Sweet corn stalk treated with saccharomyces cerevisiae alone or in combination with lactobacillus plantarum: Nutritional composition, fermentation traits and aerobic stability

Abstract

The inclusion of Saccharomyces in the ration is beneficial to ruminants. We investigated the effects of inoculating a high-dose S. cerevisiae (108 cfu/g) on the nutritional composition and fermentation traits of sweet corn stalk. A high-dose S. cerevisiae inoculum increased the crude protein concentration of sweet corn stalk silage but decreased the silage quality. Thus, a high-dose S. cerevisiae inoculum is not conducive to obtaining high-quality corn stalk silage. This study examined the effects of a high-dose Saccharomyces cerevisiae inoculant alone or jointly with Lactobacillus plantarum on nutrient preservation, fermentation quality, and aerobic stability of sweet corn stalk silage. Fresh stalks (231 g dry matter (DM)/kg) were chopped and subjected to the following treatments: (1) deionized water (Uninoculated; U); (2) S. cerevisiae at 1 × 108 cfu/g of fresh forage (S); and (3) S. cerevisiae at 1 × 108 cfu/g plus L. plantarum at 1 × 105 cfu/g (SL). Treated stalks were ensiled in 5-litre laboratory silos for 30, 60, and 90 d. The S and SL silages had a greater (p < 0.001) pH and greater crude protein, ammonia nitrogen/total nitrogen, neutral detergent fibre, acid detergent fibre, and ethanol contents at all three ensiling periods than the U silage. Acetate, propionate and volatile fatty acids in the S and SL silages after 30 and 90 d of ensiling were greater (p < 0.05) than those in the U silage, but they were lower (p < 0.05) in the S and SL silages than in the U silage after 60 d. The lactate and V-score of the S and SL silages were lower (p < 0.001) than those of the U silage at all three ensiling periods. Compared with the U group, the aerobic stability of the S silage after 90 d of ensiling decreased (p < 0.05), and the aerobic stability of the SL silage was unaffected (p > 0.05). Overall, the quality of sweet corn stalk silage was not improved by inoculation with 108 cfu/g of S. cerevisiae alone or in combination with 1 × 105 cfu/g of L. plantarum.