Objective: To survey the fungi contamination of different feed ingredients in China.
Methods: Soybean meal, cottonseed meal, wheat bran and distillers dried grains with soluble (DDGS) were collected from feed enterprises in different part of the country. Feed ingredient samples were diluted and inoculated and the key factors were screened which influenced the isolation.
Results: Potato dextrose agar (containing chloramphenicol 0.1 g/L) and 10(-1) dilution were the optimum culture medium and dilution respectively. The range of fungi contamination was from 31% (DDGS) to 88% (wheat bran). The fungi contamination frequencies of feed ingredients varied from region to region, and varied from kind to kind. The contamination of Aspergillus flavus and Fusarium spp. were also different in the regions and sample types. The average contamination percentage of Aspergillus flavus (25%) is higher than Fusarium spp. (11%), and their contamination level is highest in northeast China and lowest in south China, wheat bran and cottonseed meal were the highest and DDGS was the lowest.
Conclusion: The fungi contamination, including Aspergillus flavus and Fusarium spp. of feed ingredients all over the country should be pay more attention. It is recommended that prevention of feed ingredients from fungi contamination is needed.