Alkaline hydrogen peroxide-treated wheat straw as a source of energy for ruminal bacteria in continuous culture

Eight dual flow continuous culture fermenters were used to compare alkaline hydrogen peroxide-treated wheat straw (TS) with other carbohydrate sources tbr ruminal microbial growth and fermentation. Diets contained either 70% nontreated wheat straw (NS), solka floc (SF), corn starch (CS) or TS. The remainder of the diet consisted of soybean meal (27.5%), mineral mix (2%) and urea (.5%). True organic matter digestion was greatest (P < .05) for the CS diet and lowest (P < .05) for the NS diet. Neutral detergent fiber digestion was greatest (P < .05) for the TS diet, reflecting an increase in energy availability with alkaline hydrogen peroxide treatment. Total volatile fatty acid (VFA) concentration was greatest with CS but not different (P > .05) from the TS diet. Lower (P < .05) concentrations of VFA were observed with the NS and SF diets compared with the other diets. Total bacterial N production was 626, 739, 1,365 and 1,397 mg/d for the SF, NS, CS and TS, diets, respectively. Results of this experiment showed that when wheat straw was treated with alkaline hydrogen peroxide, degradation and fermentability of cell walls by ruminal bacteria were increased. However, efficiency of bacterial protein synthesis and protein escape were reduced by treatment of wheat straw. Treated straw was comparable to corn starch as an energy source for growth of ruminal bacteria.