Fermentation of raw poultry byproducts for animal nutrition

In this study, the fermentation of raw, inedible poultry byproducts mixed with sugarbeet pulp and dextrose and inoculated with Lactobacillus plantarum and(or) Enteroccocus faecium resulted in a drop of pH in the byproducts to approximately 4.0 to 4.5 within 48 h. To keep the fermented product stable for a period of 21 d, the addition of > or = 3% (wt/wt) of a fermentable carbohydrate was necessary. With a high inoculation level of approximately 10(8) to 10(9) L. plantarum per gram, or with acidification of the initial mixture with .4% lactic acid, the number of Enterobacteriaceae decreased faster than with inoculation at 10(5) L. plantarum per gram, or without initial acidification. After 21 d of fermentation, a high level of enzymatic breakdown of proteins and amino acids was observed: the nonprotein N level increased from 5% to between 15 and 40% of total N and the volatile N level increased from 1% to between 3 and 11% of total N. An increase in histamine, cadaverine, and putrescine was also observed. Despite the technological measures taken, such as the application of a high inoculum of starter culture and initial acidification with .4% lactic acid, this amino acid breakdown could not be reduced to an acceptable level. These results suggest that, because of biochemical deterioration, fermentation alone is not a useful method of preservation of raw poultry byproducts.