Effect of hydrogen peroxide‐dependent enzyme systems on the in‐vitro digestibility of untreated and ammonia‐treated barley straws

A series of small‐scale in vitro experiments was conducted to evaluate the effectiveness of various hydrogen peroxide (H 2 O 2 )‐dependent enzyme systems, peroxidase and glucose oxidase, in improving the nutritive value of ammonia‐treated and untreated barley straw. H 2 O 2 and peroxidase increased ( P ≤0.001) digestibilities when used individually, but their combined use did not influence digestibility significantly ( P >0.05). The effect of H 2 O 2 alone was greater than that of peroxidase alone. The combination of glucose and glucose oxidase to generate H 2 O 2 produced a small but non‐significant ( P >0.05) increase in the digestibility of straw. The combination of glucose oxidase and peroxidase was ineffective in improving digestibility of straw. The digestibility values of ammonia‐treated barley straw were always greater ( P ≤0.001) than those of untreated straw but none of the treatments showed any interaction with ammonia treatment. It is suggested that H 2 O 2 treatment improves the digestibility of straw.