Effect of Season on the Reproductive Organs of the Female African Giant Rat (Cricetomys gambianus) in Zaria, Nigeria

SUMMARY: The study was carried out to determine the effect of season on the female reproductive organs of the African Giant rat using the standard methods, with the aim of obtaining the base-line values. The weights of the oviduct/uterus, vagina and the entire tubular organ were consistently higher during the harmattan season (0.789 ± 0.07 g, 2.708 ± 0.19 g and 3.455 ± 0.25 g, respectively) than the hot – dry (0.591 ± 0.02 g, 2.239 ± 0.13 g and 2.831 ± 0.14 g, respectively) and the rainy season (0.723 ± 0.04 g, 2.412 ± 0.01 g and 3.148 ± 0.12 g, respectively). The mean weight and length of the ovary were not significantly different throughout the season, suggesting that the AGR may breed throughout the year. The slight increase in the weight of the tubular organ during the harmattan (November – February) and the rainy (June – October) season suggests that the seasons may be favourable for breeding, probably because of the abundance of food available to the rodents in the wild during the seasons. The decrease in weights of the organs during the hot-dry season (March – May) was, apparently, due to the unfavourable climatic conditions and food scarcity during the season. In conclusion, the results of the present study provide base-line morphometric data on the female reproductive organs of the AGR across the seasons