Relationship between Milk Protein Levels at an Early Postpartum Stage and Reproductive Efficiency in Dairy Cows

Abstract

In order to investigate fertility problems in dairy cows, especially regarding energy nutrition of lactating cows, relationships between milk protein levels at an early post-partum stage (16-45 days) and reproductive efficiency were estimated using Dairy Herd Improvement data from 1418 cows. Post-partum intervals to first insemination, and to conception were longer, and conception rate was lower in the cows with low milk protein concentrations (<2.9%) at an early post-partum stage. The data were then analysed based on relative protein levels which were compared with the average of the whole lactation period of each animal. Additionally, reproductive efficiency was lowest in cows with relatively low protein levels at an early stage post partum.