Bayesian inference in a quantitative genetic study of growth traits in Nelore cattle (Bos indicus)

Abstract

The objective of this study was to estimate (co)variance components and genetic parameters for weights (W) and scrotal circumferences (SC) at 365 and 450 days of age, of Nelore (Bos indicus) cattle, using Bayesian inference in single and multiple-trait animal models. The fitted linear models included, besides the animal and residual random effects, the contemporary group (herd-year-season-sex-management group) and age-of-dam as "fixed effects". The analyses were carried out using a Gibbs sampler implemented through the MTGSAM program. The heritabilities (in parentheses) obtained fitting single-trait models were W 365 (0.49), W 450 (0.52), SC 365 (0.68) and SC 450 (0.66). Estimates of means, modes and medians for genetic parameters obtained from marginal posterior distributions were similar for all traits. The W 365 and SC 365 can be considered as suitable traits to be included as selection criteria in genetic improvement programs, not only because of their relatively high heritabilities but also due to the fact that they can be measured when the animals are relatively young compared to the corresponding traits W 450 and SC 450 . The Bayesian approach appears to be an appropriate alternative for estimating genetic parameters, and has the advantage over point estimation methods of allowing inferences on marginal posterior distributions.

Heritability of stem straightness and genetic correlations in Eucalyptus cladocalyx in the semi-arid region of Chile

“…In fact, a lower accuracy is directly proportional to a greater deviation from the actual genetic value (Faria et al 2007). In this context, according to Van-Tassell et al (1998), an alternative analysis for genetic evaluation would be the Bayesian approach, which is considered accurate to predict the genetic merit.…”

Genetic association of productive and reproductive traits with stayability in Nellore cattle: analysis using Bayesian models

“…However, they are lower than those reported by Siqueira et al (2003), who analyzed weights at different ages (120, 455, and 550 days) and estimated heritabilities ranging from 0.29 to 0.58 for these traits. Faria et al (2007) obtained higher heritability estimates for weights at 365 days (0.49) and 450 days (0.52) of age.…”

Application of Random Regression Models for Growth Traits of Nellore Cattle in Brazil

“…For these parameters are reliable, the genetic evaluation methodologies must be correctly applied for the predicted values can be accurate, and thus actually represent an effective tool at selecting in search of genetic progress of the herd (FARIA et al, 2007). Breeding values for traits of beef cattle growth are predicted and the variance components are estimated considering the weight at standard ages as, for example, birth, weaning, yearling and final usingsingle-or multi-trait analyses (ALBUQUERQUE;EI FARO, 2008).…”