奶牛业的最终目标是效益,即用有限的资源尽可能多的生产出营养结构合理、低体细胞数、高蛋白、无药物及抗生寨残留的优质牛奶。20世纪50年代以来,世界奶业发展的特点和规律是,奶牛头数逐年减少,牛奶质量、单产水平每年都有新的提高,这主要得益于优良荷斯坦奶牛品种 The ultimate goal of the dairy industry is to benefit from producing as much milk as possible with the limited resources available in a nutritionally sound, low-somatic cell count, protein-rich, drug-free and antibiotic-free package. Since the 1950s, the characteristics and rules of the development of world dairy industry have been that the number of dairy cows decreased year by year, milk quality and yield per unit have been increased year by year, mainly due to the excellent Holstein dairy cows