IDENTIFICATION AND QUANTIFICATION OF MYCOTOXIGENIC FUNGI IN FOOD FOR CATTLE

Abstract

Identified and quantified Mycotoxin-producing fungal strains was identified and quantified, and the degree of contamination of aflatoxins B^₁, B₂, G₁ and G₂, in the cattle food in the town of Zapotlán El Grande Jalisco, México was determined. Samples were fed to dairy cows and beef cattle 30 production units. The identification of mycotoxin-producing fungal strains was performed by characterizing macroscopic colonies grown under the plate casting technique, and the subsequent identification of the microscopic morphology of the fungus, for which isolated the strains identified by the technique microculture. Quantification of fungal strains was performed by counting colony forming units (CFU) and classified under the criteria of three scales: a) low counts (10²-10³), b) moderate counts (10⁴-10⁵) and c) high counts (10⁶-10⁷). To identify the type of aflatoxin used the technique of thin layer chromatography. Of the samples were obtained CFU counts in the following proportions: high counts (10⁶-10⁷ CFU g^-1) 56.66%, moderate counts (10⁴-10⁵ CFU g^-1) 36.66% and low counts (10²-10³ CFU g^-1) 6.66%. A total of 148 fungal strains were isolated, the highest percentages correspond to the following genera: Cladosporium spp., Penicillium spp. and Aspergillus spp. 33.33% were detected aflatoxin positive samples, among which were identified B₁, B₂, G₁ and G₂, all in high concentrations, also was obtained 46.66% of samples with positive fluorescence did not correspond to the standards of aflatoxins and 20% of negative samples.