Lifetime Performance in Dairy Cattle. Genetic Parameters and Expected Improvement from Selection
Lifetime Performance in Dairy Cattle. Genetic Parameters and Expected Improvement from Selection
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奶牛的终生表现。
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
E. Strandberg
中科院分区：
文献类型：
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作者：
E. Strandberg
摘要本研究的目的是：(1)估计生命早期采取的一些生物学和经济措施的遗传参数，以及随后的终身经济性能性状；(2)计算基于各种选择指标的终身性能选择的预期遗传增益。育种目标性状为：生产寿命年净收入和终身收入除以成本。早期的经济指标特征是：每年的净收入和收入除以成本，在第一次哺乳或生产生命的前15个月测量。经济性状是根据大约10000头奶牛的产量、生育力和疾病数据计算出来的，这些奶牛至少有5年的生产机会。方差-协方差成分通过应用多性状限制最大似然程序估计。第一次哺乳产量的遗传率估计在40%左右，早期经济指标的遗传率为20-30%，终身收入/…
Abstract The aims of this study were (1) to estimate genetic parameters for some biological and economic measures taken early in life, and subsequent lifetime economic performance traits, and (2) to calculate the expected genetic gain in lifetime performance from selection based on various selection indices. The breeding goal traits were: net income per year of productive life and lifetime income divided by cost. The early economic index traits were: net income per year and income divided by cost, measured during the first lactation or the first 15 months of productive life. Economic traits were calculated on the basis of production, fertility, and disease data on around 10000 cows having an opportunity to produce for at least 5 years. Variance-covariance components were estimated by applying a multiple-trait restricted maximum likelihood procedure to a sire model. The heritability estimates were around 40% for yield in 1st lactation, 20–30% for the early economic measures, and 10–15% for lifetime income/...