Feed conversion ratio (FCR) tells you how much feed your flock used to produce a measured output. For broilers, that output is live-weight gain. For layers, use egg mass or feed per dozen eggs. It is one of the best farm records to keep because feed is usually one of the largest costs in a poultry business.
Do not treat one FCR number as a verdict on your farm. Compare the same type of birds at the same age, under a similar feeding and housing system. A flock can have a disappointing FCR because of feed wastage, heat, poor water access, disease, wet litter, mortality or inaccurate weighing—not only because the feed is poor.
Use the PA FCR Calculator to work from your own records.
What FCR means in simple terms
For broilers, FCR answers one question: how many kilograms of feed did the flock use to gain one kilogram of live weight?
Lower is usually better, because it means less feed was used for each kilogram of gain. But a lower result is only useful when the calculation is honest and the comparison is fair.
Broiler FCR formula
FCR = total feed consumed (kg) ÷ total live-weight gain (kg)
“Feed consumed” means feed actually eaten. Start with feed purchased or issued, then subtract feed remaining and record visible spillage or spoilage where possible. “Live-weight gain” means final flock live weight minus starting flock live weight.
Worked broiler example
- 100 chicks placed
- 98 birds alive at the final weighing
- Average starting weight: 0.045 kg per chick
- Average final live weight: 2.50 kg per live bird
- Total feed consumed: 420 kg
Final live biomass = 98 × 2.50 = 245 kg.
Starting biomass for the 98 live birds = 98 × 0.045 = 4.41 kg.
Live-weight gain = 245 − 4.41 = 240.59 kg.
FCR = 420 ÷ 240.59 = 1.75.
In plain language: the flock used about 1.75 kg of feed for every 1 kg of measured live-weight gain. Feed eaten by birds that died remains in the feed total, so mortality worsens a practical farm FCR. That is not an error; it shows the real cost pressure on the batch.
Plan the flock before placement, then use the FCR calculation during or at the end of the cycle.
Do not compare unlike records
Compare your result with an earlier batch only when the records cover the same basis. Keep these points consistent:
- same strain or a clearly stated strain difference;
- same age at measurement;
- same sex mix and production system;
- same calculation method;
- feed actually consumed, not only feed bought;
- measured flock weight, not a guessed weight.
Cumulative broiler FCR normally rises as birds become older and heavier. That is why a six-week number should not be judged against a three-week number. Breeder documents can be useful strain-specific references, but they are performance objectives under defined conditions—not guaranteed Nigerian farm targets. See the official Ross 308 broiler performance resources from Aviagen.
What is a useful Nigerian reference?
Nigerian evidence is more useful than copying a foreign benchmark, but it still needs context. One Nigerian commercial-starter-feed study reported FCR values from 1.48 to 1.83 across different feed treatments in a four-week trial. Another Nigerian study reported different results across commercial diets over 42 days. These figures show why feed brand, bird age, management and trial conditions matter. They are observations, not targets for every farm. Read the studies from the Nigerian Journal of Animal Production and its commercial-diet study.
Layer feed efficiency: use the right output
Layers do not mainly produce body-weight gain, so the broiler formula is not the best day-to-day measure. Use one or both of these:
Feed per kg egg mass = total feed consumed (kg) ÷ total egg mass (kg)
Feed per dozen eggs = total feed consumed (kg) ÷ dozens of eggs collected
To calculate egg mass, multiply egg number by average egg weight, then divide grams by 1,000.
Layer example
- 500 hens recorded for 7 days
- 2,800 eggs collected
- Average egg weight: 60 g
- Feed consumed: 385 kg
Egg mass = 2,800 × 60 ÷ 1,000 = 168 kg.
Feed per kg egg mass = 385 ÷ 168 = 2.29 kg feed per kg egg mass.
Feed per dozen eggs = 385 ÷ (2,800 ÷ 12) = 1.65 kg per dozen eggs.
Track feed per hen per day as well. If feed intake changes while egg number or egg size falls, investigate the flock before blaming one figure. Official layer resources use egg mass and feed efficiency together because egg number alone does not tell the full story. Hy-Line explains why feed efficiency is linked to egg mass.
Five records you need before calculating FCR
- Birds placed and birds alive: record deaths and culls daily.
- Feed issued: weigh bags or feed issued to the pen.
- Feed remaining: count and weigh what is left at the end of the period.
- Feed lost: note wet, mouldy, rodent-damaged or spilled feed.
- Representative body weights or egg records: weigh a spread of birds, not only the biggest birds.
When FCR worsens, check this first
| What you see | First checks |
|---|---|
| Feed use rises but weight gain slows | Check feed wastage, water supply, feed quality, heat, litter and health signs. |
| Birds are uneven | Check feeder and drinker access, brooding history, competition, disease signs and sample method. |
| Mortality increases | Separate the mortality record, review water, temperature, ventilation, litter and clinical signs. Seek veterinary or extension support for sudden or serious losses. |
| FCR changes suddenly after a new feed | Verify the feed change, mixing, storage, mould risk and the weight/stock records before drawing conclusions. |
Turn FCR into a money decision
FCR becomes more useful when you calculate feed cost per kg of gain:
Feed cost per kg gain = FCR × feed price per kg
For example, if FCR is 1.75 and feed costs ₦500 per kg, feed cost per kg gain is ₦875. That still does not include chicks, labour, medication, power, transport, housing or mortality costs. Use the Broiler Profit Calculator to see the whole batch result.
How to improve FCR without chasing a magic number
- Measure feed, birds and weights accurately.
- Set feeder height correctly and repair leaking drinkers.
- Keep water clean and available at all times.
- Maintain dry litter, ventilation and comfortable house conditions.
- Weigh birds at regular intervals and act on poor uniformity early.
- Use the Poultry Space & Stocking Density Calculator to check whether crowding is likely to be limiting feed and water access.
- Do not change feed, lighting, stocking and treatment practices all at once if you want to know what changed performance.
Final point
FCR is a management signal, not a score to copy from another farm. Keep honest records, compare like with like, and investigate the reason behind a change. A practical FCR record can show whether the next decision should be about feed, water, bird comfort, health, mortality or marketing.
Next step: calculate your FCR, then use the profit calculator to see what the result means in money.
