Effects of enzyme Additive on Nutrient intake, Digestibility and Rumen metabolites of yearling Cattle fed Grass-hay based diet

Abstract

Nutrient intake, digestibility and rumen metabolites were determined in sixteen yearling cattle fed Panicum maximum hay supplemented with concentrate diet in which an exogenous fibrolytic enzyme, ROXAZYME G2^® (which consist of Cellulase, hemicellulase and beta glucanase) was included at 0, 50, 100 and 150mg/kg. Enzyme inclusion significantly increased the nutrients intake as the lowest value for all the parameters measured was obtained at 0mg/kg enzyme inclusion level. There were no significant differences among other levels of inclusion for total dry matter intake, Crude protein intake and Acid Detergent Fibre intake. Dry matter, crude protein, neutral Detergent Fibre and Acid Detergent Lignin digestibility were highest at 150mg/kg enzyme inclusion level and lowest at 0mg/kg enzyme inclusion. Enzyme inclusion reduces the pH as the experiment progressed. It ranged from 7.1-7.2 at the start to 6.50-6.90 at the end of the experiment. Ammonia- increases as the experiment progressed and the highest value 13.50mg/100ml was obtained at 150mg/kg inclusion. The total volatile fatty acids and total viable bacteria count also follow the same trend. This study revealed that the exogenous fibrolytic enzyme used improves the nutrient intake, digestibility and rumen metabolites of yearling cattle at 150mg/kg enzyme inclusion level.

Keywords: Exogenous fibrolytic enzyme; cattle; nutrient intake; digestibility; rumen metabolites