Research Information System
PAKISTAN JOURNAL OF ZOOLOGY, vol.54, pp.1-7, 2022 (Journal Indexed in SCI Expanded)
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≤ İBY≤730 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.