EFFECTS OF ENZYME-INOCULANT SYSTEMS ON PRESERVATION AND NUTRITIVE-VALUE OF HAYCROP AND CORN SILAGES

Third-crop mixed grass-legume forage and com were ensiled in 70-tonne bunker silos to evaluate the effects of a commercial carbohydrase enzyme-inoculant mixture (220 ml/tonne) and an experimental enzyme-inoculant mixture (264 ml/tonne) on silage fermentation and composition, ruminal degradation, and milk production. Twelve Jersey and 24 Holstein early lactation cows were fed one of four TMR at 32.5:32.5:35.0 haycrop silage:corn silage:concentrate (DM basis) containing a combination of treated and untreated silages from d 2 to 100 of lactation. Bunker silages were incubated twice in situ in fistulated cows in each dietary treatment to determine rates of DM and NDF degradation. Treatment of haycrop silage significantly reduced silage pH and acetic acid concentration and increased titratable acidity, lactic acid concentration, lactate: acetate ratio, and DM and NDF disappearances after 24 h of ruminal incubation. Treated haycrop silage increased DMI:BW ratio and daily production of milk, milk protein, and SNF of early lactation cows. Application of the experimental mixture to com silage did not change silage fermentation or composition, except that the concentration of NH3 was reduced. Enzyme-treated corn silage did not improve DMI and slightly reduced daily milk production in early lactation cows.