Sheep Units Research Articles

Prevention capacity significantly reduced the livestock exposure to snow hazards across the Qinghai Plateau

Livestock snow disaster is one of the most serious natural disasters in pastoral areas during cold seasons, leading to substantial livestock losses over the past few decades. Accurate assessment of livestock exposure is crucial for reducing the risk of livestock snow disaster, while much less is known about the livestock exposure due to the lack of available gridded livestock density data with long time series. In this study, the gridded density datasets of large livestock, sheep and total livestock at a spatial resolution of 1 km across the Qinghai Plateau (QP) during 1983–2018 were generated by developing livestock density models and disaggregating livestock census data. Then, the spatiotemporal patterns of livestock exposure to snow hazards in the QP were explored and the relative contributions of influencing factors (snow hazard, livestock density and prevention capacity) were quantified. There was a significant negative trend (p < 0.10) of −1.16 × 106 standard sheep units (SSUs) decade−1 in annual total livestock number and −4.67 × 107 SSUs-day decade−1 (p < 0.05) in annual total livestock exposure across the QP from 1983 to 2018. Spatially, snow hazard, livestock density and prevention capacity dominated the total livestock exposure changes in 38.11 %, 22.70 % and 34.95 % of pastoral areas, respectively. However, the reduction in total livestock exposure across the QP was primarily contributed by prevention capacity (56.13 %). This study provides a comprehensive understanding and scientific decision-making basis for livestock snow disaster mitigation and risk management, contributing to the high-quality development of pastoral areas.

204 Detecting subclinical mastitis in meat-breed ewes using infrared thermography

Abstract Mastitis, the inflammation of the mammary gland most commonly due to bacterial infection, is an important welfare concern in meat-breed sheep. The objective of our study was to evaluate udder surface temperature obtained from infrared thermography as a diagnostic tool for subclinical mastitis. We predicted that udder halves with subclinical mastitis would have greater surface temperatures than healthy udder halves. We enrolled 39 meat-breed ewes (10 Hampshire, 24 Polypay, 5 Targhee; 2 to 9 yr of age) at the University of Wisconsin-Madison sheep unit. All procedures were approved by the UW-Madison Institutional Animal Care and Use Committee. Milk samples from each udder half were collected in duplicate weekly beginning 2 to 4 d postpartum until 8 wk postpartum. Immediately before milk sampling, the udder was photographed from the rear using a thermal camera. A sample was considered a true infection if at least 100 CFU/mL of a bacterial species were isolated. From each photo, we obtained values for minimum, maximum, and mean skin surface temperature for the right and left udders. Three linear mixed models were fit using minimum, maximum, and mean temperatures as the response variables. Fixed effects were infection status (infected or not), weeks postpartum (wk 1-8), and ambient temperature, with a random effect of udder half nested within animal ID. Contrary to our predictions, infection status did not predict udder skin surface temperature (P &amp;gt; 0.12). Healthy udder halves had a mean temperature of 35.5 ± 0.1°C (mean ± SE), minimum temperature of 29.9 ± 0.3°C, and maximum temperature of 37.8 ± 0.1°C. Infected udder halves had a mean temperature of 35.4 ± 0.1°C, minimum temperature of 30.5 ± 0.3°C, and maximum temperature of 37.7 ± 0.1°C. Our results contradict findings in dairy cows, and suggest more research is needed to evaluate the relationship between udder surface temperature and subclinical mastitis in sheep.

Estimation of the Carrying Capacity and Relative Stocking Density of Mongolian grasslands under various adaptation scenarios

Mongolia's vast grasslands, crucial for both environmental and economic stability, are currently facing challenges due to overgrazing, climate change, and land-use changes. Understanding and effectively managing their Carrying Capacity (CC) and Relative Stocking Density (RSD) is essential for maintaining ecological balance. This study rigorously evaluates the CC and RSD of Mongolia's grasslands through an innovative approach that integrates ecological models with socio-economic data, aimed at improving grazing management practices. Data from the National Agency for Meteorology and Environmental Monitoring validates the model, providing precise CC and RSD estimates at the Soum level from 2000 to 2019. The study reveals significant regional variations in CC: northern grasslands exhibit a high CC of 2.8 Sheep Units (SU) per hectare, contrasting with the fragile CC in some southern regions, like the Gobi Desert, where it is as low as 0.3 SU per hectare. Approximately 38.8 % of Mongolia's territory maintains a CC exceeding 1.0 SU per hectare, indicative of sustainable grasslands. In contrast, 41.7 % of the land, primarily in southern regions, shows CCs below 0.5 SU per hectare, highlighting ecosystem vulnerability. The RSD, reflecting livestock numbers relative to CC, averages 1.07, suggesting a high livestock concentration near Ulaanbaatar but a more sustainable density across 43.2 % of the country. The research also explores adaptation scenarios against desertification and degradation, as well as improving pasture accessibility, providing insights for future grassland management strategies. In conclusion, this study emphasizes the need for sustainable land management practices to balance carrying capacity and stocking rates, offering a vital tool for policymakers and stakeholders in grassland conservation.

Effect of grazing and climatic factors on biodiversity-ecosystem functioning relationships in grassland ecosystems -a case study of typical steppe in Inner Mongolia, China.

Biodiversity underpins grassland ecological functions and productive capacities. By studying the mechanisms for the maintenance of species diversity in animal communities, we can provide important theoretical guidance for the optimization of grazing management and biodiversity protection. The typical grassland of Xilingol in Inner Mongolia, China, was used as the experimental area, and a grazing intensity experiment was set up. This consisted of four gradient levels that were grazed by sheep, which were available for continuous monitoring, namely control standard sheep unit·day·hectare-1·year-1 (CK, 0 SSU·d·hm-2y-1), light grazing (LG, 170 SSU·d·hm-2·y-1), moderate grazing (MG, 340 SSU·d·hm-2·y-1), and high grazing (HG, 510 SSU·d·hm-2·y-1). Nine consecutive years of multi-indicator monitoring of vegetation was carried out from 2014-2022, using monitoring data coupled with time series and inter-annual climatic (relative moisture index, RMI) fluctuations. This was done to analyze the impacts of disturbances, such as grazing use and climatic fluctuations, on the diversity of species and above-ground productivity of the community, thereby exploring the relationship between diversity and productivity, and provide possible explanations for the emergence of a range of ecological responses. The statistical analysis methods used were One-way Analysis of Variance (ANOVA), general linear regression and mixed-effects models. The main conclusions of this study are as follows: (1) The grassland in the experimental area under CK had the highest diversity and productivity and the ecosystem was better able to buffer the negative impacts of climatic drought. Furthermore, the effect of climate on productivity and diversity weakened as the intensity of grazing increased. (2) LG to MG had a constant diversity. (3) Grazing utilization changed the relationship between community species diversity and aboveground productivity by releasing spatial community resources, altering the structure of plant communities, weakening competitive exclusion, and strengthening complementary effects. However, under all of the conditions there is a brief stage in the time series when diversity is stimulated to increase, and the higher the grazing intensity, the earlier this occurs.

Quantifying the ecological carrying capacity of grasslands in Inner Mongolia.

Quantifying the ecological carrying capacity has emerged as a crucial factor for maintaining ecosystem stability for sustainable development in vulnerable eco-regions. Here, we propose a new framework for ecological carrying capacity quantification suitable for vulnerable eco-regions. We applied this framework to calculate the ecological carrying capacity of Inner Mongolia from 1987-2015 and used a geographical detector to identify the driving factors behind spatial heterogeneity. Our results revealed the following. (1) The above-ground net primary production (ANPP) required to support the ecosystem service of soil conservation (ANPPSC) decreased from northeast to southwest, whereas the distribution pattern of ANPP required to support the ecosystem service of sand fixation (ANPPSF) exhibited a contrary trend. The average annual ANPP required to support the ecosystem service of natural regeneration (ANPPNR) in Inner Mongolia from 1987 to 2015 was 101.27 gCm-2year-1, revealing a similar spatial distribution with ANPP. (2) The total ecological carrying capacity of Inner Mongolian grassland was 78.52 million sheep unit hm-2. The regions with insufficient provisioning service capability accounted for 4.18% of the total area, primarily concentrated in the east and northwest. (3) The average optimal livestock number for grasslands in Inner Mongolia was 1.59 sheep unit hm-2 from 1987-2015, ranging from 0.77 to 1.69 sheep unit hm-2 across different zones. The average ecological carrying capacity of the cold temperate humid, medium-temperate arid, and warm temperate semi-humid regions was less than 1.08 sheep unit m-2, suggesting a need to prohibit grazing in these areas. (4) The primary influencing factors affecting ecological carrying capacity distribution were normalized difference vegetation index (NDVI), precipitation, and soil type. The framework developed herein can help identify sustainable development potential from the ecosystem service perspective and effectively contribute to decision-making in grassland ecosystem management.

Cost-Benefit Analysis of Herders’ Household Business Scale in the Multi Household Grassland Management Patterns: A Case Study of Maqu County in Qinghai-Tibetan Plateau

This study conducted an analysis of total production costs, gross production values, and net margins across varying scales (small, medium, and large) within herder households operating under the multi-household management pattern. Data was sourced from a random sample of 35 herder households representing six multi-household management patterns in Maqu County, Qinghai-Tibet Plateau. The results revealed that average total production costs per sheep unit were $168.43, $107.36, and $92.89 for small, medium, and large-scale operations, respectively. Gross production values in these scales were $243.50/SSU, $245.23/SSU, and $239.53/SSU. Significantly, large and medium-scale herder households achieved higher net margins, at $146.64/SSU and $137.87/SSU, while small-scale households obtained $75.06/SSU. An intriguing revelation is that net margins for large and medium-scale households predominantly fall within the range of $100.01/SSU to $200.00/SSU, signifying that while scaling may curtail total production costs per sheep unit, it does not assure enduring increases in net margins. These findings hold paramount implications for policymakers as they reassess the feasibility of upscaling multi-household management pattern operations for grassland ecological restoration on the Qinghai-Tibet Plateau. While scaling up can yield cost efficiencies, it does not inherently translate into sustained net profit growth. Hence, astute consideration of these insights is imperative in evaluating the potential of scaling up multi-household management patterns for grassland ecological restoration initiatives.

Spatiotemporal Variability of Alpine Meadow Aboveground Biomass and Sustainable Grazing in Light of Climate Warming

Understanding spatiotemporal variability of aboveground biomass (AGB) in alpine grassland ecosystems is required to better formulate sustainable grazing strategies, especially in climate-sensitive areas such as the Qinghai-Tibet Plateau. Drawing from recent modeling results, we analyzed spatial variability in grassland AGB over seasonal and annual timescales. Theoretical livestock carrying capacity (LCC) was predicted in relation to projected warming and simulated pika disturbance. We found that elevation and slope were key determinants of the distribution of AGB and its change. Although grasses and shrubs occupied an equivalent area, the latter generated approximately double the amount of total biomass, but the former generated slightly more available biomass. Although pika habitat extended over 45.3% of the study area, the impacts of pika only reduced the total available AGB (AGBV) by < 0.07%. The actual LCC (2.16 SU · ha−1 [sheep unit per hectare]) of the study area was lower than the theoretical LCC (2.77−2.96 SU · ha−1). Under climate warming scenarios of 1.0°C, 1.5°C, and 2.0°C, the actual LCC can be increased by 0.82-1.25, 0.99-1.53, and 0.77−1.23 SU · ha−1, respectively. Although systematic climate warming increased AGB, impacts were especially marked at lower elevations and on north-facing slopes because of higher soil water availability. Results highlight that rather than implementing LCC in a static manner in light of climate warming, deeper understanding of biomass availability and the combined effects of climate change and topographic heterogeneity is required to support better management of grasslands.

A Lightweight and High-Accuracy Deep Learning Method for Grassland Grazing Livestock Detection Using UAV Imagery

Unregulated livestock breeding and grazing can degrade grasslands and damage the ecological environment. The combination of remote sensing and artificial intelligence techniques is a more convenient and powerful means to acquire livestock information in a large area than traditional manual ground investigation. As a mainstream remote sensing platform, unmanned aerial vehicles (UAVs) can obtain high-resolution optical images to detect grazing livestock in grassland. However, grazing livestock objects in UAV images usually occupy very few pixels and tend to gather together, which makes them difficult to detect and count automatically. This paper proposes the GLDM (grazing livestock detection model), a lightweight and high-accuracy deep-learning model, for detecting grazing livestock in UAV images. The enhanced CSPDarknet (ECSP) and weighted aggregate feature re-extraction pyramid modules (WAFR) are constructed to improve the performance based on the YOLOX-nano network scheme. The dataset of different grazing livestock (12,901 instances) for deep learning was made from UAV images in the Hadatu Pasture of Hulunbuir, Inner Mongolia, China. The results show that the proposed method achieves a higher comprehensive detection precision than mainstream object detection models and has an advantage in model size. The mAP of the proposed method is 86.47%, with the model parameter 5.7 M. The average recall and average precision can be above 85% at the same time. The counting accuracy of grazing livestock in the testing dataset, when converted to a unified sheep unit, reached 99%. The scale applicability of the model is also discussed, and the GLDM could perform well with the image resolution varying from 2.5 to 10 cm. The proposed method, the GLDM, was better for detecting grassland grazing livestock in UAV images, combining remote sensing, AI, and grassland ecological applications with broad application prospects.

Cost-Benefit Analysis of Continuous and Rotational Grazing Systems——A Case Study in Maqu County, China

The rotational grazing systems (RGS) have been advocated as a superior grazing strategy by the Chinese government based on their significant ecological advantage compared to continuous grazing systems (CGS). In practice, however, due to the low-adoption rate of RGS the favorable effect is limited. This study analyzed the total production cost, gross production value, and net margin of CGS and RGS from the perspective of cost benefits. Data were collected from telephone and face-to-face questionnaire survey of 121 randomly sampled households in Maqu County in the Qinghai-Tibet Plateau. The results indicate that although economic benefits were achieved by herder households in both CGS and RGS, the total production costs spent on each sheep unit in RGS were higher than in the overall that of the total households, and the gross production values produced by herder households from livestock products were lower than in the overall that of the total households due to the difference in production practices. This finding suggests that higher production costs may reduce herders’ adoption rate of RGS. Furthermore, the transfer from CGS to RGS also implies that herders may have to face the challenge the change in production practices related to native grass availability, forage seeding, supplementary feeding, livestock transfer, and grazing duration. The policy implications of these findings towards the implementation of rotational grazing systems are as follows: first, policy makers can consider bringing higher economic advantages to the adopters of rotational grazing systems via incentives; Second, policy measures should assist herders to be able to adapt more easily to the production practices in RGS.

Grazing pressure index considering both wildlife and livestock in Three-River Headwaters, Qinghai-Tibetan Plateau

Grassland is not only the natural habitats for the survival of wild animals, but also the material guarantees for livestock husbandry. However, the previous studies on grassland carrying capacity are mostly only considering livestock but wild herbivores were ignored. In this study, the population of large wild herbivores, Tibetan wild ass, Tibetan gazelle and Tibetan antelope, and livestock were surveyed, and the grassland forage yield was estimated by a remote sensing-process coupled model in Qumahe Township in Three-River Headwaters, Qinghai-Tibetan in 2020. The actual carrying capacity (AC) was calculated from the both wildlife and livestock and the theoretical carrying capacity (TC) in the term on edible herbage and crude protein was estimated. Grazing pressure index was measured by the ratio of AC to TC in this region. The results showed the AC was contributed by about 20,700 standard sheep units (SHU) from wild large herbivores, and 256,500 SHU from the livestock. The theoretical carrying capacity of edible herbage, which is 274,800 SHU, was lower than the theoretical carrying capacity of crude protein in the region. If only considering livestock, the grazing capacity pressure index is 0.93, but the index will be 1.01 if the both wildlife and livestock were considered, and wildlife contributes 7.5% to the grazing pressure. This study suggested the wildlife population should be calculated in grassland ecological carrying capacity estimation though domestic livestock contributed much more to grazing pressure than wild herbivores. The new indicator would be useful in grassland management to maintain ecosystem and biodiversity balance, and society-economy sustainability.

Rest grazing start from the critical period of soil thawing optimizes plant community characteristics and grassland grazing capacity in alpine meadows

The grazing management of alpine meadows is very important for grassland health. In order to explore the optimal rest grazing period in cold season pasture of alpine meadows of the Qinghai-Tibet Plateau (QTP), the critical period of soil thawing–grass withering period (RP1), the later period of soil thawing–grass withering period (RP2), the initial period of grass regreening–grass withering period (RP3), the later period of grass regreening–grass withering period (RP4) and local traditional rest grazing (dominant plant height 5 cm–grass withering period) (RP5) was set in the Tianzhu alpine meadow on the eastern edge of the QTP. RP1 improved Gramineae and Cyperaceae coverage 140% and 37.80%, respectively, Cyperaceae aboveground biomass 58.52%, the total aboveground biomass 22.86%, and poisonous plants aboveground biomass was lower 29.39% than that in RP3. The Richness index and Shannon-Wiener index for the RP1 plant community were 12.12–24.72% and 2.46–19.75% higher than those in other rest grazing periods, respectively. The Simpson diversity index was 1.10% higher in RP1 than that in RP3, and the Pielou evenness index was 3.30% higher in RP1 than that in RP5. The neutral detergent fiber and acid detergent fiber contents of the plant increased with advanced rest grazing periods, being the highest in RP2. Crude protein, crude fat, and crude ash contents were the highest in RP5. The amount and digestible protein grazing capacities in RP1 were higher by 1.67–4.49 and 3.61–8.36 sheep units·ha− 1, respectively, than those in other rest grazing periods. RP1 rest grazing optimized the plant community structure, improved grassland productivity and plant community diversity, with a more stable plant community structure and higher grazing capacity. Therefore, the cold season pastures should be managed with a rest grazing in RP1 for the sustainable utilization of grassland ecosystem.

Prediction of plant diversity under different stocking rates based on functional traits of constructive species in a desert steppe, northern China

Excessive grazing causes a decrease in plant diversity of grassland and also leads to changes in the functional traits of grassland plants. Based on the relationship between plant diversity and the functional traits of constructive species, the patterns of change in plant diversity can be predicted based on change in plant functional traits under different stocking rates. For the present study, Stipa breviflora desert steppe in Inner Mongolia was studied to characterize the plant community and population characteristics and plant functional traits of S. breviflora in grazing areas with different stocking rates [without grazing, light grazing (LG, 0.93 sheep unit hm–2half yr–1), moderate grazing (MG, 1.82 sheep unit hm–2half yr–1), heavy grazing (HG, 2.71 sheep unit hm–2 half yr–1)]. The results showed that: (1) LG significantly weakened the competitive advantage of the constructive species (S. breviflora) (P &amp;lt; 0.05), while HG significantly strengthened its competitive advantage in the community (P &amp;lt; 0.05); (2) Changes in plant diversity were generally significantly related to changes in S. breviflora root traits. The competitive advantage of S. breviflora in the community and the change in root traits could be used to predict the change in plant diversity in the desert steppe under different stocking rates. This research can provide a theoretical basis for maintaining plant diversity and sustainability in the desert steppe.

Study on the Coupling System of Grain-Grass-Livestock of Herbivorous Animal Husbandry in Agricultural Areas: A Case Study of Najitun Farm of Hulunbuir Agricultural Reclamation in China

With the population growth and the upgrading of residents’ food consumption structures, the consumption demand for herbivorous animal products will maintain relatively rapid growth. However, restrictive factors for the development of herbivorous animal husbandry in pastoral areas have increased, and how to undertake herbivorous animal husbandry in agricultural areas has become the focus of widespread social concern. This study is based on survey data of Najitun Farm of Hulunbuir Agricultural Reclamation in China. Through field investigation and computer simulation technology of system dynamics, a development system of herbivorous animal husbandry in agricultural areas was established with the development of herbivorous animal husbandry at the core, and the balance of grassland-livestock and the combination of planting-breeding as the constraint. Moreover, the system designs the development strategy compared with the development of system inertia—strengthening and optimizing herbivorous animal husbandry and optimizing the structure of grain, economy, and the feed planting industry, and simulates the above three scenarios, respectively. The study found that without any development strategy, the inertia trend is subject to the influence of factors such as the scale of female livestock, epidemic diseases, and breeding level, so it is difficult to realize the sustainable development of the industry in the next five years. However, expanding the scale of breeding alone will occupy too much environmental capacity, and there will be a shortage in the supply of grass for a long time. According to the scheme of optimizing the structure of the grain, economy, and feed planting industry, it will not only provide feed sources for grass-feeding livestock of about 58,200 sheep units, but also realize the total agricultural output value of USD 7.02 million by the end of the 14th Five-Year Plan, which is 1.89 times of the inertia trend. At the same time, the nutrient demand of grass crops has alleviated 20.42% of the environmental pressure. Based on the results of this study, it is proven that herbivorous animal husbandry has a broad development potential in agricultural areas, and at the same time, it contributes to decisions of developing herbivorous animal husbandry in agricultural areas. This study has important theoretical and practical significance for expanding the industrial space and building a new type of planting-breeding relationship.

​Growth Performance and Biometry of Nellore Brown Lambs from Birth to Weaning under Different Systems of Rearing

Background: Among the three varieties of Nellore sheep, Nellore brown was most popular among the shepherds of Telangana state. The research on the performance of the other two varieties i.e. Palla and Dora was done extensively in their home tract but less data was available about performance of Nellore brown under different system of rearing. The growth rate of lambs was highest from birth to weaning in their life. The system of rearing can influence both growth rate and biometrical measurements of the lamb. The performance of the lambs during this stage influence the productive and reproductive performance in the lifetime. Methods: Sixty Nellore brown ewes (1.5 - 2 years) were selected from Sheep unit, Livestock Research Station, Mamnoor, Telangana for the present study. The lambs born in intensive (G1, lambs born N= 14), Semi-intensive (G2, lambs born N= 14) and Extensive (G3, lambs born N= 12) system of rearing were used to study the growth performance and biometry of lambs from birth to weaning. Result: The birth weight (kg) of lambs in G1 and G2 groups were significantly (P less than 0.01) higher than lambs in G3 group. The weaning body weight (Kg) was significantly higher (P less than 0.01) in G1 group as compared to weaning body weights in G2 and G3 group. The mean average ADG (gm) of lambs from birth to weaning was significantly (P less than 0.01) higher in G1 (105.4±0.19) followed by G2 (97.9±0.14) and G3 (92.8±0.07) group. The mean pin shoulder length (cm) of lambs at birth in G1 group was higher than G2 and G3 group but had a significant (P less than 0.05) difference with the only G3 group. In G1 group, the mean heart girth (cm) of lambs from15th day to weaning was significantly (P less than 0.01) higher than G2 and G3 groups. The mean gain in paunch girth from birth to weaning in lambs of three groups was nearly 19 cm and had no significant (P less than 0.05) difference between groups.

Alpine Grassland Aboveground Biomass and Theoretical Livestock Carrying Capacity on the Tibetan Plateau

The accurate simulation and prediction of grassland aboveground biomass (AGB) and theoretical livestock carrying capacity are key steps for maintaining ecosystem balance and sustainable grassland management. The AGB in fenced grassland is not affected by grazing and its variability is only driven by climate change, which can be regarded as the grassland potential AGB (AGBp). In this study, we compiled the data for 345 AGB field observations in fenced grasslands and their corresponding climate data, soil data, and topographical data on the Qinghai-Tibetan Plateau (TP). We further simulated and predicted grassland AGBp and theoretical livestock carrying capacity under the climate conditions of the past (2000–2018) and future two decades (2021–2040) based on a random forest (RF) algorithm. The results showed that simulated AGBp matched well with observed values in the field (R 2 = 0.76, P < 0.001) in the past two decades. The average grassland AGBp on the Tibetan Plateau was 102.4 g m–2, and the inter-annual changes in AGBp during this period showed a non-significant increasing trend. AGBp fluctuation was positively correlated with growing season precipitation (R 2 = 0.57, P < 0.001), and negatively correlated with the growing season diurnal temperature range (R 2 = 0.51, P < 0.001). The average theoretical livestock carrying capacity was 0.94 standardized sheep units (SSU) ha–1 on the TP, in which about 54.1% of the areas showed an increasing trend during the past two decades. Compared with the past two decades, the theoretical livestock carrying capacity showed a decreasing trend in the future, which was mainly distributed in the central and northern TP. This study suggested that targeted planning and management should be carried out to alleviate the forage-livestock contradiction in grazing systems on the Tibetan Plateau.

载畜率对荒漠草原冷蒿植物种群密度及其空间分布的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 载畜率对荒漠草原冷蒿植物种群密度及其空间分布的影响 DOI: 10.5846/stxb202102060390 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31760143）；内蒙古重大科技专项（ZDZX2018020）；内蒙古自治区科技成果转化项目（2020CG0013）；科技成果转化项目（2019CG069） Effects of stocking rate on population density and spatial distribution of Artemisia frigida in desert steppe Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:载畜率是衡量草原生产能力的指标之一，研究荒漠草原冷蒿（Artemisia frigida）植物种群在不同载畜率下的耐牧程度和空间分布特征，对退化草原的恢复具有重要的指导意义。以短花针茅荒漠草原优势种冷蒿为研究对象，在4个不同载畜率放牧试验设计（对照区CK （0只/hm2）、轻度放牧区LG （0.93只/hm2）、中度放牧区MG （1.82只/hm2）和重度放牧区HG （2.71只/hm2））小区中选择代表性样地（面积为40m×40m），采用机械取样法进行取样，记录冷蒿植物种群的密度，使用SAS 9.4软件对其进行描述性统计和方差分析，并用地统计学软件GS+9.0进行空间异质性统计分析。结果表明：荒漠草原优势种冷蒿密度、出现频率和单位均值上的变异值随载畜率增大都明显下降，其植物种群空间分布的决定性因素随载畜率增大由结构性因素转变为随机性因素。LG和HG处理区的空间自相关距离较大，但这两者表现结果的影响因素存在差异。在CK和HG区，冷蒿空间分布斑块化较为明显，LG区的冷蒿空间分布的特征表现为带状分布，MG区冷蒿空间分布形成了一处大的条带和零星的几块斑块。基于上述研究结果可以得出，随着载畜率增加，荒漠草原冷蒿种群密度下降，空间分布趋于单一化，导致冷蒿的生产力下降，进而影响草地的可持续利用。 Abstract:Stocking rate is one of the most important indicators to measure the productivity of grassland. Study on the grazing tolerance and spatial distribution characteristics of Artemisia frigida population under different stocking rates in desert steppe has significant effects for the restoration of the degraded grassland. The experiment design selected Artemisia frigida, a dominant species in Stipa breviflora desert steppe as the research object, which conducted with four different stocking rates (CK, 0 sheep unit hm-2; LG, 0.93 sheep unit hm-2; MG, 1.82 sheep unit hm-2; and HG, 2.71 sheep unit hm-2), and the representative sample plot (40 m×40 m) with the same terrain in each treatment was selected. The plant population density of Artemisia frigida is recorded by mechanical sampling method. Then, the descriptive statistics and variance analysis were performed by SAS9.4 software, and the spatial heterogeneity was analyzed using statistical software GS+9.0. The results showed that the density, frequency of occurrence, and the variation of mean value of Artemisia frigida decreased significantly with the increase of stocking rate. The spatial distribution decisive factor of plant population changed from structural factor to random factor with the increase of stocking rate. The fractal dimension value D0 was ranked from large to small under different stocking rates is CK>HG>MG>LG, under different grazing conditions, the values of fractal dimension were between 1.700 and 2.000, indicating that the spatial distribution of these four regions with different stocking rates was relatively uniform. The spatial auto-correlative distances in LG and HG treatments were relatively larger than other treatments, which caused by different impact factors, LG area was significantly affected by random factors, and HG area was significantly affected by structural factors. With the increase of stocking rate, the spatial correlation of Artemisia frigida gradually weakened. Artemisia frigida has different spatial states in different stocking rates, the spatial distribution of Artemisia frigida were patchy in CK and HG treatments, while it was characterized by banded distribution in LG treatment, and it formed a large strip and scattered patches in MG treatment, the density distributions of LG and MG were similar, but the uniformity of MG is greater than LG treatment. Based on the research results above mentioned, we can conclude that the population density of Artemisia frigida decreased and the spatial distribution tended to be simplified, resulted in the decrease of productivity of Artemisia frigida with the increase of stocking rate, which affected the sustainable utilization of grassland in the desert steppe. 参考文献 相似文献 引证文献

Growth and Chevon Characteristics of Indigenous Breeds of Goat (Buck) in Nigeria

A trial was conducted at the Sheep and Goat Unit of Teaching and Research Farm of the University of Ibadan, Ibadan to evaluate the effect of breeds on growth, carcass characteristics and meat yield of indigenous goats (bucks) in Nigeria. Fifteen growing bucks: five each of Sahel bucks-SB, West African Dwarf bucks (WADB) and Red Sokoto bucks(RSB) weighing 9.8±0.2, 10.0±0.4 and 9.9±0.3, respectively were fed isocaloric diet for 90 days. The experiment was laid out in a complete randomized design. Final Body Weight (FBW), Average Daily Weight Gain (ADWG) and Feed Conversion Ratio (FCR) were measured using standard procedures. Three bucks per breed were thereafter sacrificed and Dressing Percentage (DP), Meat yield, Rib eye area (REA) and Water holding capacity (WHC) were determined. The Final Body Weight of 16.1kg in Sahel bucks and 17.5kg Red Sokoto bucks were similar but significantly lower than 20.3kg of West African Dwarf bucks. Also, the Feed Conversion Ratio of 10.4 for the Sahel bucks and 9.8 of Red Sokoto bucks were significantly higher than 7.3 of West African Dwarf bucks. The Dressing Percentage was highest in West African Dwarf bucks (46.6%) and least in Sahel bucks (33.5%). West African Dwarf bucks yielded more meat lean (67.4%) and were comparatively higher than Sahel bucks (60.1%) and Red Sokoto bucks (61.5%). The Rib eye area (cm2) was also higher in West African Dwarf bucks (1.4) compared to Sahel bucks (1.1) and Red Sokoto bucks (1.1).

Heavy Grazing Altered the Biodiversity–Productivity Relationship of Alpine Grasslands in Lhasa River Valley, Tibet

Grazing is a crucial anthropogenic disturbance on grasslands. However, it is unknown how livestock grazing affects the relationship between biodiversity and productivity of alpine grasslands in Tibet. We carried out a grazing-manipulated experiment from 2016 to 2019 with grazing intensity levels of null (control, grazing exclusion, C.K.), moderate grazing [1.65 standardized sheep unit (SSU) per hectare, M.G.], and heavy grazing (2.47 SSU per hectare, H.G.) on a typical alpine grassland in the Lhasa River Basin, central Tibet. We measured aboveground biomass (AGB), species assembly (alpha and beta diversity indices), and soil nutrients’ availability. The results showed that grazing differently affected plant community in different treatments. Notably, the total dissimilarity value between C.K. and H.G. is 0.334. Grazing decreased the Shannon–Wiener index, increased the Berger–Parker index from 2016 to 2018 significantly, and decreased AGB and total soil nitrogen (STN) significantly. Our results also showed that the grazing affected the relationship between AGB and diversity indices and soil nutrients, including soil organic carbon (SOC) and total soil phosphorus (STP). Specifically, AGB decreased with increasing SOC and STP in all treatments, and heavy grazing changed the positive relationships between AGB, STP, and Shannon–Wiener index to negative correlations significantly compared with grazing exclusion. There was a significant negative correlation between Berger–Parker and Shannon–Wiener indices under each treatment. The general linear models showed that H.G. altered the relationship between diversity and productivity of grassland in central Tibet, and AGB and Shannon–Wiener index positively correlated in C.K. but negatively correlated in H.G. Our study suggests that H.G. caused a negative relationship between plant diversity and productivity. Therefore, sustainable grazing management calls for a need of better understanding the relationship between biodiversity and productivity of alpine grassland in central Tibet.

A study on behaviour of Deccani lambs reared on different flooring material

A study was conducted to evaluate the behaviour of Deccani lambs on different flooring material. Behaviour is the important indicator of animal welfare. Eighteen growing Deccani lambs of either sex with uniform body weight of 12.61±0.04 kg and aged between 3 to 6 months were selected from the Sheep and Goat unit of Livestock Farm complex. These lambs were randomly allotted to three flooring types viz., Mud floor (control, T1), Concrete floor (T2) and mud floor with rubber mats (black, rubber material, 8 mm thick (T3). The behaviour of lambs was recorded with help of Video cameras and digital video recorder (model: DS – 7B04HQHI-K1). The data on standing time (min) and percentage of standing was significantly (P

Ecosystem services under different grazing intensities in typical grasslands in Inner Mongolia and their relationships

Grazing, as the main land use of grasslands, is a key factor affecting the supply of ecosystem services11ES, ecosystem service; GI, grazing intensity; CK, control check; LG, light grazing; MG, moderate grazing; HG, heavy grazing; BI, biodiversity; HI, herbage intake; CP, crude protein content; SOCD, soil organic carbon density; SMN, soil mineralization nitrogen; AB, aboveground biomass; BB, belowground biomass; LB, litter biomass; TES, total ecosystem services; SSU, standard sheep units. (ESs) as well as the relationships between ESs. Using four grazing intensities, including control check, light grazing, moderate grazing, and heavy grazing, this paper quantified eight key ESs, including biodiversity, herbage intake, herbage quality (herbage crude protein content), climate regulation (soil organic carbon density), soil mineralization nitrogen, soil conservation (aboveground biomass), wind prevention and sand fixation (belowground biomass), and soil erosion prevention(litter biomass), in typical grassland areas of Inner Mongolia. Structural equation models were used to illustrate the impact of grazing on ESs through biodiversity, and the root mean square error was used to quantify the level of trade-offs for ES pairs. The results of this study indicated that grazing intensity (GI) significantly affected all ESs (p < 0.05), except for soil organic carbon density and soil mineralization nitrogen. As GI increased, provisioning services increased, while most regulating services decreased, and there was a general trade-off relationship between regulating services and other ones. In order to realize the maximum ESs benefit and the minimum trade-offs for ES pairs, the optimal grazing intensity for typical grasslands of Inner Mongolia should be between 170 (standard sheep units) SSU · d · hm−2 · y−1 and 340 SSU · d · hm−2 · y−1. The results of this study provide a decision-making foundation for grassland grazing management policies for the sustainable development of Inner Mongolian grasslands.