Assessment of a reproduction rhythm based on the body condition of rabbit doe: preliminary results.

The efficiency of rabbit farm mainly depends on the fertility and prolificacy of does, which in turn are modulated by genetic, feeding and management factors. The most important management factor for rabbit does is the reproductive rhythm. The aim of this work was to assess a reproductive rhythm in which the artificial insemination (AI) is done according to the body condition of doe. The study, involved 100 New Zealand White multiparous does submitted to AI for 5 consecutive cycles. Does were divided into 2 groups: CONTROL AI at 11d post partum and CONDITIONED AI when they reach a certain perirenal fat depot (between 15 and 30 g) estimated by ultrasound scanning. If does were too fat or lean, after an appropriate dietary protocol, they were weighed and submitted to ultrasound scanning again, and if they have a suitable body fat, artificially inseminated. At AI the does were weighed and submitted to ultrasound scanning of the perirenal region. Body Condition Score (loin, rump and hind leg), weight at kindling and at the weaning were also evaluated. On the day of insemination, does of both groups showed similar live weight and perirenal fat thickness (3862 vs 3813g and 0.64 vs 0.61 cm) respectively for CONDITIONED and CONTROL). These results were due to the fact that does are AI in different physiological stage; mainly lactating for the control group and dry for conditioned. Thus, during lactation does have a higher live weight for the presence of milk and for the higher incidence of the digestive tract, further the fat depot start to increase only after several days after weaning. Conditioned group showed higher fertility rate (83% vs 62%), number of live born pups (9.2 vs 7.4, P<0.05) and live weight of pups (512.8 vs 481.8 g, P<0.05), BCS of loin (1.1 vs 0.8, P<0.001), rump (1.0 vs 0.8, P<0.001) and hind leg (1.7 vs 1.4, P<0.001), perirenal fat weight (14.0 vs 10.9 , P<0.001), live weight at kindling (3865 vs 3553g, P<0.01), and doe at the weaning (3767 vs 3190g, P