EFFECTS OF THE TIME OF INSEMINATION AND LITTER SIZE ON THE GESTATION LENGTH OF RABBITS

Pannon White nulliparous and multiparous does were divided into two groups and inseminated at 8:00 a.m. (n = 587) or at 8:00 p.m. (n = 548). On the basis of 390 and 346 kindlings respectively, it was established that the 12-hour time difference between inseminations had no effect on the length of gestation (31.73 and 31.67 days, respectively). The time of parturition was also influenced by the time of day. Does most often kindled between 22:00 and 04:00 and least often during the day (between 10:00 and 16:00). Parity significantly influenced gestation length (first parity: 31.42 days, 8th-101h parities: 32.15 days, P < 0.05). Litter size at insemination had no effect but litter size at birth exerted a significant effect on gestation length: with the increase of litter size the gestation length shortened (litters of 1 and 2 young: 32.42-32.46 days, litters of 9-14 young: 31.32-31.50 days, P < 0.05).