Effect of plant extracts derived from thyme and chamomile on the growth performance, gut morphology and immune system of broilers fed aflatoxin B1 and ochratoxin A contaminated diets

Abstract

This study was conducted to evaluate the ability of chamomile flower extract (CFE) and thymeoil extract (TOE) for the preventing effect of ochratoxin A (OTA) and aflatoxin B (AFB) in broiler productivity, biochemical parameters, gut morphology and immune response of broilers. The experiment was conducted as a 3 4 factorial arrangement, being the factors: phytogenic additives (control, 3 g/kg diet of CFE, or 3 g/kg diet of TOE) and dietary contaminated diets (none, 0.50 mg/kg diet of AFB, 0.25 mg/kg diet of OTA, or 0.50 mg/kg diet of AFB þ 0.25 mg/kg diet of OTA). Each of the 12 dietary treatments was fed to six replicate pens (10 birds/pen) from 0 to 28 d of age. Inclusion of phytogenic additives increased average daily gain (ADG) and average daily feed intake (ADFI), and decreased feed conversion ratio (FCR) from day 11 to 28 and day 0 to 28 in the birds fed OTA-AFB toxin diets. Significantly increased levels of HDL, IgG, IgM and anti-Newcastle disease virus (NDV) antibody titre were observed in the two essential oil-treated groups when compared with the control group. When compared with the control, relative weights of gizzard, liver and pancreas were significantly higher for broilers fed diets containing OTA alone. The results indicated that OTA and AFB toxins, alone or in combination, reduced villous height (VH) and ratio of VH to crypt depth in the jejunum. The levels of triglycerides, total cholesterol, HDL and plasma immunoglobulin, as well as NDV antibody titre were significantly decreased by AFB-OTA toxin combination. In summary, the combination of OTA and AFB impaired chick immune function even at combined concentrations as low as 0.25 mg/kg diet of OTA and 0.50 mg/kg diet of AFB. The inclusion of TOE and CFE can be an alternative to ameliorate the adverse effects of low doses of AFB and OTA in broiler diets.