Investigation of IgA, IgM and lactoferrin in milk from different farms in spring and summer | 不同牛场春季和夏季牛奶中IgA、IgM和乳铁蛋白的调查

Chinese. 分别在北京、滁州、哈尔滨、呼和浩特、乌鲁木齐、西安6个地区选取采样牛场进行春季和夏季采样，测定乳中IgA、IgM、乳铁蛋白和SCC，数据采用SAS8.0进行描述统计和相关性分析，并以牛场、季节为主效应进行方差分析，研究牛奶中免疫球蛋白IgA、IgM和乳铁蛋白统计特征，及其随体细胞计数（SCC）的变化趋势。结果显示：乳中IgA、IgM、乳铁蛋白浓度呈对数正态分布；不同牛场奶牛乳中的IgA、IgM、乳铁蛋白差异较大，春季和夏季牛奶中IgM和乳铁蛋白含量变化显著，但IgA和SCC无显著差异。乳中IgA、IgM、乳铁蛋白（对数形式）以及体细胞评分（SCS）之间呈极显著的正相关，并且随SCS的升高，IgA、IgM和乳铁蛋白含量（对数形式）均呈现上升趋势。

English. The aim of this study was to investigate the content of IgA, IgM and lactoferrin, and their variation affected by somatic cell count (SCC) in milk. Milk from dairy farms in Beijing, Chuzhou, Harbin, Hohhot, Urumqi, Xi’an was collected in spring and summer. The content of IgA, IgM and lactoferrin and SCC in milk were determined. Data was processed by SAS 8.0 and descriptive statistics, correlation analysis, and variance analysis (effects of season and dairy farm on IgA, IgM and lactoferrin) were carried out. The results showed that the content of IgA, IgM and lactoferrin in milk obeyed lognormal distribution. Significant differences of IgA, IgM and lactoferrin content and SCC in milk from different farms were found. The IgM and lactoferrin content from samples collected in spring and summer differed remarkably, but the IgA and SCC data was similar. Correlation coefficients between IgA, IgM, lactoferrin content and somatic cell score (SCS) were significantly positive. Content (log) of IgA, IgM, lactoferrin in milk raised with the increasing of SCS. It can be concluded that significant positive correlation existed between IgA, IgM, lactoferrin content and SCC, and content of IgM and lactoferrin in milk were affected by season.