Epiphytic bacterial strains lead to variable modifications in the fermentation and nutritional characteristics of rehydrated corn grain silage

Abstract

The development of inoculants with epiphytic microorganisms is an alternative for improving the characteristics of rehydrated corn grain silage (RCGS). The aim of this study was to evaluate inoculants composed of epiphytic lactic acid bacteria on the fermentation profile, nutritional value, and aerobic stability of RCGS in different storage periods. The treatments were: RCGS without inoculant (control), RCGS inoculated with 8 epiphytic strains of Pediococcus pentosaceus (PP-52, 82, 110, 190, 221), Pediococcus acidilactici (PA-180), and Limosilactobacillus fermentum (LF-106, 116), and RCGS inoculated with Lactobacillus hilgardii (LH-4785), stored for 45 and 90 days. The grain corn was compacted into plastic buckets (5 L; density of 992.85 ± 16.37 kg/m³). A completely randomized design was used in a 10 × 2 factorial arrangement (9 inoculants plus the control × 2 storage times), with twenty treatments and three replications. The means were compared using Tukey’s test (5 % significance level). Dry matter losses stabilized but starch losses increased from 45 to 90 days. With the fermentation time, a reduction in crude protein and zein content and an increase in NH₃-N concentrations were observed. Aerobic stability increased with LH-4785. Lower NH₃-N concentrations were found in the PP-190 and PP-221 silage and zein concentration was higher in the PP-190 silage. Lower yeast counts and higher lactic acid concentrations in the S-116 silage and higher acetic acid concentrations in LH-4785 silage occurred. The PP-190 strain reduced the in situ starch disappearance. All the isolates evaluated affected the fermentative and nutritional characteristics of the silage.