Microbiological, physico‐chemical and safety parameters of cereal‐based animal diets

Introduction Feed hygiene is important for the safety of foods of animal origin. Feed hazards include mycotoxins and pathogenic bacteria responsible for foodborne diseases. The aim of this study was to evaluate the safety of samples consisting of compound feeds, feed materials and premixes, and provide information for the food chain. Methods Three series of samples were taken for analyses at monthy intervals from 25 batches of various types of feeds (75 in total) at a feed manufacturers. Standard and established methods were used for both microbiological and physico-chemical analyses. Results The water activity of the samples ranged from 0.578 to 0.648 and 0.659 to 0.741, whereas pH ranged from 5.78 to 6.19 and 5.82 to 6.41 in loose and pelleted compound feeds, respectively. The total bacterial count in loose feeds ranged from 4.44 to 6.30, yeasts–moulds 3.30 to 4.07, Enterobacteriaceae 3.23 to 4.74 and coliforms 3.21 to 4.89 log CFU g 1 . Total bacterial count in pelleted feeds ranged from o 2.0 to 3.7 log CFU g 1 , whereas values for other variables were negligible. Wheat bran was most heavily loaded with microbes. Staphylococcus aureus and aflatoxin were not found in any of the 75 samples, whereas Escherichia coli was detected in soybean, sunflower and three out of 30 samples of compound feeds. Listeria spp. was found in only one out of three batches of sugarbeet pulp and in one out of three batches of two pelleted feed not containing sugarbeet pulp. Salmonella spp. was detected in two out of 15 samples of loose feeds. Conclusion These data meet demands of recent European Union legislation on feed hygiene for establishing specific microbiological criteria for feed manufacturers and fill gaps on the traceability and development of the Hazard Analysis Critical Control Points system in the animal production sector.