Efficacy of propionic, benzoic and tartaric acids in preventing biosynthesis of aflatoxins in poultry feed

Abstract

A poultry feed was prepared using conventional feed ingredients which is free from aflatoxins. The moisture content of the feed was adjusted at 11, 13, 15 and 17%, respectively. The feeds with each level of moisture were then mixed with propionic, benzoic or tartaric acid each at various concentrations of 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45 and 0.50%, respectively. Samples were taken in a 500 ml conical flask in duplicate, inoculated with fresh spores mould (Aspergillus parasiticus NRRL 2999) producing aflatoxins, incubated at room temperature for a period of one month and then analysed for the presence of aflatoxins (AFB1, AFB2, AFG1 and AFG2). The results showed that at 11 % moisture level in feed, aflatoxin biosynthesis did not occur in any of the treatments. However, with the increase in moisture content in feed from 11 to 17%, there was increase in production of the aflatoxins. Complete inhibition of aflatoxins synthesis at 13% moisture level was achieved at 0.25% propionic or 0.30% benzoic or 0.40% tartaric acid concentration. The biosynthesis of any of the aflatoxins was completely inhibited at 0.50% propionic or benzoic acid in feed containing 15% moisture. However, propionic or benzoic or tartaric citric acid at 0.50% level in feed, failed to completely inhibit the synthesis of any of the four fractions of aflatoxins in feeds containing 17% moisture level, though with the increased concentrations of acids, the biosynthesis of total as well as individual fractions of aflatoxins decreased. It is thus concluded that the production of aflatoxin at 13% moisture level in poultry feed can be completely inhibited by adding propionic acid @ 0.25% or benzoic acid @ 0.30% or tartaric acid @ 0.40%. However, the level of organic acids varied with incresing level of moisture in the diet. Further, propionic acid was more efficaceous than benzoic or tartaric acid in inhibiting the synthesis of aflatoxins.