Impact of calving interval on milk yield and longevity of primiparous Estonian Holstein cows

Abstract

Data about 4 474 high-yielding Estonian Holstein dairy cows from 14 herds was analysed for the impact of the first calving interval length (CI1) on milk yield (MY) and lactation persistency. The results show that cows with CI1 shorter than 12 months have on average 2 345 kg lower milk yield in the first 1 000 days of productive lifetime than those with CI1 between 14 and 16 months. This is caused by lower MY in both the first and the second lactation as well as higher probability of being culled before reaching 1 000 days of productive life.