奶牛体细胞评分的变化规律研究

Study on the variation of somatic cell score (SCS) in dairy cattle

【目的】研究影响奶牛体细胞评分(SCS)的因素,为奶牛体细胞评分性状的遗传分析和乳房炎防治提供依据。【方法】收集2000-10-2009-03西安地区2个奶牛场575头中国荷斯坦牛的10 620条奶牛群改良(DHI)测定记录,应用最小二乘法原理,配合线性固定效应模型,分析了牧场、年份、月份、胎次、泌乳月份等因素对SCS的影响。【结果】不同水平的牧场、年份、月份、胎次、泌乳月份对SCS影响的差异显著性分析表明,生产管理因素显著影响牛群的SCS(P<0.05);随着DHI项目的实施,牛群SCS值逐年显著降低(P<0.05);夏季高温和冬季低温显著提高SCS值(P<0.05);伴随胎次和泌乳月份的增加,SCS不断升高(P<0.05)。【结论】通过改善挤奶技术、加强卫生管理等措施,能够降低SCS。在体细胞评分性状的遗传分析中,必须考虑环境和生理因素的效应。

【Objective】 This research was conducted to study how non-genetic factors affect somatic cell score in dairy cattle.【Method】 Between October,2000 and March,2009,10 620 DHI test-day records were taken on 575 Chinese Holstein cows in 2 herds in Xi＇an region.Linear fixed model with the principle of least square（LS） was fitted to analyze the effects of the herd,year,month,parity and milk month on somatic cell score.【Result】 The results showed that management and production of dairy farms had a significant effect on SCS（P0.05）;SCS decreased annually with launch of DHI program in dairy cattle populations（P0.05）.SCS would rise with the change of the parity and milk month（P0.05）;high temperature in summer and low temperature in winter made SCS rise significantly（P0.05）.【Conclusion】 Somatic cell score could be decreased by improving milking techniques,and strengthening health epidemic prevention on dairy farms.The physiological and environment factors should be considered in genetic analysis of SCS.