Department of Cattle Breeding, Institute of Animal Science, Přátelství 815, 10400 Prague 10 - Uhříněves, Czech Republic.
J Dairy Sci. 2011 Oct;94(10):5176-82. doi: 10.3168/jds.2010-3644.
The aim of this study was to estimate genetic parameters for fertility traits and linear type traits in the Czech Holstein dairy cattle population. Phenotypic data regarding 12 linear type traits, measured in first lactation, and 3 fertility traits, measured in each of first and second lactation, were collected from 2005 to 2009 in the progeny testing program of the Czech-Moravian Breeders Corporation. The number of animals for each linear type trait was 59,467, except for locomotion, where 53,436 animals were recorded. The 3-generation pedigree file included 164,125 animals. (Co)variance components were estimated using AI-REML in a series of bivariate analyses, which were implemented via the DMU package. Fertility traits included days from calving to first service (CF1), days open (DO1), and days from first to last service (FL1) in first lactation, and days from calving to first service (CF2), days open (DO2), and days from first to last service (FL2) in second lactation. The number of animals with fertility data varied between traits and ranged from 18,915 to 58,686. All heritability estimates for reproduction traits were low, ranging from 0.02 to 0.04. Heritability estimates for linear type traits ranged from 0.03 for locomotion to 0.39 for stature. Estimated genetic correlations between fertility traits and linear type traits were generally neutral or positive, whereas genetic correlations between body condition score and CF1, DO1, FL1, CF2 and DO2 were mostly negative, with the greatest correlation between BCS and CF2 (-0.51). Genetic correlations with locomotion were greatest for CF1 and CF2 (-0.34 for both). Results of this study show that cows that are genetically extreme for angularity, stature, and body depth tend to perform poorly for fertility traits. At the same time, cows that are genetically predisposed for low body condition score or high locomotion score are generally inferior in fertility.
本研究旨在估计捷克荷斯坦奶牛群体的生育性状和线性体型性状的遗传参数。2005 年至 2009 年，在捷克-摩拉维亚饲养者公司的后代测试计划中，收集了 12 个线性体型性状（在第一泌乳期测量）和 3 个生育性状（在第一和第二泌乳期测量）的表型数据。每个线性体型性状的动物数量为 59467 个，除了运动性状，记录了 53436 个动物。3 世代系谱文件包括 164125 个动物。（协）方差分量使用 AI-REML 在一系列双变量分析中进行估计，通过 DMU 包实现。生育性状包括第一次配种到第一次输精（CF1）的天数、开放天数（DO1）和第一次到最后一次输精（FL1）的天数，以及第一次配种到第一次输精（CF2）的天数、开放天数（DO2）和第一次到最后一次输精（FL2）的天数。具有生育数据的动物数量因性状而异，范围从 18915 到 58686。所有繁殖性状的遗传力估计值均较低，范围从 0.02 到 0.04。线性体型性状的遗传力估计值从运动的 0.03 到体型的 0.39。生育性状和线性体型性状之间的遗传相关性通常为中性或正相关，而身体状况评分与 CF1、DO1、FL1、CF2 和 DO2 之间的遗传相关性大多为负相关，BCS 与 CF2 之间的相关性最大（-0.51）。与 CF1 和 CF2 相关最大的是与运动相关的遗传力（两者均为-0.34）。本研究结果表明，在角度、体型和体深方面遗传极端的奶牛往往在生育性状方面表现不佳。同时，遗传上易患低体况评分或高运动评分的奶牛通常在生育能力方面较差。
