Fungi and natural incidence of selected mycotoxins in barley rootlets

L.R. CAVAGLIERI; K.M. KELLER; C.M. PEREYRA; M.L. GONZALEZ PEREYRA; V.A. ALONSO; F.G. ROJO; A.M. DALCERO; C.A.R. ROSA

JOURNAL OF STORED PRODUCTS RESEARCH

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2009 p. 1 - 4

0022-474X

The storage of barley rootlets is an increasing practice employed as raw material in pig feeding in Brazil. This practice represents an important alternative for animal production due to their high levels of protein, fiber and low price. Poor management of raw materials during storage can result in fungal growth, the loss of nutritive substances and contamination by mycotoxins. The aims of this work were 1) to identify fungi associated with barley rootlets used as pig feedstuff raw material, and 2) to determine selected mycotoxins naturally produced by the potential isolated mycotoxin-producer species in this substrate over a year. Samples were examined for fungal counts and genera distribution. Fumonisin B1 and aflatoxin B1 contamination were determined using high pressure liquid chromatography (HPLC). Barley rootlet samples showed a low hygienic quality. Although a broad survey was developed, a reduced fungal diversity was found. Fusarium verticillioides was the most prevalent followed by A. flavus. Despite that A. clavatus is widely associated as infecting high-moisture sprouted grains including brewers’ grains, and of causing toxicity to livestock, it was not detected in this work. Although a pre-harvest contamination of the barley crop, as in the maize, could be considered, the barley might support F. verticillioides/F. proliferatum growth when grain is remoistened during the germination and malting process and it might even continue during storage on pig farms during storage. All samples were positive for fumonisin B1 whereas aflatoxin B1 contamination was not detected. It is important to point out the potential risk of fumonisin contamination in barley rootlets used as animal feed. Fusarium toxins are important not so much for the acute effects as for the chronic syndromes reported worldwide. The obtained results reveal the need of periodic monitoring of raw materials to avoid animal production impairment and hazards to animal and human health.