Kaji field guide
Feed conversion ratio in poultry: how to calculate and interpret FCR
Feed conversion ratio, usually shortened to FCR, is a compact measure of how much feed was used to produce a unit of weight gain. It is useful only when the feed and weight data behind it are consistent.
Working formula
FCR = feed consumed ÷ live-weight gain
Use the same weight unit on both sides. For example, kilograms of feed divided by kilograms of live-weight gain.
What the FCR number means
An FCR of 1.70 means the flock used about 1.70 kg of feed for each 1 kg of live-weight gain measured under the same calculation basis. Lower values generally indicate more efficient conversion, but the number should never be interpreted without age, bird type, mortality, feed quality, environment and measurement method.
A farm should compare like with like. Comparing a young broiler flock with an older flock, or a meat flock with layers, can produce a conclusion that is numerically correct but operationally meaningless.
Use feed consumed, not feed purchased
Feed purchased and feed consumed are not the same thing. Bags may remain in stock at the end of the period, be transferred to another house or flock, or be lost through handling. FCR should be based on feed actually attributable to the flock during the measurement period.
This is one reason a connected feed inventory and flock record is valuable: purchases can remain inventory events while issued or consumed feed becomes performance data.
Be consistent about weight gain
For a simple flock calculation, weight gain should reflect the change in live biomass over the period being measured. Farms often use average bird weight multiplied by live birds, while more detailed systems may account for starting biomass and reductions. The important point is to document the method and use it consistently across comparisons.
If weight samples are small or irregular, the calculated FCR may appear more precise than the underlying measurement really is.
Do not use FCR alone
A flock can show an attractive FCR while still performing poorly financially if feed is expensive, mortality is high or sale prices are weak. Review FCR alongside livability, growth, cost per bird and profit rather than treating it as a standalone score.
Practical checklist
- Use feed actually consumed or issued to the flock.
- Use a documented and consistent live-weight-gain method.
- Compare flocks at similar ages and production types.
- Check mortality before interpreting a strong or weak FCR.
- Review feed cost as well as feed quantity.
- Treat sampled weights as estimates, not perfect measurements.
Use the same records in Kaji
Analytics & reports
Kaji keeps these calculations connected to the flock, inventory, health and money records that support them instead of asking you to maintain a separate analysis notebook.