Determination of grasscutter age (Thryonomys swinderianus Temminck, 1827) from anogenital distance

Objectives: The global objective of the survey was to determine the grasscutter age from the anogenital distance. Methodology and results: Some linear (anogenital distance) and weight measurements were taken on 390 anesthetized grasscutters (202 males and 188 females) aged from two weeks to 12 months. The results led to eight linear prediction equation models of grasscutter age from anogenital distance and body weight. The best determined grasscutter age with an elevated coefficient value was: Age = - 5.50 + 0.37 x DAG + 0.01 x WT with R2 = 0.98. The Equation determining grasscutter age with a weak determination coefficients value was: Age = -18.22 +1.26 x DAG with R2 = 0.88. These models of equations can be used by literate breeders or researchers and in semi-intensive and intensive raisings. Conclusions and application of findings: These results are useful to predict not recorded age of raised grasscutter, estimate game grasscutter age, make better management of reproduction and a good sanitary follow-up, and improvement of farming conditions, compare wild and raised grasscutter meat since meat organoleptic quality generally varies according to age. Key words: Benin, vulva, testes, brown coloration, age, model