The effect of lactic acid bacteria inoculums on in vitro rumen fermentation, methane production, ruminal cellulolytic bacteria populations and cellulase activities of corn stover silage

Abstract

The objective of this study was to investigate the effect of lactic acid bacteria (LAB) inoculums on fermentation quality and in vitro digestibility of corn stover silage. Corn stover was ensiled without (control) or with Lactobacillus plantarum (LP), Enterococcus faecalis (EF), and Enterococcus mundtii (EM) for 45 days. The fermentation characteristics were assessed, and subsequent in vitro dry matter digestibility (DM-D), neutral detergent fiber digestibility (NDF-D), volatile fatty acids (VFA), methane (CH4) production, cellulolytic bacteria proportions and their activities per corn stover silage were also determined. There was no significant difference (P>0.05) among the silage pH, lactic acid, crude protein (CP), water soluble carbohydrates (WSC) and lignocelluloses contents of different treatments. The relative proportions of Ruminococcus flavefaciens and Fibrobacter succinogenes, carboxymethyl-ocellulose and β-glycosidase activities, DM-D, NDF-D, and VFA production of in vitro incubation was higher (P<0.05) for silages inoculated with LP and EF than those of the control silage. Silage inoculated with LP showed the lowest (P<0.05) CH4 production per unit yield of VFA, which was positively corresponded to the lowest (P<0.05) ratio of acetate to propionate. In summary, the ensiling fermentation quality and subsequent utilization of corn stover silage were efficiently improved by inoculated with L. plantarum.