Microbial and nutritional aspects of feeding fermented feed (poultry by-products) to pigs.

Broiler by-products (heads, feet, and viscera) mixed with 4% dextrose were pasteurized for 4 min at 90 degrees C core temperature, cooled to 20 degrees C, and fermented with Lactobacillus plantarum as starter culture. These fermented poultry by-products were fed to 12 individually housed fattening pigs as part (17.6% of the dry matter) of their fattening ration, the remainder composed of compound pig feed. Control pigs received a compound pig feed only. Both groups of pigs were fed restrictively on the basis of body weight. The technical results of the pigs fed the experimental diet showed a significantly improved feed:gain ratio (2.46 vs 2.57), a significantly higher carcass weight (86.1 vs 81.8 kg), a lower meat percentage (50.9 vs 52.5%) and an increased backfat thickness (21.5 vs 18.7%). The bacterial flora in the intestinal tract of the pigs fed the experimental diet differed significantly from the control animals. Decreased colony counts of mesophilic aerobic bacteria, Enterobacteriaceae, enterococci and lactobacilli were found in the rectal content and the prevalence of salmonella was lower. It is suggested that the improved feed:gain ratio and the reduced bacterial activity of the measured groups of bacteria is a result of 1) the higher energy content of the diet, and(or) 2) an assumed enhanced digestibility of nutritional components in the diet, and(or) 3) the lower incidence of diarrhea in the pigs fed with fermented poultry by-products. This resulted in a lower contamination level of enteropathogenic bacteria like, salmonella and Escherichia coli, in the gastro-intestinal tract of the pigs fed fermented poultry by-products.