Food & agriculture
Feed conversion ratio (FCR)
The amount of feed needed to produce a unit of animal weight gain — the standard efficiency metric for livestock and aquaculture.
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The feed conversion ratio is the mass of feed given divided by the weight gained by the animal over a period; a lower FCR means less feed — and thus less land, water and nutrient pollution — per kilogram of output. Typical ranges differ widely by species and system: roughly 2–5 for poultry, 4–9 for pigs, 6–25 for beef cattle and 8–13 in dairy contexts, while fed aquaculture commonly achieves 1.0–2.5. Because feed can represent up to 70% of production costs, FCR is both the main economic lever and a proxy for environmental intensity in animal production.
References
FCR formula (feed ÷ weight gain), feed share of production costs up to 70%, reduced nitrogen/phosphorus excretion
species ranges (beef 6–25, dairy 8–13, pig 4–9, poultry 2–5), aquaculture 1.0–2.5
Overview
What it means
FCR converts sustainability debates about meat into measurable efficiency terms: improving FCR reduces demand for feed crops and cuts nitrogen and phosphorus excretion per unit of protein produced. Comparisons across species underpin claims that poultry and farmed fish are generally less resource-intensive than beef.
How it is used
Used by producers for cost control, by buyers in sustainability specifications, and in life-cycle assessments of animal protein.
Why it matters
Feed demand drives cropland expansion, deforestation pressure and nutrient pollution; FCR is the single most tractable metric for decoupling animal protein from those impacts.
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