Relationship of age at first calving, first lactation milk yield, reproductive performance and diseases in simmental dairy cows in Turkey

Abstract

The aim of this research was to determine the relationship between age at first calving (AFC) and first lactation milk yield [adjusted 305-day (MY305)], reproductive performance [days open (DO), calving interval (CI)] and diseases (lameness, mastitis, metritis and dystocia) in Simmental dairy cows bred under Turkey conditions. A total of 1110 Simmental cows (first calving to second calving) were assessed according to study criteria. While the relation between AFC and disease incidence and MY305 was not found significant, the relation between AFC and CI and DO was found significant and the optimum interval of AFC was determined 684 <=(I) over dotBY < 30 d for minimum CI and DO. Even though relation between AFC and diseases was not significant, it can be said that the same interval is advantageous for low disease incidence in Simmental cows. Furthermore, it can be accepted that the same interval is optimum also for the best lactation milk yield since it was not found a significant relationship among the average milk yields according to AFC. In conclusion, it can be said that planning the reproductive management practices according to these results will be beneficial for the optimal balance between economic benefit, animal health and milk yield.