Effects of aflatoxin and carotenoids on growth performance and immune response in mule ducklings

The purpose of this study was to investigate if carotenoids could alleviate the adverse effects caused by aflatoxin with respect to growth performance acid immune response. In two experiments, a total of 320 mule ducklings we re assigned to 5 treatments, i.e. control, aflatoxin B-1 (AFB(1)) 200 ppb, AFB(1) + beta -carotene (BC) 200 ppm, AFB(1) + BC 400 ppm, and AFB(1) + ast axanthin (AS) 200 ppm. In experiment 1, the addition of beta -carotene or a staxanthin in the diet containing AFB(1) 200 ppb resulted in a significant decrease in average daily gain as compared with the control. AFB(1) 200 ppb alone and the addition of BC or AS on top of AFB(1) resulted in a signific antly lower daily feed intake than for the control group. There were no sig nificant differences in relative organ weights among treatment groups. Both treatments of BC 400 ppm and AS 200 ppm had significantly more macrophages harvested per duck than the control and AFB(1) 200 ppb treatments. However , there were no significant differences among treatments in percentages of phagocytotic macrophages and number of Candida albican phagocytized by phag ocytotic macrophages. In experiment 2, blood biochemical parameters and ant ibody titers were evaluated. There were no significant differences among tr eatments in total bilirubin content and alkaline phosphatase activity in th e serum or in antibody titers against fowl cholera. However, AFB(1) treatme nt had the highest activities of AST and ALT in the serum. The addition of BC 400 ppm on top of AFB(1) significantly reduced ALT activity as compared with the AFB(1) 200 ppb treatment. These results suggest that carotenoids c ould provide a slightly toxic alleviating effect on growth performance, enh ance the chemotaxis ability of macrophages, and reduce ALT activity elevate d by AFB(1). (C) 2001 Elsevier Science Inc. All rights reserved.