Suitability of anaerobic fungi culture supernatant or mixed ruminal fluid as novel silage additives

This study investigated silage quality characteristics and ruminal fiber degradability of grass and straw ensiled with either anaerobic fungi (AF) supernatant with active fungal enzymes or mixed ruminal fluid as novel silage additives. Compared to control silages, AF supernatant improved the quality of grass and straw silages as evidenced by decreased pH, acetic acid concentration, and dry matter losses. Likewise, mixed ruminal fluid enhanced lactic acid fermentation, which further resulted in lower pH of the treated grass silage. The ruminal fiber degradability was determined using in situ incubations and, compared to controls, the cellulose degradability was higher for grass silage with AF supernatant, whereas ruminal degradability of straw silage was reduced by this treatment. In contrast, mixed ruminal fluid did not influence fiber degradability of silages in the rumen. Concluding, both novel additives improved silage quality, whereas only AF supernatant enhanced ruminal fiber degradability of grass silage and therefore may represent an approach for improving forage utilization by ruminants.

Automated summary

This study investigated the effects of anaerobic fungi supernatant and mixed ruminal fluid as additives on the quality and ruminal fiber degradability of silages. The results showed that anaerobic fungi supernatant improved the quality of grass and straw silages, while mixed ruminal fluid enhanced lactic acid fermentation in grass silage. Both additives improved silage quality, but only anaerobic fungi supernatant enhanced ruminal fiber degradability of grass silage.