摘要
Abstract
The data of reproductive traits including 1967 records of the age of first mate, breeding index, the interval from calving to conception , pregnancy period, calving interval, the age of calving from parity 1 to parity 6 of 895 Chinese Holstein from a dairy farm in Jiangsu Province were analyzed, and the association between the reproductive traits and milking performances were analyzed. The results showed that the effects of parity on breeding index, the interval from calving to conception, calving interval, milking days and dry period were significant at P <0.01, and the effect on 305 days corrected milk yield was significant at P <0. 05. With the increasing of parity, the breeding index, dry period were increasing, and the interval from calving to conception and milking days were decreasing. The season of calving have significant effects on breeding index, the interval from calving to conception, pregnancy period, 305 days corrected milk yield and milking days at P < 0. 01, and has significant effect on calving interval at P < 0. 05, and has no significant effects on the length of dry period ( P > 0. 05 ). The breeding index was maximum for the cattle calving in spring, the interval from calving to conception and calving interval for the cattle that calving in winter were significantly more than the cattle that calving in spring, summer and autumn. The pregnancy period was shortest for the cattle calving in summer. The breeding index showed significant positive correlation with the age of first mating, the interval from calving to conception, and calving age (P < 0.01). The age of first mating showed negative correlation with the interval from calving to conception, calving interval and milking days (P <0.01).关键词
中国荷斯坦牛/繁殖性能/泌乳性能Key words
Chinese Holstein/ Reproductive traits/ Milking performance分类
农业科技
