Feed Conversion Ratio

Feed conversion ratio compares how much feed an animal eats with how much body mass it puts on over the same period. It works because it is a direct ratio of input to output: the smaller the FCR, the more efficiently the animal turned feed into growth. Farmers and nutritionists use it to judge diet quality, animal performance, and production efficiency.

Use this formula when evaluating growth efficiency in livestock, poultry, aquaculture, or other feeding trials. It is especially useful for comparing different feeds, breeds, housing conditions, or management systems.

• Mixing up the units so feed and gain are not both measured over the same time period
• Using total body weight instead of only the weight gained
• Assuming a higher FCR is better, when a lower FCR indicates greater efficiency