POTENTIAL OF ENZYME MIXTURES TO IMPROVE SILAGE QUALITY AND LACTATION PERFORMANCE OF DAIRY-CATTLE

Economic benefits of adding enzyme mixtures (EM) to forages prior to e nsiling have not been clearly established. Potential benefits such as improved silage quality and animal performance have been observed in s ome studies but not in others. This study was implemented to evaluate silage quality and lactation performance of dairy cattle fed silage tr eated with commercial EM. Alfalfa (Medicago sativa L.) silage was trea ted 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 s ilage fermentation characteristics as evidenced by decreased pH and ac etate, and increased lactate content, Enzyme treatment reduced neutral detergent fiber (NDF) by 3.3 percentage units compared with the contr ol silage. Pectic fractions and hemicellulose were reduced by enzyme t reatment, Enzyme treated silage contained higher levels of ruminally u ndegraded NDF. Enzyme treatment did not alter ruminal dry matter (DM) degradation or cellulose content of alfalfa silage. Milk yield, milk c omponents, 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 chara cteristics and decreasing NDF content, but these improvements did not have a positive effect on lactation performance of dairy cows.