昆明地区中国荷斯坦牛乳中体细胞数变化规律及对乳成分影响的相关性分析

Analysis of the change of somatic cell count in milk of Chinese Holstein in Kunming and the correlation of their effects on milk composition

对在昆明市石林县某生态牧场一年内获得的中国荷斯坦退奶牛牛乳DHI检测数据进行相关性分析,阐述乳中体细胞数对牛乳中主要成分的影响以及主要乳成分之间的相关分析,为奶制品质量的检测提供依据。全年(2015年10月~2016年9月)采样共得到3 000个DHI数据,检测数据包括体细胞数、脂肪、蛋白质、乳糖和总固体。结果表明,乳中SCC与脂肪率呈显著负相关(P<0.05),与乳糖、总固体含量呈极显著负相关(P<0.01);乳中SCC与乳蛋白率呈极显著正相关(P<0.01);脂肪率、乳蛋白率和总固体含量呈极显著正相关(P<0.01);总固体含量、乳蛋白率和乳糖呈极显著正相关(P<0.01)。4~9月,乳中SCC呈逐渐上升趋势,9月份达到峰值,高达46.40%,除此之外,9月前后两个月样品平均SCC高于50×10~4m L^(-1)的比例,也保持在较高水平,7、8月份占比高达40.12%和44.05%,10、11月份分别为45.10%和43.52%。

To analyze the correlation of milk DHI data obtained from an ecological pasture in Shilin County, Kunming, and clarify the influence of somatic cell count（SCC） on the main milk components and the relevant analysis among major components, a total of 3 000 DHI data were collected during the whole year（October, 2015 to September, 2016）. The detection data included the number of somatic cell, fat, protein, lactose and total solids. The results showed that SCC was negative correlation with fat percentage（P 0.05）, and remarkably negative correlation with lactose and total solids（P 0.01）. SCC and milk protein were significantly positive（P 0.01）. There was a significantly positive correlation（P 0.01） among total fat content, milk protein percentage and total solids content（P0.01）. From april to september, SCC in milk was gradually increasing, in september reached a peak, up to 46.40%, in addition, the average SCC of the samples was higher than 50×10~4m L^（-1）in the two months before and after September, and remained at a high level, and the ratio was accounting for up to 40.12% and 44.05% in July and August, 45.10%and 43.52% in October and November, respectively.