Sexual dimorphism between live body weight and morphological traits at various age categories of African giant rats (Cricetomys gambianus) in Ghana

The experiment analysed the sex and age effect between live body weight and six morphological traits of forty (20 Bucks and 20 Does) weaned African giant rats (Cricetomys gambianus) at age 2 months in captivity. Data collected on live body weight and morphological traits (body length, heart girth, neck circumference, height at withers, tail length, and head length) at various age categories of 4, 8, 12, and 20 weeks selected at random were analysed using the t-test, Pearson’s Correlations, and Multiple Linear Regression models embedded in GenStat 11th edition. There were significant differences (p ˂ 0.05) in all the recorded traits measured with the males having higher mean values than females throughout the age categories except that there were no significant differences (p > 0.05) in body weight, tail length, and body length at 4 weeks old and the body weights at 8 weeks old. Also, the parameters assessed showed highly significant differences (p < 0.001) and strong positive correlation coefficients in both sexes with the males showing superiority over their females throughout the age categories. The highest positive correlation coefficients of body weight at all the age categories were observed with heart girth. Highly significant differences (p ˂ 0.001) and higher coefficient of determination (R2) values were found in the males (0.996 to 0.999) than the females (0.981 to 0.998) using the multiple linear regression models. It was concluded that sexual dimorphism between the live body weights and morphological traits exists at various age categories in the African giant rats.