Surveillance of micoflora from raw materials used to pet food manufacture

CAMPOS S.G.; CAVAGLIERI L., DALCERO A., ROSA C.A.R.

Nantes, Francia

Congreso; 10th Congress of the European Society of Veterinaty and Comparative Nutrition.; 2006

The animal feed industry is an integral and growing segment of the food supply chain. It supplies the feed ingredients needed to provide essential proteins and energy. Animals consume one third of the global cereal grain supply. Mineral feed phosphates, animal-by-products, vitamins and other micronutrients are mixed with home-grown grains and other feedstuffs to make complete or compound feed. Fungi capable of producing mycotoxins, such as some Fusarium and Aspergillus species, are widespread contaminants of agricultural commodities and feeds. When cereal grains and animal feed are colonized by fungi, there is a significant risk of contamination with mycotoxins. The aim of the present study was to determine the natural fungal biota of raw materials used in pet food manufacturing. A total of 30 samples of raw materials (5 for corn, 5 for ground corn, 5 for sorghum flour, 5 for corn gluten plus corn 21%, 5 for chicken by-product meal,  5 for bone and meat flour) were collected monthly during ten months from a factory located in the Rio de Janeiro State, Brazil. Isolation of moulds was carried out by the spread surface method. The cultures media used were dichloran-rose-bengal-chloranphenicol agar (DRBC), dichloran-chloranphenicol 18% glycerol agar (DG18) and Nash-Snyder medium (NS). The average number of colonies on the triplicates plates was recorded and the number of mould refers to CFU per gram of sample. Each strain isolated was identified to genera level (Pitt and Hocking, 1997). Aspergillus and Fusarium species were identified according to Klich (2002) and Nelson (1983), respectively. Mycological examination indicated the presence of six genera of filamentous fungi. The most frequent moulds were Aspergillus spp. and Fusarium spp. The most prevalent species was A. flavus in corn-based raw materials and corn, whereas A. sydowii, A. fumigatus and A. versicolor in sorghum flour, Chicken by-product meal and bone-meat flour, respectively. In general, all samples showed moderate levels of contamination in DRBC and DG18 whereas levels over 1 x 104 CFU g-1 were found in sorghum flour in DG18. These results show that the presence of toxigenic fungi indicates a potential risk of animal health. Therefore, future studies could be conducted to evaluate the mycotoxins contamination in raw materials and finished pet food.