Analysis of reproductive traits in crosses among maternal lines of rabbits

Abstract

A crossbreeding experiment, between three maternal lines of rabbits, was carried out to estimate the effects of the crosses on reproductive traits. The experiment was designed as a complete diallel cross involving the lines, A, V and H, selected for litter size. A total of 1190 does, distributed between the nine types originating from the diallel cross, and born, reared and bred on the same com- mercial farm, were controlled. The recorded traits were the total number of young born, the number of born alive and the number of stillborn per litter (3759 records), and the interval between kindlings (2505 records). A repeatability animal model was used first to obtain the REML estimates of the com- ponents of variance. This was followed by a generalised least squares analysis and the estimates of the type of doe effects were obtained. Finally the differences among the lines within direct and maternal effects, and the corresponding values of the individual heterosis were estimated. Important differ- ences in the direct effects were found between lines V and A. All the maternal effects were not signifi- cant. Favourable heterosis (4-10%) was found for prolificacy traits in the crosses of line A with lines V and H, being the heterosis, very dependent on the performance and history of the lines involved. reproduction / crosses / maternal / lines / rabbits