Investigation of sperm-induced cervical leucocytosis by a double mating study in rabbits

The cervices of 2 normally mated does at 1 h post coitum were examined for the presence of leucocytes and compared with the cervix of an unmated doe. Cervical leucocytosis (50 x 10(6) leucocytes) was demonstrated following mating with either of 2 bucks, but not in the unmated doe. Each of 16 does was single-mated with 2 bucks whose offspring could be distinguished clearly. The interval between first and second mating was 0, 0.5, 1 or 4 h. One buck produced 68 offspring, the other buck produced 37. Cervical leucocytosis did not impair the fertility of the second buck even if it was the inferior buck; so fertilizing spermatozoa may traverse the cervices, even through large numbers of leucocytes. The differences in fertility between spermatozoa from different bucks during competitive fertilization may reflect different capacitation times of these spermatozoa.