King V L, Denise S K, Armstrong D V, Torabi M, Wiersma F
Biometrics and Information Systems Center, University of Nebraska, Lincoln 68583-0712.
J Dairy Sci. 1988 Apr;71(4):1093-6. doi: 10.3168/jds.S0022-0302(88)79657-5.
Dairy Herd Improvement data from 432 Holstein cows were analyzed to determine if coat color was a significant source of variation in the performance of first lactation cows in a hot climate. One of three coat color scores was subjectively assigned to first lactation Holstein cows. White coat color was less than 40% black (15% of the cows), mixed coat color was 40 to 60% black (42% of the cows), and black coat color was greater than 60% black (43% of the cows). Coat color by season of freshening interaction was not an important source of variation for any of the production traits studied; but cows were cooled during the first 130 d of lactation, perhaps removing any advantage white cows may have had during the summer months. The interaction between coat color and season of freshening was significant for days open and services per conception. White cows freshening in February and March required fewer services per conception and had fewer open days than the mixed and black cows. The heritability estimate of coat color was .22 using a paternal half-sib analysis. Additional studies, with more white cows represented, would be useful to elucidate the effects of coat color on production in a hot climate.
分析了432头荷斯坦奶牛的奶牛群改良数据，以确定在炎热气候下，被毛颜色是否是头胎奶牛生产性能差异的一个重要来源。对头胎荷斯坦奶牛主观评定了三种被毛颜色分数之一。白色被毛颜色的奶牛黑色毛少于40%（占奶牛的15%），混合被毛颜色的奶牛黑色毛为40%至60%（占奶牛的42%），黑色被毛颜色的奶牛黑色毛大于60%（占奶牛的43%）。对于所研究任何生产性状而言，产犊季节与被毛颜色的交互作用不是差异的一个重要来源；但在泌乳的前130天奶牛进行了降温处理，这可能消除了白色奶牛在夏季可能具有的任何优势。被毛颜色与产犊季节之间的交互作用对空怀天数和每次受孕配种次数具有显著影响。在2月和3月产犊的白色奶牛每次受孕所需配种次数较少，空怀天数也比混合被毛和黑色被毛的奶牛少。使用父本半同胞分析，被毛颜色的遗传力估计值为0.22。开展更多纳入更多白色奶牛的研究，将有助于阐明在炎热气候下被毛颜色对生产的影响。
