Simčič Mojca, Luštrek Barbara, Štepec Miran, Logar Betka, Potočnik Klemen
Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
Agricultural Institute of Slovenia, Ljubljana, Slovenia.
Front Genet. 2021 Nov 22;12:724058. doi: 10.3389/fgene.2021.724058. eCollection 2021.
The aim of this study was to estimate genetic parameters of 26 individual and four composite type traits in first parity Cika cows. An analysis of variance was performed with the generalized linear model procedure of the SAS/STAT statistical package, where the fixed effects of year of recording, cow's age at recording and days after calving as a linear regression were included in the model. The variance components for the direct additive genetic effect and the herd effect in all type traits were estimated using the REML method in the VCE-6 software package. The estimated heritabilities ranged from 0.42 to 0.67 for the measured body frame traits, from 0.36 to 0.80 for the scored autochthonous traits, from 0.11 to 0.61 for the scored body frame traits, and from 0.20 to 0.47 for the scored udder traits. The estimated heritabilities for the composite traits called "autochthonous characteristics", "muscularity", "body frame" and "udder" were 0.55, 0.19, 0.19, and 0.26, respectively. The estimated genetic correlations among the measured body frame traits were positive and high, while the majority of them among the scored body frame traits were low to moderate. The estimated proportions of variance explained by the herd effect for the composite traits "autochthonous characteristics," "muscularity," "body frame" and "udder" were 0.09, 0.28, 0.14, and 0.10, respectively. The estimated heritabilities for the type traits of first parity Cika cows were similar to those reported for other breeds where breeding values have been routinely predicted for a long time. All estimated genetic parameters are already used for breeding value prediction in the Cika cattle population.
本研究的目的是估计初产契卡奶牛26个个体性状和4个复合性状的遗传参数。使用SAS/STAT统计软件包的广义线性模型程序进行方差分析，模型中纳入了记录年份、记录时奶牛年龄以及产犊后天数的线性回归等固定效应。使用VCE - 6软件包中的REML方法估计所有类型性状的直接加性遗传效应和群体效应的方差分量。测量的体躯框架性状的估计遗传力范围为0.42至0.67，评分的本土性状为0.36至0.80，评分的体躯框架性状为0.11至0.61，评分的乳房性状为0.20至0.47。名为“本土特征”“肌肉度”“体躯框架”和“乳房”的复合性状的估计遗传力分别为0.55、0.19、0.19和0.26。测量的体躯框架性状之间的估计遗传相关性为正且较高，而评分的体躯框架性状中的大多数相关性为低到中等。“本土特征”“肌肉度”“体躯框架”和“乳房”复合性状的群体效应解释的方差估计比例分别为0.09、0.28、0.14和0.10。初产契卡奶牛类型性状的估计遗传力与长期常规预测育种值的其他品种报道的遗传力相似。所有估计的遗传参数已用于契卡牛群体的育种值预测。
