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1.
Francuois L Müller Clement F Cupido Melvin BV Swarts Nefza M Amary Dawood Hattas 《African Journal of Range and Forage Science》2019,36(2):105-114
Access to good-quality forages is one of the major limitations to livestock production in semi-arid pastoral systems. This study aimed to determine whether there are differences in the nutritional quality of diets selected by herded and free-ranging goat and sheep flocks utilising Namaqualand Granite Renosterveld vegetation during the wet and dry seasons. Plant samples collected along the grazing routes of livestock were dried and analysed for their fibre, condensed tannin, total phenolic and mineral nutrient contents. The study showed that a large variety of forages were on offer and livestock groups selected different diets of which some were different to the total diet on offer. In general, significant deficiencies in phosphate, protein and energy in the diets selected by herded and free-ranging goats and sheep were observed in both wet and dry season. The quality of the diets selected by herded and free-ranging livestock was also found to be different from each other, with herded livestock generally selecting more nutrient-dense diets. Herding, therefore, allows livestock to access better-quality forage in the Namaqualand Granite Renosterveld rangeland, where it is generally poor. 相似文献
2.
The objective of this study was to determine the extent to which herbivores are able to use conditioned food aversions and preferences to learn about the nutritional and toxic properties of food plants, when food options are simultaneously available. Conditioned food aversions and preferences have been invoked as important mechanisms by which free-ranging herbivores optimize food selection by learning about the negative and positive consequences of consuming particular plant species through a series of encounters. In most previous tests of this hypothesis, access to individual test foods has been separated in time, giving animals the opportunity to associate particular foods with particular post-ingestive effects. We presented animals with a more complex scenario by offering test feeds simultaneously during the learning phase. Such a test is an important step in assessing the importance of conditioned food responses as mechanisms by which herbivores learn to select an optimal diet. We first assessed the ability of goats to learn about test foods and their post-ingestive effects, when different conifer species were offered on separate days during the learning phase and animals were dosed with compounds eliciting positive, negative, or neutral post-ingestive effects. We then investigated the ability of animals to learn to make appropriate choices when all potential test foods were simultaneously available during the learning phase. The results confirmed that goats can learn to associate particular foods with particular post-ingestive effects and adjust their diet selection accordingly. The success with which animals made such associations was greatly reduced when they were presented with test foods simultaneously during the learning phase. When test foods were simultaneously available, animals tended to select a mixed diet, thereby reducing their opportunity to learn about the post-ingestive effects of particular foods. The results suggest that caution is required in extrapolating results of artificial conditioning experiments to free-ranging herbivores. The results also suggest that reducing the risk of toxicity through selection of mixed diets is an important component of a successful foraging strategy. 相似文献
3.
通过放牧强度对羊草草地植被和家畜生产影响的研究,放牧强度不同程度地改变了土壤养分状况,三种放牧强度下草地植物群落的高度、密度、盖度、频度、可食牧草产量无明显变化,组间差异不显著(>0.05)。放牧强度影响羯羊体重。羯羊日增长量随放牧强度减小而增加,羯羊生长量以中组为最佳,中组分别比低组、高组提高30.4%、17.6%,平均日生长量组间差异显著(<0.05);牧草干物质的采食量影响羯羊生长量,而日采食量中粗蛋白较干物质对羯羊生长的影响更为重要。草地放牧以中放牧强度(6只/hm2)为最佳。 相似文献
4.
放牧家畜的采食量是人们了解放牧系统动力学的关键之一。研究已查明，了解了放牧家畜的采食量和采食成分就能明晰家畜的营养状况，预测其生产性能，从而为草地管理决策提供目标，为优化资源利用提供基础数据。然而，估测放牧家畜的采食量及其组分是困难的，也是昂贵的。虽然那些改进的技术和方法有效地增强了人们获取家畜牧食行为数据的能力，但是测定放牧动物的采食量、采食成分和养分消化率一直以来都是营养学研究的挑战，方法众多，却各有利弊。因此，本研究针对目前估测放牧家畜采食量和采食成分的常用方法，如模拟采食法、牧前牧后差额法、酸不溶灰分法、三结合法、植物蜡层指示剂法和近红外光谱技术法，对它们的利弊和准确性进行讨论，并探析未来发展趋向，为今后的研究提供资料。 相似文献
5.
M. Igshaan Samuels Nicky Allsopp M. Timm Hoffman 《Strength and Conditioning Journal》2019,72(1):195-203
Pastoral systems are regarded as complex social-ecological systems with components that interact and change over a range of spatial and temporal scales. As such, herd mobility has traditionally been used to respond to the dynamic nature of these systems. However, mobile pastoral systems around the world are becoming more constrained and increasingly fragmented with important implications for herd mobility. This study assessed the spatial distribution of 256 herds and their mobility patterns over a decade in the 10 villages that comprise the spatially constrained Leliefontein pastoral area in South Africa. We developed a hierarchical model of rangeland use, which showed that several stratified and connected socioeconomic, climatic, and environmental factors determined the spatial and temporal use of grazing areas in this 192 000-ha semiarid environment. At the highest level of use, access to the Leliefontein pastoral area is formally regulated. At the next level, the place of residence of herd owners largely defined which village commons was used by their livestock. At the third level of rangeland use, the wealth status of owners determined where in relation to human settlements their herds were located. At the lowest level in the hierarchy, the locations of water and croplands delineated seasonal grazing areas and the movement of stockposts. These stratified factors, together with the overall variability in grazing resource availability and the different decision making processes involved, resulted in high flexibility and diversity of herd mobility patterns at the lowest level of rangeland use. This, in turn, ensured heterogeneity in resource use over a range of spatial and temporal scales. It was concluded that policies should embrace the complexity of the pastoral system and enable the adaptive management of herds. This could reduce the level of vulnerability experienced by pastoralists to climate variability and wider societal change. 相似文献
6.
《Strength and Conditioning Journal》2020,73(2):243-251
Early relationships between young mammalian herbivores and social models (e.g., mothers or peers) have been proposed as playing a major role in the process of diet learning. Diet selection is an important factor influencing animal development and ecology, especially in natural and seminatural grasslands, with a large diversity of plant species. To explore the learning process of foraging behavior and diet selection choices by foals, six free-ranging Criollo foals and their respective mares were monitored through continuous bite monitoring from birth to 130 d old, in the Pampas Grasslands of southern Brazil. Cumulative suckling time decreased exponentially from birth to 130 d old, while dry matter intake, foraging time, and bite mass of foals increased continuously. It was possible to identify three marked periods in the foal’s foraging behavior development: 1) an exploratory phase (from 0 to 40 d old) marked by limited forage intake from a large diversity of plants; 2) a specialization phase (from 40 to 110 d old) with a marked increase in forage intake and a specialization around the same plants as the ones selected by the mares; and 3) a stabilization phase (after 110 d old) in which forage intake still increases but diet composition of foals stabilized similarly to the one of the respective mares. The higher diversity at young ages could be explained by exploratory hypothesis, where foals test different forages to discover their environment, given that their nutritional needs are fulfilled by milk consumption, not by forage intake. As requirements shift toward solid items, bite mass and foraging time increase and diet choices become similar to that of the mares. Our results detail how young foals develop their foraging behavior and suggest, without testing it and under the circumstances of this study, that they learn their diet through social transmission from their mothers. 相似文献
7.
《Strength and Conditioning Journal》2020,73(3):394-402
Diet overlap estimation among species is important to understand interspecific interactions. Through these interactions, one species may extinguish others through competition or adapt through mechanisms such as resource partitioning. The introduction of domestic herbivores in a native assemblage may introduce competition for resources with wild herbivores. In southern Patagonian steppes, guanaco (Lama guanicoe) populations are increasing after a drastic demise during the past century. This is occurring in protected areas and extensive ranching areas for sheep, and in the latter ranchers have rising concerns regarding competition. In this observational study, we measured diet overlap, food selection and preferences, and niche width for guanaco and sheep to compare use of food resources during the summer season. Feces were analyzed through microhistological technique to determine sheep and guanaco diets. Diets of guanaco and sheep were dominated by tussock grass (Festuca gracillima, sheep > 60%, guanaco > 50%), the most abundant plant species. Although food niche widths, measured through Levin’s Index, were narrow, guanaco presented the broadest niche (P < 0.001). Of the 17 identified plant species present in guanaco and sheep diets, 5 were always selected by both ungulates and 1 was always avoided at the four study sites. Overlap between diets was high (> 0.90), evidencing potential competition. In addition, diet overlap coupled with our results of small variation in use and selectivity of food resources suggest the absence of resource partitioning. Therefore, both species might share resources or coexist, possibly due to high availability or spatial distribution of food resources and guanaco resilience to cope with numerically dominant competition from sheep. These findings offer new insight into the understanding of these species’ interactions. It is also a management challenge to emerging wild and domestic herbivores interactions, as well as livestock production concerns at large. 相似文献
8.
The heritability of diet selection for mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb] Beetle) by grazing sheep was estimated from fecal samples collected from 549 Rambouillet ewes. Fecal samples were collected in September and October during 1996 and 1997 from free-grazing ewes on intermountain sagebrush-bunchgrass rangelands at the U.S. Sheep Experiment Station in Idaho. The total number of fecal samples was 1,949. Fecal samples were evaluated for composition of big sagebrush by near-infrared spectroscopy. Percentage of sagebrush in the diet was less in September than in October (21.6 vs 31.7%, respectively). Single-trait and bivariate derivative-free REML analyses were performed to genetically compare percentage of sagebrush in the diet in September and October. Heritability estimates were similar between September and October measurements (0.25 and 0.28, respectively). The genetic correlation between September and October percentages of sagebrush in the diet was high (0.91), implying that there is strong genetic similarity between September and October measurements and that an annual measurement may be sufficient for selection. These results contribute to a greater understanding of dietary preferences in freely grazing sheep, and suggest opportunities to improve production efficiency and forage management through selection for dietary preferences. 相似文献
9.
《Strength and Conditioning Journal》2005,58(2):99-108
Many grazing-management challenges stem from poor livestock distribution resulting in overuse of some areas and low utilization of others. Managing livestock-distribution patterns requires knowledge of pasture characteristics and animal behavior patterns. Behavioral patterns result from recognizable processes that include inherited attributes, individual and social learning systems, cue-consequence specificity, predispositions toward novel stimuli, and spatial memory. Through these behavioral mechanisms, animals form and revise preferences and aversions for specific locations in their foraging landscape. To accomplish habitat selection, domestic herbivores use sight and sound cues to seek and return to high-quality foraging locations. Nested within habitat selection are learned diet preferences and aversions by which ungulate herbivores associate taste with positive or negative postingestive feedback. The deliberate and careful modification of animal attributes and habitat characteristics could yield options for adaptive rangeland management. In this article, we describe the basic principles that underlie how animals make decisions about where to forage and how long to stay in a particular habitat. We also suggest management practices designed to modify animal behavior and alter habitat-use patterns. 相似文献
10.
Niklas Boke-Olén Veiko Lehsten Abdulhakim M. Abdi Jonas Ardö Abdelrahman A. Khatir 《Strength and Conditioning Journal》2018,71(6):792-797
Livestock production is important for local food security and as a source of income in sub-Saharan Africa. The human population of the region is expected to double by 2050, and at the same time climate change is predicted to negatively affect grazing resources vital to livestock. Therefore, it is essential to model the potential grazing output of sub-Saharan Africa in both present and future climatic conditions. Standard tools to simulate plant productivity are dynamic vegetation models (DVMs). However, as they typically allocate carbon to plant growth at an annual time step, they have a limited capability to simulate grazing. Here, we present a novel implementation of daily carbon allocation for grasses into the DVM Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) and apply this to study the grazing potential for the Kordofan region in Sudan. The results show a latitudinal split in grazing resources, where the northern parts of Kordofan are unexploited and southern parts are overused. Overall, we found that the modeled grazing potential of Kordofan is 16% higher than the livestock usage reported in the Food and Agricultural Organization of the United Nations, indicating a mitigation potential in the form of a spatial relocation of the herds. 相似文献
11.
Water buffalo are an ancient component of Turkey’s domestic livestock resources. Commonly referred to as the Anatolian buffalo
the animal is part of the Mediterranean group which includes Syrian, Egyptian and Southeast European animals. Once quite numerous,
there have been drastic reductions in their numbers since the 1970s due to intensification of dairy activities, agricultural
mechanization and changing consumer preferences. The main areas of distribution are in northwest Turkey in the Marmara and
Black Sea Regions. Buffalo are kept in small herds by livestock and mixed crop–livestock farmers. Milk is the main product,
meat is largely a by-product of the dairy function and provision of the once-important draught power is now a minor output.
Buffalo milk is used to prepare a variety of speciality products but output of both milk and meat is very low in comparison
to cattle. Conditions of welfare and health status are not optimal. Internal parasites are a constraint on productivity. Some
buffalo are being used for conservation grazing in the Black Sea area to maintain optimal conditions for bird life in a nature
reserve. Long neglected by government there are recent activities to establish conservation herds, set up in vitro banks and
undertake molecular characterization. More effort is needed by government to promote buffalo production and to engage the
general public in conservation of their national heritage. 相似文献
12.
Microcredit loans are now common for Inner Mongolian pastoralists and are encouraged by government policy on the basis of their previous success for poverty alleviation. However, the effects of the highly variable weather characteristics of many semiarid rangelands on the efficacy of microcredit have not been fully examined. Pastoralists in our study area are often trapped in a vicious cycle of borrowing more each year to pay for previous debt and the next year’s production. Instead of helping to maintain herds through bad years, microcredit has often led to reduced herds and assets. To understand why, a qualitative, interview-based approach was used to determine the kinds of loans taken out and why they are taken out, as well as to assess household livestock sales, income, and costs in three villages. In poor years, 82% of households used loans to purchase winter forage. However, borrowers sold more livestock because the standard 1-yr loan term, combined with weather and market conditions, often forced sales for repayment. Weather and market variation made annual income and costs difficult to anticipate. Loans became an added household risk, another way that environment can influence the social and economic interactions of a rangeland social-ecological system. Longer-term loans could smooth the uncertainty of weather and market conditions, and supplementary measures such as government subsidies or forage insurance could buffer the inevitable but unpredictable bad years. Globally, study of the impacts of nonequilibrial ecological dynamics on economic and policy institutions would help to understand why many development initiatives have failed in such systems. 相似文献
13.
《African Zoology》2013,48(4):139-144
Farmers in the northern, communally managed parts of the Succulent Karoo, an arid rangeland system in South Africa, historically used donkeys and horses for transport and ploughing. With increasing mechanisation, draught animal power has largely been replaced by machines. Yet, donkeys and horses have been maintained in the agricultural landscape in small feral and semi-feral herds. Research has shown that they compete directly with productive livestock (mostly sheep and goats) for forage resources, contributing little to the local economy. Local farmers identify the presence of feral donkeys and horses as one of the primary challenges in maintaining sustainable grazing regimes on their land. However, records of the number of animals roaming the rangelands are scarce and anecdotal. We therefore conducted a combination of aerial, ground, and social surveys to estimate the minimum population size and potential grazing impact of the donkey and horse population in two communally farmed sites in the Succulent Karoo. We show that, in the representative sites surveyed, there are at least 376 equines (274 donkeys and 102 horses), representing approximately the equivalent of 2 228 sheep and goats, and consuming ～8% of the potential grazing available for productive livestock in these areas. This could represent a significant lost opportunity cost for local farmers in the region. 相似文献
14.
青贮是在厌氧和湿润环境条件下,乳酸菌利用原料中的碳水化合物产生大量的乳酸积累,从而抑制各种微生物的生长和繁殖,使原料得以长期保存的饲料调制方法。青贮饲料具有柔软多汁、气味酸香、营养丰富、适口性好、利用率高和便于保存等特点,已成为家畜不可或缺的组成部分。通过对青贮原理、原料选择、窖池建设、制作步骤、取喂方法等方面的技术进行介绍,旨在为广大农牧民和饲草料生产企业与规模养殖场提供借鉴。 相似文献
15.
退牧还草改善草地生态环境 总被引：8，自引：2，他引：6
针对青海省草地生态环境趋于恶化的实际状况,提出退牧还草,改善草地生态环境建议和措施一是种植优良牧草,建立高产优质的人工草地;二是发展牧区二、三产业,搞好畜牧业服务体系建设;三是大力推广使用优质饲料产品;四是压缩非生产畜,缓解草场压力,走高效畜牧业路子;开展草地生态综合治理. 相似文献
16.
燕麦是一种一年生禾本科作物，具有耐瘠薄、耐盐碱、抗旱耐寒、适应性广等特性，可广泛种植于欧洲、北美洲和亚洲的北纬40°以北的温带地区。同时，燕麦产草量高、营养价值高、适口性好、消化率高、适于青贮和调制干草，因此，燕麦是一种粮饲兼用的重要杂粮作物。根据燕麦籽粒是否被麸皮包裹可分为皮燕麦和裸燕麦。目前，我国多种植不带麸皮的裸燕麦，主要用于食用，而国外以种植带麸皮的皮燕麦为主，主要用于饲喂牲畜。在大力发展畜牧业的今天，我国的饲用燕麦品种是严重不足的。因此，我国制定并实施了“草牧业”“粮改饲”“引草入田”等系列政策，促进了饲用燕麦产业的快速发展。在国家政策和产业需求的大力支持和引导下，饲用燕麦的种植面积不断扩大，对新品种的需求也日益迫切，对饲用燕麦的育种工作也提出更高的要求。本研究综述了国内外饲草燕麦的：1）种质资源收集、整理和鉴定评价；2）常规育种的4个发展阶段；3）分子技术在燕麦科研与育种中的利用。基于以上研究的梳理总结，明确当前饲用燕麦的育种需求，分析饲用燕麦育种的重点、难点和热点问题，为我国饲用燕麦育种的现代化发展提供重要参考。 相似文献
17.
Differing viewpoints regarding wild (feral) horse management have resulted in majorcontroversy for public land management. While the livestock industry has not advocated the eradication of wild horses, much of the publicity on the issue has given this misleading impression. The livestock industry has advocated wild horse management. Wild horse herds have, in some cases, presented major management conflicts for ranchers when they have been allowed to multiply to uncontrolled numbers. In many areas, wild horse management has been secondary in priority to completion of environmental impact statements. During this interim period, wild horse herds have gone without management. Livestock numbers have been regulated by management agencies in accordance with forage production. Wild horses also must be managed within the carrying capacity of the rangeland. Management plans developed and implemented jointly by all interested factions present the best viable solution to the wild horse controversy. 相似文献
18.
Production Objectives and Management Strategies of Livestock Keepers in South-East Kenya: Implications for a Breeding Programme 总被引：1，自引：1，他引：0
A survey of pastoralist and agropastoralist households in south-east Kenya was conducted to determine their production objectives
and management strategies in order to optimize and extend a breeding programme for indigenous small East African Shorthorn
Zebu cattle. The reasons for keeping cattle and the breed/trait preferences identified reflect the multiple objectives of
the livestock keepers, with both adaptive traits and productive/reproductive traits rated as important. Although the Maasai
and Kamba zebu (M&KZ) breeds were ranked highly with regard to adaptive traits, the population is considered to have been
in decline over recent years. In order to promote the conservation and sustainable use of the M&KZ cattle, the formation of
an open nucleus breeding scheme is recommended. In particular, such a scheme would be able to address several existing constraints
(e.g. individual herds are very small and communal use of pastures/water makes controlled mating difficult). Such interventions
would require the full participation of the livestock keepers, as well as ensuring that a holistic approach to species and
breed attributes is taken into account in setting breeding goals, such that the full array of contributions that livestock
make to livelihoods and the genetic characteristics related to these contributions are fully incorporated into the programme. 相似文献
19.
伊犁河谷半定居家庭牧场草畜平衡优化模式研究 总被引：1，自引：0，他引：1
通过对伊犁河谷新源县10户半定居家庭牧场草地资源利用、人工饲草生产、生产经营效益进行调查,研究分析暖季放牧、冷季舍饲的半定居家庭牧场在不同经营方式下饲草料供应量和牲畜数量之间的关系。结果表明：年度间天然草地生产力和降水量有显著的正相关关系;生产规模决定牧民的收入;达到草畜平衡的家庭牧场单位牲畜的生产效率更高。通过对夏牧场实施划区轮牧和分段放牧,将春秋牧场利用天数由现在的125天缩短到95天,以解决夏牧场局部退化和春秋牧场超载问题;通过扩大种植青贮玉米、苜蓿等高产优质牧草增加饲草来源,冷季舍饲时间由现在的1 相似文献
20.
干旱区黑河流域山地-绿洲-荒漠草畜耦合及其应用研究--以黑河流域中游段的临泽示范区研究为例 总被引：3，自引：0，他引：3
通过对干旱区黑河流域山地-绿洲-荒漠生态系统中草畜业发展现状及问题的认识和研究,就区域草畜耦合相关的理论及其应用方面,如耦合的目的、意义及必要性;舍饲的养畜育肥耦合机制的基础、条件、途径、形式;草畜生产特点及特色;草畜耦合机制的基本模式;草畜耦合的发展演变预测及成效体现;影响耦合发展演变的相关问题等,进行了系统的探讨和阐述.以期为本区草畜业和区域社会经济生态及环境资源的可持续稳定发展,提供有利的科学依据. 相似文献