本试验旨在研究应用奶牛群体改良(dairy herd improvement,DHI)体系对奶牛生产性能的影响。选用150头不同年龄、胎次、泌乳阶段的健康泌乳奶牛,进行为期8月(2009年6月―2010年1月)的试验。第1月为第1期,不进行调整;第2~4月第2期,进行第1次调整;第5~7月为第3期,进行第2次调整;第8月为第4期,为调整后的观察期。饲粮配方和饲养管理的调整结合试验期内内蒙自治区古巴盟地区气候条件及DHI报告中的数据信息。记录产奶量,通过DHI软件计算305 d产奶量、305 d成年当量,预测最高日产奶量及其出现时间,采集的奶样测定乳脂蛋比。结果表明:应用DHI体系能够显著提高305 d产奶量和305 d成年当量(P<0.05),显著提高最高日产奶量(P<0.05),并缩短其出现时间(P<0.05),改善乳脂蛋比。结果提示,在内蒙古自治区古巴盟地区的气候条件下,应用DHI体系能够提高奶牛生产性能。

This experiment was conducted to investigate effects of application of dairy herd improvement (DHI) system on performance of dairy cows. One hundred and fifty healthy dairy cows with different age, parity and lactation stage were selected in an 8-month (Jun., 2009 to Jan., 2010) experiment. The 1^st month was the period 1, no adjustment was done; period 2 lasted from the 2^nd to the 4^th month, in which the 1^st adjustment was carried out; period 3 lasted from the 5^th to the 7^th month, in which the 2^nd adjustment was carried out; the 8^th month was period 4, which was the observation period after adjustment. The adjustments of diet and managements were determined based on the climatic condition in Bayenaoer, Inner Mongolia and data from the DHI report during the experimental period. Milk yield was recorded. 305 d milk yield and 305 d matured equivalency were calculated, peak daily milk yield and its time were predicted by DHI software, and milk sample was collected once a month for the determination of the ratio of fat to protein in milk. The results showed that application of the DHI system significantly increased 305 d milk yield and 305 d matured equivalency (P<0.05), significantly increased peak daily milk yield and shorten its time (P<0.05), and the ratio of fat to protein in milk was improved. The results indicate that under the climatic condition in Bayenaoer, Inner Mongolia, application of the DHI system can improve performance of dairy cows.