Department of Animal Science-Centro de Ciência Animal e Veterinária (CECAV), University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.
J Anim Sci. 2011 May;89(5):1281-5. doi: 10.2527/jas.2010-3211.
Milk somatic cell count is an indicator trait for mastitis resistance. Genetic parameters for somatic cell score in the Portuguese Holstein-Friesian population were estimated by modeling the pattern of genetic correlation over the first 3 lactations (days in milk) with a random regression model. Data records from the first 3 lactations were from the national database of the Portuguese Holstein Association herds. Heritability estimates ranged from 0.05 at the beginning of the lactation for the 3 lactations, to 0.07 at the end of the lactation period for the first and third lactations, to 0.09 for the second lactation. This increase in the heritability values was due to an increase in the genetic variance and a decrease in the residual variances. Genetic correlations evaluated for monthly time points were high (0.65 to 0.99) for all 3 lactations, whereas phenotypic correlations were much less than the genetic correlations (0.13 to 0.62).
牛奶体细胞计数是乳腺炎抗性的一个指示性状。通过对前 3 个泌乳期（泌乳天数）的遗传相关模式进行随机回归模型建模，估计了葡萄牙荷斯坦-弗里森种群中体细胞评分的遗传参数。前 3 个泌乳期的数据记录来自葡萄牙荷斯坦协会牛群的国家数据库。3 个泌乳期的起始泌乳期的遗传率估计值范围为 0.05，第一和第三个泌乳期的泌乳期末的遗传率估计值为 0.07，第二个泌乳期的遗传率估计值为 0.09。遗传率值的增加是由于遗传方差的增加和残差方差的减少所致。所有 3 个泌乳期的月度时间点评估的遗传相关性均较高（0.65 至 0.99），而表型相关性远低于遗传相关性（0.13 至 0.62）。
