乳房及肢蹄洁净度对荷斯坦奶牛体细胞数的影响

乳房炎是影响奶牛生产经济效益最重要的疾病之一，而体细胞数（SCC）是反映奶牛乳房健康及牛奶品质的重要指标。本研究通过对规模化牧场670头荷斯坦奶牛后腿上部及侧面、乳房、后腿下部进行洁净度评分，探讨乳房及肢蹄洁净度对荷斯坦奶牛乳中体细胞数的影响。试验运用SAS 8.1统计软件进行最小二乘方差分析及多重比较，除了将洁净度评分作为固定效应外，其他固定效应还包括组别效应、泌乳阶段效应及胎次效应。结果表明：①组别与胎次对体细胞评分有显著影响（P<0.05）。②泌乳阶段、后腿下部洁净度评分与乳房洁净度评分对体细胞评分有极显著影响（P<0.01），其中后腿下部洁净度评分为4分的体细胞评分极显著高于1分和2分的（P<0.01），后腿下部洁净度评分为3分的体细胞评分显著高于1分和2分的（P<0.05）；乳房洁净度评分为3分的体细胞评分极显著高于1分和2分的（P<0.01）；后腿上部及侧面洁净度评分对体细胞评分影响不显著（P>0.05）。③奶牛乳中体细胞数随着奶牛后腿下部洁净度评分与乳房洁净度评分的增加有上升的趋势。试验结果显示，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，可为规模化牧场奶牛日常管理提供科学依据。

Effect of Udder and Leg Cleanliness on Somatic Cell Count in Holstein Dairy Cows

Mastitis is one of the most important diseases affecting the economic benefits of dairy production, and the number of somatic cells count (SCC) is an important indicator reflecting the health of the cow's breasts and the quality of milk.The cleanliness of the upper and lateral legs, breasts, and lower hind legs of 670 Holstein dairy cows from a large-scale pasture were evaluated, and the effects of breast and leg cleanliness on the number of somatic cells in milk were analyzed in this study.SAS 8.1 statistical software was used for least squares analysis of variance and multiple comparisons, and the cleanliness score, group effects, lactation effects and parity effects were uesd as fixed effects.The results showed that:①Group and parity had significant effects on somatic cell scores (P<0.05).②Lactation stage, lower leg cleanliness score and breast cleanliness score had extremely significantly effects on somatic cell scores (P<0.01):The somatic cell scores of the lower leg cleanliness scores of 4 were extremely significant higher than 1 and 2 points (P<0.01), and the somatic scores of the lower leg cleanliness score of 3 were significant higher than 1 point and 2 points (P<0.05);The somatic score of the breast cleanliness score of 3 was significant higher than 1 and 2 points (P<0.01);The upper leg and side cleanliness scores had no effect on somatic cell scores (P>0.05).③SCC had an increasing trend with the increase of the cleanliness score of the lower leg and udder of the cow.In conclusion, the health status of the herd breasts could be effectively understood by scoring the body cleanliness of the herd, which could provide a scientific basis for the daily management of large-scale dairy cows.