Abstract: The conduct was on the basis of 42 d propagation mode, 48 h before artificial insemination, mother rabbit were injected of different doses of cloprostenol (CLO) (0, 10, 20, 30 and 40 μg) for the same period, and total farrowing rate, litter size at birth, number born alive, litter weight at birth, mean kit weight at birth and estrogen and progesterone were recorded.Results showed that, compared with control group, the injection of different doses of the CLO to mother rabbit, the farrowing rate was very significantly improved (P<0.01), and showed increasing trend with the increasement of the dose;But between groups,the litter size at birth had no significant change (P>0.05).Results about hormone showed that after injection of CLO,the level of estrogen was increased. Progesterone concentrations significantly decreased after injection of CLO (P<0.05), respectively in 24 h and 48 h after injection of two time points,10,20 and 40 μg groups were significantly lower than 0 μg group. Therefore, using the high chlorine enol promote the mother rabbit estrus and then mother rabbit farrowing rate and production efficiency could be improved.

Key words: rabbit; estrus synchronization; artificial insemination; cloprostenol