Abstract: Nine Chinese Holstein cows were used in a replicated 3×3 Latin square design to study the effects of different zinc sources on milk yields and milk quality. Based diets supplemented with Zinc methionine(Zn-Met) and Zinc oxide(ZnO) containing 400mg zinc. The results showed that different zinc sources could increase milk yields, Zn-Met was better than ZnO, but not significant(p>0.05). No significant effect on milk fat rate (p>0.05). Zinc added to diets could increase the content of zinc in milk, significant effects were observed Zn-Met comparing with ZnO (p <0.05).

Key words: cows, zinc sources, milk yields, milk quality