Resumen de Effect of the genotype, day length, season and physiologycal stage on the reproductive performance of doe rabbits reared in Guadeloupe (F.W.I.)

E. Depres, M. Theau-Clément, O. Lorvelec

• The aim of this study was to compare under tropical climate conditions the reproductive performance of doe rabbits as affected by the genotype (NZ vs NZxCAL), lighting conditions (11 h of natural light + 5h of artificial light per day vs 11 h of natural light), the season (hot and wet vs cool and dry) and the physiological stage (nursing or non nursing females at mating ). A total of 272 matings were analysed. Fertility was not affected by any of these factors. The litter size of crossbred females (NZxCAL) was higher than that of purebred ones (NZ) (8.2 vs 7.1; P<0.05). However, this superiority was only observed during the dry and cool season (P<0.05). The analysis also showed the effects of significant interactions between the genotype and the physiological stage for the mean live weight at weaning (P<0.01 ). lncreasing the day length enhanced the litter size at birth (8.4 vs 6.9; P<0.001) and at weaning (6.6 vs 5.5; P<0.05). However, the beneficia! effect of lighting conditions was only observed during a dry and cool birth season (P<0.05). The wet and hot season (May-November) had an unfavourable effect on the litter size at birth and at weaning (7.1 vs 8.2; P<0.05 and 5.5 vs 6.6; P<0.05). Moreover, the physiological stage affected the mean birth weight of the young, the mortinatality and the post-natal mortality. lt was concluded that the genotype and lighting conditions were efficient means of improving the reproductive performance of doe rabbits during the dry and cool season in a tropical environment. However, they were not sufficient to counterbalance the unfavourable effects of the wet and hot season.