Potential of Enzyme Mixtures to Improve Silage Quality and Lactation Performance of Dairy Cattle

Abstract

Economic benefits of adding enzyme mixtures (EM) to forages prior to ensiling have not been clearly established. Potential benefits such as improved silage quality and animal performance have been observed in some studies but not in others. This study was implemented to evaluate silage quality and lactation performance of dairy cattle fed silage treated with commercial EM. Alfalfa (Medicago sativa L.) silage was treated with 7.8 oz/ton of a commercial EM and silage quality was compared with an untreated control. Diets containing experimental silages were fed in a switchback trial to 20 multiparous Holstein cows (Bos taurus) and lactation performance was evaluated. Enzyme treatment improved silage fermentation characteristics as evidenced by decreased pH and acetate, and increased lactate content. Enzyme treatment reduced neutral detergent fiber (NDF) by 3.3 percentage units compared with the control silage. Pectic fractions and hemicellulose were reduced by enzyme treatment. Enzyme treated silage contained higher levels of ruminally undegraded NDF. Enzyme treatment did not alter ruminal dry matter (DM) degradation or cellulose content of alfalfa silage. Milk yield, milk components, and DM intake of lactating dairy cows was also not improved by enzyme treatment. In this study treatment of alfalfa silage with a commercial EM improved silage quality by enhancing fermentation characteristics and decreasing NDF content, but these improvements did not have a positive effect on lactation performance of dairy cows.