Barbato G F, Vasilatos-Younken R
Department of Poultry Science, Pennsylvania State University, University Park 16802.
Poult Sci. 1991 Apr;70(4):709-18. doi: 10.3382/ps.0700709.
A study was designed to estimate the contribution of various types of genetic variation in growth of chickens using populations that widely differed in growth rate. Populations tested included a commercially developed sire line (CM), a fertility-selected, broiler-type line (FS), and the pureline Jersey Giant (JG). A full set of F1 crosses and purelines of both sexes was used to estimate the following genetic effects: heterosis due to the autosomes, heterosis due to the sex chromosomes, average line effects, maternal effects, and additive sex linkage. Average line effects were highly significant beyond hatching for both body weight and shank length, with rank-order CM greater than FS, which was greater than JG. Significant differences between the sexes within a line were observed for CM and JG line effects, confirming the existence of sex-linked factors. There was no average heterosis or sex-by-heterosis interaction for growth-related traits, but specific heterosis was frequently significant. Maternal effects were sporadic and generally of little importance beyond hatching. Additive sex linkage, however, was highly significant and influenced body weight beyond hatching. These data indicate that the primary advantages in increasing growth via cross-breeding in chickens comes from average line effects and additive sex linkage. Heterosis and maternal effects can influence performance, especially in specific crosses, but these effects appear to be sporadic and of less importance than sex linkage.
一项研究旨在利用生长速度差异很大的鸡群来估计各类基因变异对鸡生长的贡献。所测试的鸡群包括一个商业培育的父系品系（CM）、一个经过育性选择的肉鸡型品系（FS）以及纯种泽西巨人鸡（JG）。利用一整套F1杂交后代和两个性别的纯种来估计以下遗传效应：常染色体引起的杂种优势、性染色体引起的杂种优势、平均品系效应、母体效应以及加性性连锁。对于体重和胫长，平均品系效应在孵化后非常显著，排序为CM大于FS，FS大于JG。在CM和JG品系效应中，观察到品系内不同性别之间存在显著差异，证实了性连锁因子的存在。对于生长相关性状，不存在平均杂种优势或杂种优势与性别的相互作用，但特定杂种优势经常是显著的。母体效应是零星出现的，在孵化后通常不太重要。然而，加性性连锁非常显著，并且在孵化后影响体重。这些数据表明，通过鸡的杂交育种来提高生长速度的主要优势来自平均品系效应和加性性连锁。杂种优势和母体效应会影响性能，特别是在特定杂交组合中，但这些效应似乎是零星出现的，且比性连锁的重要性要小。
