Development and Validation of a 500-mL In Vitro Fermentation Bottle System for Gas Production, Methane, and Nutrient...

Area of Science:

• Rumen microbiology and nutrition
• Animal science
• Agricultural engineering

Background:

• Accurate assessment of feed digestibility and fermentation products is crucial for ruminant nutrition.
• Existing in vitro systems often have limitations in substrate volume or anaerobic condition maintenance.
• Developing a robust laboratory-scale system is essential for detailed feed evaluation.

Purpose of the Study:

• To develop and validate a modified 500-mL bottle system for laboratory-scale in vitro rumen fermentation.
• To enable simultaneous measurement of gas production, methane output, and nutrient degradability.
• To assess the system's performance with varying roughage-to-concentrate ratios in ruminant diets.

Main Methods:

• A modified 500-mL bottle system was utilized for in vitro fermentation.
• Rumen fluid from Japanese Black cattle was incubated with feed substrates at different roughage-to-concentrate ratios (80:20, 50:50, 20:80) for 24 hours at 39°C.
• Measurements included total gas production, methane production (CH4/DMD), in vitro dry matter (IVDMD) and organic matter degradability (IVOMD), pH, and short-chain fatty acid (SCFA) production.

Main Results:

• Higher concentrate proportions in diets led to increased IVDMD, IVOMD, and total gas production.
• Methane production per unit of degraded dry matter (CH4/DMD) and pH decreased with higher concentrate levels.
• Crude protein, NDF, ADF degradability, and SCFA production were not significantly affected by dietary treatments.

Conclusions:

• The modified 500-mL bottle system is a validated tool for laboratory-scale in vitro rumen fermentation studies.
• The system effectively measures gas, methane, and nutrient degradability simultaneously.
• This improved system supports detailed evaluation of ruminant feed substrates and dietary strategies.