Best F1 crossbreedings and hybrid reproducers as maternal lines for commercial rabbit production

Three diallelic crossings with simple crossings (7606 observations) and two diallelic crossings were applied, using hybrid reproducers (790 observations) with four breeds (California, C; Chinchilla, CH; New Zealand, N and Semigiant, S) under production conditions for a period of more than 30 years and analyzed together in each generation for diminishing the effects of genotype-environmental interaction and studying pre-weaning performance. Mixed generalized linear models were applied to estimate a) effects of maternal and paternal breeds, specific crossings and differences between reciprocal pairs b) (crossbreeding) breeding parameters according to Dickerson, and c) racial effects and breeding parameters of the numerical and ponderable productivities of pure and crossed genotypes. The best F1 crossings were NS, CS, CCH, SCH, SN and CHN. Breeding parameters demonstrated the superiority of maternal effects on Semi-giant and New Zealand, and direct effects on California and Chinchilla. Heterosis was high for pre-weaning traits (12-20 %). The evidence of the best crossings, estimation of breeding parameters of crossbreeding that ratifies the policy of racial use and pre-weaning productivities of each breed and crossing, as well as the proposal of a methodology for the integral evaluation of crossings constitute contributions to knowledge and characterize the genetic and heterotic potential of our breeds, their racial utilization and the selection of the best crossbreeds for commercial production. All these elements constitute the essential bases for the decision making in the Programa Nacional de Mejoramiento Genetico of the rabbit. Key words: rabbits, crossbreeding, productivity, breeding parameters