肉鸡体重杂种性能不同选择方法的比较

Comparative studies on different selection methods of meat-type chickens' crossbred performance of body weight

本文比较了纯系选择与组合选择两种方法在肉鸡三系配套杂交方案中父本品系遗传进展与近交速率的变化情况,模拟试验结果表明,在遗传参数和总的测定笼位一定的情况下,包含纯种与杂种信息的组合选择获得的累积遗传进展(△G)总是高于纯系选择,近交速率(△F)也高于纯系选择方法。例如当核心群公鸡数(ns)为90时,在组合选择下到第6世代的累积遗传进展与近交速率分别为0.8222与2.50%,均高于PLS下的0.4981与2.18%。在同样的选择方法下,核心育种群越大,近交速率越小。综合分析可以看出,组合选择优于纯系选择。

Using deterministic methods, rates of genetic gain （ △G） and inbreeding（ △ F） were compared between pure line selection （PLS） and combined crossbred purebred selection （CCPS） ,for the sire line of a three-way crossbreeding scheme. Results of the simulate selection experiments indicated that with the same genetic parameters and population size, genetic gains of crossbred performance using CCPS method, which included purebred and crossbred phenotypic information of the current generation and estimated breeding values for purebred and crossbred performance of parents from the previous generation ,were always larger than that of PLS method which included purebred phenotypic information only in the current generation. For example, with ns = 90, genetic gains of the former 6 generation was 0. 8222 for CCPS and was higher than that for PLS,which was 0. 4981 ,inbreeding coefficient was 2.50 for CCPS and was also higher than that for PLS,which was 2.18 only. Results also showed that changing from PLS to CCPS may increase the rates of inbreeding,the larger the nucleus-breeding population was, the lower the rates of inbreeding were when the selection methods were identical. We could conclude that CCPS was superior to PLS,