Genetic evaluation of reproductive performance in Canadian dairy cattle

• Main Author: F. Miglior
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2010-04-01
• Series: Italian Journal of Animal Science
• Subjects: Genetic evaluation, Test day model, Reproduction, Selection indices
• Online Access: http://www.aspajournal.it/index.php/ijas/article/view/2738

A new genetic evaluation system for the reproductive performance of dairy cattle has been developed in Canada. The evaluation system includes all traits related to reproductive performance, namely age at first service as a heifer trait, interval from calving to first service for cows and 7 traits each for both heifers and cows (56-days non return rate, interval from first service to conception, number of services to conception, gestation length, direct and maternal calving ease, direct and maternal calf survival and direct and maternal calf size). The model of analysis is a 16-trait animal model with different fixed effects according to the analyzed trait. Two indices for daughter fertility and calving performance have been developed. The impact of including the two indices in the national selection index was assessed.