Evaluation of the protein quality of solids recovered from hog manure slurry

Abstract

The purpose of this study was to explore the possibility of utilizing portions of hog manure for animal feed, based on proximal chemical, microbiological, protein quality and cooper toxicity testing. Solids recovered from hog manure (RS) were mixed in levels of substitutions of 15, 30, 45 and 60% with commercial cattle feed (CF). The protein content of the mixtures varied little. The in vitro digestibility of the protein decreased as the RS content was increased, and was 87·8% for a substitution level of 0% RS and 66% for a 60% substitution. The quality of the protein was evaluated by the Protein Efficiency Ratio (PER) and Net Protein Utilization (NOU) assigning maximum values of 1·24 and 24·12, respectively, to a 30% SR and 70% CF (commercial feed).mixture. This mixture showed an adequate amino acid profile. The microbiological analysis of the RS showed negative results for the pathogenic microorganisms studied. Total counts of microorganisms, fungi, yeast and most probable number of organisms were similar to those of commercial cattle feed. The copper content of the RS was 170·35 ppm.