Fermentation and Digestion in Ruminants

Rumen

Digestive chamber for microbial fermentation in ruminants.

Microbial Growth

Supported by warmth, moisture, and food supply.

Symbiosis

Mutual benefit between ruminants and microorganisms.

Microorganisms (MO's)

Bacteria, protozoa, and yeast aiding digestion.

Bacteria

15-50 billion/ml, digest nutrients like cellulose.

Protozoa

35 species, prey on bacteria in rumen.

Yeast

Aid in cellulose breakdown during fermentation.

Volatile Fatty Acids (VFA's)

Main energy source produced during fermentation.

Acetate

2-carbon VFA, primary energy source from forages.

Propionate

3-carbon VFA, significant energy source from grains.

Butyrate

4-carbon VFA, important for gut health.

Fermentation End Products

Includes VFA's, microbial protein, ammonia, gas, heat.

Ionophores

Feed additives shifting MO to propionic species.

Concentrate Diets

High in starch, leading to higher propionate.

Forage Diets

Higher in fiber, leading to higher acetate.

Microbial Protein

Synthesized by MO's, excellent protein source.

Ammonia (NH3)

Byproduct of protein deamination, absorbed in rumen.

Gas Production

65% CO2, 25% CH4, contributes to energy loss.

Lipid Fermentation

Saturates unsaturated fatty acids in ruminants.

Rumen pH

Varies with diet; 5.5-6.0 for concentrates.

Rumen Capacity

Assumed 50 liters, housing 2.5 x 10^15 MO's.

Nutrient Digestion

Includes starch, fiber, proteins, and fats.

Heat Production

Byproduct of fermentation, useful in winter.