Effects of lactic acid bacteria inoculant on quality, fermentation profile and nutritive value of alfalfa silage at different ensiling period

Abstract

The present study was carried out to investigate the effects of lactic acid bacteria inoculant on quality, fermentation profile and nutritive value of alfalfa silage at different fermentation periods. After harvesting, fresh alfalfa samples were packed into polyethylene film and the commercial lactic acid bacteria inoculant was used as silage additive. Totally of 21 silage packages were opened by weekly for the analysis. Smell, color, structure, and total scores of alflalfa silage were significantly increased from the first week. Silage quality was determined medium at 7th day; good between 14th and 42th days; excellent at 49th day. The Flieg point was gradually increased after d 28 of ensiling (P<0.05). While pH was reduced at 5.15; NH3-N/TN content of alfalfa silage was increased at 15.70% at the end of the study. We observed an increase in acetate concentration and decrease in propionate and butyrate concentrations in the alfalfa silage. Lactate concentration was significantly increased on day 35 of the fermentation (P<0.05). Crude fiber (CF), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF) contents of alfalfa silage were decreased, whereas nitrojen free extract (NFE) and non-fiber carbohydrate (NFC) were increased during ensiling period. According to our findings, fermentation period had a significant effect on digestible dry matter, dry matter intake and relative feed value of alfafa silage (P<0.05).