我国规模牛场奶牛个体生鲜乳乳蛋白水平及影响因素探析

本研究旨在探析我国规模奶牛场奶牛个体乳蛋白的水平、分布和影响因素。利用SAS9．0的GLM过程，统计分析覆盖16省（市、区），33个规模奶牛场，23351头中国荷斯坦牛，从2007年至2009年连续3年的237430个奶牛个体生鲜乳的乳蛋白率检测记录。分析表明，我国规模奶牛场奶牛个体生鲜乳的乳蛋白率平均3．28±0．22％。其中，乳蛋白率大于等于2．95％的奶牛个体占80．2％，所提供乳蛋白量占群体混合样生鲜乳总蛋白量的79．3％。奶牛的胎次、产奶阶段、产奶量、乳脂率、体细胞数、泌乳季节、泌乳月份都极显著影响奶牛个体生鲜乳的乳蛋白率（P〈0．01）；饲养区域、奶牛场和年度总体显著影响奶牛个体生鲜乳的乳蛋白率（P〈0．05）。我国规模奶牛场奶牛个体生鲜乳的乳蛋白率主要处于2．95％以上（〉80％），合理调控各种影响因素，可有效提高生鲜乳的乳蛋白率。

Analysis of Milk Protein in Raw Milk of Individual Dairy Cow From Dairy Farm in China

The objectives of this study were to analyze total average value, distribution frequency and main impact factors of milk protein in raw milk from individual dairy cow. The total datas were from 33 dairy farms in China, 23351 Chinese Holstein cows, covering with 16 provinces, 237430 raw milk protein records from 2007 to 2009, and they were analysed by GLM of SAS9. 0. The results showed that： the total average of milk protein in raw milk from individual dairy cow was 3.28±0.22%; the ration of milk protein above 2.95% was 88.2%, which was made up of 77.9% total milk protein. Milk protein in raw milk was significantly or extremely significantly affected by dairy parity, milk yields, stage of lactation, milk fat, SCC, milking season, milking month（P〈0.01） and farming region as well as dairy farms（P〈0.05）. It was concluded that milk protein could be regulated through controlling the population structure, nutrition and feeding strategy.