Additives Containing Bacteria and Enzymes for Alfalfa Silage

Abstract

First-cutting alfalfa was wilted, harvested from alternate rows, left untreated or treated with additives containing lactic acid bacteria and enzymes (cellulase, amylase, and pectinase), and ensiled in bag silos. Inoculation increased lactic acid bacteria from 5 × 104 to 1 × 106 cfu/g of forage. Because treatments were bagged consecutively, the DM of treated silages was higher than that of untreated silage. However, after 4 d of ensiling, the pH of treated silage, about 4.3, was lower than that of untreated silage, 4.7, and remained lower throughout the ensiling period. After 177 d of ensiling, total lactate was about 25% higher, and ammonia N was about 40% lower, in treated silage. In addition, NDF and ADF contents were lower in treated than in untreated silage. Between 51 and 177 d of storage, glucose content increased in treated silage, but not in untreated silage, suggesting that some plant cell-wall hydrolysis occurred during prolonged storage. In vitro digestion of NDF did not differ among treatments during early incubation, but the extent of digestion after 36 and 48h was lower in treated than in untreated silage. The microbial and enzyme silage additives used in this study improved fermentation characteristics and reduced fiber content of silage but decreased the in vitro digestibility of fiber.