Cue R I, Monardes H G, Hayes J F
Department of Animal Science, McGill University, Ste Anne de Bellevue, Canada.
J Dairy Sci. 1990 Dec;73(12):3586-90. doi: 10.3168/jds.S0022-0302(90)79060-1.
Type information collected by the Holstein Association of Canada was combined with calving ease data from the Quebec Dairy Herd Analysis Service. Type traits considered were overall score, general appearance, dairy character, capacity, rump, rump thurl width, rump pin setting, and set of rear legs. Calving ease was considered as a direct effect and as a maternal effect in both heifers and adult cows. After editing there were 24,618 type records, 47,023 direct effect calving ease records, and 37,068 maternal effect calving ease records from 107 sires in the analyses of heifer data. there were 26,996 type records, 16,4726 direct effect calvin ease records, and 45,261 maternal effect calving ease records in the analyses of calving involving adult cows. Multiple-trait REML was used to estimate genetic correlations between calving ease and type. The heritability of calving ease in heifers was approximately 4%, for both the direct and maternal effect, and in adult cows was approximately 1.5%. Heritability of the type traits ranged from 4 to 45%. There was a tendency for the genetic correlations between type and the direct effect of calving ease to be opposite in sign to the genetic correlations between type and the maternal effect of calving ease and for the absolute value of the correlations to be lower in adult cows than in heifers.
加拿大荷斯坦协会收集的体型信息与魁北克奶牛群分析服务中心的产犊难易度数据相结合。所考虑的体型性状包括总体评分、一般外貌、奶牛特征、体容量、尻部、尻中宽、尻尖位置以及后肢结构。产犊难易度在小母牛和成年母牛中均被视为直接效应和母体效应。经过编辑后，在小母牛数据的分析中，有来自107头公牛的24,618条体型记录、47,023条直接效应产犊难易度记录以及37,068条母体效应产犊难易度记录。在涉及成年母牛产犊的分析中，有26,996条体型记录、164,726条直接效应产犊难易度记录以及45,261条母体效应产犊难易度记录。多性状REML被用于估计产犊难易度与体型之间的遗传相关性。小母牛中产犊难易度的遗传力，直接效应和母体效应均约为4%，成年母牛中约为1.5%。体型性状的遗传力范围为4%至45%。体型与产犊难易度直接效应之间的遗传相关性在符号上往往与体型与产犊难易度母体效应之间的遗传相关性相反，且成年母牛中相关性的绝对值低于小母牛。
