乳房及腿部洁净度对奶牛体细胞数的影响

The Effects of Udder and Leg Hygiene Score on SCC of Dairy Cow

乳房炎是制约奶牛生产效益最重要的因素之一,而体细胞数(Somatic cell count,SCC)是评价牛奶品质和奶牛乳房健康的重要指标。本研究对规模化牧场536头荷斯坦母牛进行洁净度评分,其中主要涉及乳房、上腿及下腿三个部位。旨在通过分析洁净度评分对体细胞数的影响程度及规律,以期为规模化牧场奶牛饲养管理提供科学有效的管理工具及生产指导依据。通过SAS 9.1软件采用广义线性模型(GLM)对研究数据进行统计分析,除洁净度评分作为固定效益外,考虑的固定效应包括组别效应、泌乳阶段效应及胎次等。结果表明,乳房洁净度评分对SCC有显著影响(P<0.05),下腿洁净度评分对SCC有极显著影响(P<0.01),上腿洁净度评分对SCC影响不显著(P>0.05)。SCC随着乳房、下腿洁净度评分的增加有上升的趋势,但是对上腿洁净度评分不敏感,三个部位洁净度评分显著正相关。可见通过对牛群身体洁净度评分,可以有效了解牛群乳房的健康状况,对提高牧场饲养管理水平具有重要指导意义。

Mastitis is a major constraint to improve production efficiency of dairy cows. Somatic cell count （SCC） is an in- direct index to evaluate milk quality and udder health. Totally 536 dairy cows from a large--scale farm were invested, the udder and leg hygiene status were scored. The objective of the present study was to find out the relationship between body hygiene status and SCC through body hygiene scoring and provide the theoretical basis for dairy management to maintain and improve the udder health of the lactating cows. After correcting the influence of fixed effects including grouping, lactating stage and parity, the effects of udder and leg hygiene scores on SCC were analyzed using SAS9.1 with general linear model （GLM） proce dure. Results showed that udder hygiene score affected SCC significantly （P〈 0.05）, lower leg hygiene score had a very sig- nificant effect on SCC （P〈0.01）, and the upper leg hygiene score had no effect on SCC （P〉0.05）. SCC rise for a large mag- nitude with the increase of udder and lower legs hygiene scores, while was not sensitive to the upper leg hygiene scores. Among the scores of these three parts, hygiene scores were significantly positively correlated. This study indicated that cattle body hy- giene scoring can be a contribution in understanding population udder health and then improving the management of dairy farm.