Fungi and Mycotoxins from Pre- and Poststorage Brewer's Grain Intended for Bovine Intensive Rearing

The aim of the study was to determine the mycobiota and natural levels of mycotoxins such as aflatoxin B1 (AFB1), ochratoxin A (OTA), fumonisin B1 (FB1), and deoxynivalenol (DON) present in brewers grains pre- and poststored intended for bovine intensive rearing. Poststored (80%) samples had counts higher than colony-forming units (CFU/g). Cladosporium spp. and Aspergillus spp. were isolated at high frequencies. Aspergillus flavus was the prevalent isolated species. Prestored (70%) and poststored (100%) samples showed AFB1 levels over the recommended limits (20？μg/Kg), and OTA levels were below the recommended limits (50？μg/Kg) while pre- and poststored samples did not show FB1 and DON natural contamination levels. The presence of mycotoxins in this substrate indicates the existence of contamination. Regular monitoring of feeds is required in order to prevent chronic and acute toxic syndromes related to this kind of contamination. 1. Introduction The use of agroindustrial residues as a food supplement for animal production plays a significant economic role due to the availability and versatility of these materials. Brewer’s grains (beer industry residue) are an interesting alternative option as feeding for animal production, being a rich source of protein and fibber at a low price [1, 2]. Inadequate management of raw materials during storage can result in excessive moisture or dryness, condensation, heating, leakage of rainwater, and insect infestation, leading to undesirable growth of fungi [3]. Worldwide, the contamination of animal feed and the potential contamination of animal meat by mycotoxins represent a serious hazard to humans and animals. Mycotoxins are toxic, chemically diverse secondary substances or metabolites produced by a wide range of fungi. They are mainly produced by Aspergillus, Penicillium, and Fusarium genera [4]. Due to the diversity of their toxic effects and their synergetic properties, mycotoxins are considered as risky to the consumers of contaminated foods and feeds [5]. Aflatoxins (AFs), the fungal metabolites produced by some strains of A. flavus and A. parasiticus, are of great concern because of their detrimental effects on the health of humans and animals, including carcinogenic, mutagenic, teratogenic, and immunosuppressive effects [6, 7]. Ochratoxin A (OTA) is one of the most common and dangerous mycotoxin in food and feed, naturally produced by A. ochraceus, A. carbonarius and A. niger aggregate mainly in tropical regions, and P. verrucosum in temperate areas [8–10]. This toxin has a potent toxicity, and the