Energy Loss as Methane in Ruminants
Energy loss in methane (CH₄) production by ruminants is approximately what percentage of Gross Energy (GE)?
- 3–4% of GE
- 7–9% of GE — Correct Answer
- 10–12% of GE
- 15–18% of GE
Correct Answer: 7–9% of GE
In ruminants, microbial fermentation in the rumen produces methane (CH₄) and CO₂ in the ratio of 35:65. This methane represents a real energy loss to the animal — it is simply belched out.
Key Facts About Methane Energy
- Methane loss = 7% of GE (standard value used in energy partitioning)
- Gross energy of methane = 13.34 kcal/g
- Gas production rate in cow = 30 litres/hour
- Gas composition: CO₂ : CH₄ = 65 : 35
Energy Partitioning in Ruminants
GE → (−Faecal energy 40–50%) → DE → (−Urinary energy 4–5%, −CH₄ 7%) → ME → (−Heat increment) → NE → NEm + NEp
Why is Methane Reduction Important?
Ionophore antibiotics like Monensin (Rumensin) and Lasalocid (Bovitec) decrease CH₄ production by inhibiting methanogenic bacteria and shifting fermentation toward propionate.
📚 About this Topic — Animal Nutrition
This multiple choice question is from Animal Nutrition, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Nutrition to strengthen your preparation.
