Reproductive Performance, Birth Weights, And Sex Ratio Dynamics Of Captive Grasscutter (Thryonomys Swinderianus)

The grasscutter (Thryonomys swinderianus) is a micro-livestock species with increasing economic importance in sub-Saharan Africa due to its high-quality meat and domestication potential. This study examined reproductive performance, sex ratio, and birth weight patterns of a captive grasscutter colony over a seven-year period (2016–2022) to provide insights for sustainable production. Data on litter size, sex ratio, and pup birth weights were analyzed using descriptive statistics, paired-samples t-test, and Welch’s t-test. Results showed that male pups were significantly heavier than females (145.86 ± 17.24 g vs. 127.29 ± 13.29 g; p < 0.001), indicating sexual dimorphism in early growth. Seasonal variation influenced sex ratio, with the rainy season favoring more female births (M:F ratio = 0.93) and the dry season showing a slight male bias (M:F ratio = 1.05). However, the overall sex ratio (0.96) was near parity, supporting colony stability. Monthly litter distribution confirmed that grasscutters reproduced throughout the year, except in January and July, with no significant seasonal effect on litter size (p > 0.05). These findings suggest that grasscutters possess favorable reproductive adaptability under captivity, making them suitable for commercial production. The observed sexual dimorphism and balanced sex ratios highlight the importance of sex-specific growth monitoring and seasonally informed management strategies for optimizing productivity.