibility (estimated ...

The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: The effect of agro-ecological zone, grazing management and age of cattle

Directory of Open Access Journals (Sweden)

C. Rubaire-Akiiki

2004-03-01

Full Text Available Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60% was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50% were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified.

36 CFR 222.53 - Grazing fees in the East-noncompetitive procedures.

Science.gov (United States)

2010-07-01

... lands and the total costs (other than grazing fee costs) of operating on National Forest System lands... the percentage change in the cost of alternative livestock feed. (3) Computation of Annual Grazing Fee... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing fees in the East...

Traditional cattle grazing in a mosaic alkali landscape: effects on grassland biodiversity along a moisture gradient.

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Péter Török

Full Text Available Extensively managed pastures are of crucial importance in sustaining biodiversity both in local- and landscape-level. Thus, re-introduction of traditional grazing management is a crucial issue in grassland conservation actions worldwide. Traditional grazing with robust cattle breeds in low stocking rates is considered to be especially useful to mimic natural grazing regimes, but well documented case-studies are surprisingly rare on this topic. Our goal was to evaluate the effectiveness of traditional Hungarian Grey cattle grazing as a conservation action in a mosaic alkali landscape. We asked the following questions: (i How does cattle grazing affect species composition and diversity of the grasslands? (ii What are the effects of grazing on short-lived and perennial noxious species? (iii Are there distinct effects of grazing in dry-, mesophilous- and wet grassland types? Vegetation of fenced and grazed plots in a 200-ha sized habitat complex (secondary dry grasslands and pristine mesophilous- and wet alkali grasslands was sampled from 2006-2009 in East-Hungary. We found higher diversity scores in grazed plots compared to fenced ones in mesophilous- and wet grasslands. Higher cover of noxious species was typical in fenced plots compared to their grazed counterparts in the last year in every studied grassland type. We found an increasing effect of grazing from the dry- towards the wet grassland types. The year-to-year differences also followed similar pattern: the site-dependent effects were the lowest in the dry grassland and an increasing effect was detected along the moisture gradient. We found that extensive Hungarian Grey cattle grazing is an effective tool to suppress noxious species and to create a mosaic vegetation structure, which enables to maintain high species richness in the landscape. Hungarian Grey cattle can feed in open habitats along long moisture gradient, thus in highly mosaic landscapes this breed can be the most suitable

Effects of past and present livestock grazing on herpetofauna in a landscape-scale experiment.

Science.gov (United States)

Kay, Geoffrey M; Mortelliti, Alessio; Tulloch, Ayesha; Barton, Philip; Florance, Daniel; Cunningham, Saul A; Lindenmayer, David B

2017-04-01

Livestock grazing is the most widespread land use on Earth and can have negative effects on biodiversity. Yet, many of the mechanisms by which grazing leads to changes in biodiversity remain unresolved. One reason is that conventional grazing studies often target broad treatments rather than specific parameters of grazing (e.g., intensity, duration, and frequency) or fail to account for historical grazing effects. We conducted a landscape-scale replicated grazing experiment (15,000 km 2 , 97 sites) to examine the impact of past grazing management and current grazing regimes (intensity, duration, and frequency) on a community of ground-dwelling herpetofauna (39 species). We analyzed community variables (species richness and composition) for all species and built multiseason patch-occupancy models to predict local colonization and extinction for the 7 most abundant species. Past grazing practices did not influence community richness but did affect community composition and patch colonization and extinction for 4 of 7 species. Present grazing parameters did not influence community richness or composition, but 6 of the 7 target species were affected by at least one grazing parameter. Grazing frequency had the most consistent influence, positively affecting 3 of 7 species (increased colonization or decreased extinction). Past grazing practice affected community composition and population dynamics in some species in different ways, which suggests that conservation planners should examine the different grazing histories of an area. Species responded differently to specific current grazing practices; thus, incentive programs that apply a diversity of approaches rather than focusing on a change such as reduced grazing intensity should be considered. Based on our findings, we suggest that determining fine-scale grazing attributes is essential for advancing grazing as a conservation strategy. © 2016 Society for Conservation Biology.

Grazing systems research: Focusing on the managers-introduction

Science.gov (United States)

Translating experimental results into management guidelines or as bases for specific decisions presents a substantial challenge for scientists, advisors and land managers. While inductive reasoning can be a valuable tool in developing general guidelines, particular wholly science-based relationships...

Key sources and seasonal dynamics of greenhouse gas fluxes from yak grazing systems on the Qinghai-Tibetan Plateau

Science.gov (United States)

Liu, Yang; Yan, Caiyu; Matthew, Cory; Wood, Brennon; Hou, Fujiang

2017-01-01

Greenhouse gas (GHG) emissions from livestock grazing systems are contributing to global warming. To examine the influence of yak grazing systems on GHG fluxes and relationships between GHG fluxes and environmental factors, we measured carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes over three key seasons in 2012 and 2013 from a range of potential sources, including: alpine meadows, dung patches, manure heaps and yak night pens, on the Qinghai-Tibetan Plateau. We also estimated the total annual global warming potential (GWP, CO2-equivalents) from family farm grazing yaks using our measured results and other published data. In this study, GHG fluxes per unit area from night pens and composting manure heaps were higher than from dung patches and alpine meadows. Increased moisture content and surface temperature of soil and manure were major factors increasing CO2 and CH4 fluxes. High contributions of CH4 and N2O (21.1% and 44.8%, respectively) to the annual total GWP budget (334.2 tonnes) strongly suggest these GHG other than CO2 should not be ignored when estimating GWP from the family farm grazing yaks on the Qinghai-Tibetan Plateau for the purposes of determining national and regional land use policies or compiling global GHG inventories.

Impact of grazing on range plant community components under arid Mediterranean climate in northern Syria

NARCIS (Netherlands)

Niane, A.A.

2013-01-01

Keywords: Rotational grazing, full protection, continuous grazing species richness,

species diversity, soil seed bank, Bayesian methods, Salsola vermiculata, seed

longevity, rangeland management, Syria.

Rangelands represent 70% of the semi-arid and arid

Eaten out of house and home: impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands.

Science.gov (United States)

Howland, Brett; Stojanovic, Dejan; Gordon, Iain J; Manning, Adrian D; Fletcher, Don; Lindenmayer, David B

2014-01-01

Large mammalian grazers can alter the biotic and abiotic features of their environment through their impacts on vegetation. Grazing at moderate intensity has been recommended for biodiversity conservation. Few studies, however, have empirically tested the benefits of moderate grazing intensity in systems dominated by native grazers. Here we investigated the relationship between (1) density of native eastern grey kangaroos, Macropus giganteus, and grass structure, and (2) grass structure and reptiles (i.e. abundance, richness, diversity and occurrence) across 18 grassland and grassy Eucalyptus woodland properties in south-eastern Australia. There was a strong negative relationship between kangaroo density and grass structure after controlling for tree canopy cover. We therefore used grass structure as a surrogate for grazing intensity. Changes in grazing intensity (i.e. grass structure) significantly affected reptile abundance, reptile species richness, reptile species diversity, and the occurrence of several ground-dwelling reptiles. Reptile abundance, species richness and diversity were highest where grazing intensity was low. Importantly, no species of reptile was more likely to occur at high grazing intensities. Legless lizards (Delma impar, D. inornata) were more likely to be detected in areas subject to moderate grazing intensity, whereas one species (Hemiergis talbingoensis) was less likely to be detected in areas subject to intense grazing and three species (Menetia greyii, Morethia boulengeri, and Lampropholis delicata) did not appear to be affected by grazing intensity. Our data indicate that to maximize reptile abundance, species richness, species diversity, and occurrence of several individual species of reptile, managers will need to subject different areas of the landscape to moderate and low grazing intensities and limit the occurrence and extent of high grazing.

Eaten out of house and home: impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands.

Directory of Open Access Journals (Sweden)

Brett Howland

Full Text Available Large mammalian grazers can alter the biotic and abiotic features of their environment through their impacts on vegetation. Grazing at moderate intensity has been recommended for biodiversity conservation. Few studies, however, have empirically tested the benefits of moderate grazing intensity in systems dominated by native grazers. Here we investigated the relationship between (1 density of native eastern grey kangaroos, Macropus giganteus, and grass structure, and (2 grass structure and reptiles (i.e. abundance, richness, diversity and occurrence across 18 grassland and grassy Eucalyptus woodland properties in south-eastern Australia. There was a strong negative relationship between kangaroo density and grass structure after controlling for tree canopy cover. We therefore used grass structure as a surrogate for grazing intensity. Changes in grazing intensity (i.e. grass structure significantly affected reptile abundance, reptile species richness, reptile species diversity, and the occurrence of several ground-dwelling reptiles. Reptile abundance, species richness and diversity were highest where grazing intensity was low. Importantly, no species of reptile was more likely to occur at high grazing intensities. Legless lizards (Delma impar, D. inornata were more likely to be detected in areas subject to moderate grazing intensity, whereas one species (Hemiergis talbingoensis was less likely to be detected in areas subject to intense grazing and three species (Menetia greyii, Morethia boulengeri, and Lampropholis delicata did not appear to be affected by grazing intensity. Our data indicate that to maximize reptile abundance, species richness, species diversity, and occurrence of several individual species of reptile, managers will need to subject different areas of the landscape to moderate and low grazing intensities and limit the occurrence and extent of high grazing.

Impact of cutting and sheep grazing on ground-active spiders and carabids in intertidal salt marshes (Western France

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Pétillon, J.

2007-12-01

Full Text Available The aims of this study were to characterize spider (Araneae and ground beetle (Coleoptera Carabidae communities in managed (cutting and sheep grazing and non-managed salt marshes and to assess the efficiency of management regimes in these particular ecosystems. The two groups were studied during 2002 in salt marshes of the Mont Saint-Michel Bay (NW France using pitfall traps. By opening soil and vegetation structures cutting and grazing enhanced the abundances of some halophilic species of spiders and ground beetles. Nevertheless, grazing appeared to be too intensive as spider species richness decreased. We discuss the implications of management practices in terms of nature conservation and their application in the particular area of intertidal salt marshes.

Effects of livestock species and stocking density on accretion rates in grazed salt marshes

Science.gov (United States)

Nolte, Stefanie; Esselink, Peter; Bakker, Jan P.; Smit, Christian

2015-01-01

Coastal ecosystems, such as salt marshes, are threatened by accelerated sea-level rise (SLR). Salt marshes deliver valuable ecosystem services such as coastal protection and the provision of habitat for a unique flora and fauna. Whether salt marshes in the Wadden Sea area are able to survive accelerated SLR depends on sufficient deposition of sediments which add to vertical marsh accretion. Accretion rate is influenced by a number of factors, and livestock grazing was recently included. Livestock grazing is assumed to reduce accretion rates in two ways: (a) directly by increasing soil compaction through trampling, and (b) indirectly by affecting the vegetation structure, which may lower the sediment deposition. For four years, we studied the impact of two livestock species (horse and cattle) at two stocking densities (0.5 and 1.0 animal ha-1) on accretion in a large-scale grazing experiment using sedimentation plates. We found lower cumulative accretion rates in high stocking densities, probably because more animals cause more compaction and create a lower canopy. Furthermore, a trend towards lower accretion rates in horse-compared to cattle-grazed treatments was found, most likely because (1) horses are more active and thus cause more compaction, and (2) herbage intake by horses is higher than by cattle, which causes a higher biomass removal and shorter canopy. During summer periods, negative accretion rates were found. When the grazing and non-grazing seasons were separated, the impact of grazing differed among years. In summer, we only found an effect of different treatments if soil moisture (precipitation) was relatively low. In winter, a sufficiently high inundation frequency was necessary to create differences between grazing treatments. We conclude that stocking densities, and to a certain extent also livestock species, affect accretion rates in salt marshes. Both stocking densities and livestock species should thus be taken into account in management

7 CFR 760.305 - Eligible grazing losses.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Eligible grazing losses. 760.305 Section 760.305... grazing losses. (a) A grazing loss due to drought is eligible for LFP only if the grazing loss for the... period for the specific type of grazing land or pastureland for the county.) (b) A grazing loss is not...

Ingestive behavior of cattle kept in Brachiaria brizantha cv. Xaraés grass managed under different grazing heights

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Marco Aurélio Alves de Freitas Barbosa

2014-02-01

Full Text Available This experiment was conducted to evaluate the effect of grazing heights on daytime behavioral activities of Nellore beef cattle in the rainy season. The experimental area was 12 hectares divided into paddocks of one hectare each. The treatments consisted of four defoliation heights (15, 30, 45 and 60 cm in pastures of Brachiaria brizantha cv. Xaraés with three replicates each. It was used the continuos grazing method, with variable stocking rate. Forage samples collected on the plots were sent to the laboratory for separation of the botanical components, weighing and determination of dry matter, with the material collected by simulated grazing. The variables: grazing time, idle time and ruminating time were evaluated for 12 consecutive hours on days 15 and 16 February 2011, considering the morning and afternoon periods. It was used a completely randomized design. The height of the canopy significantly influenced the daily grazing time and ruminating time, with a quadratic response as a function of time of defoliation. The bite rate decreased as a function of heights studied. However the chemical composition of the material collected by simulated grazing did not differ between treatments. Xaraés grass swards grazed at around 45 cm height provide greater ease of apprehension by grazing cattle.

1000 years of sustainable grazing in Nordic conditions?

DEFF Research Database (Denmark)

Brandt, Jesper

landscapes at different spatial levels. Information on much of this sort of regulation has however been lost through modern times, tended to prefer modern (nature) scientific methods primarily developed as general (meaning not spatially contextual) recommendations for raising productivity. During the later...... years this modern tradition has also been preferred by investigations to find solutions for non-sustainable types of land use in grazing systems. However, much sustainability-relevant wisdom has been accumulated in historical grazing-systems that should be included in the repertoire of knowledge...

The evaluation of four Eragrostis curvula ecotypes with grazing sheep.

African Journals Online (AJOL)

There were no significant differences in the dry matter production and chemical composition of the clipped samples of the ecotypes. Keywords: afrikaans; chemical composition; dry matter production; ecotypes; eragrostis curvula; grazing; live mass; live mass gains; open rotational grazing system; production; sheep; south ...

The grazing capacity of sweetveld: 2. A model to estimate grazing ...

African Journals Online (AJOL)

The relations between grazing capacity and three independent variables were investigated in the False Thornveld of the Eastern Cape. The variables were veld condition, rainfall and density of woody species. These relations were used to develop a preliminary model to assess grazing capacity in the veld type. Despite its ...

Changes in semi-arid plant species associations along a livestock grazing gradient.

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Hugo Saiz

Full Text Available In semi-arid ecosystems, vegetation is heterogeneously distributed, with plant species often associating in patches. These associations between species are not constant, but depend on the particular response of each species to environmental factors. Here, we investigated how plant species associations change in response to livestock grazing in a semi-arid ecosystem, Cabo de Gata-Níjar Natural Park in South East Spain. We established linear point-intercept transects at four sites with different grazing intensity, and recorded all species at each point. We investigated plant associations by comparing the number of times that each pair of species occurred at the same spatial point (co-occurrences, with the expected number of times based on species abundances. We also assessed associations for each shrub and grass species by considering all their pairs of associations and for the whole plant community by considering all pairs of associations on each site. At all sites, the plant community had a negative pattern of association, with fewer co-occurrences than expected. Negative association in the plant community increased at maximum grazing intensity. Most species associated as expected, particularly grass species, and positive associations were most important at intermediate grazing intensities. No species changed its type of association along the grazing gradient. We conclude that in the present plant community, grazing-resistant species compete among themselves and segregate in space. Some shrub species act as refuges for grazing-sensitive species that benefit from being spatially associated with shrub species, particularly at intermediate grazing intensities where positive associations were highest. At high grazing intensity, these shrubs can no longer persist and positive associations decrease due to the disappearance of refuges. Spatial associations between plant species and their response to grazing help identify the factors that organize

Habitat relationships of eastern red-backed salamanders (Plethodon cinereus) in Appalachian agroforestry and grazing systems

Science.gov (United States)

Breanna L. Riedel; Kevin R. Russell; W. Mark Ford; Katherine P. O' Neill; Harry W. Godwin

2008-01-01

Woodland salamander responses to either traditional grazing or silvopasture systems are virtually unknown. An information-theoretic modelling approach was used to evaluate responses of red-backed salamanders (Plethodon cinereus) to silvopasture and meadow conversions in southern West Virginia. Searches of area-constrained plots and artificial...

Habitat preference of geese is affected by livestock grazing : Seasonal variation in an experimental field evaluation

NARCIS (Netherlands)

Mandema, Freek S.; Tinbergen, Joost M.; Stahl, Julia; Esselink, Peter; Bakker, Jan P.

The number of staging geese in northwestern Europe has increased dramatically. Growing goose numbers put strong grazing pressure on agricultural pastures. Damage to agricultural land may be mitigated by managing nature reserves in order to optimally accommodate large numbers of grazing geese.

Bivalve grazing can shape phytoplankton communities

Science.gov (United States)

Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

2016-01-01

The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

Composition of late summer diet by semi-domesticated reindeer in different grazing conditions in northernmost Finland

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Pauline Bezard

2015-09-01

Full Text Available This study aims to investigate the diet composition of semi-domesticated reindeer (Rangifer tarandus tarandus in late summer in different kinds of grazing conditions in northernmost Finland. The composition of diet by reindeer was determined on the grounds of microhistological analysis of feces samples collected in early August in different seasonal grazing areas (winter or summer/year-round grazing areas in three reindeer management districts. Although the proportion of different plant groups varied between the studied districts, the quantified group of ground lichens (which also contained small amounts of mushrooms was the most abundant, varying from 33.0 to 46.4% in the analyzed samples. In general, there were significant differences in the proportions of lichen between districts, but not between grazing areas. The proportion of lichen in samples increased significantly when the amount of lichen pasture around a sample site increased. The proportion of dwarf shrubs and leaves in samples varied from 24.9 to 37.9% and differed significantly between districts, but not between grazing areas. In the same way, the proportion of graminoids varied between 20.9 and 36.2% and differed significantly between districts and also between grazing areas. Higher amounts of graminoids in feces were observed in summer/year-round grazing areas than in winter grazing areas. Finally, the proportion of bryophytes varied between 2.9 and 6.5% and was significantly different between districts, but not between grazing areas. An increase in old and mature coniferous forest around a sample site significantly increased the amounts of bryophytes in samples. The results indicate that reindeer adapt their summer diet composition according to the availability of food plants. The results also show that when reindeer are allowed to select their summer ranges freely, reindeer tend to use lichen pastures intensively also during summer, which causes a considerable reduction in

The Effect of Different Type of Herbivores, Grazing Types and Grazing Intensities on Alpine Basiphillous Vegetation of the Romanian Carpathians

Science.gov (United States)

Ballová, Zuzana; Pekárik, Ladislav; Šibík, Jozef

2017-04-01

The major purpose of the present study was to test the hypothesis that there are significant differences in vegetation structure, plant species composition, and soil chemical properties in relation to type of grazing animals, various levels of grazing intensity and grazing type, and if potential differences alter with ecosystem productivity (increase in more productive ecosystems). The study was conducted in three mountain ranges of the Romanian Carpathians with a predominance of alkaline substrates (the Bucegi Mts, the Little Retezat Mts and the Ceahlău Massif). Statistical analyses were performed in R statistical software environment. The effects of grazing animals (cattle, horses and sheep), grazing types (fence, regular, irregular) and grazing intensity (low, medium, high) on the community structure were tested using ordination methods. In the case of soil properties, General Linear Mixed Model was applied. Special statistical approach eliminated the differences between the examined mountains and sites. Type of grazing animal does not significantly influence species cover but it is related to specific species occurrence. According to our results, grazing horses had similar effects as cattle compared to sheep. Grazing in restricted areas (surrounded by fence) and regular unrestricted grazing were more similar if compared to irregular grazing. When comparing the intensity of grazing, high and medium intensity were more similar to each other than to the low intensity grazing. Cattle grazed sites had significantly higher lichens cover, while the sheep patches were covered with increased overall herb layer (forbs, graminoids and low shrubs together). Medium grazing intensity decreased the lichens cover, cover of overall herb layer, and total vegetation cover compared to high and low grazing intensity. Grazing type had important impact on the lichens cover and cover of overall herb layer. The lichens cover appeared to decrease while the cover of overall herb layer

Does grazing of cover crops impact biologically active soil C and N fractions under inversion and no tillage management

Science.gov (United States)

Cover crops are a key component of conservation cropping systems. They can also be a key component of integrated crop-livestock systems by offering high-quality forage during short periods between cash crops. The impact of cattle grazing on biologically active soil C and N fractions has not receiv...

Grassland Fire and Cattle Grazing Regulate Reptile and Amphibian Assembly Among Patches

Science.gov (United States)

Larson, Danelle M.

2014-12-01

Fire and grazing are common management schemes of grasslands globally and are potential drivers of reptilian and amphibian (herpetofauna) metacommunity dynamics. Few studies have assessed the impacts of fire and cattle grazing on herpetofauna assemblages in grasslands. A patch-burn grazing study at Osage Prairie, MO, USA in 2011-2012 created landscape patches with treatments of grazing, fire, and such legacies. Response variables were measured before and after the application of treatments, and I used robust-design occupancy modeling to estimate patch occupancy and detection rate within patches, and recolonization and extinction (i.e., dispersal) across patches. I conducted redundancy analysis and a permuted multivariate analysis of variance to determine if patch type and the associated environmental factors explained herpetofauna assemblage. Estimates for reptiles indicate that occupancy was seasonally constant in Control patches ( ψ ~ 0.5), but declined to ψ ~ 0.15 in patches following the applications of fire and grazing. Local extinctions for reptiles were higher in patches with fire or light grazing ( ɛ ~ 0.7) compared to the controls. For the riparian herpetofaunal community, patch type and grass height were important predictors of abundance; further, the turtles, lizards, snakes, and adult amphibians used different patch types. The aquatic amphibian community was predicted by watershed and in-stream characteristics, irrespective of fire or grazing. The varying responses from taxonomic groups demonstrate habitat partitioning across multiple patch types undergoing fire, cattle grazing, and legacy effects. Prairies will need an array of patch types to accommodate multiple herpetofauna species.

Effect of grazing on the cow welfare of dairy herds evaluated by a multidimensional welfare index

DEFF Research Database (Denmark)

Burow, E.; Rousing, T.; Thomsen, P. T.

2013-01-01

Structural development in the prime sector has led to increasing herd sizes and new barn systems, followed by less summer grazing for dairy cows in Denmark. Effects of grazing on single welfare measures in dairy cows - for example, the presence of integument alterations or mortality - have been......) inspired multidimensional dairy cow welfare assessment protocol, the within-herd effect of summer grazing compared with winter barn housing in Danish dairy herds with cubicle free-stall systems for the lactating cows. Our hypothesis was that cow welfare in dairy herds was better during summer grazing than...... out to be more beneficial than few daily grazing hours (range average above 9 to 21 h) for the welfare of the dairy herds. In conclusion, this study reports a positive within-herd effect of summer grazing on dairy cow welfare, where many daily grazing hours were more beneficial than few daily grazing...

Effects of co-grazing dairy heifers with goats on animal performance, dry matter yield, and pasture forage composition.

Science.gov (United States)

Dennis, T S; Unruh-Snyder, L J; Neary, M K; Nennich, T D

2012-12-01

Mixed livestock grazing can offer an alternative management system for rearing dairy replacement heifers (Bos taurus). A 2-yr study was conducted during 2009 (yr 1) and 2010 (yr 2) to determine the effects of co-grazing Holstein heifers under rotational stocking with Boer × Kiko goats on animal performance, pasture DM yield, and botanical composition. Each year, 24 heifers (134 ± 6 d of age and 147.4 ± 31.2 kg BW in yr 1; 166 ± 11 d of age and 168.0 ± 27.6 kg BW in yr 2) and 6 goats (2 yr old and 39.7 ± 16.2 kg BW in yr 1; 1 yr old and 33.7 ± 7.4 kg BW in yr 2) were divided into 6 paddocks with 4 heifers and 2 goats, where applicable, per group. Low endophyte-infected tall fescue (Festuca arundinacea Schreb.) and white clover (Trifolium repens L.) pastures were used to evaluate 2 grazing strategies (heifers grazed alone [HO] or heifers co-grazed with goats [HG]). In addition, 6 goats were assigned to 2 paddocks and grazed alone (GO) each year to estimate goat pasture forage intake and compare Haemonchus contortus infection to co-grazed goats. Forage samples were taken monthly to assess DM yield and botanical composition. Samples collected for botanical composition were manually sorted into grass, legume, and weed species. Forage DMI was estimated using a rising plate meter before and after grazing. Heifer BW at the conclusion of yr 1 and yr 2 did not differ between HO and HG (P = 0.40 and P = 0.12, respectively). Likewise, overall ADG did not differ between HO and HG, averaging 0.65 kg/d and 0.63 kg/d over both grazing seasons (P = 0.70). Grazing strategy did not affect forage or total DMI in yr 1; however, HO consumed 2.3 kg/d more forage DM than HG (P pastures (P dairy heifers can be co-grazed with goats without negative effects on ADG or feed efficiency.

Parasitic Infections of West African Dwarf Goats and their Saanen Crosses in a Zero-Grazing Farming System in The Gambia

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S. Dhollander

2005-01-01

Full Text Available Twenty West African Dwarf goats (WADs and 15 Saanen x WAD crosses were managed in an intensified, zero-grazing farming system in an area with low to moderate tsetse challenge in The Gambia. During a period of one year, monthly samples were collected to monitor the helminth egg (EPG and coccidia oocyst outputs (OPG per gram of feces, the packed cell volume (PCV, and trypanosome parasitemia in the goats. High OPGs were found from September to December, resulting in a preweaning mortality rate of 20% in both breeds. The animals were moderately infested with helminths from the middle of the rainy season until early dry season. Trypanosome infections were not detected in WADs, neither were they in the crossbred goats using the buffy coat technique. The average birth weights of crossbred and WAD kids were 2.4 and 2.0 kg, respectively. The growth rate of crossbred kids was significantly higher than that of local kids. The preweaning growth rates of crossbred and WAD kids were 114.75 and 65.57 g/day, whereas the postweaning growth rates were 58.82 and 36.41 g/day, respectively. The fast growth rate of crossbred goats compared to WAD goats indicates that rearing Saanen x WAD crosses in a zero-grazing system can increase productivity. Strict hygiene in the goat sheds, however, is essential to avoid coccidiosis outbreaks.

Small mammal communities on cattle and game grazing areas in ...

African Journals Online (AJOL)

Small mammal communities on cattle and game grazing areas in Namibia. ... small mammal communities on two differently managed farmlands (cattle and game farm) in Namibia over the course of one year. ... AJOL African Journals Online.

Selective grazing from protist over enteric bacteria in an aquatic system

International Nuclear Information System (INIS)

Dominguez, M. S.; Escalante, A. H.; Folabella, A. M.; Zamora, A. S.

2009-01-01

Its very clear that the grazing from protozoan can be an important source of mortality for the suspended bacteria, both in marine and freshwater environments. Considering that the presence of fecal contamination its a frequent phenomenon in this environments, and that Escherichia coli and members of Enterococcus genera are indicators of microbiology water quality, we analyze the effect of grazing from protozoan over E. coli and Enterococcus faecalis in de Los Padres Lagoon waters (Buenos Aires, Argentina) 37 degree centigrade 56'30'' S, 57 degree centigrade 44'30'' W). (Author)

Forage production in mixed grazing systems of elephant grass with arrowleaf clover or forage peanut

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Daiane Cristine Seibt

Full Text Available ABSTRACT Most dairy production systems are pasture-based, usually consisting of sole grass species. This system facilitates pasture management, but results in high production costs, mainly because of nitrogen fertilizers. An alternative to making forage systems more sustainable is to introduce legumes into the pasture. Mixed pastures allow better forage distribution over time and reduce fertilization costs. Thus, the objective of this study was to evaluate, throughout the year, three forage systems (FS: FS1 (control - elephant grass (EG, ryegrass (RG, and spontaneous species (SS; FS2 - EG + RG + SS + arrowleaf clover; and FS3 - EG + RG + SS + forage peanut. Elephant grass was planted in rows spaced 4 m apart. Ryegrass was sown between the EG lines, in the winter. Arrowleaf clover was sown according to the respective treatments and forage peanut was preserved. Evaluation was carried out using Holstein cows. The experiment was arranged in a completely randomized design, with three treatments (FS, and three repetitions (paddocks with repeated measurements (grazing cycles. Forage mass achieved 3.46, 3.80, and 3.91 t ha-1 for the treatments FS1, FS2 and FS3, respectively. The forage systems intercropped with legumes produced the best results.

Effect of summer grazing on welfare of dairy cows reared in mountain tie-stall barns

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Simonetta Dovier

2010-09-01

Full Text Available Traditional mountain farms have an important economic, social and environmental role. The Alps management system for dairy cows consists of animals kept indoors from autumn to spring, mostly in tie-stalls, and moved to mountain pasture in summer. The aim of our study was to assess the effect of mountain summer grazing on the welfare of dairy cows housed in tie-stall barns. Twenty-four farms were considered. In twelve of them, animals were reared in tie-stalls and moved to mountain pasture for three months in summer; they were visited three times: (i four weeks before grazing during the indoor period in the stall; (ii about three weeks after the start of grazing; and (iii in the stall, in autumn, at least three weeks after returning from grazing. The other twelve farms kept the animals in tie-stalls all year; they were visited once in autumn. Data were collected following a protocol that considers animal-based measures and structure information on the basis of Quality Welfare Consortium® indications. Data allowed the calculation of both the Animal Needs Index score (ANI 35L and an overall assessment of the cows’ welfare obtained from three general aspects: housing, animal’s physical condition, and animal’s behaviour. Summer grazing had a significant positive effect on injuries, lameness and animal’s rising duration but a negative effect on faeces consistency. Moreover, a reduction of tongue playing was observed. The ANI 35L and the overall assessment did not show significant differences linked to summer grazing, which tended to have a positive but temporary effect on animal behaviour.

Aplanatic grazing incidence diffraction grating: a new optical element

International Nuclear Information System (INIS)

Hettrick, M.C.

1986-01-01

We present the theory of a grazing incidence reflection grating capable of imaging at submicron resolution. The optic is mechanically ruled on a spherical or cylindrical surface with varied groove spacings, delivering diffraction-limited response and a wide field of view at a selected wavelength. Geometrical aberrations are calculated on the basis of Fermat's principle, revealing significant improvements over a grazing incidence mirror. Aplanatic and quasi-aplanatic versions of the grating have applications in both imaging and scanning microscopes, microprobes, collimators, and telescopes. A 2-D crossed system of such gratings, similar to the grazing incidence mirror geometry of Kirkpatrick and Baez, could potentially provide spatial resolutions of --200 A

The effects of potential changes in United States beef production on global grazing systems and greenhouse gas emissions

International Nuclear Information System (INIS)

Dumortier, Jerome; Hayes, Dermot J; Carriquiry, Miguel; Elobeid, Amani; Fabiosa, Jacinto F; Dong, Fengxia; Du Xiaodong; Martin, Pamela A; Mulik, Kranti

2012-01-01

We couple a global agricultural production and trade model with a greenhouse gas model to assess leakage associated with modified beef production in the United States. The effects on emissions from agricultural production (i.e., methane and nitrous oxide emissions from livestock and crop management) as well as from land-use change, especially grazing system, are assessed. We find that a reduction of US beef production induces net carbon emissions from global land-use change ranging from 37 to 85 kg CO 2 -equivalent per kg of beef annualized over 20 years. The increase in emissions is caused by an inelastic domestic demand as well as more land-intensive cattle production systems internationally. Changes in livestock production systems such as increasing stocking rate could partially offset emission increases from pasture expansion. In addition, net emissions from enteric fermentation increase because methane emissions per kilogram of beef tend to be higher globally. (letter)

Successive sheep grazing reduces population density of Brandt's voles in steppe grassland by altering food resources: a large manipulative experiment.

Science.gov (United States)

Li, Guoliang; Yin, Baofa; Wan, Xinrong; Wei, Wanhong; Wang, Guiming; Krebs, Charles J; Zhang, Zhibin

2016-01-01

Livestock grazing has shaped grassland ecosystems around the world. Previous studies indicated grazing showed various impacts on small rodents; however, most studies were conducted over 1-2 years without controlling for confounding factors such as immigration/emigration and predation in rodents. Brandt's voles (Lasiopodomys brandtii) are generally recognized as pests because of food overlap with domestic herbivores, but are also important for biodiversity conservation because they provide nests or food to many birds. Fully understanding the ecological relationship between domestic herbivores and small mammals is essential to making ecosystem management decisions. To address these needs, we carried out a field experiment during the period 2010-2013 to assess the effects of sheep grazing on vegetation and the population density of Brandt's voles along a gradient of three grazing intensities by using 12 large-scale enclosures. Responses of Brandt's voles to livestock grazing varied with grazing intensity and year. As compared to the control group, sheep grazing had no effect on vole abundance in the first year but an overall negative effect on vole abundance in the following 3 years. Successive grazing caused decreases in survival and male body mass of voles, but had no significant effect on fecundity. Negative effects of grazing were associated with a grazing-induced deterioration in both food quantity (reflected by biomass and cover of less-preferred plants), and food quality (measured by tannin and total phenol content). Our findings highlight the urgent need for more flexible management of yearly rotational grazing to optimize livestock production while maintaining species diversity and ecosystem health.

Density and success of bird nests relative to grazing on western Montana grasslands

Science.gov (United States)

Fondell, Thomas F.; Ball, I.J.

2004-01-01

Grassland birds are declining at a faster rate than any other group of North American bird species. Livestock grazing is the primary economic use of grasslands in the western United States, but the effects of this use on distribution and productivity of grassland birds are unclear. We examined nest density and success of ground-nesting birds on grazed and ungrazed grasslands in western Montana. In comparison to grazed plots, ungrazed plots had reduced forb cover, increased litter cover, increased litter depth, and increased visual obstruction readings (VOR) of vegetation. Nest density among 10 of 11 common bird species was most strongly correlated with VOR of plots, and greatest nest density for each species occurred where mean VOR of the plot was similar to mean VOR at nests. Additionally, all bird species were relatively consistent in their choice of VOR at nests despite substantial differences in VOR among plots. We suggest that birds selected plots based in part on availability of suitable nest sites and that variation in nest density relative to grazing reflected the effect of grazing on availability of nest sites. Nest success was similar between grazed plots and ungrazed plots for two species but was lower for nests on grazed plots than on ungrazed plots for two other species because of increased rates of predation, trampling, or parasitism by brown-headed cowbirds (Molothrus ater). Other species nested almost exclusively on ungrazed plots (six species) or grazed plots (one species), precluding evaluation of the effects of grazing on nest success. We demonstrate that each species in a diverse suite of ground-nesting birds preferentially used certain habitats for nesting and that grazing altered availability of preferred nesting habitats through changes in vegetation structure and plant species composition. We also show that grazing directly or indirectly predisposed some bird species to increased nesting mortality. Management alternatives that avoid

25 CFR 166.307 - Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not...

Science.gov (United States)

2010-04-01

... § 166.307 Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not... trust or non-trust rangeland in common with the permitted land. Grazing capacity will be established... 25 Indians 1 2010-04-01 2010-04-01 false Will the grazing capacity be increased if I graze...

Effects of livestock grazing on grasshopper abundance on a native rangeland in Montana.

Science.gov (United States)

O'Neill, Kevin M; Olson, Bret E; Wallander, Roseann; Rolston, Marni G; Seibert, Catherine E

2010-06-01

Livestock grazing can affect habitat quality for grasshoppers through effects on food and oviposition site availability, microclimate, and other factors. Because of this, some authors have suggested that grazing programs can be used to help manage pest grasshopper populations. In a 6-yr study, we controlled access of cattle to replicated experimental plots on an Agropyron spicatum/Poa sandbergii pasture to create consistent year-to-year differences in postgrazing plant cover, with resultant affects on microclimate. After sampling grasshoppers multiple times after grazing treatments each summer, we found evidence of between-treatment differences in grasshopper abundance for the entire assemblage during 4 of the 6 yr. Some species, including Melanoplus sanguinipes (perhaps the worse rangeland grasshopper pest in the western United States), tended to be more abundant on ungrazed plots, whereas Melanoplus gladstoni often had greater densities on heavily-grazed plots. The effect of grazing on grasshopper densities in this study was lower in magnitude and less consistent among years than in a study we conducted simultaneously at a nearby site where the vegetation was dominated by the exotic species crested wheatgrass (Agropyron cristatum). Our results generally support proposals that grazing could be used to reduce pest grasshopper densities, although the effectiveness of a particular grazing scheme may vary among sites, years, and grasshopper and vegetation assemblages.

Experiment and application of soft x-ray grazing incidence optical scattering phenomena

Science.gov (United States)

Chen, Shuyan; Li, Cheng; Zhang, Yang; Su, Liping; Geng, Tao; Li, Kun

2017-08-01

For short wavelength imaging systems，surface scattering effects is one of important factors degrading imaging performance. Study of non-intuitive surface scatter effects resulting from practical optical fabrication tolerances is a necessary work for optical performance evaluation of high resolution short wavelength imaging systems. In this paper, Soft X-ray optical scattering distribution is measured by a soft X-ray reflectometer installed by my lab, for different sample mirrors、wavelength and grazing angle. Then aim at space solar telescope, combining these scattered light distributions, and surface scattering numerical model of grazing incidence imaging system, PSF and encircled energy of optical system of space solar telescope are computed. We can conclude that surface scattering severely degrade imaging performance of grazing incidence systems through analysis and computation.

Selective grazing from protist over enteric bacteria in an aquatic system

Energy Technology Data Exchange (ETDEWEB)

Dominguez, M. S.; Escalante, A. H.; Folabella, A. M.; Zamora, A. S.

2009-07-01

Its very clear that the grazing from protozoan can be an important source of mortality for the suspended bacteria, both in marine and freshwater environments. Considering that the presence of fecal contamination its a frequent phenomenon in this environments, and that Escherichia coli and members of Enterococcus genera are indicators of microbiology water quality, we analyze the effect of grazing from protozoan over E. coli and Enterococcus faecalis in de Los Padres Lagoon waters (Buenos Aires, Argentina) 37 degree centigrade 56'30'' S, 57 degree centigrade 44'30'' W). (Author)

36 CFR 293.7 - Grazing of livestock.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing of livestock. 293.7...-PRIMITIVE AREAS § 293.7 Grazing of livestock. (a) The grazing of livestock, where such use was established..., shall be permitted to continue under the general regulations covering grazing of livestock on the...

Effects of nitrogen deposition and cattle grazing on productivity, invasion impact, and soil microbial processes in a serpentine grassland

Science.gov (United States)

Pasari, J.; Hernandez, D.; Selmants, P. C.; Keck, D.

2010-12-01

In recent decades, human activities have vastly increased the amount of biologically available nitrogen (N) in the biosphere. The resulting increase in N availability has broadly affected ecosystems through increased productivity, changes in species composition, altered nutrient cycles, and increases in invasion by exotic plant species, especially in systems that were historically low in N. California serpentine grasslands are N-limited ecosystems historically dominated by native species including several threatened and endangered plants and animals. Cattle grazing has emerged as the primary tool for controlling the impact of nitrophilic exotic grasses whose increased abundance has paralleled the regional traffic-derived increase in atmospheric N deposition. We examined the interactive effects of cattle grazing and N deposition on plant community composition, productivity, invasion resistance, and microbial processes in the Bay Area's largest serpentine grassland to determine the efficacy of current management strategies as well as the biogeochemical consequences of exotic species invasion. In the first two years of the study, aboveground net primary productivity decreased in response to grazing and increased in response to nitrogen addition. However, contrary to our hypotheses the change in productivity was not due to an increase in exotic species cover as there was little overall effect of grazing or N addition on species composition. Microbial activity was more responsive to grazing and N. Potential net N mineralization rates increased with N addition, but were not affected by grazing. In contrast, soil respiration rates were inhibited by grazing, but were not affected by N addition; suggesting strong carbon-limitation of soil microbial activity, particularly under grazing. Site differences in soil depth and grazing intensity were often more important than treatment effects. We suspect that the unusually dry conditions in the first two growing seasons inhibited

Data resources for range-wide assessment of livestock grazing across the sagebrush biome

Science.gov (United States)

Assal, T.J.; Veblen, K.E.; Farinha, M.A.; Aldridge, Cameron L.; Casazza, Michael L.; Pyke, D.A.

2012-01-01

The data contained in this series were compiled, modified, and analyzed for the U.S. Geological Survey (USGS) report "Range-Wide Assessment of Livestock Grazing Across the Sagebrush Biome." This report can be accessed through the USGS Publications Warehouse (online linkage: http://pubs.usgs.gov/of/2011/1263/). The dataset contains spatial and tabular data related to Bureau of Land Management (BLM) Grazing Allotments. We reviewed the BLM national grazing allotment spatial dataset available from the GeoCommunicator National Integrated Land System (NILS) website in 2007 (http://www.geocommunicator.gov). We identified several limitations in those data and learned that some BLM State and/or field offices had updated their spatial data to rectify these limitations, but maintained the data outside of NILS. We contacted appropriate BLM offices (State or field, 25 in all) to obtain the most recent data, assessed the data, established a data development protocol, and compiled data into a topologically enforced dataset throughout the area of interest for this project (that is, the pre-settlement distribution of Greater Sage-Grouse in the Western United States). The final database includes three spatial datasets: Allotments (BLM Grazing Allotments), OUT_Polygons (nonallotment polygons used to ensure topology), and Duplicate_Polygon_Allotments. See Appendix 1 of the aforementioned report for complete methods. The tabular data presented here consists of information synthesized by the Land Health Standard (LHS) analysis (Appendix 2), and data obtained from the BLM Rangeland Administration System (http://www.blm.gov/ras/). In 2008, available LHS data for all allotments in all regions were compiled by BLM in response to a Freedom of Information Act (FOIA) request made by a private organization. The BLM provided us with a copy of these data. These data provided three major types of information that were of interest: (1) date(s) (if any) of the most recent LHS evaluation for each

Differential Responses of Soil Microbial Community to Four-Decade Long Grazing and Cultivation in a Semi-Arid Grassland

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Yating He

2017-01-01

Full Text Available Grazing and cultivation are two important management practices worldwide that can cause significant soil organic carbon (SOC losses. However, it remains elusive how soil microbes have responded to soil carbon changes under these two practices. Based on a four-decade long field experiment, this study investigated the effects of grazing and cultivation on SOC stocks and microbial properties in the semi-arid grasslands of China. We hypothesize that grazing and cultivation would deplete SOC and depress microbial activities under both practices. However, our hypotheses were only partially supported. As compared with the adjacent indigenous grasslands, SOC and microbial biomass carbon (MBC were decreased by 20% or more under grazing and cultivation, which is consistent with the reduction of fungi abundance by 40% and 71%, respectively. The abundance of bacteria and actinomycetes was decreased under grazing but increased under cultivation, which likely enhanced microbial diversity in cultivation. Invertase activity decreased under the two treatments, while urease activity increased under grazing. These results suggest that nitrogen fertilizer input during cultivation may preferentially favor bacterial growth, in spite of SOC loss, due to rapid decomposition, while overgrazing may deteriorate the nitrogen supply to belowground microbes, thus stimulating the microbial production of nitrogen acquisition enzymes. This decade-long study demonstrated differential soil microbial responses under grazing and cultivation and has important applications for better management practices in the grassland ecosystem.

Genetic strain and diet effects on grazing behavior, pasture intake, and milk production.

Science.gov (United States)

Sheahan, A J; Kolver, E S; Roche, J R

2011-07-01

Understanding how dairy cows adjust their grazing behavior in response to feed supplements is important for the development of management strategies that optimize profit from supplementation. New Zealand Holstein-Friesian (HF) cows have been selected for milk production on a predominantly pasture-based diet; in comparison, HF cows of North American (NA) ancestry have been selected almost exclusively for milk yield and fed diets high in nonfiber carbohydrates (NFC). We hypothesized, therefore, that supplementation would have differing effects on grazing behavior, pasture dry matter intake (DMI), and milk production in these genetic strains at peak, mid, and late lactation. A study was conducted over 2 consecutive lactations, with NA and NZ cows randomly allocated at calving to 0, 3, or 6 kg of dry matter/day concentrate plus unrestricted access to pasture. Pasture DMI, milk production, and grazing behavior were recorded at peak, mid, and late lactation. Concentrates were fed in equal amounts at morning and afternoon milking. The NA cows produced more milk and milk components, and had a greater pasture DMI, despite spending less time grazing. Declines in time spent grazing and pasture DMI were associated with increasing concentrate DMI. Grazing behavior following morning supplementation was different from that recorded following afternoon supplementation. Grazing ceased following morning supplementation before rumen fill could be a limiting factor, and the length of the grazing interval was inversely proportional to the amount of concentrate offered; these results suggest that physiological rather than physical stimuli were responsible for grazing cessation. The decrease in time spent grazing with increasing concentrate DMI is consistent with changes in neuroendocrine factors secreted in response to the presence of food in the digestive tract or with circulating products of digestion. After afternoon supplementation, sunset signaled the end of grazing irrespective of

The evolution of institutions and rules governing communal grazing ...

African Journals Online (AJOL)

This paper traces the tradition and evolution of the institutions and rules governing communal grazing lands in Botswana. It shows how the problem of resource overuse arose partly from the dismantling and delegitimization of traditional resource management institutions that occurred during the colonial period, and was ...

Goat farming systems in Martinique: management and breeding strategies.

Science.gov (United States)

Alexandre, G; Leimbacher, F; Maurice, O; Domarin, D; Naves, M; Mandonnet, N

2009-04-01

To be successful, initiatives to improve farmer's goat production should directly address the needs and objectives of the keepers while promoting rational use of local genetic resources. A survey was carried out to implement a genetic policy governing meat goat farming in Martinique (11,400 heads and 33,400 ha arable land). The questionnaire comprised a total of 27 items with 306 modalities, and included questions on farm structure, crop and animal productions, management of feeding, reproduction and health control. The sample consisted of 33 farmers with 644 ha and 2,680 goats (1,286 does and 52 bucks), 97% of does in the studied sample were crossbred, 56% of bucks were" imported" breeds (Boer or Anglo-Nubian). The number of goats per farm varied from 16 to 582. The feeding system was predominantly grazing, according to a rotation (55% of cases) or continuous grazing system (42%). On 62% of farms, the males remained with the females permanently, also 83% of farmers did not resort to methods of controlled-mating. The first criteria used for choosing animals (80 to 90% of answers) of both sex, were development and conformation. Assuming that adaptive together with productive traits are important in tropical zones, it is advisable to better define the maternal lineage of the local livestock (presently very sparse records), to improve reproduction management and culling strategies (poor and inadequate management practices do not support any genetic improvement programme), and to guide the farmers in their decisions by employing concerted interprofessional actions (choice of meat breed, market studies).

Semi-arid grassland bird responses to patch-burn grazing and drought

Science.gov (United States)

Skagen, Susan K.; Augustine, David J.; Derner, Justin D.

2018-01-01

As grassland birds of central North America experience steep population declines with changes in land use, management of remaining tracts becomes increasingly important for population viability. The integrated use of fire and grazing may enhance vegetation heterogeneity and diversity in breeding birds, but the subsequent effects on reproduction are unknown. We examined the influence of patch-burn grazing management in shortgrass steppe in eastern Colorado on habitat use and reproductive success of 3 grassland bird species, horned lark (Eremophila alpestris), lark bunting (Calamospiza melanocorys), and McCown’s longspur (Rhynchophanes mccownii), at several spatial scales during 2011 and 2012. Although no simple direct relationship to patch-burn grazing treatment existed, habitat selection depended on precipitation- and management-induced vegetation conditions and spatial scale. All species selected taller-than-expected vegetation at the nest site, whereas at the territory scale, horned larks and McCown’s longspurs selected areas with low vegetation height and sparse cover of tall plants (taller than the dominant shortgrasses). Buntings nested primarily in unburned grassland under average rainfall. Larks and longspurs shifted activity from patch burns during average precipitation (2011) to unburned pastures during drought (2012). Daily survival rate (DSR) of nests varied with time in season, species, weather, and vegetation structure. Daily survival rate of McCown’s longspur nests did not vary with foliar cover of relatively tall vegetation at the nest under average precipitation but declined with increasing cover during drought. At the 200-m scale, increasing cover of shortgrasses, rather than taller plant species, improved DSR of larks and longspurs. These birds experience tradeoffs in the selection of habitat at different spatial scales: tall structure at nests may reduce visual detection by predators and provide protection from sun, wind, and rain, yet

Sustainability of meat production beyond carbon footprint: a synthesis of case studies from grazing systems in Uruguay.

Science.gov (United States)

Picasso, Valentín D; Modernel, Pablo D; Becoña, Gonzalo; Salvo, Lucía; Gutiérrez, Lucía; Astigarraga, Laura

2014-11-01

Livestock production has been challenged as a large contributor to climate change, and carbon footprint has become a widely used measure of cattle environmental impact. This analysis of fifteen beef grazing systems in Uruguay quantifies the range of variation of carbon footprint, and the trade-offs with other relevant environmental variables, using a partial life cycle assessment (LCA) methodology. Using carbon footprint as the primary environmental indicator has several limitations: different metrics (GWP vs. GTP) may lead to different conclusions, carbon sequestration from soils may drastically affect the results, and systems with lower carbon footprint may have higher energy use, soil erosion, nutrient imbalance, pesticide ecotoxicity, and impact on biodiversity. A multidimensional assessment of sustainability of meat production is therefore needed to inform decision makers. There is great potential to improve grazing livestock systems productivity while reducing carbon footprint and other environmental impacts, and conserving biodiversity. Copyright © 2014 Elsevier Ltd. All rights reserved.

USDA soil classification system dictates site surface management

International Nuclear Information System (INIS)

Bowmer, W.J.

1985-01-01

Success or failure of site surface management practices greatly affects long-term site stability. The US Department of Agriculture (USDA) soil classification system best documents those parameters which control the success of installed practices for managing both erosion and surface drainage. The USDA system concentrates on soil characteristics in the upper three meters of the surface that support the associated flora both physically and physiologically. The USDA soil survey first identifies soil series based on detailed characteristics that are related to production potential. Using the production potential, land use capability classes are developed. Capability classes reveal the highest and best agronomic use for the site. Lower number classes are considered arable while higher number classes are best suited for grazing agriculture. Application of ecological principles based on the USDA soil survey reveals the current state of the site relative to its ecological potential. To assure success, site management practices must be chosen that are compatible with both production capability and current state of the site

The Influence of Community Management Agreements on Household Economic Strategies : Cattle Grazing and Fishing Agreements on the Lower Amazon Floodplain

Directory of Open Access Journals (Sweden)

David G. McGrath

2007-10-01

Full Text Available While the organizational dynamics of collective management systems have received much attention, relatively little work has focused on how households adapt their economic strategies in response to collective management regulations that impose constraints on the range of options available to households. In this paper we investigate the evolving interaction between household management strategies and collective management regulations for one or both of two ecologically interdependent floodplain resources, lake fisheries and seasonally inundated grasslands. Smallholder management strategies involve varying combinations of three main activities each associated with one of three main floodplain habitats: annual cropping on river levees, cattle ranching on natural grasslands and fishing in lakes. These three activities play complementary roles in the household economy. Annual cropping is both subsistence and market oriented, with cash from crop sales often invested in purchase of cattle. Fishing, in addition to providing animal protein, generates income for household purchases while crops are growing. Cattle ranching is the main savings strategy for smalholders, providing funds for family emergencies and capital investments. Despite the fertility of soils and the higher productivity per hectare of fishing, cattle ranching has expanded steadily on the floodplain at the expense of farming and fishing. Over the last two decades, communities throughout the Amazon floodplain have developed and implemented collective agreements to regulate access to and use of local lake fisheries. Depending on the measures included, the impact of these agreements on household management strategies can range from negligible to highly significant, requiring major adjustments to compensate for reduced fishing income. Expansion of smallholder cattle ranching has taken advantage of unregulated access to community grasslands. Unregulated access to community grasslands has been a

Ingestive behavior and performance of female lambs grazing on Marandu palisadegrass under different stocking rates

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Luiz Carlos Vieira Júnior

2011-11-01

Full Text Available The ingestive behavior and performance of female lambs grazing on Marandu pasture submitted to different stocking rates during the rainy and transition season were evaluated. The experimental area with 4,500 m² was divided into 45 paddocks of 100 m². Twenty-seven Santa Ines female lambs (purebred with 4 months age and 22 kg of initial body weight were distributed in a completely randomized design, with nine replicates. Lambs were divided into 9 groups with the same initial weight and submitted to three stocking rates: 2, 3 and 4 lambs/paddock, which corresponded to 40, 60 and 80 lambs/ha, respectively. Each group of animals had a module of five paddocks, managed on intermittent grazing system, with 7 days of occupation and 28 d of rest. Increase on time grazing and reduction on time ruminating and resting were observed as stocking rates increased. There was 14% raise in time grazing and 41% decline on time resting by lambs subjected to the highest stocking rate compared with those in the lower stocking rate. The number of animals/ha promoted linear effect on average daily gain, which was higher for animals in the lowest stocking rate of 90 g/d. For gain per area, the best result was obtained with 60 animals/ha featuring an average value of 426 kg/ha.

Physical impact of grazing by sheep on the dynamics of Nama ...

African Journals Online (AJOL)

UFS

Physical impact of sheep grazing on arid Karoo subshrub/grass rangeland,. South Africa ... sustainability of rangeland resources, soil and vegetation responses to various grazing systems (Teague &. Dowhower .... The only significant decrease (F3,4 = 18.14, P <0.01) in basal cover of the total herbaceous layer for the 1995 ...

Butterfly responses to prairie restoration through fire and grazing

Science.gov (United States)

Vogel, Jennifer A.; Debinski, Diane M.; Koford, Rolf R.; Miller, J.R.

2007-01-01

The development of land for modern agriculture has resulted in losses of native prairie habitat. The small, isolated patches of prairie habitat that remain are threatened by fire suppression, overgrazing, and invasion by non-native species. We evaluated the effects of three restoration practices (grazing only, burning only, and burning and grazing) on the vegetation characteristics and butterfly communities of remnant prairies. Total butterfly abundance was highest on prairies that were managed with burning and grazing and lowest on those that were only burned. Butterfly species richness did not differ among any of the restoration practices. Butterfly species diversity was highest on sites that were only burned. Responses of individual butterfly species to restoration practices were highly variable. In the best predictive regression model, total butterfly abundance was negatively associated with the percent cover of bare ground and positively associated with the percent cover of forbs. Canonical correspondence analysis revealed that sites with burned only and grazed only practices could be separated based on their butterfly community composition. Butterfly communities in each of the three restoration practices are equally species rich but different practices yield compositionally different butterfly communities. Because of this variation in butterfly species responses to different restoration practices, there is no single practice that will benefit all species or even all species within habitat-specialist or habitat-generalist habitat guilds. ?? 2007 Elsevier Ltd. All rights reserved.

Grazing patterns on signalgrass pasture according to location of cattle feces

Directory of Open Access Journals (Sweden)

Manoel Eduardo Rozalino Santos

2012-04-01

Full Text Available This study was conducted to evaluate the defoliation patterns on B. decumbens cv. Basilisk (signalgrass tiller as a function of influence of feces deposited naturally by cattle. The signalgrass was managed with an average height of 25 cm, under continuous stocking and variable stocking rate. Interval and intensity of defoliation, grazing efficiency and forage loss were evaluated in two sites on pasture - one close and the other distant from feces. The completely randomized block design with three replications was adopted. The defoliation rate of the pasture site close to feces was 40% lower than at that distant from feces. This response pattern was similar to defoliation intensity of leaf blade. The leaf blade of the tiller close to feces also achieved lower de foliation (1.64 than that in the tiller distant from feces (3.97. The relative number of grazed leaf per tiller in the tillers distant from feces was approximately 185% higher than those close to feces. The grazing efficiency was lower in the local close to feces compared with that distant, unlike forage loss. The natural deposition of feces by cattle modifies the grazing and use patterns of B. decumbens under continuous stocking.

Assessment of the Effects of Emerging Grazing Policies on Land ...

African Journals Online (AJOL)

Journal of Applied Sciences and Environmental Management ... policies on land degradation in Nigeria using soil, vegetation and sustainability as variables for the assessment. ... animals per kilometer square of land and 15,000 persons and 12,500 grazing animals per kilometer square of water. ... OTHER RESOURCES.

Grass composition and rangeland condition of the major grazing ...

African Journals Online (AJOL)

One area represented lightly grazed government ranches or parks which were used as benchmarks, another area represented the seasonal grazing areas with an intermediate grazing pressure and the remaining were the heavily grazed roadsides, lakeshores and other communal grazing lands. The range condition ...

Grazing incidence optics; Proceedings of the Meeting, Orlando, FL, Apr. 3, 4, 1986

Science.gov (United States)

Osantowski, John F. (Editor); Van Speybroeck, Leon (Editor)

1986-01-01

Papers are presented on the diffraction-limited performance of grazing incidence optical systems; transverse ray aberrations of Wolter type 1 telescopes; hybrid X-ray telescope systems; surface characterization of grazing incidence optics in the extreme UV and X-ray regions; and the surface roughness properties of synchrotron radiation optics. Topics discussed include the simulation of free-abrasive grinding of grazing incidence mirrors with vertical-honing and flexible blades; mirrors for the Extreme Ultraviolet Explorer; the design and development of conical X-ray imaging mirrors; thermal loading considerations for synchrotron radiation mirrors; and grazing incidence optics for synchrotron radiation insertion-device beams. Consideration is given to the interpretation of glancing incidence scattering measurements; damage processes in short wavelength coated FEL optics; the replication of grain incidence optics; and the assembly and alignment of the Technology Mirror Assembly.

Microbial quality of soil from the Pampa biome in response to different grazing pressures

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Rafael S. Vargas

2015-06-01

Full Text Available The aim of this study was to evaluate the impact of different grazing pressures on the activity and diversity of soil bacteria. We performed a long-term experiment in Eldorado do Sul, southern Brazil, that assessed three levels of grazing pressure: high pressure (HP, with 4% herbage allowance (HA, moderate pressure (MP, with 12% HA, and low pressure (LP, with 16% HA. Two reference areas were also assessed, one of never-grazed native vegetation (NG and another of regenerated vegetation after two years of grazing (RG. Soil samples were evaluated for microbial biomass and enzymatic (β-glucosidase, arylsulfatase and urease activities. The structure of the bacterial community and the population of diazotrophic bacteria were evaluated by RFLP of the 16S rRNA and nifH genes, respectively. The diversity of diazotrophic bacteria was assessed by partial sequencing of the 16S rDNA gene. The presence of grazing animals increased soil microbial biomass in MP and HP. The structures of the bacterial community and the populations of diazotrophic bacteria were altered by the different grazing managements, with a greater diversity of diazotrophic bacteria in the LP treatment. Based on the characteristics evaluated, the MP treatment was the most appropriate for animal production and conservation of the Pampa biome.

Temporal profiles of vegetation indices for characterizing grazing intensity on natural grasslands in Pampa biome

Directory of Open Access Journals (Sweden)

Amanda Heemann Junges

2016-08-01

Full Text Available ABSTRACT The Pampa biome is an important ecosystem in Brazil that is highly relevant to livestock production. The objective of this study was to analyze the potential use of vegetation indices to discriminate grazing intensities on natural grasslands in the Pampa biome. Moderate Resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI and Enhanced Vegetation Index (EVI images from Jan to Dec, 2000 to 2013 series, were analyzed for natural grassland experimental units managed under high (forage allowance of 5 ± 2 % live weight – LW, moderate (13 ± 5 % LW and low grazing intensity (19 ± 7 % LW. Regardless of intensity, the temporal profiles showed lower NDVI and EVI during winter, increased values in spring because of summer species regrowth, slightly decreased values in summer, especially in years when there is a water deficit, and increased values in the fall associated with the beginning of winter forage development. The average temporal profiles of moderate grazing intensity exhibited greater vegetation index values compared with low and high grazing intensities. The temporal profiles of less vegetation index were associated with lower green biomass accumulation caused by the negative impact of stocking rates on the leaf area index under high grazing intensity and a floristic composition with a predominance of tussocks under low grazing intensity. Vegetation indices can be used for distinguishing moderate grazing intensity from low and high intensities. The average EVI values can discriminate moderate grazing intensity during any season, and the NDVI values can discriminate moderate grazing intensity during spring and winter.

Modeling vegetation and carbon dynamics of managed grasslands at the global scale with LPJmL 3.6

Science.gov (United States)

Rolinski, Susanne; Müller, Christoph; Heinke, Jens; Weindl, Isabelle; Biewald, Anne; Bodirsky, Benjamin Leon; Bondeau, Alberte; Boons-Prins, Eltje R.; Bouwman, Alexander F.; Leffelaar, Peter A.; te Roller, Johnny A.; Schaphoff, Sibyll; Thonicke, Kirsten

2018-02-01

Grassland management affects the carbon fluxes of one-third of the global land area and is thus an important factor for the global carbon budget. Nonetheless, this aspect has been largely neglected or underrepresented in global carbon cycle models. We investigate four harvesting schemes for the managed grassland implementation of the dynamic global vegetation model (DGVM) Lund-Potsdam-Jena managed Land (LPJmL) that facilitate a better representation of actual management systems globally. We describe the model implementation and analyze simulation results with respect to harvest, net primary productivity and soil carbon content and by evaluating them against reported grass yields in Europe. We demonstrate the importance of accounting for differences in grassland management by assessing potential livestock grazing densities as well as the impacts of grazing, grazing intensities and mowing systems on soil carbon stocks. Grazing leads to soil carbon losses in polar or arid regions even at moderate livestock densities (management options enables assessments of the global grassland production and its impact on the terrestrial biogeochemical cycles but requires a global data set on current grassland management.

Re-visiting the nutrition of dairy sheep grazing Mediterranean pastures

Directory of Open Access Journals (Sweden)

M. Decandia

2010-04-01

Full Text Available In the light of recent findings in sheep nutrition and behaviour, the diets of grazing dairy sheep should be based on forages encompassing a variety of complementary nutritional values and containing moderate levels of complementary plant secondary metabolites, until recently regarded as "anti-nutritional". In lactating sheep, pastures of tannin-containing legumes like sulla (Hedysarum coronarium and chicory (Cichorium intybus can be integrated with annual grasses for establishing sustainable artificial pastures under rainfed conditions. Diets based on these forages, while ensuring high milking performance, can mitigate the unbalance of CP to energy ratio of grazing sheep. By grazing sulla and annual or Italian ryegrass (50:50 by area as spatially conterminal monocultures or in timely sequence (complementary grazing sheep eat more and perform better than by grazing the ryegrass pasture only. Concentrate supplementation of lactating sheep should be preferably based on fibrous sources (soyhulls or beet pulps, particularly from mid-lactation onwards and when supplementation levels are high. Milk urea concentration is confirmedly a useful monitoring tool to balance protein nutrition and curb the waste of N at animal and system level.

The Behavioural Responses of Beef Cattle (Bos taurus to Declining Pasture Availability and the Use of GNSS Technology to Determine Grazing Preference

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Jaime Manning

2017-05-01

Full Text Available Combining technologies for monitoring spatial behaviour of livestock with technologies that monitor pasture availability, offers the opportunity to improve the management and welfare of extensively produced beef cattle. The aims of the study were to investigate changes to beef cattle behaviour as pasture availability changed, and to determine whether Global Navigation Satellite System (GNSS technology could determine livestock grazing preference and hence improve pasture management and paddock utilisation. Data derived from GNSS collars included distance travelled and location in the paddock. The latter enabled investigation of individual animal interactions with the underlying Normalised Difference Vegetation Index (NDVI and pasture biomass of the paddock. As expected, there was a significant temporal decrease in NDVI during the study and an increase in distance travelled by cattle (P < 0.001; r2 = 0.88. The proportion of time budget occupied in grazing behaviour also increased (P < 0.001; r2 = 0.71. Cattle showed a partial preference for areas of higher pasture biomass/NDVI, although there was a large amount of variation over the course of the study. In conclusion, cattle behaviour changed in response to declining NDVI, highlighting how technologies that monitor these two variables may be used in the future as management tools to assist producers better manage cattle, to manipulate grazing intensity and paddock utilisation.

Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

DEFF Research Database (Denmark)

Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen

2012-01-01

-term mean. The experiment was initiated in a 4-yr-old grass-clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm......Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long...... depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal differences between treatments. However, weighted nitrate leaching estimations for G, CG and CGC showed estimated mean nitrate N...

forage systems mixed with forage legumes grazed by lactating cows

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Clair Jorge Olivo

2017-02-01

Full Text Available Current research evaluates productivity, stocking and nutritional rates of three forage systems with Elephant Grass (EG + Italian Ryegrass (IR + Spontaneous Growth Species (SGS, without forage legumes; EG + IR + SGS + Forage Peanut (FP, mixed with FP; and EG + IR + SGS + Red Clover (RC, mixed with RC, in rotational grazing method by lactating cows. IR developed between rows of EG. FP was maintained, whilst RC was sow to respective forage systems. The experimental design was completely randomized, with three treatments and two replication, subdivided into parcels over time. Mean rate for forage yield and average stocking rate were 10.6, 11.6 and 14.4 t ha-1; 3.0, 2.8 and 3.1 animal unit ha-1 day-1, for the respective systems. Levels of crude protein and total digestible nutrients were 17.8, 18.7 and 17.5%; 66.5, 66.8 and 64.8%, for the respective forage systems. The presence of RC results in better and higher forage yield in the mixture, whilst FP results in greater control of SGS. The inclusion of forage legumes in pasture systems provides better nutritional rates.

Effects of Grazing and Fire Frequency on Floristic Quality and its Relationship to Indicators of Soil Quality in Tallgrass Prairie.

Science.gov (United States)

Manning, George C; Baer, Sara G; Blair, John M

2017-12-01

Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies (P soil bulk density were also higher in grazed prairie soil over all fire frequencies (P soil N were positively correlated with FQI (P soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.

Sustainability of meat production beyond carbon footprint: a synthesis of case studies from grazing systems in Uruguay

NARCIS (Netherlands)

Picasso, V.D.; Modernel Hristoff, P.D.; Becona, G.; Salvo, L.; Gutierrez, L.; Astigarraga, L.

2014-01-01

Livestock production has been challenged as a large contributor to climate change, and carbon footprint has become a widely used measure of cattle environmental impact. This analysis of fifteen beef grazing systems in Uruguay quantifies the range of variation of carbon footprint, and the trade-offs

Grazing Affects Exosomal Circulating MicroRNAs in Cattle

Science.gov (United States)

Muroya, Susumu; Ogasawara, Hideki; Hojito, Masayuki

2015-01-01

Circulating microRNAs (c-miRNAs) are associated with physiological adaptation to acute and chronic aerobic exercise in humans. To investigate the potential effect of grazing movement on miRNA circulation in cattle, here we profiled miRNA expression in centrifugally prepared exosomes from the plasma of both grazing and housed Japanese Shorthorn cattle. Microarray analysis of the c-miRNAs resulted in detection of a total of 231 bovine exosomal miRNAs in the plasma, with a constant expression level of let-7g across the duration and cattle groups. Expression of muscle-specific miRNAs such as miR-1, miR-133a, miR-206, miR-208a/b, and miR-499 were undetectable, suggesting the mildness of grazing movement as exercise. According to validation by quantitative RT-PCR, the circulating miR-150 level in the grazing cattle normalized by the endogenous let-7g level was down-regulated after 2 and 4 months of grazing (P cattle equalized when the grazing cattle were returned to a housed situation. Likewise, the levels of miR-19b, miR-148a, miR-221, miR-223, miR-320a, miR-361, and miR-486 were temporarily lowered in the cattle at 1 and/or 2 month of grazing compared to those of the housed cattle (P cattle at 2 months of grazing (P = 0.044). The elevation of miR-451 level in the plasma was coincident with that in the biceps femoris muscle of the grazing cattle (P = 0.008), which suggests the secretion or intake of miR-451 between skeletal muscle cells and circulation during grazing. These results revealed that exosomal c-miRNAs in cattle were affected by grazing, suggesting their usefulness as molecular grazing markers and functions in physiological adaptation of grazing cattle associated with endocytosis, focal adhesion, axon guidance, and a variety of intracellular signaling, as predicted by bioinformatic analysis. PMID:26308447

A comparison of three strains of holstein-friesian grazed on pasture and managed under different feed allowances.

Science.gov (United States)

Macdonald, K A; Verkerk, G A; Thorrold, B S; Pryce, J E; Penno, J W; McNaughton, L R; Burton, L J; Lancaster, J A S; Williamson, J H; Holmes, C W

2008-04-01

This experiment compared Holstein-Friesian (HF) cows of New Zealand (NZ) origin representative of genetics present in the 1970s (NZ70; n = 45) and 1990s (NZ90; n = 60), and a group of HF cows of North American origin with 1990s genetics (NA90; n = 60), which were managed in grazing systems with a range of feeding allowances (4.5 to 7.0 t/cow per yr) over 3 yr. The NZ70 cows had the lowest Breeding Worth genetic index and the lowest breeding values for yields of fat, protein, and milk volume; the NZ90 and NA90 cows were selected to have similar breeding values for milk traits and were representative of cows of high genetic merit in the 1990s. The NZ90 cows had a higher milk protein concentration (3.71%) than either the NA90 (3.43%) or the NZ70 cows (3.41%), and a higher milk fat concentration (4.86%) than the NA90 cows (4.26%) with a level similar to the NZ70 cows (4.65%). The NZ90 cows produced significantly greater yields of fat, protein, and lactose than the NA90 and NZ70 cows. The NZ70 cows had the lowest mean annual body weight (473 kg) but the highest body condition score (BCS; 5.06). Days in milk were the same for the 2 NZ strains (286 d in milk), both of which were greater than the NA90 cows (252 d in milk). There was no genotype x environment interaction for combined milk fat and protein yield (milksolids), with NZ90 producing 52 kg/cow more than the NA90 at all feeding levels. The NZ70 strain had the highest seasonal average BCS (5.06), followed by the NZ90 (4.51) and the NA90 (4.13) strains on a 1 to 10 scale. Body condition score increased with higher feeding levels in the 2 NZ strains, but not in the NA strain. The first-parity cows commenced luteal activity 11 d later than older cows (parities 2 and 3), and the NA90 cows commenced luteal activity 4 and 10 d earlier than the NZ70 and NZ90 cows. Earlier estrus activity did not result in a higher in-calf rate. The NZ70 and NZ90 cows had similar in-calf rates (pregnancy diagnosed to 6 wk; 69%), which were

Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum.

Science.gov (United States)

Rico, Y; Wagner, H H

2016-11-01

Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations.

Models meet data: Challenges and opportunities in implementing land management in Earth system models.

Science.gov (United States)

Pongratz, Julia; Dolman, Han; Don, Axel; Erb, Karl-Heinz; Fuchs, Richard; Herold, Martin; Jones, Chris; Kuemmerle, Tobias; Luyssaert, Sebastiaan; Meyfroidt, Patrick; Naudts, Kim

2018-04-01

As the applications of Earth system models (ESMs) move from general climate projections toward questions of mitigation and adaptation, the inclusion of land management practices in these models becomes crucial. We carried out a survey among modeling groups to show an evolution from models able only to deal with land-cover change to more sophisticated approaches that allow also for the partial integration of land management changes. For the longer term a comprehensive land management representation can be anticipated for all major models. To guide the prioritization of implementation, we evaluate ten land management practices-forestry harvest, tree species selection, grazing and mowing harvest, crop harvest, crop species selection, irrigation, wetland drainage, fertilization, tillage, and fire-for (1) their importance on the Earth system, (2) the possibility of implementing them in state-of-the-art ESMs, and (3) availability of required input data. Matching these criteria, we identify "low-hanging fruits" for the inclusion in ESMs, such as basic implementations of crop and forestry harvest and fertilization. We also identify research requirements for specific communities to address the remaining land management practices. Data availability severely hampers modeling the most extensive land management practice, grazing and mowing harvest, and is a limiting factor for a comprehensive implementation of most other practices. Inadequate process understanding hampers even a basic assessment of crop species selection and tillage effects. The need for multiple advanced model structures will be the challenge for a comprehensive implementation of most practices but considerable synergy can be gained using the same structures for different practices. A continuous and closer collaboration of the modeling, Earth observation, and land system science communities is thus required to achieve the inclusion of land management in ESMs. © 2017 John Wiley & Sons Ltd.

The detectability of nitrous oxide mitigation efficacy in intensively grazed pastures using a multiple plot micrometeorological technique

Science.gov (United States)

McMillan, A. M. S.; Harvey, M. J.; Martin, R. J.; Bromley, A. M.; Evans, M. J.; Mukherjee, S.; Laubach, J.

2013-10-01

Methodologies are required to verify agricultural greenhouse gas mitigation at scales relevant to farm management. Micrometeorological techniques provide a viable approach for comparing fluxes between fields receiving mitigation treatments and control fields. However, they have rarely been applied to spatially verifying treatments aimed at mitigating nitrous oxide emission from intensively grazed pastoral systems. We deployed a micrometeorological system to compare N2O flux among several ~ 1.5 ha plots in intensively grazed dairy pasture. The sample collection and measurement system is referred to as the Field-Scale Nitrous Oxide Mitigation Assessment System (FS-NOMAS) and used a tuneable diode laser absorption spectrometer to measure N2O gradients to high precision at four locations along a 300 m transect. The utility of the FS-NOMAS to assess mitigation efficacy depends largely on its ability to resolve very small vertical N2O gradients. The performance of the FS-NOMAS was assessed in this respect in laboratory and field-based studies. The FS-NOMAS could reliably resolve gradients of 0.039 ppb between a height of 0.5 m and 1.0 m. The gradient resolution achieved corresponded to the ability to detect an inter-plot N2O flux difference of 26.4 μg N2O-N m-2 h-1 under the most commonly encountered conditions of atmospheric mixing (quantified here by a turbulent transfer coefficient), but this ranged from 11 to 59 μg N2O-N m-2 h-1 as the transfer coefficient ranged between its 5th and 95th percentile. Assuming a likely value of 100 μg N2O-N m-2 h-1 for post-grazing N2O fluxes from intensively grazed New Zealand dairy pasture, the system described here would be capable of detecting a mitigation efficacy of 26% for a single (40 min) comparison. We demonstrate that the system has considerably greater sensitivity to treatment effects by measuring cumulative fluxes over extended periods.

The detectability of nitrous oxide mitigation efficacy in intensively grazed pastures using a multiple-plot micrometeorological technique

Directory of Open Access Journals (Sweden)

A. M. S. McMillan

2014-05-01

Full Text Available Methodologies are required to verify agricultural greenhouse gas mitigation at scales relevant to farm management. Micrometeorological techniques provide a viable approach for comparing fluxes between fields receiving mitigation treatments and control fields. However, they have rarely been applied to spatially verifying treatments aimed at mitigating nitrous oxide emission from intensively grazed pastoral systems. We deployed a micrometeorological system to compare N2O flux among several ~1.5 ha plots in intensively grazed dairy pasture. The sample collection and measurement system is referred to as the Field-Scale Nitrous Oxide Mitigation Assessment System (FS-NOMAS and used a tuneable diode laser absorption spectrometer to measure N2O gradients to high precision at four locations along a 300 m transect. The utility of the FS-NOMAS to assess mitigation efficacy depends largely on its ability to resolve very small vertical N2O gradients. The performance of the FS-NOMAS was assessed in this respect in laboratory and field-based studies. The FS-NOMAS could reliably resolve gradients of 0.039 ppb between a height of 0.5 and 1.0 m. The gradient resolution achieved corresponded to the ability to detect an inter-plot N2O flux difference of 26 μg N2O–N m−2 h−1 under the most commonly encountered conditions of atmospheric mixing (quantified here by a turbulent transfer coefficient, but this ranged from 11 to 59 μg N2O–N m−2 h−1 as the transfer coefficient ranged between its 5th and 95th percentile. Assuming a likely value of 100 μg N2O–N m−2 h−1 for post-grazing N2O fluxes from intensively grazed New Zealand dairy pasture, the system described here would be capable of detecting a mitigation efficacy of 26% for a single (40 min comparison. We demonstrate that the system has considerably greater sensitivity to treatment effects by measuring cumulative fluxes over extended periods.

The detectability of nitrous oxide mitigation efficacy in intensively grazed pastures using a multiple-plot micrometeorological technique

Science.gov (United States)

McMillan, A. M. S.; Harvey, M. J.; Martin, R. J.; Bromley, A. M.; Evans, M. J.; Mukherjee, S.; Laubach, J.

2014-05-01

Methodologies are required to verify agricultural greenhouse gas mitigation at scales relevant to farm management. Micrometeorological techniques provide a viable approach for comparing fluxes between fields receiving mitigation treatments and control fields. However, they have rarely been applied to spatially verifying treatments aimed at mitigating nitrous oxide emission from intensively grazed pastoral systems. We deployed a micrometeorological system to compare N2O flux among several ~1.5 ha plots in intensively grazed dairy pasture. The sample collection and measurement system is referred to as the Field-Scale Nitrous Oxide Mitigation Assessment System (FS-NOMAS) and used a tuneable diode laser absorption spectrometer to measure N2O gradients to high precision at four locations along a 300 m transect. The utility of the FS-NOMAS to assess mitigation efficacy depends largely on its ability to resolve very small vertical N2O gradients. The performance of the FS-NOMAS was assessed in this respect in laboratory and field-based studies. The FS-NOMAS could reliably resolve gradients of 0.039 ppb between a height of 0.5 and 1.0 m. The gradient resolution achieved corresponded to the ability to detect an inter-plot N2O flux difference of 26 μg N2O-N m-2 h-1 under the most commonly encountered conditions of atmospheric mixing (quantified here by a turbulent transfer coefficient), but this ranged from 11 to 59 μg N2O-N m-2 h-1 as the transfer coefficient ranged between its 5th and 95th percentile. Assuming a likely value of 100 μg N2O-N m-2 h-1 for post-grazing N2O fluxes from intensively grazed New Zealand dairy pasture, the system described here would be capable of detecting a mitigation efficacy of 26% for a single (40 min) comparison. We demonstrate that the system has considerably greater sensitivity to treatment effects by measuring cumulative fluxes over extended periods.

Assessment of the economic viability of goat management systems in Goma Sub County and Mukono Town Council in Mukono District, Uganda.

Science.gov (United States)

Mwebe, Robert; Ejobi, Francis; Laker, Christopher Dennis

2011-04-01

This study sought to assess the profitability of the goat enterprises under different management systems. The research covered two selected sub-counties of Mukono District (Goma and Mukono Town Council). A total of 888 goats from 129 herds/farms were studied. Descriptive statistical and gross margins analyses were performed. The management system of goats in the two sub-counties was mainly by tethering. Most of the goats kept were adult female goats. Most farmers had small herds and did not keep records. Male goats were more valued on average among the crossbred goats. In the exotic types, the adult female goats were valued on average. Local goats fetch low prices. With respect to gross margins, that free range had incurred more losses, while tethering made most profits followed by zero grazing and zero grazing combined with tethering, respectively, without considering the non-monetary aspects. Farmers using the tethering management system, encountered most of the problems of lack of pastures and veterinary services. The farmers required assistance from different donors, through provision of hybrid goats and improvement of veterinary services. The management system for goat keeping in the study area was poor, especially among local breed goat farmers who use tethering management system, though it had high gross margin. There is a need to educate farmers on proper goat husbandry and provision of some farm inputs.

Characterization and typification of small ruminant farms providing fuelbreak grazing services for wildfire prevention in Andalusia (Spain).

Science.gov (United States)

Mena, Y; Ruiz-Mirazo, J; Ruiz, F A; Castel, J M

2016-02-15

Several wildfire prevention programs in Spain are using grazing livestock to maintain fuelbreaks with low levels of biomass. Even though shepherds are remunerated for these services, many of their farms are hardly viable in the current socio-economic context. By analyzing 54 small ruminant farms participating in the Grazed Fuelbreak Network in Andalusia (southern Spain), this research aimed to identify the main types and characteristics of such farms and, considering the challenges they are facing, propose strategies to improve both their economic viability and their effectiveness in fuelbreak grazing. Based on data collected through a survey on key farm management aspects, a multivariate analysis was performed and four main types of farm were identified: two clusters of dairy goat farms and two composed mostly of meat-purpose sheep farms. Farms in all clusters could benefit from improvements in the feeding and reproductive management of livestock, either to enhance their productivity or to make better use of the pasture resources available. Dairy goat farms remain more dependent on external animal feed to ensure a better lactation, therefore they should either diminish their workforce costs per animal or sell transformed products directly to consumers to improve their economic viability. Best fuelbreak grazing results were related to larger flocks combining sheep and goats, lower ratios of fuelbreak surface area per animal, and longer (year-long) grazing periods on fuelbreaks. Therefore, such farm features and adjusted fuelbreak assignments should be favored in wildfire prevention programs using grazing services. Copyright © 2015 Elsevier B.V. All rights reserved.

Grazing function g and collimation angular acceptance

Directory of Open Access Journals (Sweden)

Stephen G. Peggs

2009-11-01

Full Text Available The grazing function g is introduced—a synchrobetatron optical quantity that is analogous (and closely connected to the Twiss and dispersion functions β, α, η, and η^{′}. It parametrizes the rate of change of total angle with respect to synchrotron amplitude for grazing particles, which just touch the surface of an aperture when their synchrotron and betatron oscillations are simultaneously (in time at their extreme displacements. The grazing function can be important at collimators with limited acceptance angles. For example, it is important in both modes of crystal collimation operation—in channeling and in volume reflection. The grazing function is independent of the collimator type—crystal or amorphous—but can depend strongly on its azimuthal location. The rigorous synchrobetatron condition g=0 is solved, by invoking the close connection between the grazing function and the slope of the normalized dispersion. Propagation of the grazing function is described, through drifts, dipoles, and quadrupoles. Analytic expressions are developed for g in perfectly matched periodic FODO cells, and in the presence of β or η error waves. These analytic approximations are shown to be, in general, in good agreement with realistic numerical examples. The grazing function is shown to scale linearly with FODO cell bend angle, but to be independent of FODO cell length. The ideal value is g=0 at the collimator, but finite nonzero values are acceptable. Practically achievable grazing functions are described and evaluated, for both amorphous and crystal primary collimators, at RHIC, the SPS (UA9, the Tevatron (T-980, and the LHC.

Effects of Grazing and Fire Frequency on Floristic Quality and its Relationship to Indicators of Soil Quality in Tallgrass Prairie

Science.gov (United States)

Manning, George C.; Baer, Sara G.; Blair, John M.

2017-12-01

Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies ( P total N, and soil bulk density were also higher in grazed prairie soil over all fire frequencies ( P total organic C, and total soil N were positively correlated with FQI ( P quality and soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.

Milk from cows grazing on cool-season pastures provides an enhanced profile of bioactive fatty acids compared to those grazed on a monoculture of pearl millet.

Science.gov (United States)

Bainbridge, Melissa L; Egolf, Emily; Barlow, John W; Alvez, Juan P; Roman, Joe; Kraft, Jana

2017-02-15

The demand for dairy products from grass-fed cows is driven, in part, by their more desirable fatty acid (FA) profile, containing more n-3 FA and conjugated linoleic acids (CLA) than conventionally produced dairy products. This study investigated the effects of pearl millet (PM) vs. cool-season pasture (CSP) on animal performance and milk FA in a grazing system. Eight Holstein dairy cows were used in a repeated measures design with four-week periods. Forage type had no effect on animal performance (estimated dry matter intake, milk production, fat, or protein). The contents of CLA and n-3 FA in a serving of whole milk (3.25% fat) increased when cows grazed CSP compared to PM. A serving of whole milk from cows grazing PM had a higher content of saturated FA and branched-chain FA. In conclusion, the contents of various bioactive FA were higher in milk fat of cows grazing a CSP compared to PM. Copyright © 2016 Elsevier Ltd. All rights reserved.

X-ray diffraction study of surface-layer structure in parallel grazing rays

International Nuclear Information System (INIS)

Shtypulyak, N.I.; Yakimov, I.I.; Litvintsev, V.V.

1989-01-01

An x-ray diffraction method is described for study of thin polycrystalline and amorphous films and surface layers in an extremely asymmetrical diffraction system in parallel grazing rays using a DRON-3.0 diffractometer. The minimum grazing angles correspond to diffraction under conditions of total external reflection and a layer depth of ∼ 2.5-8 nm

Effects of multiple disturbances in seagrass meadows : shading decreases resilience to grazing

NARCIS (Netherlands)

Eklof, Johan S.; McMahon, Kathryn; Lavery, Paul S.

2009-01-01

Ecosystem shifts are often associated with multiple disturbances, but limited knowledge on the mechanisms involved hampers management. This study investigated how short-term shading affected the resilience of the seagrass Halophila ovalis to grazing by black swans (Cygnus atratus) - a historically

Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

Science.gov (United States)

Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

2011-01-01

The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area

Simulating runoff from small grazed pasture watersheds located at North Appalachian Experimental Watershed in Ohio

Science.gov (United States)

Runoff from grazing pasture lands can impact water quality in receiving streams if not well managed. Management consists of conservation practices to reduce runoff and pollutants transport. Simulation models have been effectively used to design and implement these conservation practices. The Agricul...

Forage intake and wastage by ewes in pea/hay barley swath grazing and bale feeding systems

Science.gov (United States)

Harvested feed costs, particularly during the winter, are traditionally the highest input associated with a ruminant livestock operation. Although swath grazing has been practiced for over 100 years and literature exists for cattle use of swath grazing, no published results are available on use of s...

Reproductive responses to climatic heat induced by management systems in swamp buffaloes

International Nuclear Information System (INIS)

Dollah, M.A.; Ramakrishnan, N.; Nordin, Y.; Abdullah Sani, R.

1990-01-01

Climatic heat is one of the factors influencing the reproductive performance of swamp buffaloes. Any management system that imposes high climatic heat stress tends to reduce reproductive performance. Buffaloes grazing in an open hilly ranch system reached puberty later (at an age of 33 months) and at heavier body weight (365 kg) than animals raised in confinement (26 months and 289 kg). Physiological data (water metabolism and thyroid activity) indicated that grazing animals had to tolerate a higher heat load. High climatic temperatures were found to depress ovarian activity, especially during the dry season. The effect was observed only in cycling buffaloes denied wallow. Buffaloes having access to wallows were able to maintain their heat balance under various levels of heat load by adjusting their water requirements, mobilizing their body water and adjusting their metabolic rate (thyroid activity). It is concluded that stressful climatic temperatures can depress the reproductive performance of young heifers and adult swamp buffaloes, and that climatic heat stress directly depresses ovarian activity in swamp buffaloes. (author). 16 refs, 1 fig., 4 tabs

Short communication. Behavioural activities of two dairy cow genotypes (Holstein-Friesian vs. Jersey x Holstein-Friesian in two milk production systems (grazing vs. confinement

Directory of Open Access Journals (Sweden)

A. I. Roca-Fernández

2013-02-01

Full Text Available The aim of this work was to study the behavioural activities of two cow genotypes, Holstein-Friesian (HF vs. Jersey × Holstein-Friesian (Jx, when managed within two production systems, a low inputs grazing (G system vs. a high inputs confinement (C system. Eighty spring calving cows (HF, n=40 and Jx, n=40, from AFBI Hillsborough (Northern Ireland experimental dairy cattle, were randomly assigned to one of two production systems (G, n=40 and C, n=40 in a block design with a 2×2 factorial arrangement of four treatments (HF-G, HF-C, Jx-G and Jx-C. Cow behavioural activities (feeding, lying, standing and ruminating were registered on three periods at 20-min intervals, between 16.00-22.00 h and 07.00-14.00 h. Average milk yields (kg cow-1 day-1 were higher (p<0.001 in the C system (27.0 than in the G system (20.1, with differences (p<0.001 between the two cow genotypes (HF, 25.1 vs. Jx, 22.0 kg cow-1 day-1. Milk production system showed an effect on cow behavioural activities. Animals on the G system spent more time (p<0.001 grazing (522 min than those on the C system spent feeding (173 min. Cows on the C system spent more time (p<0.001 lying (C, 411 vs. G, 212 min, standing (C, 236 vs. G, 85 min and ruminating (C, 244 vs. G, 141 min than those on the G system. There were differences between periods for time spent lying (p<0.001, feeding (p<0.05 and ruminating (p<0.001, while time spent standing did not differ between periods. Cow genotype had no effect on any of the behavioural activities.

A Systematic Review of Wild Burro Grazing Effects on Mojave Desert Vegetation, USA

Science.gov (United States)

Abella, Scott R.

2008-06-01

Wild burros ( Equus asinus), protected by the 1971 Wild Free-Roaming Horse and Burro Act on some federal lands but exotic animals many ecologists and resource mangers view as damaging to native ecosystems, represent one of the most contentious environmental management problems in American Southwest arid lands. This review synthesizes the scattered literature about burro effects on plant communities of the Mojave Desert, a center of burro management contentions. I classified 24 documents meeting selection criteria for this review into five categories of research: (i) diet analyses directly determining which plant species burros consume, (ii) utilization studies of individual species, (iii) control-impact comparisons, (iv) exclosure studies, and (v) forage analyses examining chemical characteristics of forage plants. Ten diet studies recorded 175 total species that burros consumed. However, these studies and two exclosure studies suggested that burros preferentially eat graminoid and forb groups over shrubs. One study in Death Valley National Park, for example, found that Achnatherum hymenoides (Indian ricegrass) was 11 times more abundant in burro diets than expected based on its availability. Utilization studies revealed that burros also exhibit preferences within the shrub group. Eighty-three percent of reviewed documents were produced in a 12-year period, from 1972 to 1983, with the most recent document produced in 1988. Because burros remain abundant on many federal lands and grazing may interact with other management concerns (e.g., desert wildfires fueled by exotic grasses), rejuvenating grazing research to better understand both past and present burro effects could help guide revegetation and grazing management scenarios.

Ecology of grazing lawns in Africa

CSIR Research Space (South Africa)

Hempson, GP

2014-09-01

Full Text Available otherwise outcompete lawn species for light. Regular grazing that prevents shading and maintains sward quality is thus the cornerstone of grazing lawn dynamics. The strong interplay between abiotic conditions and disturbance factors, which are central...

Response of mountain meadows to grazing by recreational pack stock

Science.gov (United States)

David N. Cole; Jan W. van Wagtendonk; Mitchel P. McClaran; Peggy E. Moore; Neil K. McDougald

2004-01-01

Effects of recreational pack stock grazing on mountain meadows in Yosemite National Park were assessed in a 5-year study. Yosemite is a designated wilderness, to be managed such that its natural conditions are preserved. Studies were conducted in 3 characteristic meadow types: shorthair sedge (Carex filifolia Nutt.), Brewer’s reed grass (...

Influence of alfalfa grazing-based feeding systems on carcass fat colour and meat quality of light lambs.

Science.gov (United States)

Ripoll, G; Albertí, P; Joy, M

2012-02-01

One hundred and twenty-seven lambs were fed as follows: lambs and dams grazing alfalfa (Gr); the same as Gr but lambs had access to concentrate (Gr + S); ewes grazed and lambs received milk and concentrate until weaning and thereafter concentrate and straw (Rat-Gr); ewes and lambs were stall-fed (Ind). Lambs were slaughtered at 22-24 kg live weight and fat and M. rectus abdominis colour was measured instrumentally and subjectively. The evolution of the instrumental colour and texture of M. longissimus lumborum was also recorded. There were significant differences in the instrumental colour of subcutaneous fat amongst feeding systems, but no differences were observed upon visual appraisal. On average, M. rectus abdominis colour in the four feeding systems was classed as pink. Differences in longissimus thoracis colour at 0 h disappeared at 24h of air exposure and there were no differences in pH or cooking losses. At no time were any differences in instrumental texture found. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of Grazing Management and Cattle on Aquatic Habitat Use by the Anuran Pseudopaludicola mystacalis in Agro-Savannah Landscapes.

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Rodolfo M Pelinson

Full Text Available Because of their strong dependence on the environment, the spatial distribution of pond-breeding amphibians can be greatly influenced by anthropogenic habitat alteration. In some agricultural landscapes in Brazil, the anuran Pseudopaludicola mystacalis appears to be highly influenced by land use. Because adult males and tadpoles of this species are usually found in marshy areas with cattle hoof prints, we hypothesized that P. mystacalis preferentially occupies aquatic habitats with marshy areas that are trampled by cattle. To test our hypothesis, we assessed whether the occurrence of P. mystacalis is associated with the presence of cattle and trampled marshy areas, and which environmental features best explain the spatial distribution and abundance of P. mystacalis. To do so, we sampled 38 aquatic habitats in an area intensely used for livestock in southeastern Brazil. We found that the presence of cattle and trampled marshy areas in aquatic habitats are positively associated to P. mystacalis occurrence. Additionally, the abundance of calling males is better predicted by variables of landscape and local habitat structure. Specifically, the size of trampled marshy areas and the proportion of herbaceous vegetation within the aquatic habitat are positively associated with abundance, while distance to nearest aquatic habitat are negatively associated with abundance of calling males. All three of these variables can be directly or indirectly linked to the presence of cattle or grazing management. Therefore, this work shows evidence that Pseudopaludicola mystacalis is positively influenced by grazing management with cattle, and draws attention to other unknown potential consequences of different land use to fresh water diversity.

Soil physical attributes in forms of sowing the annual winter pasture and intervals between grazing

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Milton da Veiga

Full Text Available The sowing of winter pastures in areas used for summer grain production and their management under direct cattle grazing can cause changes in soil physical attributes, whose intensity depends on the degree of soil mobilization, grazing interval, stocking rate and weather. To study these aspects it was conducted over four years an experiment in a randomized block with split plots design and four replications. In the main plots were applied two forms of sowing the annual winter pasture (direct seeding and seeding + harrowing and, in the subplots, four intervals between grazing (7, 14 and 28 days and ungrazed. Undisturbed soil cores were sampled at the end of each grazing cycle, in the 0-0.05 m layer to determine the saturated hydraulic conductivity and aggregate stability and in the layers of 0-0.05, 0.05-0.10, 0.10-0.15 and 0.15-0.20 m depth to determine bulk density and classes of soil pores. The direct seeding of annual winter pasture increases hydraulic conductivity and reduces soil bulk density in relation to seeding + harrowing while dairy cows trampling increases soil density and reduces macroporosity in the most superficial soil layer. The variation in climatic conditions among grazing cycles affects the soil physical attributes more markedly than forms of sowing and intervals between grazing of the annual winter pasture.

The response of spider (Araneae assemblages to structural heterogeneity and prey abundance in sub-montane vegetation modified by conservation grazing

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Peter Dennis

2015-01-01

Full Text Available The effect of experimental livestock grazing regimens (4 treatments×6 replicates on spiders via habitat structure and prey abundance was investigated on sub-montane habitats in the Southern Highlands of Scotland. The study, 2002–2004 included a baseline survey under the prior, commercial sheep grazing regimen and two assessments of spider assemblages post-treatment: commercial stocking density of sheep; 1/3 stocking density with sheep; 1/3 stocking density cattle with sheep; and no grazing. Spiders were sampled with a suction sampler, five sucks at each of 25 sample units by 24 plots (600 samples in 2003 and 2004, ca. 320 in 2002. Spider abundance and species richness increased under reduced stocking density, mixed herbivore and ungrazed treatments indirectly via changes in vegetation structure and prey abundance. The results refuted a meta-analysis that concluded species richness of spiders is unaffected by grazing. Grazing regimens caused turnover in species composition more than the net difference in species richness suggested, implying that no single, optimal grazing regimen will support as many species as a patchwork under varied grazing management. Conservation grazing benefits spiders and will have significant benefits for food webs in sub-montane ecosystems but the period to equilibrium after changes to grazing requires further investigation.

Voluntary automatic milking in combination with grazing of dairy cows : Milking frequency and effects on behaviour

NARCIS (Netherlands)

Ketelaar-de Lauwere, C.C.; Ipema, A.H.; Ouwerkerk, van E.N.J.; Hendriks, M.M.W.B.; Metz, J.H.M.; Noordhuizen, J.P.T.M.; Schouten, W.G.P.

1999-01-01

Automatic milking systems (AMS) enable cows to be milked without human interference. Such systems are more acceptable to consumers and from the animal welfare point of view if they can be combined with grazing in the summer season. In this study, grazing was combined with fully automatic milking for

Herbage intake by grazing dairy cows

NARCIS (Netherlands)

Meijs, J.A.C.

1981-01-01

An extensive review of the literature is given of
- nine possible methods for estimating herbage intake by grazing ruminants, with special attention to the sward-cutting and indirect animal methods
- the factors determining the herbage intake by grazing ruminants.

The

Grazing Behavior and Itineraries of Kacang Goat with Different Coat Color under Semi Intensive Management

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Slamet Heri Kiswanto

2015-05-01

Full Text Available The objective of this research was to analyze the effect of coat color on behavior and itineraries of kacang goat during grazing time. This research used 9 females and 3 males kacang goat. Behavior observed by one zero sampling method and analyzed using t-Test at level 5%. The result indicated that ingestion and browsing of brown goat (30.91±2.87%; 8.75±3.10% higher than black goat (28.57±2.69%; 6.07±4.78%, while black goat showed more locomotion (33.26±4.50% than brown goat (29.70±4.63%. Grazing, panting, and resting behaviors, and distance traveled of black goat (22.56±2.63%; 4.48±4.02%; 2.34±2.97%; 483.48±133.16 m were not different with brown goat (22.16±2.90%; 4.59±3.71%; 2.64±1.52%; 392.29±81.19 m. Result also  indicated that goat showed more grazing than browsing with high preference in you ng grass than old grass,  legume, and weed.

The Occurrence and Toxicity of Indospicine to Grazing Animals

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Mary T. Fletcher

2015-07-01

Full Text Available Indospicine is a non-proteinogenic amino acid which occurs in Indigofera species with widespread prevalence in grazing pastures across tropical Africa, Asia, Australia, and the Americas. It accumulates in the tissues of grazing livestock after ingestion of Indigofera. It is a competitive inhibitor of arginase and causes both liver degeneration and abortion. Indospicine hepatoxicity occurs universally across animal species but the degree varies considerably between species, with dogs being particularly sensitive. The magnitude of canine sensitivity is such that ingestion of naturally indospicine-contaminated horse and camel meat has caused secondary poisoning of dogs, raising significant industry concern. Indospicine impacts on the health and production of grazing animals per se has been less widely documented. Livestock grazing Indigofera have a chronic and cumulative exposure to this toxin, with such exposure experimentally shown to induce both hepatotoxicity and embryo-lethal effects in cattle and sheep. In extensive pasture systems, where animals are not closely monitored, the resultant toxicosis may well occur after prolonged exposure but either be undetected, or even if detected not be attributable to a particular cause. Indospicine should be considered as a possible cause of animal poor performance, particularly reduced weight gain or reproductive losses, in pastures where Indigofera are prevalent.

Wilderness and woodland ranchers in California: A total income case study of public grazing permits and their impacts on conservation

Science.gov (United States)

Oviedo Pro, J. L.; Huntsinger, L.; Campos, P.; Caparros, A.

2009-04-01

Mediterranean woodlands in California are managed as agro-silvo-pastoral systems producing a number of commercial products as well as a huge variety of environmental services, including private amenities for the landowner. In many parts of the woodlands, grazing on government owned (public) lands has traditionally had an important role in private ranching. In recent decades the risk of conversion to alternative uses (such as urban development or vineyards) has threatened these woodlands due to the increasing opportunity costs of capital. Understanding the economy of these woodlands and the potential effects of public grazing policies on the total income perceived by the landowner is crucial when considering strategies attempting to slow or stop land use change. However, traditional cash-flow analyses are lacking crucial information needed to understand all the elements that have an important role in the economic decisions that landowners make about their woodlands. For more than half a century, the use of public lands by private ranchers has been one of the most controversial debates in the American west. Wilderness conservationist groups have denounced grazing as destructive and argue for the removal of any kind of livestock. Ranchers have fought for their right to hold public grazing leases, arguing that they are crucial for the continuity of private ranching and consequently for the conservation of extensive rangeland habitat that otherwise could be converted to alternative uses. In this study, we apply the Agroforestry Accounting System (AAS) methodology to a California oak woodland case study to estimate the total private income generated in an accounting period. The presented case study is characterized by a household economy with self-employed labour and with part of the grazing dependent on public land leases. The AAS methodology extends traditional cash-flow analysis in order to estimate the total private income that would accurately explain the woodland

Traditional agroforestry systems, tree uses and management in ...

African Journals Online (AJOL)

protecting or planting the trees and shrubs on farms. ... Inadequate supply of seedlings, poor extension services, a nd lack ofland as well as ... integrated research, adoption of better land management techniques and ..... of elite men moving to town and urban centres in search of .... grazing in small scale farming areas.

Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) Slit-Jaw Imaging System

Science.gov (United States)

Wilkerson, P.; Champey, P. R.; Winebarger, A. R.; Kobayashi, K.; Savage, S. L.

2017-12-01

The Marshall Grazing Incidence X-ray Spectrometer is a NASA sounding rocket payload providing a 0.6 - 2.5 nm spectrum with unprecedented spatial and spectral resolution. The instrument is comprised of a novel optical design, featuring a Wolter1 grazing incidence telescope, which produces a focused solar image on a slit plate, an identical pair of stigmatic optics, a planar diffraction grating and a low-noise detector. When MaGIXS flies on a suborbital launch in 2019, a slit-jaw camera system will reimage the focal plane of the telescope providing a reference for pointing the telescope on the solar disk and aligning the data to supporting observations from satellites and other rockets. The telescope focuses the X-ray and EUV image of the sun onto a plate covered with a phosphor coating that absorbs EUV photons, which then fluoresces in visible light. This 10-week REU project was aimed at optimizing an off-axis mounted camera with 600-line resolution NTSC video for extremely low light imaging of the slit plate. Radiometric calculations indicate an intensity of less than 1 lux at the slit jaw plane, which set the requirement for camera sensitivity. We selected a Watec 910DB EIA charge-coupled device (CCD) monochrome camera, which has a manufacturer quoted sensitivity of 0.0001 lux at F1.2. A high magnification and low distortion lens was then identified to image the slit jaw plane from a distance of approximately 10 cm. With the selected CCD camera, tests show that at extreme low-light levels, we achieve a higher resolution than expected, with only a moderate drop in frame rate. Based on sounding rocket flight heritage, the launch vehicle attitude control system is known to stabilize the instrument pointing such that jitter does not degrade video quality for context imaging. Future steps towards implementation of the imaging system will include ruggedizing the flight camera housing and mounting the selected camera and lens combination to the instrument structure.

Livestock Grazing as a Driver of Vernal Pool Ecohydrology

Science.gov (United States)

Michaels, J.; McCarten, N. F.

2017-12-01

Vernal pools are seasonal wetlands that host rare plant communities of high conservation priority. Plant community composition is largely driven by pool hydroperiod. A previous study found that vernal pools grazed by livestock had longer hydroperiods compared with pools excluded from grazing for 10 years, and suggests that livestock grazing can be used to protect plant diversity. It is important to assess whether observed differences are due to the grazing or due to water balance variables including upland discharge into or out of the pools since no a priori measurements were made of the hydrology prior to grazing. To address this question, in 2016 we compared 15 pools that have been grazed continuously and 15 pools that have been fenced off for over 40 years at a site in Sacramento County. We paired pools based on abiotic characteristics (size, shape, slope, soil type) to minimize natural variation. We sampled vegetation and water depth using Solinst level loggers. We found that plant diversity and average hydroperiod was significantly higher in the grazed pools. We are currently measuring groundwater connectivity and upland inputs in order to compare the relative strength of livestock grazing as a driver of hydroperiod to these other drivers.

Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

Science.gov (United States)

Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A; Oomen, Roelof J; du Preez, Chris C; Ruppert, Jan C; Ewert, Frank

2014-01-01

Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be useful

FORAGES AND PASTURES SYMPOSIUM: Improving efficiency of production in pasture- and range-based beef and dairy systems.

Science.gov (United States)

Mulliniks, J T; Rius, A G; Edwards, M A; Edwards, S R; Hobbs, J D; Nave, R L G

2015-06-01

Despite overall increased production in the last century, it is critical that grazing production systems focus on improving beef and dairy efficiency to meet current and future global food demands. For livestock producers, production efficiency is essential to maintain long-term profitability and sustainability. This continued viability of production systems using pasture- and range-based grazing systems requires more rapid adoption of innovative management practices and selection tools that increase profitability by optimizing grazing management and increasing reproductive performance. Understanding the genetic variation in cow herds will provide the ability to select cows that require less energy for maintenance, which can potentially reduce total energy utilization or energy required for production, consequently improving production efficiency and profitability. In the United States, pasture- and range-based grazing systems vary tremendously across various unique environments that differ in climate, topography, and forage production. This variation in environmental conditions contributes to the challenges of developing or targeting specific genetic components and grazing systems that lead to increased production efficiency. However, across these various environments and grazing management systems, grazable forage remains the least expensive nutrient source to maintain productivity of the cow herd. Beef and dairy cattle can capitalize on their ability to utilize these feed resources that are not usable for other production industries. Therefore, lower-cost alternatives to feeding harvested and stored feedstuffs have the opportunity to provide to livestock producers a sustainable and efficient forage production system. However, increasing production efficiency within a given production environment would vary according to genetic potential (i.e., growth and milk potential), how that genetic potential fits the respective production environment, and how the grazing

Signal grass structure at different sites of the same pasture under three grazing intensities - doi: 10.4025/actascianimsci.v35i1.11801

Directory of Open Access Journals (Sweden)

Ronan Lopes Albino

2013-01-01

Full Text Available The experiment was conducted to evaluate Brachiaria decumbens cv. Basilisk at different sites of the same pasture featuring varying grazing intensities (under grazed, properly grazed and overgrazed. The pasture was managed under continuous stocking using 200-kg cattle and grass height kept at about 25 cm. The randomized block design was used, with three replications. Sward height (38.0 cm and extended plant height (85.2 cm were greater at the under grazed site. The falling index was lower at the properly grazed site (1.28. At the under grazed site, the masses of green leaf blade (3442 kg ha-1 DM, green stem (8370 kg ha-1 DM, green forage (11812 kg ha-1 DM and total forage (14137 kg ha-1 DM were higher when compared to the overgrazed and properly grazed sites. Dead material mass was higher at the properly grazed (3422 kg ha-1 DM and under grazed (2324 kg ha-1 DM sites. At the under grazed sites, there was a higher occurrence of tillers taller than 40 cm. Tillers with sizes between 10 and 30 cm predominated in properly grazed sites. In overgrazed site there was a higher share of tillers with sizes smaller than 20 cm. There is spatial variability of vegetation in the same pasture of Brachiaria decumbens cv. Basilisk due to uneven grazing by cattle.

Restoring sand shinnery oak prairies with herbicide and grazing in New Mexico

Science.gov (United States)

Zavaleta, Jennifer C.; Haukos, David A.; Grisham, Blake A.; Boal, Clint W.; Dixon, Charles

2016-01-01

Sand shinnery oak (Quercus havardii) prairies are increasingly disappearing and increasingly degraded in the Southern High Plains of Texas and New Mexico. Restoring and managing sand shinnery oak prairie can support biodiversity, specific species of conservation concern, and livestock production. We measured vegetation response to four treatment combinations of herbicide (tebuthiuron applied at 0.60 kg/ha) and moderate-intensity grazing (50% removal of annual herbaceous production) over a 10-year period in a sand shinnery oak prairie of eastern New Mexico. We compared the annual vegetation response to the historical climax plant community (HCPC) as outlined by the U.S. Department of Agriculture Ecological Site Description. From 2 to 10 years postapplication, tebuthiuron-treated plots had reduced shrub cover with twice as much forb and grass cover as untreated plots. Tebuthiuron-treated plots, regardless of the presence of grazing, most frequently met HCPC. Tebuthiuron and moderate-intensity grazing increased vegetation heterogeneity and, based on comparison of the HCPC, successfully restored sand shinnery oak prairie to a vegetation composition similar to presettlement.

Population fluctuations, losses to grazing, and reproductive success of Dactylorhiza sambucina on Bornholm, Denmark

DEFF Research Database (Denmark)

Sonne, Mette Nordvig; Hauser, Thure Pavlo

2014-01-01

generally increased in the early 1990s but declined after that. We could find no effect of vegetation management, neither were the fluctuations related to suggested climatic factors. High proportions of plants were lost to grazing in the study year; same could be deduced for previous years when more than...... one census was available. Grazing in spring and early summer may therefore contribute to the decline of D. sambucina, as suggested by others. Populations seemed not to be affected by lack of pollination or population inbreeding, as fruit set and reproductive size was as high as in large...

Grazing disturbance increases transient but decreases persistent soil seed bank.

Science.gov (United States)

Ma, Miaojun; Walck, Jeffrey L; Ma, Zhen; Wang, Lipei; Du, Guozhen

2018-04-30

Very few studies have examined whether the impacts of grazing disturbance on soil seed banks occur directly or indirectly through aboveground vegetation and soil properties. The potential role of the seed bank in alpine wetland restoration is also unknown. We used SEM (structural equation modeling) to explore the direct effect of grazing disturbance on the seed bank and the indirect effect through aboveground vegetation and soil properties. We also studied the role of the seed bank on the restoration potential in wetlands with various grazing intensities: low (fenced, winter grazed only), medium (seasonally grazed), and high (whole-year grazed). For the seed bank, species richness and density per plot showed no difference among grazing intensities for each depth (0-5, 5-10, 10-15 cm) and for the whole depth (0-15 cm) in spring and summer. There was no direct effect of grazing disturbance on seed bank richness and density both in spring and summer, and also no indirect effect on the seed bank through its direct effect on vegetation richness and abundance. Grazing disturbance indirectly increased spring seed bank density but decreased summer seed bank density through its direct effect (negative correlation) on soil moisture and total nitrogen and its indirect effect on vegetation abundance. Species composition of the vegetation changed with grazing regime, but that of the seed bank did not. An increased trend of similarity between the seed bank and aboveground vegetation with increased grazing disturbance was found in the shallow depth and in the whole depth only in spring. Although there was almost no change in seed bank size with grazing intensities, grazing disturbance increased the quantity of transient seeds but decreased persistent seeds. Persistent seeds stored in the soil could play a crucial role in vegetation regeneration and in restoration of degraded wetland ecosystems. The seed bank should be an integral part of alpine wetland restoration programs. �

Changes in soil carbon cycling accompanying conversion of row-crop fields to grazing dairy pastures

Science.gov (United States)

Thompson, A.; Kramer, M. G.; Hill, N.; Machmuller, M. B.; Cyle, K.

2011-12-01

Increasingly, the dairy industry in the eastern US is transitioning from total confinement dairy systems (TCD) toward pasture-based, management intensive grazing dairy (MiGD) systems. This transition is driven by the fact that MiGDs require substantially less operating capital and are more economically efficient than TCD systems. Consequently, the impact of this transition and shift in land-use practice on carbon dynamics may be considerable. Land-use in a Management intensive Grazing Dairy (MiGD) system is fundamentally different than conventional confinement dairies and conventional no-till pastures. The forage system involves rotational grazing at optimal digestibility, when the plants are immature (~20-days) and consequently protein-rich. MiGD cows spend >90% of their time in the field and deposit > 90% of their waste directly to the soil surface. Thus, little above ground plant residues are directly returned to the soil, but rather substantial C inputs derive from bovine manure. We sampled a MiGD-chronosequence of row-crop to MiGD conversion established in 2007 in eastern Georgia. All soils across the MiGD-chronosequence, all occur in relative (40 km) close proximity to one another, are deep, well-drained, fine and fine sandy loam Ultisols formed on Coastal Plain sediments. Prior to MiGD established, the soils were farmed for > 50 yrs using conventional tillage techniques. Our current sampling to 1m depths captures fields at 0, 2, 3, and 5 yrs since conversion. Total soil carbon (C) and the carbon concentration of the clay fraction increased following conversion, with the greatest increases occurring between 3 and 5 yrs since conversion. These C increases were limited to the upper 40cm of the soil, with minimal change occurring at depth. Characterization of the protein and ligand content of these soils via 13C NMR and chemolytic techniques as a function of soil particle density and size is in progress and will be presented along with estimates of carbon

Milk production, grazing behavior and nutritional status of dairy cows grazing two herbage allowances during winter

Directory of Open Access Journals (Sweden)

Miguel Ruiz-Albarran

2016-03-01

Full Text Available Winter grazing provides a useful means for increasing the proportion of grazed herbage in the annual diet of dairy cows. This season is characterized by low herbage growth rate, low herbage allowance, and low herbage intake and hence greater needs for supplements to supply the requirements of lactating dairy cows. The aim of this study was to determine the influence of herbage allowance (HA offered to autumn calving dairy cows grazing winter herbage on milk production, nutritional status, and grazing behavior. The study took 63 d using 32 multiparous Holstein-Friesian dairy cows. Prior to experimental treatment, milk production averaged 20.2 ± 1.7 kg d-1, body weight was 503 ± 19 kg, and days in milking were 103 ± 6. Experimental animals were randomly assigned to two treatments according to HA offered above ground level: low (17 kg DM cow-1 d-1 vs. high HA (25 kg DM cow¹ d¹. All cows were supplemented with grass silage supplying daily 6.25 and 4.6 kg DM of concentrate (concentrate commercial plus high corn moisture. Decreasing HA influenced positively milk production (+25%, milk protein (+20 kg, and milk fat (+17 kg per hectare; however no effects on milk production per cow or energy metabolic status were observed in the cows. In conclusion, a low HA showed to be the most significant influencing factor on milk and milk solids production per hectare in dairy cows grazing restricted winter and supplemented with grass silage and concentrate; but no effect on the milk production per cow was found.

The relationships between biodiversity and ecosystem services and the effects of grazing cessation in semi-natural grasslands

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S. Wehn

2018-04-01

Full Text Available Land use change can affect biodiversity, and this has an impact on ecosystem services (ESs, but the relationships between biodiversity and ESs are complex and poorly understood. Biodiversity is declining due to the abandonment of extensively grazed semi-natural grasslands.We therefore aim to explore relationships between biodiversity and ESs provided by extensively managed semi-natural grasslands. Focusing on vascular plant species richness, as well as the ESs fodder quantity, quality, and stability, allergy control, climate regulation, nutrient cycling, pollination, and aesthetic appreciation, we carried out botanical field surveys of 28 paired extensively grazed and abandoned semi-natural grassland plots, with four subplots of 4 m2 in each plot. The management of the semi-natural grasslands is and has been at low intensity. We calculated the influence of abandonment on the ES indicators, measured the correlation between the biodiversity measure of vascular plant species richness and ES indicators, and finally determined how the relationships between plant species richness and the ES indicators were affected by the cessation of the extensive management.ES indicators are often, but not always, positively correlated with species richness. Cessation of extensive grazing has both negative and positive effects on ES indicators but the relationships between species richness and ES indicators are often different in extensively managed and abandoned semi-natural grasslands. The relationships between species richness and ES indicators are less pronounced in the extensively managed semi-natural grassland than for the abandoned. One possible reason for this outcome is high functional redundancy in the extensively managed semi-natural grasslands.

Diet selection and performance of horses grazing on different heathland types.

Science.gov (United States)

López López, C; Ferreira, L M M; García, U; Moreno-Gonzalo, J; Rodrigues, M A M; Osoro, K; Ferre, I; Celaya, R

2017-10-01

The number of horses in northern Spanish mountains has increased in recent decades, but little is known about their grazing behaviour, performance and potential for foal meat production. This research aimed to study the diet selection, liveweight (LW) changes and parasitic status of dry and lactating mares, and foals' LW gains, grazing on heathlands with different botanical composition. The experimental design consisted of three vegetation types: dominated by heather (Ericaceae) species (H), dominated by gorse (Ulex gallii; G) and co-dominated by gorse and heath-grasses (G-G), with four replicates per treatment (12 paddocks of 1.2 ha). The study lasted three grazing seasons (2010-12). Each year, 24 crossbred mature mares (310±52 kg LW) were used, managing one lactating mare with her foal plus one non-lactating mare per paddock from May to late summer or early autumn. In the case of H paddocks, animals had to be removed before (late August to early September) because of apparent loss of body condition. Animals were periodically weighed. Mares' diet composition was estimated using alkane markers, analysing the discrepancies in alkane concentrations between dietary plant components and faeces. Faecal samples were also analysed for gastrointestinal nematodes ova. Chemical composition of the main plant components (i.e. heather, gorse and grasses) revealed a low nutritive value, averaging 79, 115 and 113 g CP/kg dry matter (DM), respectively, that could restrict livestock performance. Mares initially selected gorse and grasses (0.47 and 0.40, respectively, in 2010), increasing heather consumption over time (from 0.13 in 2010 to 0.29 in 2012) as gorse availability decreased. The performance of both mares and foals was lower in H compared with G and G-G paddocks (-216 v. 347 g/day for mares, Phorses on gorse- and grass-gorse-dominated shrublands could be sustainable at least during part of the year (4 to 6 months). However, heather-dominated heathlands are not able to

Developmental instability and fitness in Periploca laevigata experiencing grazing disturbance

Science.gov (United States)

Alados, C.L.; Giner, M.L.; Dehesa, L.; Escos, J.; Barroso, F.; Emlen, J.M.; Freeman, D.C.

2002-01-01

We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long‐standing natural stress (grazing) in a palatable tannin‐producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant’s condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium‐grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.

Multisensor sampling of pelagic ecosystem variables in a coastal environment to estimate zooplankton grazing impact

Science.gov (United States)

Sutton, Tracey; Hopkins, Thomas; Remsen, Andrew; Burghart, Scott

2001-01-01

Sampling was conducted on the west Florida continental shelf ecosystem modeling site to estimate zooplankton grazing impact on primary production. Samples were collected with the high-resolution sampler, a towed array bearing electronic and optical sensors operating in tandem with a paired net/bottle verification system. A close biological-physical coupling was observed, with three main plankton communities: 1. a high-density inshore community dominated by larvaceans coincident with a salinity gradient; 2. a low-density offshore community dominated by small calanoid copepods coincident with the warm mixed layer; and 3. a high-density offshore community dominated by small poecilostomatoid and cyclopoid copepods and ostracods coincident with cooler, sub-pycnocline oceanic water. Both high-density communities were associated with relatively turbid water. Applying available grazing rates from the literature to our abundance data, grazing pressure mirrored the above bio-physical pattern, with the offshore sub-pycnocline community contributing ˜65% of grazing pressure despite representing only 19% of the total volume of the transect. This suggests that grazing pressure is highly localized, emphasizing the importance of high-resolution sampling to better understand plankton dynamics. A comparison of our grazing rate estimates with primary production estimates suggests that mesozooplankton do not control the fate of phytoplankton over much of the area studied (<5% grazing of daily primary production), but "hot spots" (˜25-50% grazing) do occur which may have an effect on floral composition.

Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

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Anja Linstädter

Full Text Available Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs. Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses and two-trait PFTs (e.g. perennial grasses performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may

The reliability of grazing rate estimates from dilution experiments: Have we over-estimated rates of organic carbon consumption by microzooplankton?

Directory of Open Access Journals (Sweden)

J. R. Dolan,

2005-01-01

Full Text Available According to a recent global analysis, microzooplankton grazing is surprisingly invariant, ranging only between 59 and 74% of phytoplankton primary production across systems differing in seasonality, trophic status, latitude, or salinity. Thus an important biological process in the world ocean, the daily consumption of recently fixed carbon, appears nearly constant. We believe this conclusion is an artefact because dilution experiments are 1 prone to providing over-estimates of grazing rates and 2 unlikely to furnish evidence of low grazing rates. In our view the overall average rate of microzooplankton grazing probably does not exceed 50% of primary production and may be even lower in oligotrophic systems.

Grazing behavior and production characteristics among cows differing in residual feed intake while grazing late season Idaho rangeland

Science.gov (United States)

The objectives were to determine if cows classified as either low- or high-residual feed intake (LRFI or HRFI) differed in BW, BCS, and winter grazing activity over time. Thirty Hereford x Angus (LRFI = 16; HRFI = 14) 2-year-old cows grazed sagebrush-steppe for 78 d beginning 29 September 2016. Body...

A farm platform approach to optimizing temperate grazing-livestock systems: metrics for trade-off assessments and future innovations

Science.gov (United States)

Harris, Paul; Takahashi, Taro; Blackwell, Martin; Cardenas, Laura; Collins, Adrian; Dungait, Jennifer; Eisler, Mark; Hawkins, Jane; Misselbrook, Tom; Mcauliffe, Graham; Mcfadzean, Jamie; Murray, Phil; Orr, Robert; Jordana Rivero, M.; Wu, Lianhai; Lee, Michael

2017-04-01

Global agriculture is at a critical juncture when competing requirements for maximal production and minimal pollution have led to the concept of sustainable intensification. Livestock production, especially ruminant livestock is central to this debate. Ruminants make an important contribution to global food security by converting feed that is unsuitable for human consumption to high value protein, demand for which is currently increasing at an unprecedented rate. Sustainable intensification of ruminant livestock production may be applied to pastoral grazing, mixed-cropping, feedlot and housed production systems. All these systems have associated environmental risks such as water and air pollution, greenhouse gas emissions and soil degradation, as well as issues affecting production efficiency, product quality and consumer acceptability, such as reduced animal fertility, health and welfare, reflected in the development of agricultural sustainability policies. Further, in many societies livestock represent a resource far greater than just food, e.g. fibre, draught, fertiliser, fuel, bank and social. These challenges necessitate multidisciplinary solutions that can only be properly researched, implemented and tested in real-world production systems which are suited to their geographical and climatic production practice, e.g. temperate grassland. The North Wyke Farm Platform (http://www.rothamsted.ac.uk/farmplatform) was established during 2010 as a UK national capability for collaborative research, training and knowledge exchange in agro-environmental sciences. Its remit is to research agricultural productivity and ecosystem responses to different management practices for beef and sheep production in lowland temperate grasslands. Following construction, a typical beef and sheep system based on permanent pasture receiving chemical fertilisers on first grade pasture (>60% perennial ryegrass) was implemented across the 67.2 ha farm platform in order to obtain baseline

High motility reduces grazing mortality of planktonic bacteria

DEFF Research Database (Denmark)

Matz, Carsten; Jurgens, K.

2005-01-01

We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum......(3), >50 mum s(-1)) illustrated the combined protective action of small cell size and high motility. Our findings suggest that motility has an important adaptive function in the survival of planktonic bacteria during protozoan grazing....

Are There Consistent Grazing Indicators in Drylands? Testing Plant Functional Types of Various Complexity in South Africa’s Grassland and Savanna Biomes

Science.gov (United States)

Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A.; Oomen, Roelof J.; du Preez, Chris C.; Ruppert, Jan C.; Ewert, Frank

2014-01-01

Despite our growing knowledge on plants’ functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa’s grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be

Green leaf allowance and dairy ewe performance grazing on tropical pasture.

Science.gov (United States)

De Souza, J; Batistel, F; Ticiani, E; Sandri, E C; Pedreira, C G S; Oliveira, D E

2014-06-01

pattern in responses to GLA levels as reported in the literature with temperate pastures, the magnitude of the process changed and the maximum response in milk yield from lactating dairy ewes grazing a tropical pasture would be achieved with higher forage allowances than in temperate pastures. Overall, Aruana guineagrass grazed by lactating dairy ewes should be managed to provide 7 to 10 GLA in kg DM/100 kg BW according to the production goals.

Longer rest periods for intensive rotational grazing limit diet quality ...

African Journals Online (AJOL)

Longer rest periods for intensive rotational grazing limit diet quality of sheep without enhancing environmental benefits. ... This experiment was established to compare three intensive rotational grazing strategies (fast rotation [FR], average 57-day rest; slow rotation [SR], average 114-day rest; and flexible grazing [FX], based ...

Postfledging survival of Grasshopper Sparrows in grasslands managed with fire and grazing

Science.gov (United States)

Hovick, Torre J.; Miller, James R.; Koford, Rolf R.; Engle, David M.; Debinski, Diane M.

2011-01-01

More accurate estimates of survival after nestlings fledge are needed for population models to be parameterized and population dynamics to be understood during this vulnerable life stage. The period after fledging is the time when chicks learn to fly, forage, and hide from predators. We monitored postfledging survival, causespecific mortality, and movements of Grasshopper Sparrows (Ammodramus savannarum) in grassland managed with fire and grazing. In 2009, we attached radio transmitters to 50 nestlings from 50 different broods and modeled their survival in response to climatic, biological, and ecological variables. There was no effect of treatment on survival. The factor most influencing postfledging survival was age; no other variable was significant. The majority of chicks (74%) died within 3 days of radio-transmitter attachment. We attributed most mortality to mesopredators (48%) and exposure (28%). Fledglings' movements increased rapidly for the first 4 days after they left the nest and were relatively stable for the remaining 10 days we tracked them. On average, fledglings took flight for the first time 4 days after fledging and flew ≥10 m 9 days after fledging. Our data show that the Grasshopper Sparrow's survival rates may be less than most models relying on nest-success estimates predict, and we emphasize the importance of incorporating estimates of survival during the postfledging period in demographic models.

Short communication: grazing pattern of dairy cows that were selected for divergent residual feed intake as calves.

Science.gov (United States)

Gregorini, P; Waghorn, G C; Kuhn-Sherlock, B; Romera, A J; Macdonald, K A

2015-09-01

The aim of this study was to investigate and assess differences in the grazing pattern of 2 groups of mature dairy cows selected as calves for divergent residual feed intake (RFI). Sixteen Holstein-Friesian cows (471±31kg of body weight, 100 d in milk), comprising 8 cows selected as calves (6-8 mo old) for low (most efficient: CSCLowRFI) and 8 cows selected as calves for high (least efficient: CSCHighRFI) RFI, were used for the purpose of this study. Cows (n=16) were managed as a single group, and strip-grazed (24-h pasture allocation at 0800h) a perennial ryegrass sward for 31 d, with measurements taken during the last 21 d. All cows were equipped with motion sensors for the duration of the study, and jaw movements were measured for three 24-h periods during 3 random nonconsecutive days. Measurements included number of steps and jaw movements during grazing and rumination, plus fecal particle size distribution. Jaw movements were analyzed to identify bites, mastication (oral processing of ingesta) during grazing bouts, chewing during rumination, and to calculate grazing and rumination times for 24-h periods. Grazing and walking behavior were also analyzed in relation to the first meal of the day after the new pasture was allocated. Measured variables were subjected to multivariate analysis. Cows selected for low RFI as calves appeared to (a) prioritize grazing and rumination over idling; (b) take fewer steps, but with a higher proportion of grazing steps at the expense of nongrazing steps; and (c) increase the duration of the first meal and commenced their second meal earlier than CSCHighRFI. The CSCLowRFI had fewer jaw movements during eating (39,820 vs. 45,118 for CSCLowRFI and CSCHighRFI, respectively), more intense rumination (i.e., 5 more chews per bolus), and their feces had 30% less large particles than CSCHighRFI. These results suggest that CSCLowRFI concentrate their grazing activity to the time when fresh pasture is allocated, and graze more efficiently

Solid-state 13C NMR experiments reveal effects of aggregate size on the chemical composition of particulate organic matter in grazed steppe soils

Science.gov (United States)

Steffens, M.; Kölbl, A.; Kögel-Knabner, I.

2009-04-01

Grazing is one of the most important factors that may reduce soil organic matter (SOM) stocks and subsequently deteriorate aggregate stability in grassland topsoils. Land use management and grazing reduction are assumed to increase the input of OM, improve the soil aggregation and change species composition of vegetation (changes depth of OM input). Many studies have evaluated the impact of grazing cessation on SOM quantity. But until today little is known about the impact of grazing cessation on the chemical quality of SOM in density fractions, aggregate size classes and different horizons. The central aim of this study was to analyse the quality of SOM fractions in differently sized aggregates and horizons as affected by increased inputs of organic matter due to grazing exclusion. We applied a combined aggregate size, density and particle size fractionation procedure to sandy steppe topsoils with different organic matter inputs due to different grazing intensities (continuously grazed = Cg, winter grazing = Wg, ungrazed since 1999 = Ug99, ungrazed since 1979 = Ug79). Three different particulate organic matter (POM; free POM, in aggregate occluded POM and small in aggregate occluded POM) and seven mineral-associated organic matter fractions were separated for each of three aggregate size classes (coarse = 2000-6300 m, medium = 630-2000 m and fine =

Zooplankton grazing in a eutrophic lake: implications of diel vertical migration

International Nuclear Information System (INIS)

Lampert, W.; Taylor, B.E.

1985-01-01

During summer and fall, depth profiles of zooplankton community grazing were determined in situ during day and night in the Schoehsee, a small eutrophic lake. Labeled algae of two different sizes were mixed with the natural suspension of phytoplankton in a grazing chamber. A small blue-green alga (Synechococcus, 1 μm) was labeled with 32 P; a larger green alga (Scenedesmus, 4-15 μm) was labeled with 14 C. During summer, grazing in the upper 5 m was negligible during day but strong at night. Hence, algae grow relatively unimpeded by grazing during daytime but are harvested at night. Vertical and diel differences in grazing rates disappeared when the vertical migration ceased in fall. Selectivity of grazing was controlled by the zooplankton species composition. Eudiaptomus showed a strong preference for Scenedesmus. Daphnia showed a slight preference for Scenedesmus, but Ceriodaphnia preferred Synechococcus. Cyclopoid copepodites did not ingest the small blue-green. Because Daphnia and Eudiaptomus were dominant, grazing rates on larger cells were usually higher than grazing rates on the small cells. Negative electivity indices for scenedesmus occurred only when the biomass of large crustaceans was extremely low (near the surface, during day). Zooplankton biomass was the main factor controlling both vertical and seasonal variations in grazing. Highest grazing rates (65%/d) were measured during fall when zooplankton abundance was high. Because differential losses can produce substantial errors in the results, it was necessary to process the samples on the boat immediately after collection, without preservation

Soil physico-hydrical properties resulting from the management in Integrated Production Systems

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André Carlos Auler

Full Text Available Anthropic action, such as the soil use and management systems, promote changes in the soil structure. These changes might hamper the development of plants in soil management practices that involve its mobilization, and the negative effects might be increased due to intensive use. The aim of this study was to evaluate the physico-hydrical properties of a Haplohumox in integrated production systems under different soil managements. The soil superficial (0.0-0.10 m and sub-superficial (0.10-0.20 m layers were evaluated in the different systems: conventional tillage (CT, minimum tillage (MT, no-tillage (NT and chiseled no-tillage (CNT, taking into consideration the annual ryegrass cropped for different uses [cover crop (C, grazing (G and silage (S] during the winter. Soil bulk density (Db, total porosity (TP, macro (Ma and microporosity (Mi, water retention curves (SWRC and water retention due to pore size (r were determined. The annual ryegrass used as C produced lower Db and Mi and higher TP and Ma in CT, MT and CNT systems. No difference was verified between G and S in any of the management systems or soil layers. The superficial layer SWRC presented similar behavior regarding CT, MT and CNT. Under NT, C resulted in higher water retention. However, G and S provided higher water retention due to the pore size in this system.

36 CFR 251.103 - Mediation of term grazing permit disputes.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Mediation of term grazing... Lands § 251.103 Mediation of term grazing permit disputes. (a) Decisions subject to mediation. In those States with Department of Agriculture certified mediation programs, any holder of a term grazing permit...

Synergistic Interactions within a Multispecies Biofilm Enhance Individual Species Protection against Grazing by a Pelagic Protozoan

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Prem K. Raghupathi

2018-01-01

enhance overall community fitness under stressful conditions such as grazing. These emerging inter- and intra-species interactions could play a vital role in biofilm dynamics in natural environments like soil or aquatic systems.

Grazing-incident PIXE Analysis Technology

International Nuclear Information System (INIS)

Li Hongri; Wang Guangpu; Liang Kun; Yang Ru; Han Dejun

2009-01-01

In the article, the grazing incidence technology is first applied to the PIXE (proton induced X-ray emission) analysis. Three pieces of samples were investigated, including the contaminated aluminium substrate, the SIMOX (separated by oxygen implantation) SOI (Silicon on Insulator) sample and the silicon wafer implanted with Fe + . The results reveal that the grazing-incident proton can improve the sensitivity of PIXE in trace analysis, especially for samples contaminated on surface. With the penetration depth of the proton bean decreased, the ratio of the peak area to the detection limit raised observably and the sensitivity near the sample surface increased. (authors)

Evidence for strain-specific exometabolomic responses of the coccolithophore Emiliania huxleyi to grazing by the dinoflagellate Oxyrrhis marina.

Directory of Open Access Journals (Sweden)

Kelsey L Poulson-Ellestad

2016-01-01

Full Text Available The coccolithophore Emiliania huxleyi forms massive blooms and plays a critical role in global elemental cycles, sequestering significant amounts of atmospheric carbon dioxide on geological time scales via production of calcium carbonate coccoliths and emitting dimethyl sulfoniopropionate (DMSP which has the potential for increasing atmospheric albedo. Because grazing in pelagic systems is a major top-down force structuring microbial communities, the influence of grazers on E. huxleyi populations has been of interest to researchers. Roles of DMSP (and related metabolites in interactions between E. huxleyi and protist grazers have been investigated, however, little is known about the release of other metabolites that may influence, or be influenced by, such grazing interactions. We used high-resolution mass spectrometry in an untargeted approach to survey the suite of low molecular weight compounds released by four different E. huxleyi strains in response to grazing by the dinoflagellate Oxyrrhis marina. Overall, a strikingly small number of metabolites were detected from E. huxleyi and O. marina cells, but these were distinctly informative to construct metabolic footprints. At most, E. huxleyi strains shared 25% of released metabolites. Furthermore, there appeared to be no unified metabolic response in E. huxleyi strains to grazing; rather these responses were strain specific. Concentrations of several metabolites also positively correlated with grazer activities, including grazing, ingestion, and growth rates; however, no single metabolite responded uniformly across all strains of E. huxleyi tested. Regardless, grazing clearly transformed the constituents of dissolved organic matter produced by these marine microbes. This study addresses several technical challenges, and presents a platform to further study the influence of chemical cues in aquatic systems and demonstrates the impact of strain diversity and grazing on the complexity of

Power and Conflict in Adaptive Management: Analyzing the Discourse of Riparian Management on Public Lands

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Jennifer S. Arnold

2012-03-01

Full Text Available Adaptive collaborative management emphasizes stakeholder engagement as a crucial component of resilient social-ecological systems. Collaboration among diverse stakeholders is expected to enhance learning, build social legitimacy for decision making, and establish relationships that support learning and adaptation in the long term. However, simply bringing together diverse stakeholders does not guarantee productive engagement. Using critical discourse analysis, we examined how diverse stakeholders negotiated knowledge and power in a workshop designed to inform adaptive management of riparian livestock grazing on a National Forest in the southwestern USA. Publicly recognized as a successful component of a larger collaborative effort, we found that the workshop effectively brought together diverse participants, yet still restricted dialogue in important ways. Notably, workshop facilitators took on the additional roles of riparian experts and instructors. As they guided workshop participants toward a consensus view of riparian conditions and management recommendations, they used their status as riparian experts to emphasize commonalities with stakeholders supportive of riparian grazing and accentuate differences with stakeholders skeptical of riparian grazing, including some Forest Service staff with power to influence management decisions. Ultimately, the management plan published one year later did not fully adopt the consensus view from the workshop, but rather included and acknowledged a broader diversity of stakeholder perspectives. Our findings suggest that leaders and facilitators of adaptive collaborative management can more effectively manage for productive stakeholder engagement and, thus, social-ecological resilience if they are more tentative in their convictions, more critical of the role of expert knowledge, and more attentive to the knowledge, interests, and power of diverse stakeholders.

Implementing Rotational Partial Rest/Patch-Burn Grazing in the Flint Hills, Kansas

Science.gov (United States)

2008-09-30

recently published a paper about the project in Ecological Restoration, titled Managing for Grassland Diversity: A Study on Grazing-Fire Interactions in...Eagle, print and online editions July 2008 From Beef to Butterflies: Enhancing Diversity in the Tallgrass Prairie Plants & Pollinators Symposium...Wolfe, E. Shochat, and S.K. Sherrod. 2005. Habitat fragmentation, rapid evolution and population persistence. Evolutionary Ecology Research 7: 235-249

Impact of cow strain and concentrate supplementation on grazing behaviour, milk yield and metabolic state of dairy cows in an organic pasture-based feeding system.

Science.gov (United States)

Heublein, C; Dohme-Meier, F; Südekum, K-H; Bruckmaier, R M; Thanner, S; Schori, F

2017-07-01

As ruminants are able to digest fibre efficiently and assuming that competition for feed v. food use would intensify in the future, cereals and other field crops should primarily be destined to cover the dietary needs of humans and monogastric animals such as poultry and pigs. Farming systems with a reduced or absent concentrate supplementation, as postulated by organic agriculture associations, require adapted dairy cows. The aim of this experiment was to examine the impact of concentrate supplementation on milk production, grazing and rumination behaviour, feed intake, physical activity and blood traits with two Holstein-Friesian cow strains and to conclude the consequences for sustainable and organic farming. The experiment was a cross-over study and took place on an organic farm in Switzerland. In all, 12 Swiss Holstein-Friesian (HCH) cows and 12 New Zealand Holstein-Friesian (HNZ) cows, which were paired according to lactation number, days in milk and age for primiparous cows, were used. All cows grazed full time and were supplemented either with 6 kg/day of a commercial, organic cereal-grain mix or received no supplement. After an adaptation period of 21 days, a measurement period of 7 days followed, where milk yield and composition, pasture dry matter intake estimated with the n-alkane double-indicator technique, physical activity based on pedometer measurements, grazing behaviour recorded by automatic jaw movement recorder and blood samples were investigated. Non-supplemented cows had a lower milk yield and supplemented HCH cows produced more milk than supplemented HNZ cows. Grazing time and physical activity were greater for non-supplemented cows. Supplementation had no effect on rumination behaviour, but HNZ cows spent longer ruminating compared with HCH cows. Pasture dry matter intake decreased with the concentrate supplementation. Results of blood analysis did not indicate a strong negative energy balance for either non-supplemented or supplemented cows

Eddy covariance methane flux measurements over a grazed pasture: effect of cows as moving point sources

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Felber, R.; Münger, A.; Neftel, A.; Ammann, C.

2015-06-01

Methane (CH4) from ruminants contributes one-third of global agricultural greenhouse gas emissions. Eddy covariance (EC) technique has been extensively used at various flux sites to investigate carbon dioxide exchange of ecosystems. Since the development of fast CH4 analyzers, the instrumentation at many flux sites has been amended for these gases. However, the application of EC over pastures is challenging due to the spatially and temporally uneven distribution of CH4 point sources induced by the grazing animals. We applied EC measurements during one grazing season over a pasture with 20 dairy cows (mean milk yield: 22.7 kg d-1) managed in a rotational grazing system. Individual cow positions were recorded by GPS trackers to attribute fluxes to animal emissions using a footprint model. Methane fluxes with cows in the footprint were up to 2 orders of magnitude higher than ecosystem fluxes without cows. Mean cow emissions of 423 ± 24 g CH4 head-1 d-1 (best estimate from this study) correspond well to animal respiration chamber measurements reported in the literature. However, a systematic effect of the distance between source and EC tower on cow emissions was found, which is attributed to the analytical footprint model used. We show that the EC method allows one to determine CH4 emissions of cows on a pasture if the data evaluation is adjusted for this purpose and if some cow distribution information is available.

Grass species selection patterns on rotationally-grazed Dohne ...

African Journals Online (AJOL)

Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...

Assessment of the Effects of Emerging Grazing Policies on Land ...

African Journals Online (AJOL)

ADOWIE PERE

carbon sequestration and water filtration. ... temperature of 13oc in the north during the harmattan in ... vegetation cover is removed with the view to obtain ... data concerning environmental degradation mitigation ... in terrestrial ecosystems and driving processes that .... Grazing systems, ecosystem response, and global.

Contrasting Effects of Cattle Grazing Intensity on Upland-Nesting Duck Production at Nest and Field Scales in the Aspen Parkland, Canada

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Jeffrey M. Warren

2008-12-01

field was 33.9% (95% CI = 17.0-51.8%. Across the range of residual cover observed in this study, nests with above-average nest-site vegetation density had nesting success rates that exceeded the levels believed necessary to maintain duck populations. Our findings on complex and previously unreported relationships between grazing, nest density, and nesting success provide useful insights into the management and conservation of ground-nesting grassland birds.

Sustainability of US Organic Beef and Dairy Production Systems: Soil, Plant and Cattle Interactions

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Kathy J. Soder

2013-07-01

Full Text Available In 2010, the National Organic Program implemented a rule for the US stating that pasture must be a significant source of feed in organic ruminant systems. This article will focus on how the pasture rule has impacted the management, economics and nutritional value of products derived from organic ruminant systems and the interactions of grazing cattle with pasture forages and soils. The use of synthetic fertilizers is prohibited in organic systems; therefore, producers must rely on animal manures, compost and cover crops to increase and maintain soil nitrogen content. Rotational and strip grazing are two of the most common grazing management practices utilized in grazing ruminant production systems; however, these practices are not exclusive to organic livestock producers. For dairy cattle, grazing reduces foot and leg problems common in confinement systems, but lowers milk production and exposes cows to parasites that can be difficult to treat without pharmaceuticals. Organic beef cattle may still be finished in feedlots for no more than 120 days in the US, but without growth hormones and antibiotics, gains may be reduced and illnesses increased. Grazing reduces the use of environmentally and economically costly concentrate feeds and recycles nutrients back to the soil efficiently, but lowers the rate of beef liveweight gain. Increased use of pasture can be economically, environmentally and socially sustainable if forage use efficiency is high and US consumers continue to pay a premium for organic beef and dairy products.

Effect of Grazing Intensity on Some Soil Chemical Characteristics in Gardaneh Zanburi Rangeland of Arsanjan

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zeinab khademolhosseini

2016-02-01

Full Text Available Introduction:Changes caused by grazing on range ecosystem are generally assessed based on the soil conditions and vegetation. Livestock as one of the major elements in range land ecosystems has different effects on different parts of this ecosystem. One of these impacts is excessive livestock grazing capacity which can have different effects on soils and plants in various intensities. Materials and Methods:Gardaneh ZanbooriRangelandis located in Arsanjan in Fars province. This isanareaof mountains, hillsandplains with the maximum height of 2280 meters and minimum height of 1640 meters above sea level. Related areas were separated under three different management methods of enclosure, moderate grazing and heavy grazing. These three areas are considered as symbolic areas of grazing intensity including the reference area where no grazing intensity was observed, the key area where medium to heavy grazing was applied and critical area where heavy grazing was used. These areas were similar in all characteristics such as topography, soil type and rainfall and differed only in their grazing intensity factor. Then, soil samples were collected. Random systematic soil sampling was conducted at two horizons of 0 -15 and 15 -30 cm. Therefore, five profiles in each area (enclosure, moderate grazing and heavy grazing, a total of 15 soil profiles, were excavated and two samples were taken in each profile (one sample from each horizon. Finally, the thirty soil samples were transported to the laboratory. Samples were dried in the air laboratory and passed a two millimeter sieve after smashing. Factors such as N, P, K, OM, EC and PH were measured in each sample In the laboratory, the percentage of P was determined by the Olsen method while the percentage of K was determined using the flamephotometry method. Moreover, N was measured using the Kjeldhal method. C was measured by the Walkley and Black method. The percentage of OM was found by carbon multiplying

Effect of pre-grazing herbage mass on dairy cow performance, grass dry matter production and output from perennial ryegrass (Lolium perenne L.) pastures.

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Wims, C M; Delaby, L; Boland, T M; O'Donovan, M

2014-01-01

A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumulation under grazing was lowest (Ppastures required more grass silage supplementation during the grazing season (+73 kg DM/cow) to overcome pasture deficits due to lower pasture growth rates (Ppasture intake, although cows grazing the L pastures had to graze a greater daily area (Ppasture reduces pasture DM production and at a system level may increase the requirement for imported feed.

Forage accumulation in brachiaria grass under continuous grazing with single or variable height during the seasons of the year

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Manoel Eduardo Rozalino Santos

2013-05-01

Full Text Available The objective of this study was to evaluate grazing management strategies of Brachiaria decumbens cv. Basilisk managed with different heights under continuous grazing with cattle. Two grazing management strategies were evaluated: maintenance of pasture with an average height of 25 cm throughout the experimental period and maintenance of pasture on the average of 15 cm in height during winter, up to 25 cm from the beginning of spring. The split-plot scheme and the randomized block design with four replications were adopted. The grazing management strategies corresponded to the primary factor, while the seasons (winter, spring and summer corresponded to secondary factor. The reduction of the average sward height to 15 cm in the winter resulted, when compared with pasture maintained at 25 cm, in overall higher growth rates (95 kg/ha.day DM and leaf blade (66.1 kg/ha.day DM, as well as higher rates of total accumulation (81.5 kg/ha.day DM and leaf blade (52.6 kg/ha.day DM. The accumulated forage production (from winter to summer was higher in the pasture lowered to 15 cm in winter (25.6 t/ha DM compared with that managed with an average height of 25 cm (22.2 t/ha DM. Regarding the seasons of the year, in the winter, there were lower rates of overall growth (6.4 kg/ha.day DM, leaf blade (5.6 kg/ha.day DM and pseudostem (0.8 kg/ha.day DM, and also lower total (-6.6 kg/ha.day DM and leaf blade (-7.5 kg/ha.day DM accumulation rates. In the spring there was a higher rate of leaf senescence (22.4 kg/ha.day DM. The accumulation of forage is incremented when the pasture of B. decumbens is lowered to 15 cm during the winter, and in the spring and summer, its average height is increased to 25 cm.

Governing Grazing and Mobility in the Samburu Lowlands, Kenya

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Annemiek Pas

2018-03-01

Full Text Available Pastoral mobility is seen as the most effective strategy to make use of constantly shifting resources. However, mobile pastoralism as a highly-valued strategy to manage grazing areas and exploit resource variability is becoming more complex, due to recurrent droughts, loss of forage, government-led settlement schemes, and enclosure of land for community conservation, among other reasons. Yet knowledge of how Samburu pastoralists perceive these changes, and govern and innovate in their mobility patterns and resource use, has received limited attention. This paper seeks to understand how Samburu pastoralists in the drylands of northern Kenya use and govern natural resources, how livestock grazing and mobility is planned for, and how boundaries and territory are constructed and performed both within and beyond the context of (nongovernmental projects. Fieldwork for this paper was conducted in Sesia, Samburu East, and consisted of interviews, focus group discussions, and participatory observation. Findings show that livestock mobility involves longer periods and more complex distances due to a shrinking resource base and new rules of access. Although access was previously generated based on the value of reciprocity, the creation of new forms of resource management results in conditional processes of inclusion and exclusion. Policy and project implementation has historically been driven by the imperative to secure land tenure and improve pasture in bounded areas. Opportunities to support institutions that promote mobility have been given insufficient attention.

Milk yield and blood urea nitrogen in crossbred cows grazing Leucaena leucocephala in a silvopastoral system in the Mexican tropics

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Maria B. Bottini-Luzardo

2016-09-01

Full Text Available The aim of the study was to assess milk yields, estimate the intake of crude protein (CP and determine the concentrations of blood urea nitrogen (BUN in early post-partum crossbred cows grazing irrigated Leucaena leucocephala (leucaena in a silvopastoral system relative to those in an irrigated grass monoculture.  Twenty-four multiparous cows were randomly allotted at calving on the basis of previous milk yields to 2 grazing treatments: grass monoculture system (MS of Cynodon nlemfuensis (n=12; and an intensive silvopastoral system (ISS composed of leucaena and C. nlemfuensis (n=12.  Cows were supplemented with sorghum grain (ISS or a conventional concentrate (MS during milking to ensure availability of metabolizable energy (ME and CP required for milk production.  Mean estimated intake of leucaena was 5.1±1.3 kg DM/d and estimated CP intakes were 1,479±3.3 and 1,258±3.3 g/d for ISS and MS, respectively (P>0.05, while estimated intakes of ME were 161±1.3 and 131±1.4 MJ/d for ISS and MS, respectively (P<0.05.  Milk yields were 13.5 and 14.5 kg/cow/d for cows on ISS and MS, respectively (P>0.05.  Concentrations of BUN were 19.1 mg/dL for cows in ISS and 15.3 mg/dL for cows in MS (P<0.05.  We conclude that intake of leucaena and sorghum grain in an irrigated silvopastoral system was sufficient to substitute for expensive concentrate in the diets of lactating cows grazing irrigated grass monoculture.  However, the higher levels of BUN found in ISS suggest a lower efficiency of N utilization in this treatment.  Restricting consumption of leucaena might be a means of improving efficiency of its use and this warrants investigation. Keywords: Cattle, crude protein, Cynodon nlemfuensis, leucaena, tropical pasturesDOI: 10.17138/TGFT(4159-167

Management applicability of the intermediate disturbance hypothesis across Mongolian rangeland ecosystems.

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Sasaki, Takehiro; Okubo, Satoru; Okayasu, Tomoo; Jamsran, Undarmaa; Ohkuro, Toshiya; Takeuchi, Kazuhiko

2009-03-01

The current growing body of evidence for diversity-disturbance relationships suggests that the peaked pattern predicted by the intermediate disturbance hypothesis (IDH) may not be the rule. Even if ecologists could quantify the diversity-disturbance relationship consistent with the IDH, the applicability of the IDH to land management has rarely been addressed. We examined two hypotheses related to the generality and management applicability of the IDH to Mongolian rangeland ecosystems: that the diversity-disturbance relationship varies as a function of landscape condition and that some intermediate scales of grazing can play an important role in terms of sustainable rangeland management through a grazing gradient approach. We quantified the landscape condition of each ecological site using an ordination technique and determined two types of landscape conditions: relatively benign and harsh environmental conditions. At the ecological sites characterized by relatively benign environmental conditions, diversity-disturbance relationships were generally consistent with the IDH, and maximum diversity was observed at some intermediate distance from the source of the grazing gradient. In contrast, the IDH was not supported at most (but not all) sites characterized by relatively harsh environmental conditions. The intermediate levels of grazing were generally located below the ecological threshold representing the points or zones at which disturbance should be limited to prevent drastic changes in ecological conditions, suggesting that there is little "conundrum" with regard to intermediate disturbance in the studied systems in terms of land management. We suggest that the landscape condition is one of the primary factors that cause inconsistencies in diversity-disturbance relationships. The ecological threshold can extend its utility in rangeland management because it also has the compatibility with the maintenance of species diversity. This study thus suggests that some

Review: Behavior and daily grazing patterns of cattle

NARCIS (Netherlands)

Gregorini, P.; Tamminga, S.; Gunther, S.A.

2006-01-01

Grazing ruminants consume their food in discrete grazing events. The frequency and distribution of these events depend on the current physiological state of the animal and its environment. Within a small spatio-temporal scale, foraging decisions such as when to begin, which frequency, and how to

Grazing livestock are exposed to terrestrial cyanobacteria.

Science.gov (United States)

McGorum, Bruce C; Pirie, R Scott; Glendinning, Laura; McLachlan, Gerry; Metcalf, James S; Banack, Sandra A; Cox, Paul A; Codd, Geoffrey A

2015-02-25

While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.

Physiological response curves reveal differences among season advancement and timing of grazing experimental treatments in a coastal Alaskan wetland

Science.gov (United States)

Leffler, A. J.; Kelsey, K.; Beard, K. H.; Choi, R. T.; Welker, J. M.

2016-12-01

The phenology of northern ecosystems is rapidly changing as high latitude regions warm. Spring green-up has advanced 1-3 days per decade since the early 1980's and sea ice retreat is likely to further accelerate the arrival of spring in coastal Alaska. One result of spring advancement is a phenological mismatch with the arrival of migratory geese that bread in the region. As green-up advances, geese arrive into a phenologically older system where vegetation has a higher C:N ratio than younger grasses with potential consequences for goose nutrition and C and N cycling. In 2014 and 2015 we established a season advancement X timing of grazing experiment to examine the ecosystem consequences of this mismatch. We used a LI-Cor 8100 automated, chamber-based C flux system to monitor hourly net ecosystem exchange (NEE) in eight plots: four were warmed in June to advance the growing season, four received ambient temperatures; two each experienced early, typical, late, or no grazing. The experiment is replicated six times, but the automated system is capable of measuring only one block; other blocks are measured twice weekly with a portable system. We fit physiological light response curves to weekly data and used incident sunlight to estimate daily NEE. Results suggest that daily carbon uptake ranged from ca. 0.6 to 4.5 g m-2 d-1 in the different treatments. Carbon uptake in the season advancement plots was lower than in the ambient plots by ca. 0.5 g m-2 d-1 averaged during the summer. Delaying grazing into the later season, the expectation of climate change, greatly increased NEE to 4.5 g m-2 d-1, a value much greater than the typical grazing period in 2015. Completely eliminating grazing from the system resulted in NEE of 2.9 g m-2 d-1. Differences were likely driven by warmer soils enhancing respiration, removal of photosynthetic biomass, and grazing maintaining tissue in a young, highly photosynthetic form. Overall our results suggest that timing of grazing in the

The Marshall Grazing Incidence X-ray Spectrometer

Science.gov (United States)

Kobayashi, Ken; Winebarger, Amy R.; Savage, Sabrina; Champey, Patrick; Cheimets, Peter N.; Hertz, Edward; Bruccoleri, Alexander R.; Golub, Leon; Ramsey, Brian; Ranganathan, Jaganathan; Marquez, Vanessa; Allured, Ryan; Parker, Theodore; Heilmann, Ralf K.; Schattenburg, Mark L.

2017-08-01

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument designed to obtain spatially resolved soft X-ray spectra of the solar atmosphere in the 6-24 Å (0.5-2.0 keV) range. The instrument consists of a single shell Wolter Type-I telescope, a slit, and a spectrometer comprising a matched pair of grazing incidence parabolic mirrors and a planar varied-line space diffraction grating. The instrument is designed to achieve a 50 mÅ spectral resolution and 5 arcsecond spatial resolution along a +/-4-arcminute long slit, and launch is planned for 2019. We report on the status and our approaches for fabrication and alignment for this novel optical system. The telescope and spectrometer mirrors are replicated nickel shells, and are currently being fabricated at the NASA Marshall Space Flight Center. The diffraction grating is currently under development by the Massachusetts Institute of Technology (MIT); because of the strong line spacing variation across the grating, it will be fabricated through e-beam lithography.

Comparative Assessment of Goods and Services Provided by Grazing Regulation and Reforestation in Degraded Mediterranean Rangelands

NARCIS (Netherlands)

Papanastasis, Vasilios P.; Bautista, Susana; Chouvardas, Dimitrios; Mantzanas, Konstantinos; Papadimitriou, Maria; Garcia Mayor, Angeles; Koukioumi, Polina; Papaioannou, Athanasios; Vallejo, Ramon V.

2017-01-01

Several management actions are applied to restore ecosystem services in degraded Mediterranean rangelands, which range from adjusting the grazing pressure to the removal of grazers and pine plantations. Four such actions were assessed in Quercus coccifera L. shrublands in northern Greece: (i)

Milk quality as affected by grazing time of day in Mediterranean goats.

Science.gov (United States)

Avondo, Marcella; Bonanno, Adriana; Pagano, Renato I; Valenti, Bernardo; Grigoli, Antonio Di; Luigia Alicata, M; Galofaro, Vittorio; Pennisi, Pietro

2008-02-01

We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two groups were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19.8% DM; Ptitrable acidity ( degrees SH) increased in the PM group (respectively 3.56 v. 3.42%; P=0.01; 3.55 v. 3.22 degrees SH/50 ml; P=0.01). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81% of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.

Seroepidemiological study of Q fever in domestic ruminants in semi-extensive grazing systems.

Science.gov (United States)

Ruiz-Fons, Francisco; Astobiza, Ianire; Barandika, Jesús F; Hurtado, Ana; Atxaerandio, Raquel; Juste, Ramón A; García-Pérez, Ana L

2010-01-20

Q fever, a worldwide zoonotic disease caused by Coxiella burnetii, is endemic in northern Spain where it has been reported as responsible for large series of human pneumonia cases and domestic ruminants' reproductive disorders. To investigate pathogen exposure among domestic ruminants in semi-extensive grazing systems in northern Spain, a serosurvey was carried out in 1,379 sheep (42 flocks), 626 beef cattle (46 herds) and 115 goats (11 herds). Serum antibodies were analysed by ELISA and positive samples were retested by Complement Fixation test (CFT) to detect recent infections. ELISA anti-C. burnetii antibody prevalence was slightly higher in sheep (11.8 +/- 2.0%) than in goats (8.7 +/- 5.9%) and beef cattle (6.7 +/- 2.0%). Herd prevalence was 74% for ovine, 45% for goat and 43% for bovine. Twenty-one percent of sheep flocks, 27% of goat and 14% of cattle herds had a C. burnetii seroprevalence >or= 20%. Only 15 out of 214 ELISA-positive animals reacted positive by CFT. Age-associated seroprevalence differed between ruminant species with a general increasing pattern with age. No evidence of correlation between abortion history and seroprevalence rates was observed despite the known abortifacient nature of C. burnetii in domestic ruminants. Results reported herein showed that sheep had the highest contact rate with C. burnetii in the region but also that cattle and goats should not be neglected as part of the domestic cycle of C. burnetii. This work reports basic epidemiologic patterns of C. burnetii in semi-extensive grazed domestic ruminants which, together with the relevant role of C. burnetii as a zoonotic and abortifacient agent, makes these results to concern both Public and Animal Health Authorities.

Stream chemistry responses to four range management strategies in eastern Oregon.

Science.gov (United States)

A.R. Tiedemann; D.A. Higgins; T.M. Quigley; H.R. Sanderson

1989-01-01

Responses of stream chemistry parameters, nitrate-N (NO3-N), phosphate (PO4), calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), and hydrogen ion activity (pH) were measured on 13 wildland watersheds managed at four different grazing strategies. Range management strategies tested were (A) no grazing, (B) grazing without control of livestock distribution (8.2 ha/...

Grazing reduces soil greenhouse gas fluxes in global grasslands: a meta-analysis

Science.gov (United States)

Tang, Shiming; Tian, Dashuan; Niu, Shuli

2017-04-01

Grazing causes a worldwide degradation in grassland and likely alters soil greenhouse gas fluxes (GHGs). However, the general patterns of grazing-induced changes in grassland soil GHGs and the underlying mechanisms remain unclear. Thus, we synthesized 63 independent experiments in global grasslands that examined grazing impacts on soil GHGs (CO2, CH4 and N2O). We found that grazing with light or moderate intensity did not significantly influence soil GHGs, but consistently depressed them under heavy grazing, reducing CO2 emission by 10.55%, CH4 uptake by 19.24% and N2O emission by 28.04%. The reduction in soil CO2 was mainly due to decreased activity in roots and microbes (soil respiration per unit root and microbial biomass), which was suppressed by less water availability due to higher soil temperature induced by lower community cover under heavy grazing. N2O emission decreased with grazing-caused decline in soil total N. The inhibitory effect on methanotroph activities by water stress is responsible for the decreased CH4 uptake. Furthermore, grazing duration and precipitation also influenced the direction and magnitude of responses in GHGs fluxes. Overall, our results indicate that the reduction in soil CO2 and N2O emission under heavy grazing is partially compensated by the decrease in CH4 uptake, which is mainly regulated by variations in soil moisture.

Taxonomical and functional diversity turnover in Mediterranean grasslands: interactions between grazing, habitat type and rainfall

Czech Academy of Sciences Publication Activity Database

Carmona, C. P.; Azcárate, F. M.; de Bello, Francesco; Ollero, H. S.; Lepš, Jan; Peco, B.

2012-01-01

Roč. 49, č. 5 (2012), 1084-1093 ISSN 0021-8901 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Institutional support: RVO:67985939 ; RVO:60077344 Keywords : Dehesa * diversity partitioning * functional redundancy * grazing management Subject RIV: EH - Ecology, Behaviour Impact factor: 4.740, year: 2012

Population Dynamics and Transcriptomic Responses of Chorthippus albonemus (Orthoptera: Acrididae to Herbivore Grazing Intensity

Directory of Open Access Journals (Sweden)

Xinghu Qin

2017-11-01

Full Text Available Livestock grazing can trigger outbreaks of insect pests in steppe ecosystems of Inner Mongolia in China. However, the physiological responses of the grasshopper Chorthippus albonemus to grazing are not well-understood. Here we investigated the effects of sheep grazing on the population dynamics and transcriptomic response of C. albonemus. We collected the insects three times (about 20 days apart in 1.33-ha plots in which there were no grazing, light grazing, moderate grazing, heavy grazing, or overgrazing. Our results showed that continuous grazing significantly decreased plant biomass and influenced plant succession. Total insect species diversity significantly declined along the grazing intensity gradient and over time. Results of the first two collections of C. albonemus indicated that moderate grazing significantly increased the abundance of C. albonemus. However, abundance was significantly decreased in plots that were overgrazed, possibly because of food stress and environmental pressures. Under moderate grazing, betA and CHDH genes were significantly upregulated in C. albonemus. In response to higher grazing intensity, upregulated genes included those involved in serine-type peptidase activity, anatomical structure development, and sensory organ development; downregulated genes included those involved in the structural constituents of the ribosome and ribosome processes. Genes strongly upregulated in response to heavy grazing pressure included adaptive genes such as those encoding ankyrin repeat domain-containing protein and HSP. These findings improve our understanding of the role of the transcriptome in C. albonemus population response to livestock grazing and may provide useful targets for grasshopper control.

Reproductive performance of ewes grazing lucerne during different periods around mating.

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Robertson, S M; Clayton, E H; Friend, M A

2015-11-01

High intake of lucerne pastures or feeding of other high quality diets during early pregnancy may increase embryo mortality, negating any benefit of improved nutrition on ovulation rate in ewes. This study was conducted to determine whether grazing ewes on lucerne (Medicago sativa) pastures for 7 days prior to and throughout joining would result in greater foetal numbers than if ewes were removed 7 days after the commencement of joining, or if ewes grazed senescent pasture throughout the joining period. Merino ewes (300) were allocated to two replicates of three treatments, grazing pastures between Days -7 and 36 of an unsynchronised, natural autumn joining. Grazing lucerne to Day 7 of joining resulted in 30% more (Pewe than grazing senescent pasture (1.60±0.07 and 1.31±0.07, respectively), and 19% more lambs marked per ewe joined. Extending grazing of lucerne past Day 7 of joining did not result in additional foetuses per ewe (1.61±0.06) in comparison with only grazing lucerne to Day 7 of joining. Greater than 80% of ewes mated during the first 14 days of joining, and the proportions of ewes returning to oestrus and re-mating (0.18±0.022) and of non-pregnant (0.09±0.017) ewes were similar (P>0.05) among all treatment groups, suggesting no differences between treatments in embryo mortality. Grazing naturally cycling ewes on lucerne prior to and during joinings in autumn is recommended as a means to increase the number of lambs born, although additional gains may not be obtained by grazing past day seven of joining. Copyright © 2015 Elsevier B.V. All rights reserved.

Soil Properties and Plant Biomass Production in Natural Rangeland Management Systems

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Romeu de Souza Werner

Full Text Available ABSTRACT Improper management of rangelands can cause land degradation and reduce the economic efficiency of livestock activity. The aim of this study was to evaluate soil properties and quantify plant biomass production in four natural rangeland management systems in the Santa Catarina Plateau (Planalto Catarinense of Brazil. The treatments, which included mowed natural rangeland (NR, burned natural rangeland (BR, natural rangeland improved through the introduction of plant species after harrowing (IH, and natural rangeland improved through the introduction of plant species after chisel plowing (IC, were evaluated in a Nitossolo Bruno (Nitisol. In the improved treatments, soil acidity was corrected, phosphate fertilizer was applied, and intercropped annual ryegrass (Lolium multiflorum, velvet grass (Holcus lanatus, and white clover (Trifolium repens were sown. Management systems with harrowed or chisel plowed soil showed improved soil physical properties; however, the effect decreased over time and values approached those of burned and mowed natural rangelands. Natural rangeland systems in the establishment phase had little influence on soil organic C. The mowed natural rangeland and improved natural rangeland exhibited greater production of grazing material, while burning the field decreased production and increased the proportion of weeds. Improvement of the natural rangelands increased leguminous biomass for pasture.

Integrating the pastoral component in agricultural systems

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Paulo César de Faccio Carvalho

2018-03-01

Full Text Available ABSTRACT This paper aims to discuss the impact of the introduction of pastures and grazing animals in agricultural systems. For the purposes of this manuscript, we focus on within-farm integrated crop-livestock systems (ICLS, typical of Southern Brazil. These ICLS are designed to create and enhance the synergisms and emergent properties have arisen from agricultural areas where livestock activities are integrated with crops. We show that the introduction of the crop component will affect less the preceding condition than the introduction of the livestock component. While the introduction of crops in pastoral systems represents increasing diversity of the plant component, the introduction of animals would represent the entry of new flows and interactions within the system. Thus, given the new complexity levels achieved from the introduction of grazing, the probability of arising emergent properties is theoretically much higher. However, grazing management is vital in determining the success or failure of such initiative. The grazing intensity practiced during the pasture phase would affect the canopy structure and the forage availability to animals. In adequate and moderate grazing intensities, it is possible to affirm that livestock combined with crops (ICLS has a potential positive impact. As important as the improvements that grazing animals can generate to the soil-plant components, the economic resilience remarkably increases when pasture rotations are introduced compared with purely agriculture systems, particularly in climate-risk situations. Thus, the integration of the pastoral component can enhance the sustainable intensification of food production, but it modifies simple, pure agricultural systems into more complex and knowledge-demanding production systems.

Effects of nitrogen fertilization and grazing on the emission of nitrous oxide from grassland

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Velthof, G.L.; Brader, A.B.; Oenema, O. [NMI, Dept. of Soil Science and Plant Nutrition, Wageningen Agricultural Univ. (Netherlands)

1995-11-01

In the Netherlands, managed grasslands are potentially a large source of nitrous oxide (N{sub 2}O), because of the large nitrogen (N) input and the relatively high ground water levels. To provide insight into the major factors that contribute to N{sub 2}O emission from grassland and to provide quantitative N{sub 2}O emission rates, a monitoring study was carried out on four sites, during March 1992 to March 1994. Fluxes of N{sub 2}O increased after N fertilizer application and grazing, especially during wet conditions. Fluxes were higher from peat soils than from sand and clay soils. Fluxes were low during the winter periods. Total N{sub 2}O losses were 2 to 4.5 times higher on grassland fertilized with 160-460 kg N ha{sup -1} yr{sup -1} than on unfertilized grassland. Losses from grazed grasslands were 1.5 to 3.5 times higher than losses from mown grassland. This study shows that management practice of grassland and soil type are major factors controlling N{sub 2}O emission from grasslands. 2 figs., 3 refs.

Impact of Graze-­‐Out in Hard Red Winter Wheat Production

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Neupane, Diwash; Moss, Charles B.

2014-01-01

We investigate the relationship between wheat graze-­‐out and cattle-­‐wheat price ratio and moisture level and examine the impact of graze-­‐out on wheat yield in major wheat-­‐producing states in US. Results indicate that cattle-­‐wheat price ratio and moisture level affect farmers’ graze out decision and graze-­‐out have significant impact on wheat yield.

Effects of Grazing Abandoned Grassland on Herbage Production and Utilization, and Sheep Preference and Performance

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Håvard Steinshamn

2018-05-01

Full Text Available Large areas of farmland are abandoned in Norway, which for various reasons are regarded as undesirable. Loss of farmland may have negative implications for biodiversity and ecosystem function and food production potential. The objectives of this study were to assess forage mass production and utilization, botanical composition, lamb performance, and grazing distribution pattern when reintroducing livestock grazing to an abandoned grassland. The study area was located in Central Norway, unmanaged for 12 years. Sheep grazed the area for 10 weeks in 2013 and 4 weeks in spring and autumn, respectively, in 2014 and 2015. During the summer of 2014 and 2015, the area was subjected to the following replicated treatments: (1 No grazing, (2 grazing with heifers, and (3 grazing with ewes and their offspring. The stocking rate was similar in the grazed treatments. Forage biomass production and animal intake were estimated using grazing exclosure cages and botanical composition by visual assessment. Effect on lamb performance was evaluated by live weight gain and slaughter traits in sheep subjected to three treatments: (1 Common farm procedure with summer range pasturing, (2 spring grazing period extended by 1 month on the abandoned grassland before summer range pasturing, and (3 spring and summer grazing on the abandoned grassland. Grazing distribution patterns were studied using GPS position collars on ewes. Total annual biomass production was on average 72% higher with summer grazing than without. Annual consumption and utilization was on average 218 g DM/m2 and 70% when summer grazed, and 25 g DM/m2 and 18% without grazing, respectively. Botanical composition did not differ between treatments. Live weight gain was higher in lambs subjected to an extended spring grazing period (255 g/d compared to common farm practice (228 g/d and spring and summer grazing on the abandoned grassland (203 g/d, and carcass value was 14% higher in lambs on extended spring

Corticosterone metabolite concentrations in greater sage-grouse are positively associated with the presence of cattle grazing

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Jankowski, M.D.; Russell, Robin E.; Franson, J. Christian; Dusek, Robert J.; Hines, M.K.; Gregg, M.; Hofmeister, Erik K.

2014-01-01

The sagebrush biome in the western United States is home to the imperiled greater sage-grouse (Centrocercus urophasianus) and encompasses rangelands used for cattle production. Cattle grazing activities have been implicated in the range-wide decline of the sage-grouse, but no studies have investigated the relationship between the physiological condition of sage-grouse and the presence of grazing cattle. We sampled 329 sage-grouse across four sites (two grazed and two ungrazed) encompassing 13 600 km2 during the spring and late summer–early autumn of 2005 to evaluate whether demographic factors, breeding status, plasma protein levels, and residence in a cattle-grazed habitat were associated with the stress hormone corticosterone. Corticosterone was measured in feces as immunoreactive corticosterone metabolites (ICM). Males captured during the lekking season exhibited higher ICM levels than all others. Prenesting female sage-grouse captured in a grazed site had higher ICM levels than those in ungrazed sites and prenesting female plasma protein levels were negatively correlated with ICM concentrations. With the use of a small-scale spatial model, we identified a positive correlation between cattle pat count and sage-grouse ICM levels. Our model indicated that ICM levels increased by 2.60 ng · g-1 dry feces for every increase in the number of cow pats found in the vicinity. Management practices will benefit from future research regarding the consistency and mechanism(s) responsible for this association and, importantly, how ICM levels and demographic rates are related in this species of conservation concern.

Grazing preference and utilization of soil fungi by Folsomia candida (Collembola)

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Hedenec, Petr; Frouz, Jan

2016-04-01

Soil fungi are important food resources for soil fauna. Here we ask whether the collembolan Folsomia candida shows selectivity in grazing between four saprophytic fungi (Penicillium chrysogenum, Penicillium expansum, Absidia glauca, and Cladosporium herbarum), whether grazing preference corresponds to effects on collembolan reproduction, and whether the effects of fungi on grazing and reproduction depends on the fungal substrate, which included three kinds of litter (Alnus glutinosa, Salix caprea, and Quercus robur) and one kind of agar (yeast extract). On agar, Cladosporium herbarum and Absidia glauca were the most preferred fungi and supported the highest collembolan reproduction. On fungal-colonized litter, grazing preference was more affected by litter type than by fungal species whereas collembolan reproduction was affected by both litter type and fungal species. On fungal-colonized litter, the litter type that was most preferred for grazing did not support the highest reproduction, i.e., there was an inconsistency between food preference and suitability. Alder and willow were preferred over oak for grazing, but alder supported the least reproduction.

Correlation between intake and ingestive behavior of pasture-grazed heifers

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Hermógenes Almeida Santana Junior

2013-12-01

Full Text Available The objective of this study was to evaluate the correlation between intake and ingestive behavior of crossbred heifers in grazing tropical. The experiment was conducted on the Princesa do Mateiro Farm, in the city of Ribeirão do Largo, Bahia. A total of 20 heifers with genetic makeup 5/8 dairy Guzerá and 3/8 Holstein, average age of 18 months and body weight of 187 ± 13.1 kg have been used. The experiment lasted 224 days and involved animals raised in a rotational grazing system with Brachiaria brizantha cv. Marandú. Grazing time was not correlated with any of the variables associated with intake. Rumination time showed positive correlations with the intake of forage dry matter (DMIF and neutral detergent fiber (NDFI. Variables associated with the time spent on feeding at the trough, overall feeding and total chewing were not correlated with intake (P>0.05. There have been positive correlations between the number of grazing periods (NGP and rumination periods (NRP and total DM intake (TDMI, organic matter (OMI, forage (DMIF, neutral detergent fiber (NDFI, total carbohydrates (TCHI and ether extract (EEI. Crude protein intake (CPI was positively correlated with NGP and NRP. The mouthful rate was positively correlated with TDMI, OMI, DMIF, NDFI, TCHI, EEI and CPI. Average time per swallow was negatively correlated with TDMI, OMI, NDFI, TCHI and EEI. Positive correlations have been observed between the number of mouthfuls per day and TDMI, OMI, DMIF, NDFI, TCHI, EEI. The number of chews per bolus showed negative correlations with DMIS and CPI. The time per cake ruminated has correlated negatively with the intake of crude protein. The number of chews per bolus showed positive correlations with the intakes of dry matter and neutral detergent fiber. The number of boli per day showed positive correlations with DMIF and TCHI. The time spent on chewing showed no significant correlation with intake. In conflict with the national and international

Grazing exit versus grazing incidence geometry for x-ray absorption near edge structure analysis of arsenic traces

International Nuclear Information System (INIS)

Meirer, F.; Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

2009-01-01

In the presented study the grazing exit x-ray fluorescence was tested for its applicability to x-ray absorption near edge structure analysis of arsenic in droplet samples. The experimental results have been compared to the findings of former analyses of the same samples using a grazing incidence (GI) setup to compare the performance of both geometries. Furthermore, the investigations were accomplished to gain a better understanding of the so called self-absorption effect, which was observed and investigated in previous studies using a GI geometry. It was suggested that a normal incidence-grazing-exit geometry would not suffer from self-absorption effects in x-ray absorption fine structure (XAFS) analysis due to the minimized path length of the incident beam through the sample. The results proved this assumption and in turn confirmed the occurrence of the self-absorption effect for GI geometry. Due to its lower sensitivity it is difficult to apply the GE geometry to XAFS analysis of trace amounts (few nanograms) of samples but the technique is well suited for the analysis of small amounts of concentrated samples

Seroepidemiological study of Q fever in domestic ruminants in semi-extensive grazing systems

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Atxaerandio Raquel

2010-01-01

Full Text Available Abstract Background Q fever, a worldwide zoonotic disease caused by Coxiella burnetii, is endemic in northern Spain where it has been reported as responsible for large series of human pneumonia cases and domestic ruminants' reproductive disorders. To investigate pathogen exposure among domestic ruminants in semi-extensive grazing systems in northern Spain, a serosurvey was carried out in 1,379 sheep (42 flocks, 626 beef cattle (46 herds and 115 goats (11 herds. Serum antibodies were analysed by ELISA and positive samples were retested by Complement Fixation test (CFT to detect recent infections. Results ELISA anti-C. burnetii antibody prevalence was slightly higher in sheep (11.8 ± 2.0% than in goats (8.7 ± 5.9% and beef cattle (6.7 ± 2.0%. Herd prevalence was 74% for ovine, 45% for goat and 43% for bovine. Twenty-one percent of sheep flocks, 27% of goat and 14% of cattle herds had a C. burnetii seroprevalence ≥ 20%. Only 15 out of 214 ELISA-positive animals reacted positive by CFT. Age-associated seroprevalence differed between ruminant species with a general increasing pattern with age. No evidence of correlation between abortion history and seroprevalence rates was observed despite the known abortifacient nature of C. burnetii in domestic ruminants. Conclusions Results reported herein showed that sheep had the highest contact rate with C. burnetii in the region but also that cattle and goats should not be neglected as part of the domestic cycle of C. burnetii. This work reports basic epidemiologic patterns of C. burnetii in semi-extensive grazed domestic ruminants which, together with the relevant role of C. burnetii as a zoonotic and abortifacient agent, makes these results to concern both Public and Animal Health Authorities.

Cut and carry vs. grazing of cultivated pastures in small-scale dairy systems in the central highlands of Mexico

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Paola Estefania Pincay-Figueroa

2016-12-01

Full Text Available Small-scale dairy systems are an option to alleviate poverty and contribute up to 37% of milk production in Mexico; however high costs affect their economic sustainability. Since grazing may reduce feeding costs, a participatory on farm experiment was undertaken to compare animal performance and feeding costs of the traditional cut-and-carry strategy or grazing cultivated pastures, during the dry season in the highlands of Mexico. Pastures of perennial and annual ryegrasses with white clover were utilised, complemented with maize silage and commercial concentrate. Five dairy cows were assigned to each strategy. The experiment ran for 12 weeks, recording weekly milk yields and fat and milk protein content; live-weight and body condition score every 14 days. Analysis was as a split-plot design. The adjusted (covariance mean milk yield was 18.78 kg/cow/day with no significant differences (P>0.05 between treatments, and no significant differences for live-weight or body condition score. There were no significant differences for milk fat (P>0.05, but there were for protein in milk (P

A model of ammonia volatilization from a grazing livestock farm

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Hutchings, N. J.; Sommer, S. G.; Jarvis, S. C.

A dynamic model was developed to predict the ammonia volatilization from grazing livestock farms and to allow potential control measures to be evaluated. The relationships within the model were based on the underlying physical and chemical processes but empirically based factors were used to reduce the demand for input data and where the understanding of the underlying processes was inadequate. On a daily basis, the model simulates the partitioning of dietary nitrogen into dung and urine and its subsequent fate within the pasture or the slurry handling system. The fate of dry matter and water added in dung, urine and from other sources is also predicted. The model illustrates the indirect interactions between ammonia sources, highlights the influence of slurry management on ammonia losses, stresses the need for integrated, whole farm measurements and demonstrates that assessments of the impact of control measures may be misleading unless considered at the scale of the whole farm.

Environmental Assessment of Beale AFB Grazing Lease Program

Science.gov (United States)

2012-12-01

Beale AFB will use livestock (cattle, sheep and goats ) on its properties throughout the year as needed for the control of noxious weeds, reduction...initiating a wildfire. California Farm Bureau Federation policy recognizes that grazing is the most practical and environmentally acceptable way to...Site Monitoring Well Installation and Annual Targeted Goat Grazing Project, Placer County, California. 21 September 2011.  

Optimal management of on-farm resources in small-scale dairy systems of Central Mexico: model development and evaluation.

Science.gov (United States)

Castelán-Ortega, Octavio Alonso; Martínez-García, Carlos Galdino; Mould, Fergus L; Dorward, Peter; Rehman, Tahir; Rayas-Amor, Adolfo Armando

2016-06-01

This study evaluates the available on-farm resources of five case studies typified as small-scale dairy systems in central Mexico. A comprehensive mixed-integer linear programming model was developed and applied to two case studies. The optimal plan suggested the following: (1) instruction and utilization of maize silage, (2) alfalfa hay making that added US$140/ha/cut to the total net income, (3) allocation of land to cultivated pastures in a ratio of 27:41(cultivated pastures/maize crop) rather than at the current 14:69, and dairy cattle should graze 12 h/day, (4) to avoid grazing of communal pastures because this activity represented an opportunity cost of family labor that reduced the farm net income, and (5) that the highest farm net income was obtained when liquid milk and yogurt sales were included in the optimal plan. In the context of small-scale dairy systems of central Mexico, the optimal plan would need to be implemented gradually to enable farmers to develop required skills and to change management strategies from reliance on forage and purchased concentrate to pasture-based and conserved forage systems.

Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management.

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Kevin A Wood

Full Text Available Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i food quantity, (ii food quality, and (iii the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems.

Fall-grown oat to extend the fall grazing season for replacement dairy heifers.

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Coblentz, W K; Brink, G E; Hoffman, P C; Esser, N M; Bertram, M G

2014-03-01

, respectively. Across the 2-yr trial, average daily gain for grazing heifer groups tended to be greater than heifers remaining in confinement (0.85 vs. 0.74 kg/d), but both management strategies produced weight gains within reasonable proximity to normal targets for heifers in this weight range. Fall-grown oat should be managed as stockpiled forage for deferred grazing, and good utilization of fall-oat forage can be accomplished by a one-time removal of standing forage, facilitated by a single lead wire advanced daily to prevent waste. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Feeding strategies and manure management for cost-effective mitigation of greenhouse gas emissions from dairy farms in Wisconsin.

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Dutreuil, M; Wattiaux, M; Hardie, C A; Cabrera, V E

2014-09-01

Greenhouse gas (GHG) emissions from dairy farms are a major concern. Our objectives were to assess the effect of mitigation strategies on GHG emissions and net return to management on 3 distinct farm production systems of Wisconsin. A survey was conducted on 27 conventional farms, 30 grazing farms, and 69 organic farms. The data collected were used to characterize 3 feeding systems scaled to the average farm (85 cows and 127ha). The Integrated Farm System Model was used to simulate the economic and environmental impacts of altering feeding and manure management in those 3 farms. Results showed that incorporation of grazing practices for lactating cows in the conventional farm led to a 27.6% decrease in total GHG emissions [-0.16kg of CO2 equivalents (CO2eq)/kg of energy corrected milk (ECM)] and a 29.3% increase in net return to management (+$7,005/yr) when milk production was assumed constant. For the grazing and organic farms, decreasing the forage-to-concentrate ratio in the diet decreased GHG emissions when milk production was increased by 5 or 10%. The 5% increase in milk production was not sufficient to maintain the net return; however, the 10% increase in milk production increased net return in the organic farm but not on the grazing farm. A 13.7% decrease in GHG emissions (-0.08kg of CO2eq/kg of ECM) was observed on the conventional farm when incorporating manure the day of application and adding a 12-mo covered storage unit. However, those same changes led to a 6.1% (+0.04kg of CO2eq/kg of ECM) and a 6.9% (+0.06kg of CO2eq/kg of ECM) increase in GHG emissions in the grazing and the organic farms, respectively. For the 3 farms, manure management changes led to a decrease in net return to management. Simulation results suggested that the same feeding and manure management mitigation strategies led to different outcomes depending on the farm system, and furthermore, effective mitigation strategies were used to reduce GHG emissions while maintaining

Impact of cattle grazing on soil and vegetation - a case study in a mountainous region of Austria

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Bohner, Andreas; Foldal, Cecilie; Jandl, Robert

2015-04-01

In mountainous regions of Austria and of many other European countries, climate change may cause a further intensification of grassland management. Therefore, the effects of intensive cattle grazing on selected soil chemical and physical properties, above- and below-ground phytomass, forage quality, plant species composition and plant species richness at the scale of a representative paddock in a mountainous region of Austria were investigated. At the study site (Styrian Enns valley; 675 m a.s.l.), climate is relatively cool and humid, with a mean annual air temperature of 6.7°C and a mean annual precipitation of 970 mm, of which 66% falls during the vegetation period (April-October). The soil is a deep, base-rich Cambisol with a loamy sand texture. The paddock investigated has a total area of about 2 ha and had been grazed by dairy cows (Brown Swiss) five times per grazing season. The stocking density was 4 cows ha-1 during 180 days from early May to the end of October with a grazing time of about 8 hours per day. The strip grazed permanent pasture was manured annually for a long time, mostly with cattle slurry. Vegetation surveys were carried out using the method of Braun-Blanquet. Above- and below-ground phytomass, forage quality and mineral element concentration in the harvestable above-ground plant biomass were determined by using standard methods. During the grazing season surface soil samples (0-10 cm depth) for chemical analyses were collected before each grazing period (5 analyses of composite samples per site). At the beginning and the end of the grazing season also soil samples for physical analyses were taken from the topsoil (0-15 cm depth). Heavy cattle treading led to a substantial soil compaction especially in the 5-10 cm layer and to a deterioration of topsoil structure. The porous crumb structure was replaced by a compact platy structure. The topsoil was enriched with nutrients (mainly nitrogen, potassium, phosphorus and boron). The degree of

Fire and grazing influence site resistance to Bromus tectorum through their effects on shrub, bunchgrass and biocrust communities in the Great Basin (USA)

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Condon, Lea A.; Pyke, David A.

2018-01-01

Shrubs, bunchgrasses and biological soil crusts (biocrusts) are believed to contribute to site resistance to plant invasions in the presence of cattle grazing. Although fire is a concomitant disturbance with grazing, little is known regarding their combined impacts on invasion resistance. We are the first to date to test the idea that biotic communities mediate the effects of disturbance on site resistance. We assessed cover of Bromus tectorum, shrubs, native bunchgrasses, lichens and mosses in 99 burned and unburned plots located on similar soils where fires occurred between 12 and 23 years before sampling. Structural equation modeling was used to test hypothesized relationships between environmental and disturbance characteristics, the biotic community and resistance to B. tectorum cover. Characteristics of fire and grazing did not directly relate to cover of B. tectorum. Relationships were mediated through shrub, bunchgrass and biocrust communities. Increased site resistance following fire was associated with higher bunchgrass cover and recovery of bunchgrasses and mosses with time since fire. Evidence of grazing was more pronounced on burned sites and was positively correlated with the cover of B. tectorum, indicating an interaction between fire and grazing that decreases site resistance. Lichen cover showed a weak, negative relationship with cover of B. tectorum. Fire reduced near-term site resistance to B. tectorum on actively grazed rangelands. Independent of fire, grazing impacts resulted in reduced site resistance to B. tectorum, suggesting that grazing management that enhances plant and biocrust communities will also enhance site resistance.

FEED RESOURCES AND THEIR MANAGEMENT SYSTEMS IN ETHIOPIAN HIGHLANDS:THE CASE OF UMBULO WHACO WATERSHED IN SOUTHERN ETHIOPIA

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Senbeto Funte

2009-07-01

Full Text Available A study was conducted to assess the prevailing feed resources and feeding management systems in Umbulo Wacho watershed, southern Ethiopia. The data used in the current study were obtained through individual interviews conducted on 85 randomly selected livestock owners, group discussions with key informants and from secondary sources. In the study area, livestock provide draught power, milk, meat and manure. Cattle were the dominant livestock species and cows comprised 36% of the total number of cattle. The average landholding per household was 0.7 ha, of which 0.1 ha was reported as grazing land. Communal and private grazing lands were gradually shrinking due to the expansion of crop production. This led to the growing practice of tethering and stall-feeding. The annual feed DM yield was only two-third of the DM requirement for livestock kept in the area. Natural pasture, crop residues, crop stubbles, enset by-products and sugarcane top were among the main feed resources. Crop residues were found to be major feed resources for the livestock in the study area, particularly during the dry season in which the biomass of the natural grazing lands is very minimal. Enhancing the quantity and quality of crop-residues will, therefore, be expected to bring about a positive impact on livestock production.

Use of scanning electron microscopy to confirm the identity of lice infesting communally grazed goat herds

OpenAIRE

P.J. Sebei; C.M.E. McCrindle; E.D. Green; M.L. Turner

2004-01-01

Lice have been described on goats in commercial farming systems in South Africa but not from flocks on communal grazing. During a longitudinal survey on the causes of goat kid mortality, conducted in Jericho district, North West Province, lice were collected from communally grazed indigenous goats. These lice were prepared for and viewed by scanning electron microscopy, and micromorphological taxonomic details are described. Three species of lice were found in the study area and identif...

How grazing affects soil quality of soils formed in the glaciated northeastern United States.

Science.gov (United States)

Cox, Alissa H; Amador, José A

2018-02-21

Historically, much of the New England landscape was converted to pasture for grazing animals and harvesting hay. Both consumer demand for local sustainably produced food, and the number of small farms is increasing in RI, highlighting the importance of characterizing the effects livestock have on the quality of pasture soils. To assess how livestock affect pasture on Charlton and Canton soils series in RI, we examined soil quality in farms raising beef cattle (Bos taurus), sheep (Ovis aries), and horses (Equus ferus caballus), using hayed pastures as a control. We sampled three pastures per livestock type and three control hayed pastures in May, August, and October 2012. Hay fields and pastures grazed by sheep had statistically significant (P soil quality than pastures grazed by beef cattle or horses. This was driven by parameters including penetration resistance, bulk density, aggregate stability, and infiltration rate. Hayfields also showed higher soil quality measures than grazed pastures for organic matter content and active C. In addition, significant differences in nitrate and phosphate concentrations were observed among livestock types. Respiration and infiltration rates, pH, and ammonium concentrations, on the other hand, did not differ significantly among pasture types. When all soil quality indicators in this study were weighed equally, soil quality scores followed the order: hay > sheep > beef cattle > horses. The results of our study provide baseline data on the effect different types of livestock have on pasture soil quality in RI, which may be useful in making sound land use and agricultural management decisions.

Enhancing the diversity of breeding invertebrates within field margins of intensively managed grassland: Effects of alternative management practices.

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Fritch, Rochelle A; Sheridan, Helen; Finn, John A; McCormack, Stephen; Ó hUallacháin, Daire

2017-11-01

Severe declines in biodiversity have been well documented for many taxonomic groups due to intensification of agricultural practices. Establishment and appropriate management of arable field margins can improve the diversity and abundance of invertebrate groups; however, there is much less research on field margins within grassland systems. Three grassland field margin treatments (fencing off the existing vegetation "fenced"; fencing with rotavation and natural regeneration "rotavated" and; fencing with rotavation and seeding "seeded") were compared to a grazed control in the adjacent intensively managed pasture. Invertebrates were sampled using emergence traps to investigate species breeding and overwintering within the margins. Using a manipulation experiment, we tested whether the removal of grazing pressure and nutrient inputs would increase the abundance and richness of breeding invertebrates within grassland field margins. We also tested whether field margin establishment treatments, with their different vegetation communities, would change the abundance and richness of breeding invertebrates in the field margins. Exclusion of grazing and nutrient inputs led to increased abundance and richness in nearly all invertebrate groups that we sampled. However, there were more complex effects of field margin establishment treatment on the abundance and richness of invertebrate taxa. Each of the three establishment treatments supported a distinct invertebrate community. The removal of grazing from grassland field margins provided a greater range of overwintering/breeding habitat for invertebrates. We demonstrate the capacity of field margin establishment to increase the abundance and richness in nearly all invertebrate groups in study plots that were located on previously more depauperate areas of intensively managed grassland. These results from grassland field margins provide evidence to support practical actions that can inform Greening (Pillar 1) and agri

Application of a Statistical Linear Time-Varying System Model of High Grazing Angle Sea Clutter for Computing Interference Power

Science.gov (United States)

2017-12-08

STATISTICAL LINEAR TIME-VARYING SYSTEM MODEL OF HIGH GRAZING ANGLE SEA CLUTTER FOR COMPUTING INTERFERENCE POWER 1. INTRODUCTION Statistical linear time...beam. We can approximate one of the sinc factors using the Dirichlet kernel to facilitate computation of the integral in (6) as follows: ∣∣∣∣sinc(WB...plotted in Figure 4. The resultant autocorrelation can then be found by substituting (18) into (28). The Python code used to generate Figures 1-4 is found

The influence of grazing on surface climatological variables of tallgrass prairie. Final Technical Report

International Nuclear Information System (INIS)

Seastedt, T.R.; Dyer, M.I.; Turner, C.L.

1992-01-01

Mass and energy exchange between most grassland canopies and the atmosphere are mediated by grazing activities. Ambient temperatures can be increased or decreased by grazers. Data have been assembled from simulated grazing experiments on Konza Prairie Research Natural Area and observations on adjacent pastures grazed by cattle show significant changes in primary production, nutrient content, and bidirectional reflectance characteristics as a function of grazing intensity. The purpose of this research was to provide algorithms that would allow incorporation of grazing effects into models of energy budgets using remote sensing procedures. The approach involved: (1) linking empirical measurements of plant biomass and grazing intensities to remotely sensed canopy reflectance, and (2) using a higher resolution, mechanistic grazing model to derive plant ecophysiological parameters that influence reflectance and other surface climatological variables

Fungi regulate response of N2O production to warming and grazing in a Tibetan grassland

Science.gov (United States)

Zhong, Lei; Wang, Shiping; Xu, Xingliang; Wang, Yanfen; Rui, Yichao; Zhou, Xiaoqi; Shen, Qinhua; Wang, Jinzhi; Jiang, Lili; Luo, Caiyun; Gu, Tianbao; Ma, Wenchao; Chen, Guanyi

2018-03-01

Lack of understanding of the effects of warming and winter grazing on soil fungal contribution to nitrous oxide (N2O) production has limited our ability to predict N2O fluxes under changes in climate and land use management, because soil fungi play an important role in driving terrestrial N cycling. Here, we examined the effects of 10 years' warming and winter grazing on soil N2O emissions potential in an alpine meadow. Our results showed that soil bacteria and fungi contributed 46 % and 54 % to nitrification, and 37 % and 63 % to denitrification, respectively. Neither warming nor winter grazing affected the activity of enzymes responsible for overall nitrification and denitrification. However, warming significantly increased the enzyme activity of bacterial nitrification and denitrification to 53 % and 55 %, respectively. Warming significantly decreased enzyme activity of fungal nitrification and denitrification to 47 % and 45 %, respectively, while winter grazing had no such effect. We conclude that soil fungi could be the main source for N2O production potential in the Tibetan alpine grasslands. Warming and winter grazing may not affect the potential for soil N2O production potential, but climate warming can alter biotic pathways responsible for N2O production. These findings indicate that characterizing how fungal nitrification/denitrification contributes to N2O production, as well as how it responds to environmental and land use changes, can advance our understanding of N cycling. Therefore, our results provide some new insights about ecological controls on N2O production and lead to refine greenhouse gas flux models.

Poultry performance in different grazing densities: forage characteristics, losses due to grazing and feed intake

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Luciano Cristiano França

2014-02-01

Full Text Available Morphological characteristics of three forage species grazed by rustic poultry in stocking were evaluated. Coast-cross fodder, kikuyu grass, and stylosanthes were planted in 33-m2 paddocks with two densities (m2/animal: D1 = 3m2/animal and D2 = 1m2/animal. The design was a randomized complete block with a 3 x 2 factorial (three grasses and two densities and three replications. Grass canopy height, grass mass, morphological composition (leaf, stem, and dead material, losses due to grazing, poultry weight gain and consumption, and concentrate feed conversion ratio and efficiency were evaluated. At the end of the experiment, forage and leaves masses were considered low to stylosanthes in D2 (0.28 to 0.03 kg/m2 and to kikuyu grass in D1 (0.13 to 0.05 kg/m2 and in D2 (0.11 and 0.03 kg/m2, respectively. In addition, the grass canopy height was considered low for stylosanthes (6.50 cm that could jeopardize the entry of new poultry lot. The three grass species had similar weight gain and revealed better results for 3m²/ chicken (3.20 kg/animal. Coast-cross fodder, kikuyu grass, and stylosanthes, with some exceptions, can be considered suitable for grazing fattening poultry at 3m2/animal at the evaluated time of the year (autumn.

Day and night grazing by cattle in the Sahel

NARCIS (Netherlands)

Ayantunde, A.A.; Fernandez-Rivera, S.; Hiernaux, P.H.; Keulen, van H.; Udo, H.M.J.

2002-01-01

The influence of night grazing on feeding behavior, nutrition and performance of cattle was studied. Twenty-four steers weighing 367 kg (SD = 76) grazed either from 0900 to 1900 (day grazers), 2100 to 0700 (night grazers) or 0900 to 1900 and 2400 to 0400 (day-and-night grazers) during 13 weeks. Four

Intervalo hídrico ótimo na avaliação de sistemas de pastejo contínuo e rotacionado Least limiting water range in the evaluation of continuous and short-duration grazing systems

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T. P. Leão

2004-06-01

Full Text Available A qualidade física do solo sob sistemas de pastejo contínuo e rotacionado foi avaliada pelo Intervalo Hídrico Ótimo (IHO. A amostragem foi realizada na área experimental da Embrapa Gado de Corte. Foi estudado um Latossolo Vermelho distrófico. Foram avaliados quatro piquetes, sendo dois no sistema de pastejo contínuo e dois no sistema de pastejo rotacionado. No sistema de pastejo contínuo, implementado com a espécie Brachiaria decumbens cv. Basilisk, foram retiradas 30 amostras por piquete, não tendo um dos piquetes recebido adubação de manutenção (Cs, enquanto o outro havia recebido adubação bianual de manutenção (Cc. No sistema de pastejo rotacionado, implementado com a espécie Panicum maximum cv. Tanzânia, foram retiradas 30 amostras por piquete; em um dos piquetes, o resíduo pós-pastejo era mantido entre 2,0 e 2,5 t ha-1 de matéria seca total (MST (R1, enquanto no outro era mantido entre 3,0 e 3,5 t ha-1 MST (R2. As amostras foram submetidas a um gradiente de tensão de água e, posteriormente, utilizadas nas determinações da densidade do solo (Ds, resistência do solo à penetração (RP, umidade volumétrica (tetav e do IHO. O sistema de pastejo rotacionado apresentou piores condições físicas do solo para o crescimento vegetal, avaliadas pelo critério do IHO. Os maiores valores de Ds e menor IHO foram observados no R1, o que foi atribuído às taxas de lotação mais elevadas aplicadas neste piquete.Soil physical quality in continuous and short-duration rotational cattle grazing systems was evaluated using the Least Limiting Water Range (LLWR approach. Soil samples were collected on an experimental site at the Embrapa - Beef Cattle Research Center (Campo Grande, MS, Brazil. The studied soil was a Typic Acrudox. Four sampling sites were selected: two under a short-duration continuous grazing system and two under intensive short-duration rotational grazing system. Thirty soil cores were collected in each site

Comparative aspects of ruminants and camels grazing on a thornbush savannah pasture

International Nuclear Information System (INIS)

Engelhardt, W. von; Rutagwenda, T.; Lechner-Doll, M.; Kaske, M.; Schultka, W.

1989-01-01

A factor limiting animal production in a savannah pasture is the ability of the animals to adapt and survive during the harsh dry season. Survival strategies for the various species are different. Compared to cattle and sheep, camels, and to a lesser extent goats, have the advantage of being able to select high quality plant species. Camels and goats compete very little for forage that is predominantly grazed by cattle, donkeys and sheep. As a result, camels and goats are less subject to the grazing pressures experienced by other animals. During the harsh dry season, cattle, and also sheep, eat mostly low quality forage. When doing this, they are able to increase the retention time of feed particles in the forestomach by increasing forestomach volume. This strategy allows the digestion of poor quality, fibre rich diets to be improved. Camels are superior because they are able to use two different strategies. When fed a very poor quality diet they selectively retain feed particles in the forestomach for a considerable length of time. When grazing in the thornbush savannah, on the other hand, they select medium or high quality plants, which are not used by cattle, donkeys and sheep and are only partly used by goats. A multispecies grazing system may help to improve livestock productivity on a semiarid pasture because the available plant biomass is utilized more efficiently. At the same time overgrazing and its consequences are diminished. (author). 11 refs

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering.

Science.gov (United States)

Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole; Chorkendorff, Ib

2016-03-01

The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.

An investigation into the causes of low calving percentage in communally grazed cattle in Jericho, North West Province

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E. Mokantla

2004-06-01

Full Text Available The communal grazing system is generally understood to have a low input, low output type of management. However, the actual inputs and outputs of the farmers are not well known and the farmers are often unaware of their problems. Although the causes of low calving percentage are well understood in commercial beef farming enterprises in South Africa, the same is not true for communal farming systems. The aim of this study was to determine the reproductive performance of beef cattle on a communal farming system in Jericho, NorthWest Province. Ten farmers from five villages with a total of 265 cows and 13 bulls were purposively selected. The selection criteria were that each farmer had to have a minimum of 10 breeding cows and a bull and be willing to participate in the study. This was followed by a 12-month longitudinal study with monthly herd visits where cows were examined rectally and bulls (n = 13 were subjected to a single breeding soundness evaluation. The calving percentage was found to be 37.7 %. This is lower than the recorded percentages for commercial beef cattle on extensive grazing. The factors playing a role in low calving percentage were ranked using field data. From this it appeared that failure of cows to become pregnant was the main cause of poor calving percentage as opposed of loss of calves through abortion or resorption. Sub-fertility of the bulls was found to be of great significance and it is proposed that this be included in extension messages and that bulls be fertility tested routinely. Poor body condition score of cows, mainly caused by poor management, was also considered to play a major role in reducing pregnancy rates. Infectious diseases like trichomonosis, campylobacteriosis and brucellosis played a much leser role than anticipated.

Global versus local environmental impacts of grazing and confined beef production systems

International Nuclear Information System (INIS)

Modernel, P; Astigarraga, L; Picasso, V

2013-01-01

Carbon footprint is a key indicator of the contribution of food production to climate change and its importance is increasing worldwide. Although it has been used as a sustainability index for assessing production systems, it does not take into account many other biophysical environmental dimensions more relevant at the local scale, such as soil erosion, nutrient imbalance, and pesticide contamination. We estimated carbon footprint, fossil fuel energy use, soil erosion, nutrient imbalance, and risk of pesticide contamination for five real beef background-finishing systems with increasing levels of intensification in Uruguay, which were combinations of grazing rangelands (RL), seeded pastures (SP), and confined in feedlot (FL). Carbon footprint decreased from 16.7 (RL–RL) to 6.9 kg (SP–FL) CO 2 eq kg body weight −1 (BW; ‘eq’: equivalent). Energy use was zero for RL–RL and increased up to 17.3 MJ kg BW −1 for SP–FL. Soil erosion values varied from 7.7 (RL–RL) to 14.8 kg of soil kg BW −1 (SP–FL). Nitrogen and phosphorus nutrient balances showed surpluses for systems with seeded pastures and feedlots while RL–RL was deficient. Pesticide contamination risk was zero for RL–RL, and increased up to 21.2 for SP–FL. For the range of systems studied with increasing use of inputs, trade-offs were observed between global and local environmental problems. These results demonstrate that several indicators are needed to evaluate the sustainability of livestock production systems. (letter)

A study of short term grazing patterns on Coastcross 2 under ...

African Journals Online (AJOL)

In this study the disc meter was successfully used to measure pasture yield in situ and thus provide an objective basis to adjust animal numbers on treatments with variable stocking rates. Realistic estimates of pasture dry matter consumption and production were made on rotational grazing systems and animal selection ...

Grazing exclusion increases soil CO2 emission during the growing season in alpine meadows on the Tibetan Plateau

Science.gov (United States)

Guo, Na; Wang, Aidong; Allan Degen, A.; Deng, Bin; Shang, Zhanhuan; Ding, Luming; Long, Ruijun

2018-02-01

Soil CO2 emission is a key part of the terrestrial carbon cycle. Grazing exclusion by fencing is often considered a beneficial grassland management option to restore degraded grassland, but its effect on soil CO2 emission on the northeastern Tibetan Plateau is equivocal and is the subject of this study. Using a closed static chamber, we measured diurnal soil CO2 flux weekly from July, 2008, to April, 2009, in response to grazing and grazing exclusion in the alpine meadow and alpine shrub meadow. Concomitantly, soil temperature was measured at depths of 5 cm, 10 cm, 15 cm and 20 cm with digital temperature sensors. It emerged that: 1) non-grazed grasslands emitted more soil CO2 than grazed grasslands over the growing season; 2) the alpine shrub meadow emitted more soil CO2 than the alpine meadow; the annual cumulative soil CO2 emissions of alpine meadow and alpine shrub meadow were 241.5-326.5 g C/m2 and 429.0-512.5 g C/m2, respectively; 3) seasonal patterns were evident with more soil CO2 flux in the growing than in the non-growing season; and 4) the diurnal soil CO2 flux exhibited a single peak across all sampling sites. In addition, soil CO2 flux was correlated positively with soil temperature at 5 cm, but not at the other depths. We concluded that grazing exclusion enhanced soil CO2 emission over the growing season, and decreased carbon sequestration of alpine meadow and alpine shrub meadow on the northeastern Tibetan Plateau. Since an increase in soil temperature increased soil CO2 flux, global warming could have an effect on soil CO2 emission in the future.

Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity

Science.gov (United States)

1. Wildfire is an ecological and economic risk for many semi-arid rangelands across the globe. This coupled with extreme wildfire seasons and mega-fires over the last decade have resulted in a call for more pre-suppression management actions. Dormant season grazing has been suggested as a treatment...

CO2 Dynamics in winter wheat and canola under different management practices in the Southern Great Plains

Science.gov (United States)

Wagle, P.; Manjunatha, P.; Gowda, P. H.; Northup, B. K.; Neel, J. P. S.; Turner, K.; Steiner, J. L.

2017-12-01

Rising atmospheric carbon dioxide (CO2) concentration and increased air temperature and climatic variability concerns have prompted considerable interest regarding CO2 dynamics of terrestrial ecosystems in response to major climatic and biophysical factors. However, detailed information on CO2 dynamics in winter wheat (Triticum aestivum L.) and canola (Brassica napus L.) under different agricultural management practices is lacking. As a part of the GRL-FLUXNET, a cluster of eight eddy covariance (EC) systems was deployed on the 420-ha Grazinglands Research on agroEcosystems and the ENvironment (GREEN) Farm at the United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Grazinglands Research Laboratory (GRL), El Reno, OK. The GRL is also one of 18 USDA-ARS Long-Term Agroecosystem Research (LTAR) network sites in the United States. A 4-year crop rotation plan at the farm includes winter wheat for grain only, graze-grain, and graze-out, and canola under conventional till and no-till management conditions. Biometric measurements such as biomass, leaf area index (LAI), canopy cover %, canopy height, and chlorophyll content were collected approximately every 16 days to coincide with Landsat satellite overpass dates. As expected, biomass and LAI were highest in the grain only wheat fields followed by graze-grain and graze-out wheat fields, but they were similar for till and no-till wheat fields within the same grazing practice. Biomass and LAI were similar in till and no-till canola in fall 2016, but both were substantially lower in no-till compared to tilled canola during spring 2017 due to more severe winter damage. Because net ecosystem CO2 exchange (NEE) is strongly regulated by vegetation cover, the magnitudes of NEE were highest in the grain only wheat fields due to more biomass and LAI, followed by graze-grain and graze-out wheat fields. Similarly, the magnitudes of NEE were also higher in tilled canola (i.e., higher biomass and LAI) than

Resilience of soils and vegetation subjected to different grazing ...

African Journals Online (AJOL)

The resilience of rangeland soils and vegetation to different levels of grazing is still poorly understood. A study was conducted to determine the recovery of a rangeland grazed at different intensities and allowed a two-year rest period. The following treatments were applied to 0.5 hectare plots: 0, 4, 8 and 16 heifers per ...

Herbaceous vegetation restoration potential and soil physical condition in a mountain grazing land of Eastern Tigray, Ethiopia

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Gebrewahd Amha Abesha

2014-06-01

Full Text Available An existence of information in the form database and full knowledge of grazing land vegetation resources and trend over time is essential for management decisions. This study was conducted in Kiltew -Awelaelo, eastern Tigray, Ethiopia. The study aimed to investigate species composition and diversity of the herbaceous vegetation, and examine the physical soil condition of the grazing lands. A total of 45 quadrats measuring 20m×20m (400m2 were laid out in 15 sample sites from three corresponding land use types (i.e. ten year enclosure, five year enclosure and open grazing land. From each land use type five sites having three quadrats were investigated. Each quadrat was laid out at an interval of 400m in five parallel transects each 200m apart from other. To collect data of herbaceous and soil five randomly located 1m2 area each, was selected and marked, within each 400m2 sample quadrat of sample sites located along the main transect. There was significant (PBracharia sp., Bromus pectinatus, Chloris gayana, Cenchurs cilarias, chloris radiata, Cynodon dactylon, Dactyloctenium aegyptium, Digitaria Velutina, Eragrostis teniufolia, Lintonia nutans, Setaria pumila, Seteria verticillate, and Tragus racemosus all occurred frequently forming the major constituents of the sites. Therefore, regeneration from area enclosure can be on advocated practice for grazing lands rehabilitation.

Effect of Grazing Behavior on Weight Regain Post-Bariatric Surgery: A Systematic Review

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Nathalia Pizato

2017-12-01

Full Text Available Grazing, a type of maladaptive eating behavior, has been associated with poor weight outcomes in bariatric patients. The purpose of this study was to conduct a systematic review of the association between grazing behavior and weight regain post-bariatric surgery. Literature searches, study selection, design of the method, and quality appraisal were carried out by two independent authors. The search strategy was performed until October 2017 in Medline, Embase, Cochrane, Lilacs, Scopus, Web of Science, Google Scholar, ProQuest Dissertation & Theses, and Open Grey. Of a total of 3764 articles, five papers met the inclusion criteria (four original articles and one thesis, comprising 994 subjects, mostly women. The prevalence of grazing behavior ranged from 16.6 to 46.6%, and the highest prevalence of significant weight regain was 47%. The association between grazing and weight regain was observed in four of the five evaluated studies. Our findings support an association between grazing behavior and weight regain after bariatric surgery, regardless of surgery type and contextual concept of grazing. Further studies are needed to confirm the clarity of the real prevalence and interfering factors related to grazing behavior and weight outcomes.

Tree-shrub associations in grazed woodlands: First rodents, then cattle?

NARCIS (Netherlands)

Smit, C.; Verwijmeren, M.

2011-01-01

Spatial associations of tree saplings with spiny or toxic plants in grazed woodlands are generally explained by associational resistance, i. e., protection against grazing via a well-defended neighbor. In this study, we tested whether directed seed dispersal and post-dispersal seed removal by wood

Morphological Responses Explain Tolerance of the Bamboo Yushania microphylla to Grazing

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Kesang Wangchuk

2014-01-01

Full Text Available Mechanisms of tolerance of the bamboo Y. microphylla to ungulate herbivory were investigated by measuring above- and belowground morphogenetic traits and biomass allocation patterns of the bamboo Y. microphylla under grazed and ungrazed conditions in a Himalayan mixed conifer forest. Data were collected from 5 populations consisting of 10 ramets each in adjacent grazed and ungrazed plots. Compared with ungrazed ramets, the aboveground morphological modifications of grazed ramets were higher culm density, shorter and thinner culms, shorter internode, and shorter top leaf. The belowground morphological modifications for the grazed ramets were thinner rhizomes, lower rhizome biomass and dry matter, more nodes, and shorter internodes. Despite the lower biomass and dry matter, the root-to-shoot ratio was higher for grazed ramets. Results suggest that Y. microphylla subjected to herbivory shows aboveground overcompensation in terms of densification at the cost of belowground biomass, but at the same time maintains a higher proportion of belowground reserves, as compared to ungrazed conditions. These responses provide adequate evidence to conclude that Y. microphylla tolerates ungulate herbivory through above- and belowground morphological modifications.

Growth rates, grazing, sinking, and iron limitation of equatorial Pacific phytoplankton

International Nuclear Information System (INIS)

Chavez, F.P.; Buck, K.R.; Coale, K.H.; Martin, J.H.; DiTullio, G.R.; Welschmeyer, N.A.; Barber, R.T.; Jacobson, A.C.

1991-01-01

Concentrations of phytoplankton and NO 3 are consistently low and high in surface waters of the oceanic eastern and central equatorial Pacific, and phytoplankton populations are dominated by small solitary phytoplankton. Growth rates of natural phytoplankton populations, needed to assess the relative importance of many of the processes considered in the equatorial Pacific, were estimated by several methods. The growth rates of natural phytoplankton populations were found to be ∼0.7 d -1 or 1 biomass doubling d -1 and were similar for all methods. To keep this system in its observed balance requires that loss rates approximate observed growth rates. Grazing rates, measured with a dilution grazing experiment, were high, accounting for a large fraction of the daily production. Additions of various forms of Fe to 5-7-d incubations utilizing ultraclean techniques resulted in significant shifts in autotrophic and heterotrophic assemblages between initial samples, controls, and Fe enrichments, which were presumably due to Fe, grazing by both protistan and metazoan components, and incubation artifacts. Estimated growth rates of small pennate diatoms showed increases in Fe enrichments with respect to controls. The growth rates of the pennate diatoms were similar to those estimated for the larger size fraction of the natural populations

Biological soil crusts exhibit a dynamic response to seasonal rain and release from grazing with implications for soil stability

Science.gov (United States)

Jimenez, Aguilar A.; Huber-Sannwald, E.; Belnap, J.; Smart, D.R.; Arredondo, Moreno J.T.

2009-01-01

In Northern Mexico, long-term grazing has substantially degraded semiarid landscapes. In semiarid systems, ecological and hydrological processes are strongly coupled by patchy plant distribution and biological soil crust (BSC) cover in plant-free interspaces. In this study, we asked: 1) how responsive are BSC cover/composition to a drying/wetting cycle and two-year grazing removal, and 2) what are the implications for soil erosion? We characterized BSC morphotypes and their influence on soil stability under grazed/non-grazed conditions during a dry and wet season. Light- and dark-colored cyanobacteria were dominant at the plant tussock and community level. Cover changes in these two groups differed after a rainy season and in response to grazing removal. Lichens with continuous thalli were more vulnerable to grazing than those with semi-continuous/discontinuous thalli after the dry season. Microsites around tussocks facilitated BSC colonization compared to interspaces. Lichen and cyanobacteria morphotypes differentially enhanced resistance to soil erosion; consequently, surface soil stability depends on the spatial distribution of BSC morphotypes, suggesting soil stability may be as dynamic as changes in the type of BSC cover. Longer-term spatially detailed studies are necessary to elicit spatiotemporal dynamics of BSC communities and their functional role in biotically and abiotically variable environments. ?? 2009 Elsevier Ltd.

Dry grassland biodiversity conservation using low-intensity sheep and goat grazing management: case study in Prague (Czech republic)

Czech Academy of Sciences Publication Activity Database

Dostálek, J.; Frantík, Tomáš

2008-01-01

Roč. 17, č. 3 (2008), s. 1439-1454 ISSN 0960-3115 Institutional research plan: CEZ:AV0Z60050516 Keywords : dry grassland * grazing * plant diversity conservation Subject RIV: EF - Botanics Impact factor: 1.473, year: 2008

Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System

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C. E. F. Clark

2014-03-01

Full Text Available Pasture-based automatic milking systems (AMS require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group with a 2×2 Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov. pasture (pasture or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ≈18 L/cow/d in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation relative to pasture (4.7 kg/cow/d/allocation. Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages.

Grazing exclusion, substrate type, and drought frequency affect plant community structure in rangelands of the arid unpredictable Arabian Deserts

Science.gov (United States)

El-Keblawy, Ali; El-Sheikh, Mohamed

2017-04-01

Grazing and drought can adversely affect the ecology and management of rangeland ecosystems. Several management actions have been applied to restore species diversity and community structure in degraded rangelands of the unpredictable arid environment. Protection from grazing is considered as a proper approach for restoration of degraded rangelands, but this depends on substrate type and sometime is hindered with water deficiency (drought). In this study, the effect of protection from grazing animals on species diversity and plant community structure was assessed after a dry and wet periods in both sandy and gravelly substrates in the Dubai Desert Conservation reserve (DDCR), United Arab Emirates. Two sites were selected during November 2012 on the two substrate types (fixed sandy flat and gravel plain) in the arid DDCR. An enclosure was established in each site. Plant community attributes (plant cover, density, frequency, species composition, and diversity indices) were assessed in a number of permanent plots laid inside and outside each enclosure during November 2012, April 2014 and April 2016. The results showed that protection improved clay content, but decreased the organic matters. Interestingly, the protection reduced the concentrations of most estimated nutrients, which could be attributed to the high turnover rate of nutrients associated grazing and low decomposition of accumulated dry plants of non-protected sites. Protection significantly increased all plant community attributes, but the only significant effect was for plant density. Plant density was almost twice greater inside than outside the enclosures. During the dry period, protection resulted in significantly greater deterioration in cover, density and all diversity indices in gravel, compared to sandy sites. Most of the grasses and shrubby plants had died in the gravel plains. However, plant community of the gravel plains was significantly restored after receiving considerable rainfalls. The

Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

Directory of Open Access Journals (Sweden)

Carlos Cáceres

Full Text Available Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E. Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1, especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1, suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.

Phytoplankton Growth and Microzooplankton Grazing in the Subtropical Northeast Atlantic

Science.gov (United States)

Cáceres, Carlos; Taboada, Fernando González; Höfer, Juan; Anadón, Ricardo

2013-01-01

Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. PMID:23935946

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

DEFF Research Database (Denmark)

Kehres, Jan; Pedersen, Thomas; Masini, Federico

2016-01-01

at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.......The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing......-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments...

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

Science.gov (United States)

Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole

2016-01-01

The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles. PMID:26917133

Modeling dynamics of tundra plant communities on the Yamal Peninsula, Russia, in response to climate change and grazing pressure

International Nuclear Information System (INIS)

Yu, Q; Epstein, H E; Frost, G V; Walker, D A; Forbes, B C

2011-01-01

Understanding the responses of the arctic tundra biome to a changing climate requires knowledge of the complex interactions among the climate, soils and biological system. This study investigates the individual and interaction effects of climate change and reindeer grazing across a variety of climate zones and soil texture types on tundra vegetation community dynamics using an arctic vegetation model that incorporates the reindeer diet, where grazing is a function of both foliar nitrogen concentration and reindeer forage preference. We found that grazing is important, in addition to the latitudinal climate gradient, in controlling tundra plant community composition, explaining about 13% of the total variance in model simulations for all arctic tundra subzones. The decrease in biomass of lichen, deciduous shrub and graminoid plant functional types caused by grazing is potentially dampened by climate warming. Moss biomass had a nonlinear response to increased grazing intensity, and such responses were stronger when warming was present. Our results suggest that evergreen shrubs may benefit from increased grazing intensity due to their low palatability, yet a growth rate sensitivity analysis suggests that changes in nutrient uptake rates may result in different shrub responses to grazing pressure. Heavy grazing caused plant communities to shift from shrub tundra toward moss, graminoid-dominated tundra in subzones C and D when evergreen shrub growth rates were decreased in the model. The response of moss, lichen and forbs to warming varied across the different subzones. Initial vegetation responses to climate change during transient warming are different from the long term equilibrium responses due to shifts in the controlling mechanisms (nutrient limitation versus competition) within tundra plant communities.

X-ray grazing incidence diffraction from multilayers

Energy Technology Data Exchange (ETDEWEB)

Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

EFEITO DO CREEP FEEDING E CREEP GRAZING NAS CARACTERÍSTICAS DA PASTAGEM DE TIFTON E AZEVÉM E NO DESEMPENHO DE OVINOS

Directory of Open Access Journals (Sweden)

Cláudio José Araújo da Silva1, 2, 3, 4, 3,

2012-06-01

Full Text Available The objective of this study was to evaluate the influence of creep feeding and creep grazing on the pasture characteristics and on performance and productivity of sheep. Three systems of lambs production on Tifton 85 (Cynodon spp. pastures oversown with Italian ryegrass (Lolium multiflorum Lam were studied: lambs with dams until slaughter without supplementation (1; lambs with dams until slaughter fed concentrate in creep feeders at 2% BW.day-1 (2; and lambs with dams until slaughter and supplemented with white clover (Trifolium repens in creep grazing system ad libitum (3. The characteristics of the pasture did not differ (P>0.05 among the systems. Individual lamb growth was higher with creep feeding (307g/day and creep grazing (274g/day compared to no supplemented systems (204g/day; p<0.05. Animal productivity per area on supplemented treatments (2.4 kg BW/ha/day was significantly greater than no supplemented one (1.8kg BW/ha/day; p<0.05. White clover showed to be a particularly good supplement for raising lambs on pastures. It may be concluded that systems of feeding lambs in creep feeding and creep grazing yielded favorable productivity mainly if there is forage deficit in spring.

Effect of mowing and grazing on ramet emergence of Leymus ...

African Journals Online (AJOL)

user

2011-03-21

Mar 21, 2011 ... experiment was conducted in the spring of 2004 to investigate the effects on the surface soil temperature caused by mowing, grazing and grazing exclusion, and the influence of these factors on the ramets emergence characteristics. The primary effect of the treatments was significant changes in.

Qatar Exoplanet Survey: Qatar-6b—A Grazing Transiting Hot Jupiter

Science.gov (United States)

Alsubai, Khalid; Tsvetanov, Zlatan I.; Latham, David W.; Bieryla, Allyson; Esquerdo, Gilbert A.; Mislis, Dimitris; Pyrzas, Stylianos; Foxell, Emma; McCormac, James; Baranec, Christoph; Vilchez, Nicolas P. E.; West, Richard; Esamdin, Ali; Dang, Zhenwei; Dalee, Hani M.; Al-Rajihi, Amani A.; Al-Harbi, Abeer Kh.

2018-02-01

We report the discovery of Qatar-6b, a new transiting planet identified by the Qatar Exoplanet Survey (QES). The planet orbits a relatively bright (V = 11.44), early-K main-sequence star at an orbital period of P ∼ 3.506 days. An SED fit to available multi-band photometry, ranging from the near-UV to the mid-IR, yields a distance of d = 101 ± 6 pc to the system. From a global fit to follow-up photometric and spectroscopic observations, we calculate the mass and radius of the planet to be M P = 0.67 ± 0.07 M J and R P = 1.06 ± 0.07 R J, respectively. We use multi-color photometric light curves to show that the transit is grazing, making Qatar-6b one of the few exoplanets known in a grazing transit configuration. It adds to the short list of targets that offer the best opportunity to look for additional bodies in the host planetary system through variations in the transit impact factor and duration.

Herbage availability €rs a stress factor on grazed Coastcross II ...

African Journals Online (AJOL)

) relationships for Coastcross ll Bermuda grass grazed for four consecutive summer periods by young growing beef cattle. Stocking rate affected the daily. LWG/animal through its influence on herbage availability. Rota- tional grazing showed a ...

Plasma protein loss associated with gastrointestinal parasitism in grazing sheep.

Science.gov (United States)

Yakoob, A Y; Holmes, P H; Parkins, J J; Armour, J

1983-01-01

Some pathophysiological effects of parasitic gastroenteritis in two groups of lambs grazing paddocks either heavily or lightly contaminated with trichostrongyle larvae were investigated between July and October 1980. The leak of plasma protein was measured on three occasions at pasture using 51chromic chloride. Total faecal output was measured indirectly using chromic oxide. Losses of 51chromic chloride-labelled plasma protein into the gastrointestinal tract were significantly higher in the lambs grazing the heavily contaminated pasture than in those grazing lightly infected ground in both July and August. The increased plasma losses were associated with high faecal egg counts, hypoalbuminaemia and elevated levels of plasma pepsinogen.

Adjustable Grazing-Incidence X-Ray Optics

Science.gov (United States)

O'Dell, Stephen L.; Reid, Paul B.

2015-01-01

With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

MICROBIAL CHARACTERISTICS OF SOILS UNDER AN INTEGRATED CROP-LIVESTOCK SYSTEM

Directory of Open Access Journals (Sweden)

Andréa Scaramal da Silva

2015-02-01

Full Text Available Integrated crop-livestock systems (ICLs are a viable strategy for the recovery and maintenance of soil characteristics. In the present study, an ICL experiment was conducted by the Instituto Agronômico do Paraná in the municipality of Xambre, Parana (PR, Brazil, to evaluate the effects of various grazing intensities. The objective of the present study was to quantify the levels of microbial biomass carbon (MBC and soil enzymatic activity in an ICL of soybean (summer and Brachiaria ruziziensis (winter, with B. ruziziensis subjected to various grazing intensities. Treatments consisted of varying pasture heights and grazing intensities (GI: 10, 20, 30, and 40 cm (GI-10, GI-20, GI-30, and GI-40, respectively and a no grazing (NG control. The microbial characteristics analysed were MBC, microbial respiration (MR, metabolic quotient (qCO2, the activities of acid phosphatase, β-glucosidase, arylsuphatase, and cellulase, and fluorescein diacetate (FDA hydrolysis. Following the second grazing cycle, the GI-20 treatment (20-cm - moderate grazing intensity contained the highest MBC concentrations and lowest qCO2 concentrations. Following the second soybean cycle, the treatment with the highest grazing intensity (GI-10 contained the lowest MBC concentration. Soil MBC concentrations in the pasture were favoured by the introduction of animals to the system. High grazing intensity (10-cm pasture height during the pasture cycle may cause a decrease in soil MBC and have a negative effect on the microbial biomass during the succeeding crop. Of all the enzymes analyzed, only arylsuphatase and cellulase activities were altered by ICL management, with differences between the moderate grazing intensity (GI-20 and no grazing (NG treatments.

Mixed farming in a grazing reserve in Northern Nigeria | Babalobi ...

African Journals Online (AJOL)

Nigeria's main pastoral development strategy is the settlement of pastoralists in grazing reserves. The goal of the strategy is to turn such nomadic pastoralists into mixed farmers who will take up crop farming to supplement livestock farming. Using the Bobi Grazing Reserve, Niger State, Nigeria as case study, the attainment ...

Transformation of a savanna grassland by drought and grazing | O ...

African Journals Online (AJOL)

The relative effects of drought and heavy grazing on the floristic composition, population size and and structure, and basal cover of an African savanna grassland were differentiated by comparing changes over eight years over eight years, which included a severe drought year, across a gradient of grazing history. Drought ...

The grazing index method of range condition assessment | du Toit ...

African Journals Online (AJOL)

Owing to the difficulty of examining succession theory in the Karoo, it is suggested the ecological index method (EIM), be replaced by the grazing index method (GIM), through the introduction of grazing index values (GIV) for Karoo plant species. The GIM may provide more acceptable range condition scores and more ...

Forage selection and performance of sheep grazing dry annual range.

NARCIS (Netherlands)

Ridder, de N.; Benjamin, R.W.; Keulen, van H.

1986-01-01

During 114 days of grazing, sheep grazing a dry annual pasture in Israel selected the fine fraction available with a higher nutritive value. As this fraction became depleted and feed quality dropped, organic matter intake dropped from 1.73 to 0.75 kg/sheep/d. Sheep lost weight, body condition and

Grasses grazed by springbok and sheep | R. | African Journal of ...

African Journals Online (AJOL)

Grazing habits were determined by analysis of rumina from slaughtered springbok and sheep where springbok grazed together with Merino sheep in False Upper Karoo and together with Dorper sheep in Kalahari Thornveld. Results show that in both veld types, grass constituted about 39 percent of the dry mass intake of ...

Modelling carbon and water exchange of a grazed pasture in New Zealand constrained by eddy covariance measurements.

Science.gov (United States)

Kirschbaum, Miko U F; Rutledge, Susanna; Kuijper, Isoude A; Mudge, Paul L; Puche, Nicolas; Wall, Aaron M; Roach, Chris G; Schipper, Louis A; Campbell, David I

2015-04-15

We used two years of eddy covariance (EC) measurements collected over an intensively grazed dairy pasture to better understand the key drivers of changes in soil organic carbon stocks. Analysing grazing systems with EC measurements poses significant challenges as the respiration from grazing animals can result in large short-term CO2 fluxes. As paddocks are grazed only periodically, EC observations derive from a mosaic of paddocks with very different exchange rates. This violates the assumptions implicit in the use of EC methodology. To test whether these challenges could be overcome, and to develop a tool for wider scenario testing, we compared EC measurements with simulation runs with the detailed ecosystem model CenW 4.1. Simulations were run separately for 26 paddocks around the EC tower and coupled to a footprint analysis to estimate net fluxes at the EC tower. Overall, we obtained good agreement between modelled and measured fluxes, especially for the comparison of evapotranspiration rates, with model efficiency of 0.96 for weekly averaged values of the validation data. For net ecosystem productivity (NEP) comparisons, observations were omitted when cattle grazed the paddocks immediately around the tower. With those points omitted, model efficiencies for weekly averaged values of the validation data were 0.78, 0.67 and 0.54 for daytime, night-time and 24-hour NEP, respectively. While not included for model parameterisation, simulated gross primary production also agreed closely with values inferred from eddy covariance measurements (model efficiency of 0.84 for weekly averages). The study confirmed that CenW simulations could adequately model carbon and water exchange in grazed pastures. It highlighted the critical role of animal respiration for net CO2 fluxes, and showed that EC studies of grazed pastures need to consider the best approach of accounting for this important flux to avoid unbalanced accounting. Copyright © 2015. Published by Elsevier B.V.

Grazing and Rangeland Development for Livestock Production. A Handbook for Volunteers. Agriculture Technology for Developing Countries. Appropriate Technologies for Development. Reprint R-47.

Science.gov (United States)

Sprague, Howard B.; And Others

This handbook, developed for training Peace Corps volunteers, reviews the basic principles that underlie sound grazing land management and indicates the application of these principles for livestock production in the tropics and subtropics. The handbook is made up of three technical series bulletins. The first bulletin covers management of…

Herds of methane chambers grazing bubbles

Science.gov (United States)

Grinham, Alistair; Dunbabin, Matthew

2014-05-01

Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique

Evapotranspiration in winter wheat under different grazing and tillage practices in the southern Great Plains

Science.gov (United States)

Precipitation in the Southern Great Plains (SGP) is highly variable both spatially and temporally with recurring periods of severe drought. Winter wheat (Triticum aestivum L.) – summer fallow system with conventional tillage is the principal dryland cropping system in this region for both grazing an...

An investigation on forage yield capacity of kermes oak (Quercus coccifera L.) and grazing planning of Mediterranean maquis scrublands for traditional goat farming.

Science.gov (United States)

Tolunay, Ahmet; Adıyaman, Elif; Akyol, Ayhan; İnce, Duygu; Türkoğlu, Türkay; Ayhan, Veysel

2014-01-01

This study investigated grazing capacities of maquis scrubland and preparation principles of grazing management in forest resources. Kermes oak (Quercus coccifera L.), which is widespread as a main shrub species in maquis vegetation in Turkey, and pure hair goats (Capra hircus L.) feeding on shoots and leaves of this shrub were selected for study. The study was conducted in two stages. Green leaf and shoot samples were taken from kermes oaks in the first stage and the amount of green herbage yield (g ∗ m(-1)) and dry matter yield (kg ∗ ha(-1)) that may be obtained per unit area from these samples was identified. The considered amount of dry matter consumed by pure hair goats daily and the number of goats being fed within 1 year on land of 1 ha according to different land coverage rates of kermes oaks (goat head ∗ ha ∗ yr) were calculated. In the second stage, grazing capacities of sample areas where kermes oak spread were identified and compared with the grazing plan prepared by the forestry administration for this area. Forage yield variance according to land coverage rates of maquis scrublands should be considered when determining optimum animal numbers for grazing per area for sustainable goat farming.

An Investigation on Forage Yield Capacity of Kermes Oak (Quercus coccifera L. and Grazing Planning of Mediterranean Maquis Scrublands for Traditional Goat Farming

Directory of Open Access Journals (Sweden)

Ahmet Tolunay

2014-01-01

Full Text Available This study investigated grazing capacities of maquis scrubland and preparation principles of grazing management in forest resources. Kermes oak (Quercus coccifera L., which is widespread as a main shrub species in maquis vegetation in Turkey, and pure hair goats (Capra hircus L. feeding on shoots and leaves of this shrub were selected for study. The study was conducted in two stages. Green leaf and shoot samples were taken from kermes oaks in the first stage and the amount of green herbage yield (g*m−1 and dry matter yield (kg*ha−1 that may be obtained per unit area from these samples was identified. The considered amount of dry matter consumed by pure hair goats daily and the number of goats being fed within 1 year on land of 1 ha according to different land coverage rates of kermes oaks (goat head*ha*yr were calculated. In the second stage, grazing capacities of sample areas where kermes oak spread were identified and compared with the grazing plan prepared by the forestry administration for this area. Forage yield variance according to land coverage rates of maquis scrublands should be considered when determining optimum animal numbers for grazing per area for sustainable goat farming.

Aridity and grazing as convergent selective forces: an experiment with an Arid Chaco bunchgrass.

Science.gov (United States)

Quiroga, R Emiliano; Golluscio, Rodolfo A; Blanco, Lisandro J; Fernández, Roberto J

2010-10-01

It has been proposed that aridity and grazing are convergent selective forces: each one selects for traits conferring resistance to both. However, this conceptual model has not yet been experimentally validated. The aim of this work was to experimentally evaluate the effect of aridity and grazing, as selective forces, on drought and grazing resistance of populations of Trichloris crinita, a native perennial forage grass of the Argentinean Arid Chaco region. We collected seeds in sites with four different combinations of aridity and grazing history (semiarid/ subhumid x heavily grazed/lightly grazed), established them in pots in a common garden, and subjected the resulting plants to different combinations of drought and defoliation. Our results agreed with the convergence model. Aridity has selected T. crinita genotypes that respond better to drought and defoliation in terms of sexual reproduction and leaf growth, and that can evade grazing due to a lower shoot: root ratio and a higher resource allocation to reserves (starch) in stem bases. Similarly, grazing has selected genotypes that respond better to drought and defoliation in terms of sexual reproduction and that can evade grazing due to a lower digestibility of leaf blades. These results allow us to extend concepts of previous models in plant adaptation to herbivory to models on plant adaptation to drought. The only variable in which we obtained a result opposite to predictions was plant height, as plants from semiarid sites were taller (and with more erect tillers) than plants from subhumid sites; we hypothesize that this result might have been a consequence of the selection exerted by the high solar radiation and soil temperatures of semiarid sites. In addition, our work allows for the prediction of the effects of dry or wet growing seasons on the performance of T. crinita plants. Our results suggest that we can rely on dry environments for selecting grazing-resistant genotypes and on high grazing pressure

Long-term lesser prairie-chicken nest ecology in response to grassland management

Science.gov (United States)

Fritts, Sarah R.; Grisham, Blake A.; Haukos, David A.; Boal, Clint W.; Patten, Michael; Wolfe, Don H.; Dixon, Charles; Cox, Robert D.; Heck, Willard R.

2016-01-01

Long-term population and range declines from habitat loss and fragmentation caused the lesser prairie-chicken (Tympanuchus pallidicinctus) to be a species of concern throughout its range. Current lesser prairie-chicken range in New Mexico and Texas is partially restricted to sand shinnery oak (Quercus havardii; hereafter shinnery oak) prairies, on which cattle grazing is the main socioeconomic driver for private landowners. Cattle producers within shinnery oak prairies often focus land management on shrub eradication using the herbicide tebuthiuron to promote grass production for forage; however, herbicide application alone, and in combination with grazing, may affect nest site selection and nest survival of lesser prairie-chickens through the reduction of shinnery oak and native grasses. We used a controlled, paired, completely randomized design study to assess the influence of grazing and tebuthiuron application and their combined use on nest site selection and nest survival from 2001 to 2010 in Roosevelt County, New Mexico, USA at 2 spatial scales (i.e., treatment and microhabitat) in 4 treatments: tebuthiuron with grazing, tebuthiuron without grazing, no tebuthiuron with grazing, and a control of no tebuthiuron and no grazing. Grazing treatment was a short-duration system in which plots were grazed once during the dormant season and once during the growing season. Stocking rate was calculated each season based on measured forage production and applied to remove ≤25% of available herbaceous material per season. At the treatment scale, we compared nest site selection among treatments using 1-way χ2 tests and nest survival among treatments using a priori candidate nest survival models in Program MARK. At the microhabitat scale, we identified important habitat predictors of nest site selection and nest survival using logistic regression and a priori candidate nest survival models in Program MARK, respectively. Females typically used treatments as expected and

Effects of grazing and feedlot finishing duration on the performance of three beef cattle genotypes in Uganda

DEFF Research Database (Denmark)

Asizua, Denis; Mpairwe, Denis; Kabi, Fred

2017-01-01

genotype (212±35 kg). The bulls were allotted to two feeding systems and three finishing durations. The feeding systems comprised sole grazing as the control where animals only grazed natural pastures and feedlot finishing where animals were fed a locally formulated total mixed ration containing 200 maize...... stover, 300 maize bran, 447 brewers’ spent grain, 50 molasses and 3 salt (NaCl) as g/kg on dry matter (DM) basis. The three durations were 60, 90 and 120 days excluding 14 days of adaptation period. Data was collected on feed intake, growth, slaughter and carcass characteristics. The Boran consumed less....... However, carcass quality grade scores were higher (Pcarcass...

Using NDVI to estimate carbon fluxes from small rotationally grazed pastures

Science.gov (United States)

Satellite-based Normalized Difference Vegetation Index (NDVI) data have been extensively used for estimating gross primary productivity (GPP) and yield of grazing lands throughout the world. However, the usefulness of satellite-based images for monitoring rotationally-grazed pastures in the northea...

[Community structure and diversity of soil arthropods in naturally restored sandy grasslands after grazing].

Science.gov (United States)

Liu, Ren-tao; Zhao, Ha-lin; Zhao, Xue-yong

2010-11-01

Taking the Naiman Desertification Research Station under Chinese Academy of Sciences as a base, an investigation was conducted on the community structure of soil arthropods in the naturally restored sandy grasslands after different intensity grazing disturbance, with the effects of vegetation and soil on this community structure approached. In the non-grazing grassland, soil arthropods were rich in species and more in individuals, and had the highest diversity. In the restored grassland after light grazing, soil arthropods had the lowest evenness and diversity. In the restored grassland after moderate grazing, the individuals of soil arthropods were lesser but the major groups were more, and the evenness and diversity were higher. In the restored grassland after heavy grazing, the individuals of soil arthropods were more but the major groups were lesser, and the diversity was higher. Plant individuals' number, vegetation height and coverage, and soil alkalinity were the main factors affecting the soil arthropod community in naturally restored grasslands after different intensity grazing disturbance. It was implied that after 12-year exclosure of grassland, soil arthropod community could be recovered to some degree, while grazing disturbance had long-term negative effects on the arthropod community.

Radiobiological problems concerning grazing animals following the Chernobyl accident

International Nuclear Information System (INIS)

Prister, B.S.; Lazarev, N.M.; Romanov, L.M.

1997-01-01

Chernobyl accident took place on April 26 1986, which was the beginning of the grazing season, when there was not enough fodder on the farms and the cattle was grazed on the open territory. Therefore grazing animal-breeding was the most radioactively affected branch. The consumption of contaminated fodder and surface contamination with radioactive precipitation caused the accumulation of considerable ingested doses in the organisms of animals (up to 1 GY). Radioactive damage caused to the thyroid by the selective accumulation of radioiodine (mainly 131 I) is of particular attention. Cumulative doses of thyroid irradiation in mammals were much higher than for the other organs. Thus, in cows during their grazing on the contaminated pastures outside 30-km zone the ratio of ingested doses of the thyroid and whole body was 130:1 and more, therefore, radiation effects could have a certain negative effect, concerning the agricultural animals in the zone of accidental release influence. Accumulated ingested doses in the thyroid of cows on the contaminated territory in a number of cases caused the complete destruction of the thyroid (doses above 600 Gy), which provided the loss of milk productivity and reproductive qualities of the animals. Lower doses caused the functional disturbances, which in most cases have been levelled during the years after the accident

Impact of processing on in vitro digestion of milk from grazing organic and confined conventional herds

Science.gov (United States)

Debate on differences between milk from grazing and non-grazing cows has not addressed the effects that standard processing may have on milk digestibility. In this study, raw milk from grazing organic (ORG) and non-grazing conventional (CONV) herds was adjusted to 0 and 3.25% fat and processed as fo...

Regional livestock grazing, human demography and fire incidence in the Portuguese landscape

Directory of Open Access Journals (Sweden)

Filipa Torres-Manso

2014-04-01

Full Text Available Aim of study:Wildfire incidence in Portugal is high in comparison with other Mediterranean Europe countries. Wildfire problems have been worsened by complex interactions between land use, livestock grazing and human population during the 20th century. In this study we try to understand these interactions and relationships.Area of study: Portugal country. Material and Methods: For the mainland Portuguese territory we present a statistical temporal analysis (1930-2001 based on the densities of livestock grazing and human inhabitants at the smallest administrative unit level, the parish. We compare these data with fire incidence descriptors (average area burned and average fire density between 1990 and 2007. Research highlights: We have identified clusters of parishes sharing common trends in the evolution of livestock and human inhabitant densities. A cause-effect relationship was not detected between livestock grazing density and fire incidence. However, the results point out clusters of parishes where conflicts between forest, fire and livestock grazing are important in the North, Centre and South regions of Portugal.Key Words: Livestock grazing; inhabitants; forest; fire; vegetation.

Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems.

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Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

2015-03-15

This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Dairy cows increase ingestive mastication and reduce ruminative chewing when grazing chicory and plantain.

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Gregorini, P; Minnee, E M K; Griffiths, W; Lee, J M

2013-01-01

Although the nutritive value of chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) has been thoroughly studied, little is known about the grazing behavior of cattle feeding on chicory and plantain swards. The objective of the present study was to assess and describe the grazing behavior of dairy cows as affected by dietary proportions of chicory and plantain fed as monocultures for part of the day. Ninety Holstein-Friesian cows (489±42 kg of body weight; 4.1±0.3 body condition score, and 216±15 d in milk) were randomly assigned to 15 groups (6 cows per group) and grazed according to 7 treatments: control (CTL, 3 groups), perennial ryegrass (Lolium perenne L.) dominant sward (24-h pasture strip); 3 chicory treatments comprising 20, 40, and 60% of the diet, strip-grazing a monoculture of chicory to a fixed postgrazing residual before strip-grazing a perennial ryegrass dominant sward (2 groups of cows per treatment); and 3 plantain treatments comprising 20, 40, and 60% of the diet, strip-grazing a monoculture of plantain to a fixed postgrazing residual before strip-grazing a perennial ryegrass dominant sward (2 groups of cows per treatment). Four focal animals per group were equipped with 3-dimensional motion sensors, which provided the number of steps taken at each minute of the day. These cows were also fitted with automatic jaw-movement recorders that identified bites, mastication during ingestion, chewing during rumination, and determined grazing, rumination and idling times and bouts. Daily grazing time and bouts were not affected by treatments but rumination time differed and was reduced by up to 90 min when cows were allocated to chicory and plantain as 60% of their diet. Ruminative chewing was reduced in cows grazing chicory and plantain by up to 20% in cows allocated to the 60% treatments. Compared with perennial ryegrass, as the dietary proportion of chicory and plantain increased, cows spent more time idling and less time ruminating

Assessment of herd management on organic and conventional dairy farms in the United States.

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Stiglbauer, K E; Cicconi-Hogan, K M; Richert, R; Schukken, Y H; Ruegg, P L; Gamroth, M

2013-02-01

The objective of this study was to evaluate management characteristics on organic and similarly sized conventional dairy farms located in New York, Wisconsin, and Oregon. Data from 192 organic farms (ORG), 64 conventional nongrazing farms (CON-NG), and 36 conventional grazing farms (CON-GR) were collected during farm visits and were size-matched and analyzed. The average lactation number of animals on ORG and CON-GR farms was 2.6 lactations, which was greater than that on CON-NG farms (2.3 lactations). A greater percentage of first-lactation heifers were found on conventional farms than on ORG farms. Facilities used by adult animals, including housing and milking facilities, did not differ among the grazing systems. Cattle on conventional farms were fed approximately twice as much grain as cattle on ORG farms and had greater milk production. Little difference was found for the average reported somatic cell count and standard plate count, suggesting that milk quality is not dependent on grazing system. Milking procedures were similar across all 3 grazing systems, indicating that an industry standard now exists for milking and that milk quality problems will need to be addressed with other management problems in mind. Although some disease prevention measures were commonly utilized on ORG farms, such as keeping a closed herd and having a written record of treatments administered to the animals, the use of outside support and vaccinations were found to be less prevalent on organic farms than on conventional farms. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Comparison of techniques for estimating herbage intake by grazing dairy cows

NARCIS (Netherlands)

Smit, H.J.; Taweel, H.Z.; Tas, B.M.; Tamminga, S.; Elgersma, A.

2005-01-01

For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments in 2002 and 2003 with the recently developed n-alkanes technique and with the net energy method. The first method estimates herbage intake by the difference between the herbage

Enhancing Soil Productivity Using a Multi-Crop Rotation and Beef Cattle Grazing

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Şentürklü, Songül; Landblom, Douglas; Cihacek, Larry; Brevik, Eric

2016-04-01

Agricultural production systems that include complimentary plant, soil and animal interaction contribute to sustainability. In sustainable livestock systems integrated with crop production, the soil resource is impacted positively. The goal of this research was to maximize beef cattle and crop economic yield, while improving the soil resource by increasing soil organic matter (SOM) and subsequently seasonal soil nitrogen fertility over a 5-year period (2011-2015). Each experimental crop field used in the study was 1.74 ha. Small-seeded crops were planted using a JD 1590 No-Till drill. Corn (C) and sunflowers (SF) were planted using a JD 7000 No-Till planter. The cropping sequence used in the study was SF, hard red spring wheat (HRSW), fall seeded winter triticale-hairy vetch (T-HV), spring harvested for hay/mid-June seeded 7-species cover crop (CC; SF, Everleaf Oat, Flex Winter Pea, HV, Winfred Forage Rape, Ethiopian Cabbage, Hunter Leaf Turnip), C (85-day var.), and field pea-barley intercrop (PBY). The HRSW and SF were harvested as cash crops and the PBY, C, and CC were harvested by grazing cattle. In the system, yearling beef steers grazed PBY and unharvested C before feedlot entry, and after weaning, gestating cows grazed CC. Seasonal soil nitrogen fertility was measured at 0-15, 15-30, and 30-61 cm depths approximately every two weeks from June to October, 2014. The regression illustrating the relationship between SOM and average seasonal available mineral nitrogen shows that for each percentage increase in SOM there is a corresponding N increase of 1.47 kg/ha. Nitrogen fertilizer applications for the 5-year period of the study were variable; however, the overall trend was for reduced fertilizer requirement as SOM increased. At the same time, grain, oilseed, and annual forage crop yields increased year over year (2011-2015) except for the 2014 crop year, when above average precipitation delayed seeding and early frost killed the C and SF crops prematurely

Grazing intensity on the plant diversity of alpine meadow in the eastern Tibetan plateau

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Wu Ning

2004-04-01

Full Text Available Because ofthe remoteness and harsh conditions of the high-altitude rangelands on the eastern Tibetan Plateau, the relationship between yak grazing and plant diversity has not been so clear although livestock increase was thought as the main issue leading to the degradation of rangeland. In the debate of rangeland degradation, biodiversity loss has been assumed as one of the indicators in the last two decades. In this paper authors measured the effects of different grazing intensities on the plant diversity and the structure of Kobresia pygmaea community in the case-study area, northwestern Sichuan. The results indicated that plant diversity of alpine meadow has different changing trends respectively with the change of grazing intensity and seasons. In June the highest plant diversity occurred in the intensively grazed (HG plots, but in July and September species biodiversity index of slightly grazed (LG plots is higher than other experimental treatments. In August the intermediate grazed (IG plots has the highest biodiversity index. Moreover, it was found that intensively grazing always leads to the increase of plant density, but meanwhile the decrease of community height, coverage and biomass. Over-grazing can change the community structure and lead to the succession from Kobresia pygmaea dominated community to Poa pratensis dominated. Analyzing results comprehensively, it can be suggested that the relationship between grazing intensity and plant diversity is not linear, i.e. diversity index is not as good as other characteristics of community structure to evaluate rangeland degradation on the high altitude situation. The change of biodiversity is so complicated that it can not be explained with the simple corresponding causality.

Cattle management practices and milk production on mixed smallholder organic pineapple farms in Central Uganda

DEFF Research Database (Denmark)

Nalubwama, S; Kabi, F; Vaarst, M

2016-01-01

A longitudinal study to assess animal management practices and milk production was conducted for a period of 12 months on 30 smallholder farms keeping dairy cattle and certified organic pineapple production in Luwero and Kayunga districts, based on questionnaire and on-farm collected data. Farm...... sizes were 9.3 ± 6.7 acres in tethering system and 4.3 ± 2.6 acres in zero-grazing. Fifty-four percent of the zero-grazing herds had animal housing facilities. All farmers in tethering system kept cows on earthen floors and calves without bedding. Hygiene level in existing farms was low. Majority...... of calves were fed once a day by restricted suckling (77 %). Seventy-four percent of tethered cows were only fed on natural grass, while cows under zero-grazing system had a more diversified diet but with 82 % feeding mainly Napier grass. Most farms (87 %) used bulls for breeding. Milk production was higher...

Rendimento de soja em sistema de integração lavoura-pecuária: efeito de métodos e intensidades de pastejo Soybean yield in an animal-crop rotation system: effects of grazing methods and intensities

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Robson Lunardi

2008-06-01

Full Text Available Sistemas de integração lavoura-pecuária têm despertado o interesse de produtores que buscam a diversificação das atividades e o aumento da rentabilidade. O objetivo deste trabalho foi avaliar a influência de métodos e intensidades de pastejo de ovinos no rendimento da soja cultivada em dois espaçamentos entre linhas, em um sistema de integração lavoura-pecuária. O experimento foi conduzido no município de Eldorado do Sul - RS, na Estação Experimental Agronômica - UFRGS na safra 2003/2004, cujas coordenadas geográficas são 30005'22" S de latitude e 51039'08" W de longitude. O delineamento experimental foi em blocos casualizados num fatorial com duas intensidades de pastejo, baixa e moderada, dois métodos de pastejo, contínuo e rotacionado, e dois espaçamentos entre fileiras de soja, 0,2 e 0,4m, com quatro repetições. Uma área foi adicionada como testemunha sem pastejo. Avaliaram-se o rendimento e os componentes do rendimento da soja. A produção de soja foi superior nos tratamentos submetidos a pastejo em comparação aos não-pastejados. Dentre os pastejados, o rendimento de soja foi superior na intensidade de pastejo baixa em comparação com a intensidade moderada. A intensidade de pastejo utilizada no inverno é o principal determinante do sucesso desse sistema de integração lavoura-pecuária.Animal-crop rotation systems are fostering the interest of farmers searching for diversification and the increase of profitability. The experiment aimed to evaluate the influence of grazing methods and intensities applied on winter pastures grazed by lambs and its consequence for soybean yield cultivated in succession. This crop-animal rotation trial was conducted in 2003/2004 at UFRGS Agricultural Research Station (Universidade Federal do Rio Grande do Sul in Eldorado do Sul, Rio Grande do Sul state, Brazil, whose geographical coordinates are 30005'22" S latitude and 51039'08" W longitude. The experimental design was a

Modeling the influence from ocean transport, mixing and grazing on phytoplankton diversity

DEFF Research Database (Denmark)

Adjou, Mohamed; Bendtsen, Jørgen; Richardson, Katherine

2012-01-01

Phytoplankton diversity, whether defined on the basis of functional groups or on the basis of numbers of individual species, is known to be heterogeneous throughout the global ocean. The factors regulating this diversity are generally poorly understood, although access to limiting nutrients...... in generating and maintaining diversity, we apply the model to quantify the potential role of zooplankton grazing and ocean transport for the coexistence of competing species and phytoplankton diversity. We analyze the sensitivity of phytoplankton biomass distributions to different types of grazing functional...... responses and show that preferential grazing on abundant species, for example as formulated by the Holling type III grazing function, is a key factor for maintaining species’ coexistence. Mixing and large-scale advection are shown to potentially have a significant impact on the distribution of phytoplankton...

Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics.

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Canestrari, Niccolo; Chubar, Oleg; Reininger, Ruben

2014-09-01

X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick-Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in the Synchrotron Radiation Workshop (SRW) computer code and extensively tested against the geometrical ray-tracing code SHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between the SRW and SHADOW simulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

The impact of cattle and goats grazing on vegetation in oak stands of varying coppicing age

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Papachristou, Thomas G.; Platis, Panayiotis D.

2011-01-01

The effects of cattle and goats grazing on oak shoot growth and herbaceous vegetation in three oak forest stands with different coppicing age (1, 4 and 7 yrs after the clear cutting) were investigated. In April 1997, an experimental area was chosen with three forest stands, which were clear cut in 1996 (CL1996), 1993 (CL1993), and 1990 (CL1990). All stands were grazed by cattle and goats after they were clear cut. In each forest stand, five 10 m × 10 m paired plots were located, which represented grazed and protected patches. Herbage biomass within protected and grazed plots was measured four times each year (spring: May-June, summer: July-August, autumn: September-October, and winter: November-December). Behavioural observations on grazing animals were conducted in the same periods. In both protected and open plots the height and basal diameter of all oak shoots on 5 preselected stumps were measured at the end of five growing periods from 1997 to 2001. All forest stands carried a similar amount of available herbage (averaged over forest stands and growing season, 2614 kg/ha). Grazing animals removed on average 1057 kg/ha throughout the growing period. Cattle mainly consumed herbage (97% of bites) while goats consumed a mixture of oak browse (41% bites), herbaceous species (34% bites), and other woody species browse (25% bites). The height, diameter and volume of oak shoots were affected by grazing. The three forest stands had similar shoot heights in the protected plots in 2001 after 5 years of grazing protection. The volume of oak shoots of the grazed plots were 146.7 cm3 for CL1996, 232.9 cm3 for CL1993, and 239.1 cm3 for CL1990 in 2001 (i.e. 5, 8, and 11 years grazing after the clear cuttings, respectively). The protected plots carried greater volumes of oak shoots, CL1996: 496.0 cm3 (few months grazing before protection), CL1993: 690.0 cm3 (4 years grazing before protection), and CL1990: 344.0 cm3 (7 years grazing before protection). In conclusion, almost

SIMULATION MODEL OF THE PRODUCTIVITY OF A HERD OF GOATS GRAZING UNDER DIFFERENT SCENARIOS OF HANDLING IN THE SOUTHWESTERN REGION OF TAMAULIPAS, MEXICO

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A. Villanueva-Castillo

2013-11-01

Full Text Available One of the major current challenges in the livestock industry is meeting the demand for livestock products of a growing world population. Bio-economic models integrate animal biology and rural enterprise management, which allows for the study of complex animal production systems. This paper aims at simulating the productive performance of a herd grazing under different management conditions. To do so, a simple simulation model of a goat herd (MSSRC, rangeland forage growth, and the dynamics of animal population in the semi-arid region of Southwestern Tamaulipas under three rainfall scenarios (300, 500, and 700 mm. of average annual precipitation was built. The objective was to evaluate the sustainability of extensive grazing under different animal loads. Nine different scenarios were evaluated, corresponding to the different combinations of the three rainfall scenarios and three levels of initial loads (Hi and nannies maximum load (HMAX. Evaluated variables are: kids sales (C; total number of nannies (female goats, HT; sales of replacement nannies (VREE; sales of scrap goats (CDS; rangeland condition (CA; voluntary consumption (CV; mortality rate (M; abortion rate (A;  and average annual profits (UPA. Simulation was performed on a 1,000 hectares plot, and three 10-year periods were used as time framework. Analysis of Variance (ANOVA revealed statistically significant (P < 0.05 differences between scenarios for all studied variables. Biomass primary net production under the 300, 500, and 700 mm of rainfall was found to be 1,132.2 ± 362.9, 2,244.2 ± 517.0, and 3,113.3 ± 598.7 kg DM ha-1 per year, and the average annual production of kids was 36 ± 17, 90 ± 31, and 132 ±37, respectively. The low loads scenarios showed a stable behavior, with a constant rate of kids production over the three simulation periods (0-30 years, which resulted in a higher average annual profit, and a more sustainable profile than those with heavier

Active Full-Shell Grazing-Incidence Optics

Science.gov (United States)

Davis, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Gubarev, Mikhail V.

2016-01-01

MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

Estimating legume N-2 fixation in grass-clover mixtures of a grazed organic cropping system using two N-15 methods

DEFF Research Database (Denmark)

Vinther, F.P.; Jensen, E.S.

2000-01-01

The input of Nitrogen (N) through symbiotic N-2 fixation (SNF) in grass-clover mixtures was determined in an organic cropping. system for grazing during 3 years. The mixture of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) was established by undersowing in spring...... barley (Hordeum vulgare L.) and maintained subsequently for two production years. Dinitrogen fixation was determined using the N-15 isotope dilution techniques and two labelling procedures. Using either pre-labelling of the soil with immobilisation of the N-15 by addition of a carbon source before...

Productive and Economic Responses in Grazing Dairy Cows to Grain Supplementation on Family Farms in the South of Brazil

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Luiz Carlos Pinheiro Machado Filho

2014-07-01

Full Text Available Pasture-based dairy production has been a major source of income for most family farms in the south of Brazil. Increasing milk prices have spurred an increase in grain supplementation, which has been poorly implemented, resulting in low levels of efficiency. To evaluate the consequences of supplementation on milk production and composition, grazing behavior and economic return, the widely used grain management system (CC-commercial concentrate, containing 21% CP, offered at 1 kg per 3.7 L of milk was compared with an energy supplement (GC-ground corn, with 9.5% CP, offered at 0.4% of live weight. Ten Holstein cows were paired into two groups, and subjected to the two treatments in a crossover design. The cows remained in the same grazing group, and the grain supplement was offered individually at milking time and consumed completely. Each experimental period lasted 14 days, with 10 days for diet adaptation and four days for data collection; individual milk production and samples were collected to determine levels of fat, protein, lactose, carotenoids, vitamin A and N-urea. Grazing behavior was observed (scans every 5 min in the first 4 h after the morning milking, and chemical composition of hand plucked samples of forage were measured. The cost of the supplement and profitability per treatment were calculated. Cows supplemented with GC consumed herbage with higher crude protein (CP: 16.23 vs. 14.62%; p < 0.05, had higher biting rate (44.21 vs. 39.54 bites/min; p < 0.03 and grazing time (22.20 vs. 20.55 scans; p < 0.05 than when receiving CC. There were no differences in milk composition between treatments (p > 0.05. However, higher concentrations of β-carotene and total carotenoids were detected in the milk of cows at 70–164 days of lactation, compared to <70 days of lactation (p < 0.05. Milk production was higher (13.19 vs. 11.59 kg/day; p < 0.05 when cows consumed CC, but resulted in lower profitability compared to GC (US$ 4.39 vs. US$ 4

Bermudagrass Management in the Southern Piedmont U.S. IV. Soil Surface Nitrogen Pools

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Alan J. Franzluebbers

2001-01-01

Full Text Available The fate of nitrogen (N applied in forage-based agricultural systems is important for understanding the long-term production and environmental impacts of a particular management strategy. We evaluated the factorial combination of three types of N fertilization (inorganic, crimson clover [Trifolium incarnatum L.] cover crop plus inorganic, and chicken [Gallus gallus] broiler litter pressure and four types of harvest strategy (unharvested forage, low and high cattle [Bos Taurus] grazing pressure, and monthly haying in summer on surface residue and soil N pools during the first 5 years of ̒Coastal̓ bermudagrass (Cynodon dactylon [L.] Pers. management. The type of N fertilization used resulted in small changes in soil N pools, except at a depth of 0 to 2 cm, where total soil N was sequestered at a rate 0.2 g ‧ kg–1‧ year–11 greater with inorganic fertilization than with other fertilization strategies. We could account for more of the applied N under grazed systems (76–82% than under ungrazed systems (35–71%. As a percentage of applied N, 32 and 48% were sequestered as total soil N at a depth of 0 to 6 cm when averaged across fertilization strategies under low and high grazing pressures, respectively, which was equivalent to 6.8 and 10.3 g ‧ m–2 ‧ year–1. Sequestration rates of total soil N under the unharvested-forage and haying strategies were negligible. Most of the increase in total soil N was at a depth of 0 to 2 cm and was due to changes in the particulate organic N (PON pool. The greater cycling of applied N into the soil organic N pool with grazed compared with ungrazed systems suggests an increase in the long-term fertility of soil.

Investigations on the effect of grazing intensity on the transfer of radionuclides to cow`s milk

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Voigt, G. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Schotola, C. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Crout, N.M.J. [Nottingham Univ. (United Kingdom). Dept. of Physiology and Environmental Science; Absalom, J. [Nottingham Univ. (United Kingdom). Dept. of Physiology and Environmental Science

1997-03-01

For these investigations two farms were chosen. Farm A carries out a rotational grazing regime with 4 grazed pastures which is the more commonly used farm practice in Bavaria, farm B practises a continuous grazing regime with one grazed pasture only. In farm B a tenfold lower Cs-137 activity concentration was observed in milk though activity concentrations in soil and pasture grass were the same as that at farm A, indicating the same transfer rate soil-plant at both locations. It could be shown under normal agricultural conditions that with a higher grazing pressure lower activity concentrations in milk (in this case a factor of about 2 to 3) were obtained. Therefore changing stock density in combination with a continuous grazing regime on a given pasture after a major nuclear accident can be considered as a possible countermeasure which can be easily applied. Mainly to get more synchronised growth rates and a homogeneous distribution of radiocontamination plot experiments were performed to simulate the influence of grazing intensity. Under the experimental design used here no effect of grazing intensity on the transfer of radionuclides to vegetation could be found. Effects of grazing intensity as found for the farm experiment, therefore must be due to other sources than vegetation activities, and are presumably due to soil ingestion preventing uptake of soluble plant incorporated radiocaesium in the animal rumen. (orig./MG)

Grazing impact on desert plants and soil seed banks: Implications for seed-eating animals

Science.gov (United States)

Pol, Rodrigo G.; Sagario, M. Cecilia; Marone, Luis

2014-02-01

We assess whether the knowledge of livestock diet helps to link grazing effects with changes in plant cover and soil seed bank size, aiming at inferring the consequences of grazing on seed-eating animals. Specifically, we test whether continuous and heavy grazing reduce the cover, number of reproductive structures and seed reserves of the same grass species whose seeds are selected and preferred by granivorous animals in the central Monte desert, Argentina. Grass cover and the number of grass spikes usually diminished under grazing conditions in the two localities studied (Telteca and Ñacuñán), and soil seed bank was consistently reduced in all three years evaluated owing to a decline of perennial grass and forb seeds. In particular, the abundance of those seeds selected and preferred by birds and ants (in all cases grass species) declined 70-92% in Ñacuñán, and 52-72% in Telteca. Reduction of perennial grass cover and spike number in grazed sites reinforced the causal link between livestock grazing and the decline of grass soil seed reserves throughout failed plant reproduction. Grass seed bank depletion suggests that grazing may trigger a "cascade" of mechanisms that affect the abundance and persistence of valuable fodder species as well as the availability of seed resources for granivorous animals.

Some effects of winter grazing of Dohne sour veld | PF | African ...

African Journals Online (AJOL)

The utilisation of spared sour veld poses practical problems. As a result of the development of high level protein or nitrogen supplements it has however become possible to efficiently graze spared veld. Results of experiments during three winters where spared sour veld was grazed off either by sheep or by cattle are given.

Effect of Mixed Systems on Crop Productivity

Science.gov (United States)

Senturklu, Songul; Landblom, Douglas; Cihacek, Larry; Brevik, Eric

2017-04-01

The goals of this non-irrigated research has been to determine the effect of mixed systems integration on crop, soil, and beef cattle production in the northern Great Plains region of the United States. Over a 5-year period, growing spring wheat (HRSW-C) continuously year after year was compared to a 5-year crop rotation that included spring wheat (HRSW-R), cover crop (dual crop consisting of winter triticale/hairy vetch seeded in the fall and harvested for hay followed by a 7-species cover crop that was seeded in June after hay harvest), forage corn, field pea/barley, and sunflower. Control 5-year HRSW yield was 2690 kg/ha compared to 2757 kg/ha for HRSW grown in rotation. Available soil nitrogen (N) is often the most important limitation for crop production. Expensive fertilizer inputs were reduced in this study due to the mixed system's complementarity in which the rotation system that included beef cattle grazing sustained N availability and increased nutrient cycling, which had a positive effect on all crops grown in the rotation. Growing HRSW continuously requires less intensive management and in this research was 14.5% less profitable. Whereas, when crop management increased and complementing crops were grown in rotation to produce crops and provide feed for grazing livestock, soil nutrient cycling improved. Increased nutrient cycling increased crop rotation yields and yearling beef cattle steers that grazing annual forages in the rotation gain more body weight than similar steers grazing NGP native range. Results of this long-term research will be presented in a PICO format for participant discussion.

Changes in composition and structure of a tropical dry forest following intermittent Cattle grazing

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Margaret Stern

2002-12-01

Full Text Available In northwestern Costa Rica, cattle are being used as a "management tool" to reduce the amount of combustible material, mainly dominated by Hyparrhenia rufa, an African grass. This project is being developed within Parque Nacional Palo Verde and Reserva Biológica Lomas Barbudal, both of which fonn part of the only remaining tropical dry forests in Mesoamerica. To determine the short-term effects of cattle grazing on the natural vegetation, we compared the floristic composition within Palo Verde in an area under intermittent cattle grazing with an area that has not been grazed. There were significantly fewer plant species in the area with intermittent cattle grazing compared to the area with no grazing. Floristic composition of these two habitats was different as reflected by both Fisher's alpha values and the Shannon index of diversity, both of which were significantly higher in the ungrazed site. The ungrazed area contained more plant species and was more similar to mature forest. The structure of the vegetation was significantly different between the intermittently grazed and ungrazed sites with more small stems (1-5 cm dbh and fewer large stems (>5 cm dbh in the intermittently grazed habitat. These results indicate that cattle grazing has an impact on the dry forest by reducing the relative abundance and density of larger tree species and by changing the species composition and structure of the community. The current management plan implemented in Palo Verde and Lomas Barbudal is not appropriate because of the impact that cattle have on the structure of the natural vegetation and should not be considered a viable alternative in other protected areas of dry forest in the Neotropics. We suggest that alternative fire prevention measures be evaluated including hand-cutting H. rufa, the creation of more frequent and larger fire breaks, and the development of green breaks.En el noroeste de Costa Rica se utiliza ganado como una "herramienta de

Steers grazing of a rye cover crop influences growth of rye and no-till cotton

Science.gov (United States)

Small grain cover crops offer opportunities for grazing but effects on following row crops are not well understood. From 1999 through 2008, stocker steers sequence grazed small grains in a 2-paddock rye-cotton-wheat-fallow- rye rotation. Treatments imposed on rye included 1) zero-grazing from 1999; ...

Goats on alpine grazing: study on metabolic and hematologic profiles

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A. Gaviraghi

2011-03-01

Full Text Available Summering on alpine pastures from June to October has long been the traditional management of goat flocks in the mountain areas of Lombardy. At present most of the 50.000 goats farmed in Lombardy are still summered, even though only a few thousands - belonging to local breed - are regularly milked. For these goats summering appears to be fundamental not only to allow milk production but also to restore body reserves. The increasing interest in commercial goat milk production in Lombardy involves mainly intensive farming with zero or minimum grazing. However, semi-extensive goat milk production, including summering, could respond to social and environmental goals (Citterio et al., 2002 being able to exploit some economic opportunities...

Methane Emission By Grazing Livestock. A Synopsis Of 1000 Direct Measurements

Energy Technology Data Exchange (ETDEWEB)

Lassey, K.R. [National Institute of Water and Atmospheric Research (NIWA), Wellington (New Zealand); Ulyatt, M.J. [New Zealand Pastoral Agriculture Research Institute (AgResearch), Palmerston North (New Zealand)

2000-07-01

In a series of field campaigns since 1995, a team of atmospheric and ruminant-nutrition scientists have measured methane emissions directly from individual ruminant livestock freely grazing representative New Zealand pastures. The technique collects integrated 'breath' samples during grazing, using an implanted SF6 source as a conservative calibrated tracer, an approach pioneered by Johnson et al. [1994]. Most of these measurements have been on grazing sheep (942 animal-days to Aug 1999), others on grazing dairy cows (283), with some measurements also on sheep under controlled feeding conditions (305) [eg, Lassey et al., 1997; Ulyatt et al., 1999]. The aim is to characterise the variability of emission rates, including their dependence on pasture quality and physiological condition. The research goal is two-fold: (1) to provide a better scientific basis for assessing the national emissions inventory; and (2) to investigate options for mitigating livestock emissions. Here, we discuss the research strategy and overview the principal research findings. We note in particular, that as a source of enterically fermented methane, sheep may not be merely 'small cattle'. 5 refs.