Yellow serofluid-inclusion enhanced anaerobic preservation of whole plant maize for subsequently reducing potential methane emission during in vitro ruminal fermentation.

Yellow serofluid, a wine industry by-product, may alter microbial communities, enhance fermentation, and reduce methane emissions from ruminal fermentation. However, the effect of yellow serofluids on silage fermentation and subsequent methane emissions from maize has not been studied. Therefore, this study aims to investigate the effects of yellow serofluid (Y) and Lentilactobacillus buchneri (L) on the silage preservation, bacterial community, and in vitro fermentation of maize. Whole-plant maize was prepared in a small-silage production system and treated with either 10 mL/kg FM (Y2) or 20 mL/kg FM (Y4) yellow serofluids on a fresh matter basis, with untreated maize serving as the control (CK), inoculation Lentilactobacillus buchneri (L, 10 cfu/g FM). The silages were stored anaerobically for 60 d before undergoing in vitro gas production analysis. Results showed that all treatments enhanced the silage maize preservation. Y4 and L treatments decreased acid detergent fibre content by 0.81% and 1.35%, respectively, compared to that in CK. The Y4-treated silage maintained the highest water-soluble carbohydrate (WSC) content of 4.06% DM. Next-generation sequencing of the microbial community showed that all treatments, particularly Y4, significantly increased the relative abundance of Lactobacillus acetotolerans by 2.93-28.06%. Furthermore, silages treated with Y2 and Y4 produced a significant amount of lactic acid, subsequently reducing the pH and delaying the decline in WSC by inhibiting the proliferation of undesirable bacteria during silage storage. Adding yellow serofluid to silage maize can effectively reduce the gas production of in vitro fermentation and reduce the rumen greenhouse gas emission. These findings suggest that yellow serofluid inclusion can enhance the silage preservation of maize and reduce methane emissions into the environment.