Genetic evaluation of weight gain and feed-to-gain ratio of White New Zealand rabbits raised in different environments

This research evaluates whether the selection for feed-to-gain ratio (FGR) and weight gain (WG), based on individual and/or collective performance of rabbits, can lead to genetic gain in collectively-raised rabbit progenies. Animals were submitted to an evaluation period at the age of 50 to 70 days, using Bayesian inference. Six two-trait analyses were done. Performance testing observed WG and FC traits in both environments. Heritability values ranged from 0.42 to 0.60. Both the genetic correlation, 0.44 to 0.68 (WG) and 0.23 to 0.56 (FGR), and the phenotypic correlation, 0.30 (WG) and 0.17 (FGR), were positive when evaluated in the same trait between collective or individual environments; correlations between traits in the same or in different environments were negative, or almost null. It can be concluded that use of performance testing, in individual cages, for WG and FGR, can result in genetic progress when progenies are raised in collective environments, as there is a small re-classification of the breeders from one environment to another.