Genetic associations between hip height, body conformation scores, and pregnancy probability at 14 months in Nelore cattle

Genetic parameters for hip height (HH), finishing precocity score (PRE), muscling score (MUS), bone score (BONE), and probability of pregnancy at 14 months (HP) were estimated using records of 121,086 Nelore animals born between 1984 and 2008 on 12 farms from three Brazilian states. The Bayesian linear-threshold analysis via the Gibbs sampler was used to estimate the (co)variance components applying a multi-trait animal model. Posterior mean estimates of heritability for HH, PRE, MUS, BONE, and HP were 0.36, 0.26, 0.26, 0.26, and 0.50, respectively. Therefore, the genetic improvement of these traits is possible. The genetic correlations between all traits studied were of low to high magnitude. High genetic correlations were observed between visual scores (0.85 and 0.99). Therefore, the simultaneous inclusion of PRE, MUS and BONE in a selection index does not seem to be necessary for the present population. The genetic correlation of HP with HH and visual scores ranged from −0.06 to 0.25, indicating that selection for traits related to body structure and conformation has little or no effect on HP.