Effects of brewers’ spent grain protein hydrolysates on gas production, ruminal fermentation characteristics, microbial protein synthesis and microbial community in an artificial rumen fed a high grain diet

Abstract Background Brewers’ spent grain (BSG) typically contains 20% – 29% crude protein (CP) with high concentrations of glutamine, proline and hydrophobic non-polar amino acid, making it an ideal material for producing value-added products like bioactive peptides which have antioxidant properties. For this study, was extracted from BSG, hydrolyzed 1% alcalase flavourzyme, the generated hydrolysates (AlcH FlaH) showing activities. This study evaluated effects AlcH FlaH on gas production, ruminal fermentation characteristics, nutrient disappearance, microbial synthesis community using artificial rumen system (RUSITEC) fed a high-grain diet. Results As compared to control only, supplementation decreased ( P < 0.01) disappearances dry matter (DM), organic (OM), CP starch, without affecting fibre disappearances; while had no effect disappearance. Neither nor affected production or VFA profiles, however they increased NH 3 -N H 2 production. Supplementation percentage CH 4 in total dissolved-CH (dCH ) dissolved gas. Addition monensin reduced disappearance nutrients, improved efficiency emissions. Total nitrogen 0.05) but proportion feed particle associated (FPA) bacteria supplementation. Numbers OTUs Shannon diversity indices FPA were unaffected by FlaH; whereas both monensin. Taxonomic analysis revealed relative abundance (RA) at phylum level, RA Firmicutes Bacteroidetes enhanced Proteobacteria. genus Prevotella , Selenomonas Shuttleworthia Bifidobacterium Dialister as control; enhaced Succinivibrio . Conclusions The diets may potentially protect starch degradation, adversely degradation profiles. It also showed promising reducing suppressing Protein enzymatic BSG flavourzyme potential application bio-products.