Interaction of reproduction rhythm, suckling and parity on mating incidence, ovarian dynamics and estrogen secretion in the rabbit doe

The effects of suckling and remating interval (11 or 21 dpost partum) were studied
in primiparous (P=25) and multiparous (M=23) hybrid rabbits. In P rabbits, suckling had no significant
effect on mating incidence; however, a higher percentage of females accepted the male on d 11
than on d 21 (P<0.01). In M rabbits, no significant differences in mating performance due to either
day, suckling or their interaction were found. A higher proportion of nonsuckled than suckled P rabbits
ovulated (P<0.01). Ovulation incidence was not affected significantly by day of mating, suckling
or their interaction in M rabbits. A comparison of the day influence in P and M rabbits on mating
incidence showed a greater effect in the P (P<0.05) while the suckling effect on ovulation performance
showed an insignificant difference in the two parity groups. Ovulation rate, as assessed by
ultrasound, was not influenced significantly by day or suckling in either P or M rabbits. The follicle
distribution was marked by fewer large follicles and lower plasma estrogen levels were detected in
suckled than in nonsuckled P and M rabbits (P<0.05). Further research is needed to elucidate these
phenomena also when AI is performed.