Combined effects of aflatoxin B1 and corticosterone treatment on selected performance indices and liver histopathology in Japanese quail

Abstract

Animal feed may be contaminated with different mycotoxins, with aflatoxin B1 (AFB1) being a very common and toxic compound. Considering that birds normally have to cope with different stressful situations at the same time, the present study aims to evaluate the effects of feed contamination with AFB1 in combination with corticosterone treatment in drinking water (a model to induce physiological stress in birds) on selected performance indices: BW, feed conversion, egg production, and macroscopic and microscopic liver alterations. At 5 wk of age, quails were randomly assigned to 1 of 6 dietary treatment groups that resulted from the combination of the presence or absence of corticosterone in drinking water (5 mg/L) with the presence or absence of AFB1 contamination (0, 100, or 500 μg/kg). The animals remained in these treatments from 5 to 11 wk of age. There were 6 replicates per treatment, each containing 2 males and 2 females. Contamination with 100 μg of AFB1 per kilogram of feed induced no changes in BW, feed conversion, and egg production parameters. Quail fed with 500 μg of AFB1 per kilogram of feed showed significant decreases in BW and feed consumption compared with their control counterparts. Corticosterone in combination with 500 μg of AFB1 per kilogram of feed intensified the negative effects observed on BW and feed consumption and also had negative effects on feed conversion rate and egg production parameters, suggesting that the adverse effects of contamination with AFB1 are intensified in situations of chronic stress. Quail treated with 500 μg of AFB1 per kilogram showed hepatocytes with degree 1 and 2 lesions, and all quail treated with 500 μg of AFB1 per kilogram of feed in combination with corticosterone showed degree 2 liver lesions (i.e., hepatocytes with fatty macro and microvacuoles and necrosis). This result is also consistent with the hypothesis that chronic stress exacerbates the effect of AFB1 contamination. In conclusion, this study suggests that the negative effects of AFB1 contamination are increased when overlapped with chronic stressful stimulation.