Determining the best response level of performance parameters in broilers fed with different levels of aflatoxins and amino acids

Food or feed contamination with aflatoxin B1, which is a secondary and toxic metabolite of Aspergillus flavus and Aspergillus parasiticus, is a major problem in most parts of the world, especially in developing countries. Harmful consequences of the presence of aflatoxins in food encouraged the researchers to find the safe, effective and efficient procedures to control this toxin prior to entering the human food chains. The aim of this study was to investigate the effects of the amino acids glycine, glutamic acid and N-acetylcysteine on the growth performance of broilers under aflatoxicosis, and to determine optimum level of these amino acids. 690 Ross 308 broilers in 17 experimental groups were fed with feeding 5 different levels of amino acids of glycine, glutamic acid, N-acetylcysteine and Aflatoxin with 4 replications and each replication included 10 chickens. Performance traits including feed intake, body weight gain and feed conversion ratio were measured weekly from one to 21 days of age. The results of performance traits were analyzed using the Response Surface Methodology (RSM) model and the central composite design. The results of the central composite design were more consistent and significant in broiler chickens with the quadratic regression model which had the highest values of R2. The results of the present study showed the negative effects of aflatoxin on feed intake and body weight gain, which in turn increased the feed conversion ratio. The results also showed that supplementation of glycine, glutamic acid, N-acetylcysteine amino acids to the diet moderated the negative effects of aflatoxin B1. Dietary supplementation with three amino acids glycine, glutamic acid and N-acetylcysteine as the main precursors of glutathione can reduce the negative effects of aflatoxin on the performance parameters of broilers by improving the antioxidant system. Also, using the response level methodology by providing appropriate statistical and graphical information has a high ability to identify the superior model and determine the optimal level of these amino acids in the diet contaminated with aflatoxin.