Theory 083/Food & Agriculture /Animal science
Livestock Emissions Follow Feed Conversion
Diet is the lever of choice. The animal's efficiency may dominate it.
Emissions per unit of animal product are set by feed conversion ratio rather than by diet composition, so a high-conversion animal on a mediocre diet can emit less than a low-conversion animal on a good one.
01The evidence
Emissions intensity varies widely between production systems, and the variation tracks feed conversion more closely than diet formulation.
02The tension
Mitigation focuses on diet additives and on feed composition, which predict emissions per animal and miss the conversion effect that sets emissions per product.
03The mechanism
Ruminant emissions come largely from feed that is digested but not converted into product. The fraction lost is set by conversion efficiency, so emissions per kilogram of product scale inversely with it.
That makes conversion the determinant, and predicts that improving conversion reduces intensity more than changing diet at constant conversion.
04What this is not
Diet models target the rumen. This targets conversion, which sets the denominator.
05Predictions
- P1Intensity should track conversion ratio.
- P2Conversion gains should beat diet swaps.
- P3High-conversion animals should emit less per product.
06Refutation
Intensity tracking diet at controlled conversion would restore diet mitigation.
07What it changes
It would redirect breeding and management toward conversion.