Ensiling Time and Mixed Microbe Fermented Liquid Modulate In Vitro Digestibility and Rumen Fermentation of Fermented...

Area of Science:

• Animal Science
• Ruminant Nutrition
• Forage Preservation and Fermentation

Background:

• Fermented total mixed rations (FTMR) are crucial for ruminant nutrition, but optimizing their production requires understanding the impact of ensiling duration and microbial additives.
• Mixed microbes fermented liquid (MMFL) is a potential additive to enhance silage fermentation and nutrient utilization, yet its optimal inclusion level and fermentation period are not well-defined.

Purpose of the Study:

• To investigate the effects of varying ensiling periods and MMFL inclusion rates on the chemical composition, in vitro degradability, and rumen fermentation of FTMR.
• To assess the impact of these treatments on the microbial ecology within the FTMR.
• To determine the optimal combination of ensiling duration and MMFL level for improved FTMR quality and fermentation efficiency.

Main Methods:

• A 4 × 4 factorial design experiment was conducted using four fermentation durations (0, 7, 14, 21 days) and four MMFL inclusion rates (0, 0.5, 1.0, 1.5% of dry matter).
• Evaluated parameters included chemical composition (crude protein, fiber fractions), in vitro dry matter (DM) and organic matter (OM) digestibility, rumen fermentation end-products (volatile fatty acids), and microbial populations (bacteria, fungi, protozoa).

Main Results:

• A 14-day fermentation period combined with 0.5% MMFL significantly improved FTMR quality, increasing crude protein (12.0% to 14.3% DM) and reducing neutral-detergent fiber (54.2% to 49.1%).
• In vitro digestibility of DM and OM increased by 9-12%, total volatile fatty acids rose by 15%, and the propionate proportion increased, lowering the acetate-to-propionate ratio.
• Estimated methane production decreased by 18%, while bacterial and fungal populations increased, and protozoa decreased, indicating a shift towards a more efficient microbial community.

Conclusions:

• A 14-day ensiling period with moderate MMFL supplementation (0.5%) effectively enhances nutrient conservation and fermentation efficiency in FTMR.
• The findings suggest practical benefits for improving FTMR utilization in ruminant feeding systems.
• Further in vivo and economic evaluations are recommended to fully validate these results.