Benomyl toxicity in chickens

The affect of the fungicide benomyl on the mixed-function oxidases and liver in chickens was investigated. Chickens were injected with a single dose of 100 mg/kg benomyl, and results were compared to controls. In a complmentary experiment, chickens were fed benomyl orally at 4000 ppm for 15 d and compared to controls. At the end of the treatment periods, chickens were killed, and blood and liver tissues were examined. Single-dose results indicated serious affects on mixed-function oxidases and liver, shown by the marked induction of cytochrome P450, cytochrome b5, cytochrome c reductase, benzphetamine N-demethylase, amino-pyrine N-demethylase, and aniline hydroxylase activity. No hepatotoxicity was indicated, however. These effects were not found in chickens fed benomyl for 15 d.