北京及周边地区牛乳的凝固性分析

Coagulation Properties of Milk from Beijing and Surrounding Areas

通过对北京和山东等地不同规模奶牛饲养场的牛乳凝固性的调查,分析奶牛年龄、胎次、泌乳期、季节和饲养方式等因素对牛乳凝固性的影响。结果表明:牛乳经发酵或凝乳酶作用后所形成的凝乳质量与牛乳的来源密切相关。随着奶牛年龄和胎次的增长,牛乳的凝乳质量呈现下降趋势,同时,产仔后泌乳中期的牛乳的凝乳质量较之前期和后期更低;全年中秋季和冬季凝乳质量较好。较大规模化的牛群饲养方式有利于牛乳品质及凝乳质量的提高。

The coagulation properties of milk from dairy farms of different scales in Beijing and its surrounding areas such as Shandong were investigated in this study.Analyses were carried out with physiological factors （age,parity and lactation stage） and environmental factors （season,raising condition） affecting milk coagulation.The results showed that milk coagulation properties induced by fermentation or rennet were strongly related to milk source.Milk coagulation properties decreased with the extension of cow＇s age and parity and were poorer during middle lactation stage.Coagulation properties reached the peak point in fall and winter among the four seasons.Large-scaled and modernized raising conditions were helpful in improving milk coagulation properties.