Performance of dairy cows fed forage treated with fibrolytic enzymes prior to feeding

Fifty multiparous Holstein dairy cows in early lactation were used to evaluate production responses to cellulase, xylanase and ferulic acid esterase (FAE) enzyme application on the forage portion of the diet. Cows were assigned to five treatments in a randomized complete block design experiment. During weeks 10–21 of lactation, cows were fed a basal diet (CTL), or a basal diet treated just prior to feeding with a blend of cellulase and xylanase enzyme applied to the forage mixture at the rate of 1.30 l/t forage DM (C); or blend of cellulase and xylanase plus additional FAE enzyme at a low rate of 0.002 l/t forage DM (C-LF); or FAE enzyme alone at a low rate of 0.002 l/t forage DM (LF); or FAE at a high rate of 0.030 l/t forage DM (HF). Immediately before application, the required amount of enzyme was diluted with water to bring the volume to 16.5 l/t forage DM and sprayed on the forage. Water was added in CTL. Enzymes provided 3557 units of cellulase+10,394 units of xylanase/kg forage DM in treatment C; 3557 units of cellulase+10,394 units of xylanase+5.4 units of FAE/kg in C-LF; 5.4 units of FAE in LF; and 80.7 units of FAE/kg in HF. The basal diet had 460 g/kg DM forage (500 g alfalfa hay and 500 g corn silage per kg DM) and 540 g/kg DM concentrate containing minerals and vitamin. Diets were fed as a total mixed ration (TMR) twice daily. Feed intake, milk yield, milk energy output, milk components and body weight (BW) gain of cows were not affected by enzyme treatment. Diets containing enzyme-treated forages were consumed at a similar rate to untreated forage diets. Results suggest that treating the forage portion of the diet with a blend of cellulase and xylanase enzymes with or without FAE, or FAE alone, prior to feeding did not improve the performance of dairy cows during early lactation.