Abstract: Calving interval is the time interval between calving,which can comprehensively reflect the reproductive performance of dairy cows,such as estrus,breeding,pregnancy and calving.Calving interval is an important index to measure the reproductive performance of dairy cows,and it is also an important factor affecting the milk yield and calving quantity of dairy cows,which has a direct impact on the economic benefits of dairy farming.The latest research showed that the suitable calving interval was correlated with the lactation ability of cattle.The higher the lactation ability,the longer the suitable calving interval should be.However,even though the milk yield of large-scale cattle farms in China has been greatly improved,most farms in China are still pursuing shorter calving intervals.Therefore,this paper summarized the factors affecting calving interval of Holstein dairy cows,especially high-yielding cows,and analyzed calving interval and economic benefits of dairy farms,in order to provide some references and theoretical basis for determining suitable calving interval for Holstein dairy cows farming in China.

Key words: Holstein dairy cows; calving interval; reproductive performance; economic benefits