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

Abstract

The effects of suckling and remating interval (11 or 21 d post partum) were studied in primiparous (P=25) and multiparous (M=23) hybrid rabbits. In P rabbits, suckling had no signifi- cant 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 rab- bits 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 perform- ance 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.