Determination of mycobiota and mycotoxins in pig feed in central Argentina.

Aims: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home-corn grains intended for fattening pigs.
Methods and Results: Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin-layer chromatography and fumonisins by high-pressure liquid chromatography. Fungal counts were generally higher than 1 x 10(5) colony forming units (CFU) ml(-1). Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB(1) and FB(2) were detected in all feed and corn samples. Aflatoxin B(1) was detected in 33.33% of initial and growing feed and in 44.44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB(2), AFG(1), AFG(2) and ZEA presence during all growing stages tested.
Conclusions: Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations.
Significance and Impact of the Study: The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.