Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus, PO Box 50, DK-8830 Tjele, Denmark.
J Dairy Sci. 2010 Sep;93(9):4386-90. doi: 10.3168/jds.2009-2894.
Over the last few years, an increasing awareness has arisen in Denmark of the existence of cows with a generally lowered health and production status, referred to as "loser cows." A previous study has estimated that the overall prevalence of loser cows in Danish Holstein herds is 3.2%. The aim of this study was to estimate genetic and phenotypic parameters for the loser cow state and the underlying traits: lameness, hock lesions, other cutaneous lesions, and condition of hair coat. Records on 6,098 cows were analyzed with an animal model including fixed effects of herd, season of scoring and location of scoring, age at first calving, lactation stage, and parity in addition to additive genetic effects and permanent environmental effects. The heritability of the loser cow score was 0.08 and for the underlying traits the heritability ranged from 0.05 to 0.12. The genetic correlations between various pairs of traits included in the loser cow score ranged from 0.04 to 0.68 and the phenotypic correlations ranged from 0.09 to 0.21. The genetic and phenotypic correlations between the loser cow score and the underlying traits ranged from 0.25 to 0.89 and 0.20 to 0.85, respectively, supporting the concept of the loser cow score. The traits included in the loser cow score are easy to assess and all showed genetic variation. They are therefore suitable for inclusion in a total merit index aimed at breeding for more robust cows.
在过去的几年中，丹麦越来越意识到存在健康和生产状况普遍较差的奶牛，这些奶牛被称为“ loser cows（ loser cows）”。先前的一项研究估计，丹麦荷斯坦奶牛群中 loser cows 的总体流行率为 3.2%。本研究旨在估计 loser cow 状态和潜在特征的遗传和表型参数：跛行、跗关节病变、其他皮肤病变和被毛状况。使用动物模型分析了 6098 头奶牛的记录，该模型包括固定效应的牛群、评分季节和评分位置、初产年龄、泌乳阶段和胎次，以及加性遗传效应和永久环境效应。 loser cow 评分的遗传力为 0.08，潜在特征的遗传力范围为 0.05 至 0.12。包括在 loser cow 评分中的各个特征之间的遗传相关性范围为 0.04 至 0.68，表型相关性范围为 0.09 至 0.21。 loser cow 评分与潜在特征之间的遗传和表型相关性分别为 0.25 至 0.89 和 0.20 至 0.85，支持 loser cow 评分的概念。包括在 loser cow 评分中的特征易于评估，并且都显示出遗传变异。因此，它们适合纳入旨在培育更健壮奶牛的综合优势指数。
