湖羊初生重性状影响因素分析及遗传力估计

【目的】研究旨在分析场、出生季节、出生月份、出生类型和性别对湖羊初生重性状的影响，并估计该性状的遗传力。【方法】运用SAS 9.2软件对2021年新疆地区3个规模化湖羊养殖企业共计4 570只母羊所产的8 352只羔羊初生重作非遗传因素分析，使用DMU软件对湖羊初生重性状进行方差组分估计，并使用两种单性状动物模型估计该性状的遗传力，根据赤池信息准则(Akaike’s information criterion, AIC)确定最佳固定效应组合和动物模型。【结果】场、出生季节、出生月份、出生类型和性别对湖羊的初生重均有极显著影响(P<0.01)。场1和场2羔羊初生重无显著差异(P>0.05),且均极显著大于场3羔羊的初生重(P<0.01);冬季出生的羔羊的初生重整体较大，其中以1月出生的羔羊初生重最大；出生类型越丰富，其羔羊初生重越小，各出生类型间羔羊初生重均呈现出极显著差异(P<0.01);根据单性状动物模型(考虑母体效应)的计算得出，湖羊初生重性状的直接、母体、总体遗传力分别为0.251、0.668、0.211,属于中等遗传力。【结论】在对羊场首年的生产数据分析...

Analysis of Influencing Factors of Birth Weight Traits and Estimation of Heritability in Hu Sheep

【Objective】 The purpose of this study was to analyze the effects of farms,birth season,birth month,birth type and sex on the birth weight trait of Hu sheep,and estimate the heritability of this trait.【Method】 The non-genetic factor analysis of 8 352 lambs produced by a total of 4 570 ewes in three large-scale Hu sheep breeding enterprises in Xinjiang in 2021 was carried out using SAS 9.2 software,and the variance components of the birth weight traits of Hu sheep was analyzed by DMU software.The heritability of the trait was estimated using two single-trait animal models,and the optimal fixed-effects combination and animal model were determined according to Akaike’s information criterion (AIC).【Result】 The farms,birth season,birth month,birth type and sex had extremely significant effects on the birth weight of Hu sheep (P＜0.01).There was no significant difference in the mean birth weight between farm 1 and farm 2 (P＞0.05),and both were extremely significantly higher than that of farm 3 (P＜0.01).The birth weight of lambs born in winter was generally large,and the birth weight of lambs born in January was the largest.The more abundant the birth type were,the smaller the birth weight of lambs was,and the birth weight of lambs among different birth type showed extremely significant difference (P＜0.01).According to the calculation of single trait animal model (considering maternal effect),the direct,maternal and total heritability of birth weight traits of Hu sheep were 0.251,0.668 and 0.211,respectively,which belonged to medium heritability.【Conclusion】 When analyzing the production data of the first year of the sheep farm,it was more appropriate to choose the month of birth as the time factor than the birth season.It could not only analyze the production of Hu sheep in each month to make the corresponding breeding plan adjustment,but also select the month as the fixed effect to increase the accuracy of the estimated genetic parameters of traits.The heritability estimation of the birth weight trait of Hu sheep would be too large without considering the maternal effect,so the maternal effect should be given priority in the early stage which was greatly affected by the maternal effect.