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1.
本文在分析畜牧业的本质和特点的基础上,提出生态畜牧业是畜牧业发展的高级阶段,并介绍了生态畜牧业的基本设计及基本类型。 相似文献
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Managing the introduction of nonindigenous species is becoming a major goal of policy-makers at regional, national and international scales. Here we investigate, at the national level, the ideal design and expected net benefits of a risk assessment program for evaluating the desirability of nonindigenous species imports. We show how to enhance the statistical rigor of such a system by correcting a common non-random sampling problem encountered in the data. This correction enables model output to be interpreted in an economically relevant way and facilitates a theoretically rigorous characterization of the balance between trade and nonindigenous species establishment risk. Using reptiles and amphibians imported to the U.S. as a case study, we characterize economic outcomes over a range of cases and demonstrate substantial expected returns to such a screening program, relative to the current effectively open-door policy. Our results are informative for the current debate in the U.S. about whether to require federal agencies to apply risk assessment before allowing a species for import. The framework presented decomposes a complex argument about risk management into component economic and statistical parts, allowing for debate and improved understanding over each element to inform the overall program in a transparent fashion. 相似文献
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松辽平原是我国重要的种植业和畜牧业生产基地,发展循环农业是其实现农业现代化的重要战略选择。根据循环农业内涵、技术目标和基本原理,结合松辽平原农业发展现状,分析了其发展农牧结合循环农业的必要性。最后,在循环农业研究实践基础上,探讨了未来松辽平原循环农业科技的重点研究方向。 相似文献
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Policy makers in the European Union are envisioning the introduction of a community farm animal welfare label which would allow consumers to align their consumption habits with their farm animal welfare preferences. For welfare labelling to be viable the market for livestock products produced to higher welfare standards has to be sufficiently segmented with consumers having sufficiently distinct and behaviourally consistent preferences. The present study investigates consumers’ preferences for meat produced to different welfare standards using a hypothetical welfare score. Data is obtained from a contingent valuation study carried out in Britain. The ordered probit model was estimated using Bayesian inference to obtain mean willingness to pay. We find decreasing marginal WTP as animal welfare levels increase and that people’s preferences for different levels of farm animal welfare are sufficiently differentiated making the introduction of a labelling scheme in the form of a certified rating system appear feasible. 相似文献
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动物对环境温度的适应,会使自身的细胞内转录和表达模式发成变化,以适合环境的变化,此时它会出现新的基因开放和新蛋白因子的合成,这总的来说是动物对自身的一种保护方式。本文从基因水平、蛋白质水平、细胞膜水平等三个方面综述了动物对环境温度适应的研究概况,并讨论了动物对环境温度适应的分子生物学机制以及在进化中的意义。 相似文献
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Nina Lind Helena Hansson Ulf Emanuelson Carl Johan Lagerkvist 《Journal of Risk Research》2020,23(2):194-209
AbstractMastitis infections cause severe pain in dairy cows and are the most costly illness to farmers. This study combined differentiation and consolidation (Diff-Con) theory with risk-benefit analysis to explore how risky decisions are perceived and justified after a decision has been taken. More specifically, using survey data from 428 Swedish dairy farmers, their decisions about adopting preventive measures to control mastitis (mastitis control options, MCO) in dairy herds were examined. The analyses included group comparisons with non-parametric rank tests and use of both ordinary least squared regression and seemingly unrelated regression analysis to examine how prior adoption of MCO affects farmers’ attitudes to the MCO. The results showed that MCOs already adopted were rated higher in perceived riskiness (if not implemented) and in expected benefit (for illness prevention) than non-adopted MCOs. Having made the decision to implement a strategy increased the likelihood of that decision being perceived as more beneficial (reducing mastitis) and risky (in terms of disease increase if not implemented), irrespective of the combination of strategies used on the farm, during the post-consolidation stage. No difference in perceived illness prevalence could explain the farmers’ rating of the MCOs. These findings suggest that there may be a path dependency in farmers’ decision-making with respect to MCO. This implies that novel MCOs may have difficulty in achieving wider implementation. These results have implications for the development of strategies to communicate best practices for use of MCOs and for new research on MCOs and farmers’ decision-making. 相似文献
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China has the second largest area of pastoral land in the world, and these lands and their peoples play a very beneficial role in the global environment. Because of China's huge population, rate of social reform, and economic development, the pastoral ecosystems are at a critical turning point. There is a conflict between national benefit and the land users (mainly herders) benefit. This paper introduces the scale of pastoral land, the history of its management institutions, past and current projects and programs, as well as the current framework of policy and law as relevant to land management. The challenges for pastoral management in terms of institutions, administration, technology and their shifting role in regional economies of scale are also analyzed. Opportunities for sustainable development in China's pastoral lands are presented. Finally, this paper highlights the available approaches for enhancing livelihoods and conserving pastoral land, including establishment of law and policy framework at the national level, redefining use rights for community management, promoting Integrated Ecosystem Management (IEM) as a basis for natural resource utilization, preserving and respecting cultural aspects of pastoral peoples, and shifting the focus from GDP generation to environmental protection. 相似文献
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中国农产品对荷兰出口实证研究 总被引:2,自引:0,他引:2
本文运用出口量、出口金额、出口均价等综合指标对我国出口荷兰的农产品进行了总量、结构的统计分析,重点研究了动物类产品、蔬菜类产品、水果类产品的品种构成和出口变化,提出政府应积极发展农产品加工业,培育拳头产品的出口,同时建立起对荷兰农产品标准和贸易法规的跟踪系统,以及对国内生产和出口企业的完备监控体系。 相似文献
10.
James Madzimure Michael Chimonyo Kennedy Dzama Stephen T. Garnett Kerstin K. Zander 《Journal of Agricultural Economics》2015,66(3):812-831
Although there is growing demand for animal products in Africa, production is stagnating. Appropriate management of livestock diversity could help reinvigorate production, contribute to food security and improve farmers’ livelihoods, particularly in subsistence‐oriented systems. We assess differences in farmers’ preferences and economic values for pig traits across different production systems and across areas that have been affected and unaffected by classical swine fever (CSF). Not surprisingly, market‐oriented farmers derived higher values from the productive traits such as heavy slaughter weight and large litter size found in exotic pig genotypes. Subsistence‐oriented farmers, particularly in swine fever affected areas, placed high value on tolerance to disease. We found that CSF changed farmers’ preferences for adaptive traits, and less so for productive traits. Therefore, indigenous breeds become more valuable for subsistence farmers and crossbreeds for market‐oriented farmers if CSF is a risk. Our results can have implications for breeding and conservation strategies and for compensation strategies after culling, and will become increasingly relevant if, as predicted, heat waves and disease outbreaks become more frequent in pig production systems in South Africa with climate change. 相似文献