乳成分随季节的变化规律及其相关性研究

The Variability and Its Correlation Analysis of Milk Component with Seasons

为探讨原料乳主要理化指标随季节的变化规律及其之间的相关关系,并分析原料乳指标产生变化的原因,采集武汉市某奶牛场70头荷斯坦奶牛一个自然年度(2009年6月至2010年5月)的奶样,检测原料乳的主要乳成分(乳脂率、乳蛋白率、乳干物质),根据所得数据绘制变化曲线图,并利用SAS软件分析季节对乳脂率、乳蛋白率和乳干物质含量的影响及三者之间的相关性。结果表明,在试验期间季节对牛乳中脂肪、蛋白质及干物质含量影响明显。该牧场秋季的牛乳脂肪含量最高,稍高于冬季,夏季最低;乳蛋白和乳干物质含量冬季最高,夏季最低。相关性分析表明乳脂肪含量、乳蛋白质含量和乳干物质含量之间呈极显著的正相关。结果提示,在实际生产中应该根据季节的变化并结合奶牛的营养需求采取具体措施调控影响乳成分的因素,从而提高原料奶的质量。

The raw milk in a natural year（from June 2009 to May 2010）was collected from 70 Holsteins in a dairy farm in Wuhan to study the variability of main physicochemical indices of the raw milk under different seasons and the correlations among the components.The main physicochemical indices including the content of fat,protein,and the dry matter of the raw milk in different seasons were detected to plot the dynamic curves.The effection of seasons on the content of fat,protein,and the dry matter of the raw milk,and the correlations of the components were also analized by SAS software（Ver.8.0）.The results showed that the content of fat,protein and the dry matter in milk were significantly influenced by seasons.The content of fat was highest in autumn,which was a little higher than that in winter,while lowest in summer.The content of protein and dry matter were both highest in winter,while lowest in summer.In addition,it showed positive correlations among the fat content,protein content,and dry matter in the milk.The results indicated that specific adjustments of farm management according to seasons and the nutritional needs of dairy cow would be helpful to improve milk quality in production.