DIET SUPPLEMENTATION WITH YEAST BETA-GLUCANS, DIETARY ANTIOXIDANTS AND VITAMIN K IN BROILER CHICKENS MITIGATED AFLATOXIN-INDUCED GROWTH RETARDATION

Abstract

Mitigation of inevitably absorbed aflatoxins following the addition of toxin binders are insufficiently reported. Therefore, effect of yeast beta-glucans, antioxidants such as vitamins C (VC) and E (VE), selenium (Se) and anti-haemorrhagic agent (vitamin K- VK) in the diet on changes in biochemical processes that characterised aflatoxins poisoning in broiler chickens was investigated. Aspergillus flavus 3228 inoculated maize was used to formulate a basal diet (BD) containing 270 ± 16µg.kg-1 total aflatoxins (AFB1 and AFB2). Unsexed one-day-old Arbor-Acres broiler chicks (n = 180) were randomly assigned into six dietary treatments, comprising Negative Control (NC- aflatoxin-free diet), BD and BD containing beta-glucans, VC, VE, VK and selenium. Two levels of beta-glucans: 250 and 375 mg.kg-1 (BD250 and BD375) and two combinations of vitamins with or without selenium: [(VE + VC) +VK] = ECK and [(VE + VC) + VK + Se] = ECKSe were combined to give BD250 + ECK; BD250 + ECKSe; BD375 + ECK and BD375 + ECKSe. Selenium, VC, VE and VK, were included in the diets at 0.3, 250, 200 and 3.0 mg.kg-1 of feed, respectively in augmented (2 x 2) +2 factorial arrangement in completely randomised design. The diets were fed to the chicken ad libitum for seven weeks. Serum malondialdehyde, reduced (GSH) and oxidised (GSSG) glutathione levels and ratio, body weight gain (BWG) were measured and feed conversion ratio (FCR) and percentage mortality were determined. Data were analysed using ANOVA at α0.05. Serum malondialdehyde and GSSG levels were significantly reduced (P < 0.05) from 159.41 ± 23.68 nM.mL-1 and 5.96 ± 5.20 µM.mL-1 in BD, to 69.68 ± 26.97 nM.mL-1 and 2.21 ± 0.88 µM.mL-1 in birds on BD375 + ECKSe. Birds fed BD375 + ECKSe had GSH:GSSG (3.58 ± 1.71), BWG (1,903.98 ± 32.56 g.bird-1) significantly higher and FCR (1.88 ± 0.04) was reduced (P < 0.05) compared to 1.06 ± 0.81; 956.27 ± 19.34 g.bird-1 and 2.38 ± 0.04, respectively, in birds on BD. Birds fed BD375 + ECKSe had no variation (P > 0.05) in performance when compared to NC. Mortality decreased significantly (P < 0.05) from 39.39 ± 5.25 % in BD to 9.09 ± 5.25 % in BD375 + ECK. Combinations of 375 mg.kg-1 beta-glucans, vitamins E, C, K and selenium reduced lipid peroxidation activity, feed conversion ratio and oxidative stress, with increased bodyweight gain. Finally, combinations of beta-glucans, antioxidants and vitamin K demonstrated effectiveness in preventing changes in biochemical processes leading to aflatoxins deleterious effects in broiler chickens.