淮南地区荷斯坦奶牛乳用特征的线性评定

Linear Appraisal of Holstein Milk Traits in Huai'nan District

随机选择安徽淮南乳品公司的荷斯坦奶牛493头(1～11胎)进行奶牛乳用特征性状即楞角性、尻宽、尻角度、后肢侧视、蹄角度的线性评定。结果表明:淮南地区荷斯坦奶牛乳用特征性状的表现中等偏好,楞角性、尻宽、尻角度、后肢侧视、蹄角度的评定等级分别是佳、优、中、中、良;优秀率是20%,中等率为40%。同时,楞角性、尻宽、蹄角度的线性评分随胎次变化而变化的幅度很小,且未表现出一定的规律;而后肢侧视、尻角度的线性评分在1～5胎内随胎次的升高而有明显的升高,并且前者的变异幅度大于后者。

493 heads of Holstein cows, aged from 1 year to 11 years, were randomly selected an linearly evaluated in milky traits, including angularity, rump width, rump angle, side view of rear legs, foot angle. Results showed that milk trait performance is better than middling. Grades of angularity, rump width, rump angle, side view of rear legs, foot angle were excellent, good, middle, middle, good, respectively. Percentage of excellence and middle grade were 20 % and 40%, respectively. Linear score of angularity, rump width and foot angle at different ages changed nonsignificantly and irregularly, while rump angle, side view of rear legs increased from the first to fifth pregnancy and increasing tendency of rump angle was larger than that of side view of rear legs.