Effects of Isolated Bacteria Application on Chemical Composition and Fermentation Characteristic of Rye Silage

This study was conducted to estimate the effect of two isolated bacteria on chemical composition and fermentation characteristics of rye silage harvested at 20 days after heading stage. Two microbes, which had confirmed the effect of antifungal activity (Lactobacillus brevis, LB) or fibrinolysis ability (Leuconostoc holzapfelii, LH), were selected from 832 dominant microbes by the tests of antimicrobial activities against fungi and fibrinolysis ability with three enzyme plate assay (cellulase, xylanase, and esterase). Rye forage was harvested at 20 days (27.3% DM) after heading stage, chopped into 3-5 cm length, and divided into four treatments: applications of 2 ml/kg of distilled water (CON), 1.2 x 10⁵cfu/g of LB, 1.0 x 10⁵cfu/g of LH, or combo of LB and LH at 1:1 ratio (MIX). The forages with applied bacterial additives were ensiled into 10 L mini silo with 4 replications for 100 days. The bacterial additives were not affected on chemical composition and in vitro digestibility of rye forages. However, all silages with applied bacterial additives had lower neutral detergent fiber concentration (P<0.05, 67.1 vs. 69.0%) than CON silage while only AT silage had lower acid detergent fiber concentration (P<0.05, 41.6 vs. 43.4%). The silages with applied LH alone and combo with LB had higher (P<0.05, 67.5 vs. 63.2%) in vitro dry matter digestibility than the other silages, whereas bacterial additives were not affected on in vitro NDF digestibility. The pH was lowest (P<0.05, 4.26 vs. 5.04) in LB and MIX silages, but highest in CON silage. In contrast, lactate concentration was higher (P<0.05, 5.36 vs. 0.50%) in all silages applied bacterial additives than in CON silage. Silages applied LB and MIX had higher acetate concentration (P<0.05, 5.43 vs. 2.82%) than the other silages, while silages applied LH and MIX had lower propionate concentration (P<0.05, 0.35 vs. 0.66%) than CON silage. Lactic acid bacteria (6.75 vs. 5.13 log10 cfu/g) and yeast (6.56 vs. 5.42 log10 cfu/g) were more abundant (P<0.05) in CON and LH silages than in LB and MIX silages, while mold was not detected in any silages. Therefore, it could be concluded that LB is more effective on antifungal activity by the results of lower pH and yeast, but higher lactate and acetate concentrations. And again, LH is more effective on fibrinolysis ability by the results of lower neutral detergent fiber concentration, but higher in vitro DM digestibility.