Topics:
Animal Nutrition, Animal Refresher
Energy Loss via Methane in Ruminants
Energy loss in methane production is:
- 7-9% of GE — Correct Answer
- 10-12% of GE
- 3-4% of GE
- None
Explanation:
Correct Answer: 7–9% of GE
In ruminants, anaerobic microbial fermentation in the rumen produces methane (CH₄) as a by-product. This represents approximately 7–9% of Gross Energy (GE) intake — a significant and unrecoverable energy loss.
Energy Partitioning in Ruminants
| Energy Loss Type | % of GE Lost | Notes |
|---|---|---|
| Faecal energy (roughage diet) | 40–50% | Largest loss in ruminants |
| Faecal energy (concentrate diet) | 20–30% | Lower because concentrate is more digestible |
| Urinary energy | 4–5% | Mainly as urea; higher in ruminants than pigs |
| Methane (CH₄) | 7–9% (stated as 7%) | From rumen fermentation; energy completely lost |
| Heat of fermentation (HF) + Heat of nutrient metabolism (HNM) | Variable | Remaining losses before Net Energy |
Methane — Key Facts
- CH₄ energy content: 13.34 Kcal/g
- Rumen gas production ratio: CO₂ : CH₄ = 65 : 35
- Produced by methanogenic bacteria: Methanobacterium ruminantium
Why Other Options Are Wrong
- 10–12% → too high; exceeds standard values for CH₄ loss
- 3–4% → too low; underestimates the actual methane production in ruminants
- None → incorrect; the value is well established
📚 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.
