DⅢ系母猪繁殖力的选择方法与选择效果研究

Studies on selection method and selection effect for prolificacy in pigs of DⅢ line:

通过遗传选择提高瘦肉型猪种的产仔数对养猪生产力具有重要作用。本文通过对浙江中白猪ＤⅢ系繁殖力的遗传研究，制定了选择方法，重点解决了提高选种准确度的措施。经过７年６个世代的选择，使ＤⅢ系猪第一胎的总产仔数提高１．２４头，平均每代提高０．２头。产活仔数提高１．１６头，平均每代提高０．１９头。经统计分析，第六世代的产仔数已明显高于选择前０世代的群体产仔数（Ｐ＜０．０５）。选择群体的平均近交系数从１．８１％上升至８．３５％，这一近交增量未对繁殖力产生明显影响。

Genetic improvement of litter size in pigs of lean-meat type by selection has great impact on production efficiency. Through the studies on genetics of reproductive traits in DⅢ line of Zhejiang White breed, selection method was established and measures of improving selection accuracy were applied. After 6 generations' selection during 7 years, the total piglets born of the first parity in gilts rose by 1.24, 0.2 for each generation; and piglets alive rose by 1.16. Statistical analysis showed that the litter size for sixth generation was significantly higher than that for 0 generation(P<0.05). The inbreeding coefficient of the herd raised from 1.81% to 8.35%, but the gain of inbreeding coefficient did not produce obvious negative influence on reproductive performance of selection herd.