Pathological effects of benomyl in male Japanese quails (Coturnix japonica)

The purpose of this experimental study was to observe the pathological and genotoxic effects of a systemic fungicide, Benomyl[methyl 1-(butyl carbamoyl)-2 benzimidazole carbamate] in male Japanese quails (Coturnix japonica). Benomyl (Benlate (R) DoPont 50% w/w benomyl) at dose rates of 0, 100, 400 and 1000 mg/kg for 8 consecutive days was administered into crops of quails kept in different groups. A significant decrease (p < 0.05) in feed intake, body weight and relative weight of testes was observed in benomyl-administered quails in a dose related manner. The size of testes decreased in benomyl treated quails. Microscopically, seminiferous tubules of testes exhibited a decreased number of spermatocytes, necrotic spermatids and syncytial cell formation. The number of quails developing testicular alterations increased in a dose-related pattern. These alterations reversed following a withdrawal of benomyl with the exception of the 1000 mg benomyl group, where these persisted till the end of the experiment (56(th) day). The mean tail length (mu m) of the comets produced by leukocytes in single cell gel electrophoresis of 0, 100 and 400 mg dose level groups were 3.48, 3.24 and 3.29, respectively. The mean tail length of comets of the 1000 mg dose level group was 12.03 mu m and significantly higher (p < 0.01) than in all other groups indicating DNA strand breaks at this dose level. These results suggested gonadotoxic effects of benomyl (Benlate (R)) and also a possible genotoxic effect at 1000 mg/kg level in Japanese quails.