不同泌乳期、胎次对牛乳乳成分的差异分析

Effect of lactation and parity on the milk composition

为探明牛乳中乳成分随泌乳期、胎次的变化规律,采集了辽宁、山东、云南、福建4个牧场的不同泌乳时期(泌乳早期、中期、晚期)、胎次(一胎次、三胎次)共计232份奶样,测定其蛋白、脂肪和脂肪酸含量。结果表明,泌乳期和胎次对牛乳中蛋白质、脂肪和脂肪酸有不同程度的影响。蛋白质和脂肪含量随着泌乳时间的延长而显著增加,一胎次显著小于三胎次(P<0.05 )。泌乳期对脂肪酸组成的影响差异显著。泌乳早期的饱和脂肪酸显著高于中期,与晚期的差异不显著,不饱和脂肪酸的变化趋势与之相反。不同胎次牛乳中脂肪酸组成差异不大,除单不饱和脂肪酸外均无显著差异。

To investigate the effect of lactation and parity on the milk composition,232 samples were collected in different lactation and parity from four pastures in Liaoning, Shandong, Yunan, Fujian Province. The concentration of protein, fat, and fatty acid were detected. The results showed, Lactation and parity have different effects on protein, fat and fatty acid in milk. The concentration of protein and fat increased significantly as the lactation time lengthened, while the concentration of protein and fat was significantly higher in three fetal times than in first fetal times(P<0.05). The concentration of saturated fatty acid of early lactation was significantly higher than late lactation(P<0.05), while the trend of unsaturated fatty acid was opposite. The concentration of monounsaturated fatty acid was significantly higher in three fetal times than in first fetal times(P<0.05).