Genetic modelling of feed intake in rabbit

Abstract Text: Feed intake was recorded weekly for 4,584 rabbits from weaning to 70 days of age. Character process, orthogonal polynomials and structured antedependence models were fitted to the data to model appropriately the structure of the covariance matrices for the genetic, permanent and litter random effects of feed intake. Models were compared using the Bayesian information criterion. The model that best fitted the data and provided good phenotypic covariance matrix estimation was a structured antedependence model of order 2 for the genetic and permanent environmental effects and a uniform correlation matrix with heterogeneous variance for the litter effect. Nonetheless, this model tended to overestimate heritability. Thus, even if it fitted less well to the data, orthogonal polynomial of order 2 that provided a good estimate of the heritability and covariance structures seemed to be the most appropriate model for studying rabbit feed intake.

Keywords:

feed intake

covariance matrix

rabbit