Bayesian models linear and threshold for marbling and score body in breed goats Anglonubian

In animal breeding, estimates of genetic parameters are very important for decision making as animal selection. Furthermore, in the processing of data for these estimates must take into account the nature of the data, allowing to obtain more accurate results. Therefore, with the Bayesian methodology, we estimated the components of (co) variance and genetic parameters of categorical traits of carcass, comparing analysis by linear mixed model and threshold model in goats of Anglonubian. Were estimated components (co) variance and genetic parameters for categorical traits body condition score and marbling, through animal model in single and two-trait, the latter under linear-threshold models, combining categorical features with traits continuous, being: ribeye area, fat thickness of the sternum, hip height, leg circumference and body weight. The database information comprised of 385 animals and used a relationship matrix with 793 animals. Comparing the models, the threshold model was of best fit for categorical data of carcass, being the most recommended for the inferences of the parameters, because has greater ability to detect genetic variability compared to linear models. In the analysis under the linear model was super estimates of heritability estimates with value of 0,29 and 0,12 for marbling and body condition score, respectively, which causes erroneous estimates of breeding values. In the analyzes two-trait the contribution of the increase in information and correlations between traits, contributed to the increase of the estimated values for the (co) variance and heritability values for the traits studied in comparative with the analysis single, 0,13 (analysis single 0,11) e 0,09 (analysis single 0,03) body condition score and marbling, respectively. The heritability values estimated for the traits studied were of moderate magnitude, with this genetic progress is possible with the inclusion of these features in the selection indices, except for marbling, which showed heritability of low magnitude. Direct selection of the continuous distribution of traits such as thickness sternal fat and hip height, allows to obtain the indirect selection for marbling in the ribeye.