Fat quality assessments of feed-grade and pet food-grade poultry by-product meals

Ether extract composition of poultry by-product meal (PBM) varies among feed-grade and pet: food-grade sources. Because feed-grade PBM contains a wider variety of processing residues than pet food-grade PBM, it is presumed to be of lower fat quality (i.e., stability). This potential difference in fat quality, or stability, between PBM sources can be accentuated by high environmental temperatures. A total of 46 PBM samples (25 feed-grade and 21 pet food-grade) were collected from commercial feed mills located in the southeastern US within 60-d intervals during the winter and summer months. For samples from winter collection, feed-grade PBM had lower fat stability than pet food-grade PBM. Conversely, pet food-grade PBM samples received in the summer were characterized as having poor stability, and the amount of analyzed residual antioxidant concentration in pet food-grade PBM was half that found in the feed-grade PBM samples. Seasonal effects appeared to be related to the extent of fat oxidation. In general, samples obtained in the summer had poor stability when compared with those collected during the winter, regardless of source. These results confirmed that fat in PBM requires an adequate amount of antioxidant protection, even when meals are derived from prime offal components.