【作者】 覃盟琳；

【导师】 周道玮；

【作者基本信息】 东北师范大学 ， 草业科学， 2005， 硕士

【摘要】 中国东北农牧交错区饲养大量的东北细毛羊,为当地的经济做出了重要的贡献。但长期以来,作为整个畜群重要组成部分的基础母畜年龄结构对整个畜群产出的影响得不到充分重视。 本文通过野外调查与实验获得东北细毛羊基础母畜的种群现实结构与其生产力,在此基础上分析基础母畜群的种群结构与生产力特点,为深入了解和分析东北农牧交错区东北细毛羊生产体系提供基础数据。同时利用种群统计理论方法和线性规划手段对东北细毛羊基础母畜群年龄结构进行优化,找出现实基础母畜年龄结构与优化母畜群年龄结构的差异,从而得出基础母畜年龄结构有必要优化的结论;同时,建立了基础母畜不同生产目的的最优年龄结构,并提出相应的基础母畜淘汰策略（以1000头基础母畜为规划对象）: Ⅰ、以产肉为目的进行优化,基础母畜年龄结构及相应淘汰策略为:1龄、2龄母畜分别占总畜群的46.1%,3龄、4龄母畜分别占总畜群的3.9%;1龄、3龄的年淘汰率都为0,2龄、4龄的年淘汰率分别为0.92、1;畜群的年总淘汰率为0.461,母畜的最大使用年限为4龄。相应数学表示为:P₁=P₂=46.1%、P₃=P₄=3.9%;R₁=R₃=0、R₂=0.92、R₄=1、R=0.461; Ⅱ、以产毛为目的进行优化,基础母畜年龄结构及相应淘汰策略为:1龄、2龄、3龄、4龄、5龄母畜分别占总畜群的20%,1龄、2龄、3龄、4龄的年淘汰率都为0,5龄的年淘汰率为1;畜群的年总淘汰率为0.2,母畜的最大使用年限为5龄。相应数学表示为:P₁=P₂=P₃=P₄=P₅=20%;R₁=R₂=R₃=R₄=0、R₅=1、R=0.2; Ⅲ、以产羔为目的进行优化,基础母畜年龄结构及相应淘汰策略为:1龄、2龄、3龄、4龄、5龄、6龄母畜分别占总畜群的16.7%,1龄、2龄、3龄、4龄、5龄母畜的年淘汰率都为0,6龄的年淘汰率为1;畜群的年总淘汰率为0.167,母畜的最大使用年限为6龄。相应数学表示为:P₁=P₂=P₃=P₄=P₅=P₆=16.7%;R₁=R₂=R₃=R₄=R₅=0、R₆=1、R=0.167; Ⅳ、以综合生产为目的进行优化,基础母畜年龄结构及相应淘汰策略为:1龄、2龄母畜分别占总畜群的46.1%,3龄、4龄母畜分别占总畜群的3.9%;1龄、3龄的年淘汰率都为0,2龄、4龄的年淘汰率分别为0.92、1;畜群的年总淘汰率为0.461,母畜的最大使用年限为4龄。相应数学表示为:P₁=P₂=46.1%、P₃=P₄=3.9%;R₁=R₃=0、R₂=0.92、R₄=1、R=0.461;更多还原

【Abstract】 A great number of sheep were fed in China Northeast Agro-pastoral Ecotone, which played an important role in the economy of the region. In the passed several decades, we did not concern about the livestock population age structure, especially the stocked ewe population age structure.Field investigation and experiments were conducted to research the realistic stocked ewe population age structure and productivity performance of stocked ewe. Demography and linear programming way were conducted to optimize the age structure of stocked ewe population. In finally we could find the distinctions that between optimized stocked ewe age structure and the reality’s, and got the conclusions that the it was need to optimize the stocked ewe population age structure. Most of all, this thesis came up with the optimal stocked ewe population age structure and the relative off-take strategies, as follows:I . Attending the maximum total LW（liveweight） output, the optimal stocked ewe population age structure and relative off-take strategy as follows: P₁=P₂=46.1%, P₃=P₄=3.9%; R₁=0. R₂=0.92, R₃=0 R₄=1 R=0.46;II. Attending the maximum total W（wool） output, the optimal stocked ewe population agestructure and relative off-take strategy as follows: P₁=P₂=P₃=P4=P5=20%; R₁=R₂=R₃=R₄=0 R₅=1 R=0. 2;III. Attending the maximum total LR（lambing rate）, the optimal stocked ewe populationage structure and relative off-take strategy as follows: P₁=P₂=P₃=P₄=P₅=P₆=16.7%; R₁=R₂=R₃=R₄=R₅=0 R₆=1 R=0.167;IV. Attending the maximum multi-product output, the optimal stocked ewe population agestructure and relative off-take strategy as follows:P₁=P₂=46. 1%, P₃=P4=3.9%; R₁=0 R₂=0.92 R₃=0 R₄=1 R=0. 46;更多还原