Resumen de Quantitative genetic study of milk production in goats of the Saanen breed
P. Tholon, S. A. Queiroz, António C. Ribeiro, K.T. De Resende, S. D. Ribeiro
Astudy was conducted to estimate the genetic and phenotypic parameters of milk yield (MY) and the individual breeding value of 447 Saanen goats belonging to 5 herds enrolled in the PROCAPRI program. The fixed effects considered in the statistical model were contemporary group (herd, year and season of kidding), type (single or multiple) of kidding; the covariates age at kidding (linear and quadratic) and lactation length (linear); and the random effects of animal and permanent environment. Variance components and heritability estimates were obtained by the Multiple Trait Derivative Free Restricted Maximum Likelihood Method. Heritability and repeatability estimates for MY were 0.37 and 0.47, respectively. The results suggest that selection for MY can be based on performance and that culling decisions should be based on more than one lactation. The genetic trend in MY indicated no evolution of the animals during the period studied.
