Use of relationship matrix in the evaluation of natural service Limousin bulls

• Published in: Genetics selection evolution (Paris) 1992-05, Vol.24 (2), p.137-145, Article 137
• Main Authors: LALOË, D, RENAND, G, SAPA, J, MENISSIER, F
• Format: Article
• Language: English
• Subjects: Analysis; Animals; Biological and medical sciences; Cattle; Classical genetics, quantitative genetics, hybrids; Fundamental and applied biological sciences. Psychology; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Life Sciences; Vertebrata
• ISSN: 0999-193X; 1297-9686; 1297-9686
• DOI: 10.1186/1297-9686-24-2-137

In France, natural service bulls of beef breeds are progeny tested using reference sires and planned matings. The evaluation is made with a single-trait best linear unbiased prediction (BLUP) procedure applied to a sire model on pre-weaning calf performance, where sires are considered as unrelated. The purpose of this investigation was to examine the impact of using relationships between sires on breeding value estimates, their accuracies, and the connectedness between sires. Two mixed models, with or without sire interrelations were used. Weaning weights of 4 207 Limousin calves from 219 sires were analysed. A total of 53 sires were related by a Malecot relationship coefficient greater than or equal to 0.25. The correlation between breeding value estimates obtained with the 2 models was 0.969. The gain in accuracy was characterized by the reduction of prediction error variances and expressed by the ratio of these variances obtained with the 2 models. This gain averaged 4%, reached 26% and was related to the sire relationship coefficient means (correlation of 0.63).