Contaminação fúngica toxígena e qualidade micotoxicológica de silagens destinadas a alimentação de bovinos no Estado de São Paulo

Abstract

Despite having the second largest cattle herd in the world. The Brazilian has low rates of productivity. The performance of the animals in pastures is reasonable during the rainy season, being in the dry food deficiency, caused by the low availability and quality of grass, which results in weight loss of animals. Thus ensiled foods are a recently solution to this situation in the production process. But we have a very few studies on the food substrate in Brazil and Latin America. The objectives of this study were primarily to establish the natural frequency of species of the genera Aspergillus, Penicillium and Fusarium potentially produce mycotoxins in samples of vegetable and silage components intended for cattle and other fungal genera present and detect mycotoxins presents in the same (aflatoxins, ochratoxin A, fumonisin B1, deoxinivalenol and glyotoxin). We are evaluated a total of 168 samples of corn and sorgum silos, from Janerie 2009 to October 2012. These farms creators of beef cattle were located in the state of São Paulo. We evaluated the pre and post fermented samples during this period. In all substrates had evaluated more than 50% of samples contaminated above the recommended limits feed of 1.0 x 104 ufc.g-1 (GMP, 2006). As in other studies the genera Aspergillus and Penicillium have high occurrence following related studies in the Americas and worldwide. Aspergillus flavus was the species of greatest occurrence in the samples evaluated, followed by A. niger aggregate, A. fumigatus and A. parasiticus. Presence was detected in high levels of toxins produced by these genera mainly: aflatoxins (up to 70 ppb) glyotoxin (up to 30 ppm) and ochratoxin A (up to 10 ppm). The Fusarium sp. showed a low variability of species in the samples evaluated, even in pre-fermented samples where counts were higher in this genera, had the occurrence of only two species F. verticillioides and F. gramineraum. Next to it was also the detection of toxins produced by these genera at low levels (levels of 0.32-2 ppm).T hese observations creates the need to expand studies related to ensiled food, which the animals were feed during major periods of the year.