Effects of strain, sex, and season on body weight development of cane rat (Thryonomys swinderianus) in the humid tropics.

The effects of strain (G), sex (H), and season (S) on live weight development of cane rats (Thryonomys swinderianus) reared in captive system were investigated during the dry (35.95 °C) and wet seasons (25.81 °C) from February to August of a tropical environment. The field experiment took place at the University of Ibadan. Seventy-nine cane rats spreading among three genotypes (Bamidele, FRIN, and Lawole) of different age and body weight groups were randomly distributed into cages using randomized complete block design in factorial. Data on live weight collected at 30 days interval over the experimental period was submitted for statistical analysis using the factorial ANOVA procedures of SAS® (2012). Strain was fixed factor while sex and season were random factors. Mean separation showed that G, H, S, and G×H, significantly (P < 0.05) affected live weight development of cane rats. G×H revealed sexual dimorphism. G×S and G×H×S did not demonstrate significant (P > 0.05) effects on live weight development in model. G×S showed mean weight gain levels of 0.21, 0.15, and 0.07 kg between wet and dry season for Bamidele, FRIN, and Lawole. The superiority of growth rate among genotypes between seasons were 57.1, 14.3, and 7.14 g/month for Bamidele > FRIN > Lawole, respectively. Lawole recorded highest body weight of 2.50 and 3.78 kg for female and male. FRIN recorded highest mixed body weight of 3.06 kg, highest body weights of 2.99 and 3.14 kg for dry and wet seasons. Bamidele demonstrated least average live weights of 2.76 and 2.97 kg for dry and wet seasons, the least body weight fluctuations between months in seasons and between seasons. Knowledge on the performance of cane rat genotypes by sex and season in captivity will provide information on adaptability to season and management systems for cane rat.