Effect of lactic acid bacteria inoculants on fermentation characteristics and aerobic stability of three native grasses in Mongolian steppe

Leymus chinensis, Leymus secalinus and Elymus nutans are three common grasses of the steppes of Central Asia. This study examined the effects of lactic acid bacteria on the fermentation qualities and aerobic stabilities of L.chinensis, L.secalinus and E.nutans silages. The forages were directly ensiled with or without lactic acid bacteria. Lactobacillus plantarum (LP), Lactobacillus brevis (LBR) and Lactobacillus buchneri NCIMB40788 (LBU) from a commercial inoculant were used as additives at 1.0x10(5)cfu g(-1) of fresh matter. The control was sprayed with the same volume of distilled water. Six replicates from each treatment were ensiled in 3-L plastic buckets and stored at ambient temperature (similar to 30 degrees C). Fermentation quality and aerobic stability were determined after 60days of ensiling. LP increased lactic acid content, lowered pH and decreased the content of butyric acid and ammonia nitrogen (P<0.001) of the three silages. LBU increased the aerobic stabilities of the silages (P<0.001). Lactobacillus brevis slowed the increase in pH, ammonia N content, and yeast count and slowed the decrease of lactic acid content during exposure to air. Overall, LP improved fermentation quality and LBU increased the aerobic stabilities of the native grass silages. Lactobacillus brevis reduced aerobic spoilage of L.chinensis and L.secalinus silages.