EFFECT OF ADDITIVES CONTAINING LACTIC ACID BACTERIA AND/OR HYDROLYTIC ENZYMES WITH AN ANTIOXIDANT UPON THE PRESERVATION OF CORN OR ALFALFA SILAGE

Abstract

A silage additive containing lactic acid bacteria was tested for its effect upon preservation of corn silage, 35–40% dry matter (DM), in four pairs of upright silos (100-t capacity). The additive did not affect (P > 0.05) final pH, lactic or acetic acid concentration, crude protein or NPN-N and NH4+-N expressed as a percent of total N. Recovery of energy from treated silage was greater than control in the two pairs of silos where this was determined, but recoveries of dry matter and crude protein were not consistently affected. Two silage additives, containing hydrolytic enzymes and an antioxidant with or without lactic acid bacteria, were tested on alfalfa, 20, 30, 36.5 and 47.3% DM, in 250-mL laboratory silos. The experimental design used a4 (DM level) × 4 (added glucose — 0,4,8 and 12%, DM basis) × 3 (additive — control, a hydrolytic enzyme/antioxidant additive (E/AO), and E/AO plus lactic acid bacteria (E/AO +)) factorial arrangement of treatments. Alfalfa was harvested using farm equipment. For 60-day silage, the additives as either a primary factor in the design or in second-order interactions with either silage DM or glucose showed no effect (P > 0.05) upon pH, lactic acid, acetic acid, butyric acid, Fleig score, residual water-soluble carbohydrate and percent of total N as NPN-N or ammonia-N. Poor quality silage resulted from the fermentation of alfalfa at 20 and 30% DM, and although additional glucose resolved this problem the additives did not. Beneficial effects of additional water-soluble carbohydrate in alfalfa silage fermentation are evident in data presented. Thus an additive containing an antioxidant and hydrolytic enzymes was not very effective and numbers of lactic acid bacteria in untreated alfalfa harvested with farm equipment must already be sufficient for adequate fermentation.