母猪产仔数的选择方法

根据母猪产仔数、公猪母亲产仔数、家系指数（Ｉ６）和简化复合育种值（＾Ａ复）对小耳猪闭锁选育群进行提高产仔数选择方法的比较。结果表明：根据母猪产仔数、公猪母亲产仔数选留的女儿，其产仔数受亲代和祖代产仔数的影响，亲代、祖代产仔９头以下时后代产仔有随亲代和祖代产仔数提高而提高的趋势。新代和祖代产仔数超过９头，则后代产仔数呈下降趋势，依据Ｉ６选择，３个年度分别提高了０７１、０６３和０５０头，而＾Ａ复选择分别提高了０７０、０５５和０４０头。

A Comparative Study on Selecting Methods of Litter Size in Sows

The different selecting methods of improving litter size in sows were used in close selecting and beeding group of small ear pigs.The selecting method was based on litter size,litter size of boars mother,family selection index and simplified complex breeding value respectively.The result indicate that the litter daughter selected by liter size of dom and litter size of boars mother was effected by their parents and gradpatents.When the litter size of their parents and grandparents were below 9,the litter size of daughter increased with the litter size of their parents and grandparents .The litter size increased 0.71,0.63 and 0.50 respectively based on method of family selection index during three years,whereas the litter size increased 0.70,0.55 and 0.40 respectively based on method of simlified complex breeding value.