Genetic parameters of birth weight and weaning weight for Holstein female calves

Genetic parameters of birth weight and weaning weight were estimated to conduct a breeding value estimation for these both traits. Analysed data were obtained from three commercial farms with overall 3200 German Holstein cows. These farms are integrated in a project for further development of performance testing in dairy cattle. Data included birth weights and weaning weights from 4325 female calves. Measuring of weights took place within the first two days after calving and after finishing the weaning period. Birth weight shows a mean of 41.4 kg, and the mean weaning weight was 91.8 kg. Variance components were estimated bivariate with an animal model by REML. Direct heritabilities were 0.63 for birth weight, and 0.50 for weaning weight. Maternal heritabilities were 0.07 and 0.02, respectively. The direct genetic correlation between birth weight and weaning weight was 0.75. The estimated breeding values show clear differences between sires combined with high reliabilities. Different rankings of sire breeding values for both traits allow to select sires with both average and low birth weights and high daily gains.

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