Age and weight at first calving and subsequent performance in Dutch dairy cattle from rearing farms.

Abstract

Calf-cow records from 1081 replacement heifers raised on 42 specialised rearing farms in the province of Noord-Brabant have been analysed. The predominant breed was Meuse-Rhine-Yssel (MRY). The objective was to study the relationship between weight and age at first calving and milk production in subsequent lactations, herd life span, dystocia and first calving interval. Weight appeared to be a better predictor for first lactation Fat and Protein Corrected Milk production (FPCM-1) than age. First lactation FPCM had a significant and positive effect on herd life FPCM. First lactation FPCM was significantly associated with first calving interval.