Genetic parameters for yield, fitness, and type traits in US Brown Swiss dairy cattle
Genetic parameters for yield, fitness, and type traits in US Brown Swiss dairy cattle
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DOI：
10.3168/jds.2017-13041
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发表时间：
2018-02-01
影响因子：
3.5
通讯作者：
Dechow, C. D.
中科院分区：
文献类型：
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作者：
Gibson, K. D.;Dechow, C. D.
本研究的目的是评估2000年及以后出生的美国瑞士棕色牛的产量、适合度和类型性状之间的遗传力和遗传相关性。使用的数据集包括来自45,464头奶牛的108,633头至第5次泌乳记录，包括产量、体细胞评分（SCS）、开放天数和生产寿命。大约一半的记录有17个类型性状的观察结果，41,074个记录有挤奶速度的观察结果。利用3个性状模型对这些数据进行分析。每个性状的遗传率估计与之前报道的荷尔斯坦和其他国家的棕色瑞士人的遗传率相似。产奶量、脂肪量和蛋白质产量与生产寿命呈极显著正相关（0.67 ~ 0.71），而日数和SCS与生产寿命呈极显著负相关（分别为-0.60和-0.69）。开日数与乳型（棱角）的相关性大于与产量的相关性。乳深与产奶量呈负相关（-0.40），后乳高（0.20）和后乳宽（0.48）与产奶量呈正相关。乳房深度与SCS具有良好的遗传相关性（-0.26）。与生产生活遗传相关性最强的类型性状为乳房依恋、移动性和最终得分（分别为0.44、0.50和0.57）。这些更新的遗传参数将允许改进瑞士棕色品种的遗传选择。
The objective of this research was to evaluate heritabilities and genetic correlations among yield, fitness, and type traits for US Brown Swiss cattle born in 2000 and later. The data set used consisted of 108,633 first through fifth lactation records from 45,464 cows for yield, somatic cell score (SCS), days open, and productive life. Approximately half of the records had observations for 17 type traits and 41,074 had observations for milking speed. These data were analyzed using a series of 3 trait models. Heritability estimates of each trait were similar to previously reported values for both Holsteins, and Brown Swiss in other countries. Milk, fat, and protein yield had strong positive genetic correlations with productive life (0.67 to 0.71), whereas days open and SCS had strong negative correlations with productive life (-0.60 and -0.69, respectively). Days open was more unfavorably correlated with dairy form (angularity) than with yield. The genetic correlation of udder depth and milk yield was unfavorable (-0.40), whereas rear udder height (0.20) and width (0.48) were favorably correlated with milk yield. Udder depth had a favorable genetic correlation with SCS (-0.26). Type traits with the strongest genetic correlations with productive life were fore udder attachment, mobility, and final score (0.44, 0.50, and 0.57, respectively). These updated genetic parameters will allow for improved genetic selection within the Brown Swiss breed.