When rabbits give birth in winter, the survival rate of rabbit cubs is low because of the cold weather in winter. In order to improve the survival rate of rabbits, female rabbits usually prolong pregnancy and postpone the birth time of rabbits by 1 to 5 days.
When the mother rabbit is pregnant, the pregnancy period varies with nutrition, pregnancy times, fetal sex and parity. The gestation period is generally 29 ~ 34 days, with an average of 30 days.