Estimation of genetic parameters for body weight and ten body measurements at different age stages in Breton and Percheron horses

Abstract

We estimated the genetic parameters for body weight and ten measurements (height at withers, height at croup, body length, chest depth, chest width, hip width, croup width, rump length, chest girth, and cannon bone circumference) at different ages in Breton and Percheron horses. Data included 307 Breton and 324 Percheron horses born between 1999 and 2011 at the Tokachi Station, National Livestock Breeding Center, Japan. The animals were measured every two months on average. Three age groups (birth to 6 months for stage 1, 7 to 19 months for stage 2, and 20 to 34 months for stage 3) were defined. Each stage was treated as a different character and a three-trait animal model was applied for the estimation of variance components. Heritabilities for Breton for each stage ranged from 0.05 to 0.36, 0.16 to 0.54, and 0.08 to 0.66, and 0.05 to 0.38, 0.03 to 0.76, and 0.23 to 0.84 for Percheron. Genetic correlations between stages were all positive in both breeds and ranged from 0.37 to 1.00.