Genetic parameter estimates of conformation and performance traits in station-tested Limousin bulls

Abstract

Genetic and residual parameters were computed for conformation and performance traits of Limousin bulls in Ontario central test stations. Following editing, data were available on 456 bulls tested in 1990. Genetic parameters for performance traits were similar to those reported in the literature. Heritability of bone score (1 — light to 9 — heavy) was 0.22 ± 0.23. Heritability of a composite muscular development score was 0.51 ± 0.14. Muscular development was positively correlated genetically with all traits studied, including average daily gain (140 d), height, scrotal circumference and bone, and very highly correlated genetically with backfat thickness and weight at end of test. Selection for muscular development using a linear scoring system is feasible, but consideration should be given to correlated responses in other economically important traits. Key words: Multiple-trait analysis, growth and type traits correlations, station-tested beef bulls