Mycotoxins and mycobiota in feedstuffs intended for swine at different growth stages.

M.L GONZÁLEZ PEREYRA, ; C. PEREYRA, ; CARLOS A. R. ROSA, ; ANA M. DALCERO, ; L. CAVAGLIERI.

Carlos Paz, Argentina

Congreso; Integration of mycotoxin and toxigenic fungi MYCO-GLOBE Research for Food Safety in Global System”; 2006

Mycotoxins And Mycobiota In Feedstuffs Intended For Swine At Different Growth Stages María L. GONZALEZ PEREYRA, Carina M. PEREIRA, Carlos A. R. ROSA, Ana M. DALCERO, Lilia R. CAVAGLIERI. e-mail: mgonzalezpereyra@exa.unrc.edu.ar A Departamento de Microbiologia e Imunologia Veterinária. Universidade Federal Rural do Rio de Janeiro. Instituto de Veterinária. Rio de Janeiro. 23890-000. b Departamento de Microbiología e Inmunología. Universidad Nacional de Río Cuarto. Ruta 36 km. 601. (5800) Río Cuarto. Argentina.    The contamination of agricultural commodities with fungi able to produce toxic metabolites is of worldwide concern. Adverse effects on animal health and on productivity may occur when mycotoxin-contaminated feeds are consumed.  The aims of this work were: 1) to determine the swine feed and corn mycobiota, 2) to evaluate the feedstuffs´ mycotoxins contamination, specially  aflatoxins, fumonisins and zearalenone, 3) to compare the mycobiota and mycotoxins occurrence at different swine growth stages, 4) to correlate the Aspergillus spp. and Fusarium spp. presence versus specific mycotoxins contamination. Samples of  swine feed were collected from a farm located in the department of Rio Cuarto, in Córdoba province, Argentina. From June to November 2005, 4 samples (2 kg each) of different composition (1) Initial feed. 72% corn, 25% concentrate (proteins, vitamins and minerals), 3% alfalfa; 2) Growing feed. 80% corn, 17% concentrate, 3% alfalfa; 3) Finishing feed. 82% corn, 15% concentrate, 3% alfalfa; 4) 100% corn intended for feed manufacturing) were obtained every 2 weeks and taken to the laboratory. They were examined for total moulds on dichloran rose bengal chloramphenicol and dichloran 18% glycerol media and for Fusarium spp. and Aspergillus spp. occurrence. The aflatoxins and zearalenone production was determined by TLC and fumonisins production by HPLC. Total mould counts were generally higher than 1 x 104 CFU ml-1 at all swine growth stages tested. Fusarium and Aspergillus species were isolated in the highest numbers. Aspergillus flavus-parasiticus and Fusarium verticillioides were the most prevalent species. There was no significant difference between mycobiota and mycotoxin levels in feedstuffs at different swine growth stages. The amount of fumonisins and aflatoxins detected in these feedstuffs were lower than the regulation limits established. Even though, a synergistic toxic response is possible in swine on simultaneous exposure. Fusarium spp counts and fumonisins contamination followed the same tendency (r2=1, p<0.001). Further methods are required to reduce infection by mycotoxin-producing fungi in swine feed and procedures for treating heavily contaminated feed lots are also important to avoid animal production impairment and hazards to animal and human health.