Effects of gamma radiation on fungal microbiota and mycotoxins in broiler chicken feed

The purpose of this work was to study the control of toxigenic fungi and mycotoxins in broiler feed by gamma radiation. Feed samples were treated with gamma radiation (0, 5 and 10 kGy) and contaminated with aflatoxins or fumonisins. Performance, hematological and biochemical results indicated that a 5 kGy dose was effective on the control of the deleterious effects caused by mycotoxins on broilers. No significant alterations were observed on the feed chemical composition. Irradiated samples presented lower fungal contamination than those not irradiated. We did not detect alterations on aflatoxin or fumonisin content of feed samples after irradiation. AFLP results demonstrated that Aspergillus flavus and Fusarium verticillioides did not present any correlation between groups, toxin production and irradiation dose. We can conclude that the dose of 5 kGy is indicated for treatment of broiler feed. Despite the fact that it does not change the mycotoxin levels found in the samples, this dose significantly reduces the fungal microbiota and modifies the feed digestibility, increasing the final weight of broiler chickens. (author)