Effect of Age at Breeding on Female African Giant Rat (Cricetomys gambianus) Fertility in Captivity

This study aimed to evaluate the influence of age at breeding one female African giant rat (FAGR) fertility. Twenty-four nulliparous FAGR of 6, 8, or 10 months old were allocated to one of the three groups according to their age. They were housed individually and fed ad libitum. After five days of accommodation, a male was transferred into a female cage, and daily vaginal smears were performed to evidence mating for a period not exceeding 30 days. Reproductive parameters were then evaluated. Results showed a significant reduction (P<0.05) in pre-coitus cohabitation time in 8 (6.75±4.23days) and 10 (5.13±1.25days) months old females as compared to those aged six months (22.25±1.75days). There was an increase in mating rates, fertile mating, fertility, and stillbirth in 8 and 10 months old FAGR. The litter size significantly increased (P<0.05) in 8 and 10 months old compared to 6 months old FAGR. Preimplantation embryo losses rates were 60.00±39.44, 66.66±34.96, and 35.00±21.19% in 6, 8, and 10 months old FAGR, respectively. In this study, fertility increased with age, so it was better in the FAGR older than six months.