Short answer: The Cornish Cross is a white, heavy-breasted broiler that most small and medium farms finish between six and eight weeks at roughly 2.5 to 3.5 kilograms. In our planning table a batch reaches about 3.25 kilograms by week seven at a cumulative feed conversion near 2.3. Its weight comes with leg, walking and heat risks, so it needs disciplined feeding, a managed light programme and enough floor space.
Key takeaways
- Plan a Cornish batch around seven weeks, at about 3.25 kilograms and a cumulative FCR near 2.3, and judge it against its own table.
- Step the feed down from about 22 percent protein to 18 to 19 percent across three phases, and move on when the birds clean the current ration.
- Walk the house every morning from week four, because the breast weight is what puts strain on the hocks and feet.
- Use long, dim light in week one and reduce the day to about 18 hours to slow the early rush.
- Stock finishing birds at about 10 per square metre on dry litter, and plan the house for the heaviest week rather than the first.
What the Cornish Cross is, and what it is not
The Cornish Cross is not the fastest broiler you can buy, and that is exactly why some farmers keep it. It is a cross of a heavy, broad-breasted Cornish male line with a White Plymouth Rock female line. The result is a white-feathered bird with a deep, full breast, and most small and medium farms finish it between six and eight weeks at around 2.5 to 3.5 kilograms.
It is a meat bird and nothing else. Do not expect eggs from the hens in any useful quantity, and do not keep the cockerels for breeding unless you know what you are doing with a mixed flock. Its value is the weight it reaches on a moderate feed bill, and the way it fills the market when you need a heavy bird for a festive order.
On our own price page, the broilers we list are Ross 308 and Cobb 500, from GH₵20 a chick in a box of 1,000 for the Ross and the same starting price for the Cobb. The Cornish Cross is a different animal from both. Read our Ross 308 guide and Cobb 500 guide side by side with this one before you decide which bird fits your house and your buyers.
If you want the chick-level basics for any broiler, our broiler day-old chicks page covers ordering and dispatch, and the delivery page explains how boxes reach you in any of the 16 regions.
The week-by-week targets we plan a Cornish batch around
These are the planning targets we use when a farmer asks what a Cornish batch should look like at each week. They are typical values for a well-managed flock on a standard three-phase programme. Your breeder's performance guide is the figure to follow for your birds, and if a batch runs well below these numbers for two weeks in a row, something in the house needs looking at.
| Week | Target live weight (g) | Cumulative feed per bird (kg) | Cumulative FCR |
|---|---|---|---|
| 1 | 165 | 0.14 | 1.14 |
| 2 | 450 | 0.52 | 1.27 |
| 3 | 950 | 1.35 | 1.49 |
| 4 | 1,550 | 2.55 | 1.69 |
| 5 | 2,150 | 3.95 | 1.87 |
| 6 | 2,750 | 5.55 | 2.05 |
| 7 | 3,250 | 7.30 | 2.28 |
| 8 | 3,700 | 9.20 | 2.52 |
The FCR column is the cumulative feed conversion from a day-old chick weighing about 42 grams. It climbs every week, and the climb speeds up after week five, when the birds are eating heavily and the breast is filling out. A rising FCR is normal. An FCR that climbs faster than this table in the same week is a warning that feed is being wasted or the birds are not eating what they should.
The gap between week five and week seven is where a Cornish batch makes or loses money. Feed is most of your cost, and every extra day you hold a bird past its best conversion costs more than the day before.
Feeding on the bird's timetable: three rations, three protein levels
A Cornish Cross should be fed by age and by the protein it needs at that age, not by how many bags are left in the store. We run three phases, and we step the protein down as the birds grow. The phases below are typical values; check your feed label and ask your feed supplier to confirm the protein and energy on the bag.
- Starter, days 0 to 14: about 22 to 23 percent crude protein, finely crumbled, with clean water beside the feed from the first hour.
- Grower, days 15 to 28: about 20 percent crude protein, pelleted or crumbled, and checked for mould or clumping in the humid months.
- Finisher, day 29 until processing: about 18 to 19 percent crude protein, fed in a feeder that a heavy bird can reach without climbing.
The switch between phases is where we see most of the waste. Changing ration on a set date while the birds are still growing fast can leave half a day's feed in the trough and a few hungry birds at the far end of the house. Move to the next phase when the birds are eating the current feed cleanly, and keep a little of the old ration in the store in case a batch needs a day more.
Feed space matters more for this bird than it does for a lighter one. Aim for at least 5 centimetres of trough per bird in the finisher phase, and check that the heaviest birds are not being pushed off the feeder by the faster-moving ones.
Why the breast weight shows up in the legs by week five
The Cornish's deep breast is the reason it sells, and it is also the reason its legs take strain. By week four and five the front of the bird is heavy enough to shift its centre of gravity, and the hocks and the feet carry the load on litter that may be damp or caked. A bird that sits down to eat, or that stops to rest after three steps, is telling you the legs are struggling.
Walk the house every morning from week four. Look for birds that do not get up when you approach, birds with swollen hocks, and birds that roll onto their backs when they try to rise. Remove the worst cases to a quiet pen, and note the count. If the number grows week on week, check the litter first, then the feed balance for calcium and phosphorus, and then the stocking density.
Our leg problems guide covers the causes and the signs in more detail, and the ascites article explains the other problem a fast-growing heavy bird can develop, which is fluid in the abdomen when the heart and lungs cannot keep up with demand.
Lighting that slows the early rush
Long light programmes push a broiler to eat more, and a Cornish Cross on long light will eat and grow faster than the table above assumes. Many small producers use a long, dim light in the first week so the chicks find the feeder and the drinker, then reduce the day to around 18 hours of light. The slower rise in the middle of the grow-out gives the legs and the heart time to keep pace with the body.
Keep the light even across the house. A bright spot at the feeder and a dark corner by the wall will send birds into a crowd, and a crowd on a cold morning is where smothering and bruising start. Use a dimmer or a timer if your house allows it, and check the light level at bird height rather than on the ceiling.
- Week one: long, dim light so chicks find feed and water.
- Week two onward: reduce to about 18 hours, with a dark period the birds can rely on.
- Check the light at bird height, not at the roof.
- Write the programme on the house door so every helper runs the same one.
Density for a bird heading to three kilograms
A heavy bird needs floor space in a way a light one does not. By the last two weeks, a Cornish Cross at around 3 kilograms needs room to turn round, and the litter under her feet has to stay dry enough that she does not sit in it. We aim for about 10 birds per square metre for birds heading toward that weight, and we would sooner see a farmer under-stock by a few birds than over-stock by a few kilograms.
Density is not only about the floor. Feeder and drinker space, ventilation and the number of birds per house all add up. A house that is full at 35 days can be dangerously short of air at 49 days, when the same birds weigh almost twice as much and breathe harder. Plan your house for the heaviest week, not the lightest one.
If you are sizing a house for a full batch, the stocking density article sets out the general rules, and our bulk page explains how larger orders are quoted so you can match the number of birds to the house.
Feed cost per kilo: a worked example for a 45-bird batch
Take a batch of 45 Cornish Cross birds processed at seven weeks, at the target of 3.25 kilograms each. That is roughly 146 kilograms of live meat. Each bird has eaten 7.30 kilograms of feed by then, so the batch used about 329 kilograms of ration.
The feed conversion ratio over that period is 2.28. Take GH₵8 a kilo as a placeholder for the arithmetic, and replace it with the figure on your own receipt. At that price, each kilo of live gain costs about GH₵18.24 in feed, and the batch feed bill comes to roughly GH₵2,630.
Run the same sum with your own ration price and your own weights. The useful number is the feed cost per kilo of gain, because it lets you compare a Cornish batch with a faster or slower line on the same feed. If your local price per kilo of live bird is well above that, the Cornish makes sense. If it is not, check your weights and your waste before you change the breed.
Before you buy chicks, check the current figures on our prices page, and place the order through the order form once you have the numbers for your house.
Need chicks for your next batch?
Send breed, number and town. We reply with price, hatch date and delivery cost in writing.
Processing at six, seven or eight weeks
The processing age is a business decision, and the bird does not choose it for you. At six weeks, a Cornish is lighter, cheaper to feed per bird and quicker to turn the house. At seven weeks it sits near the top of its growth curve and the feed bill per kilo is still reasonable. At eight weeks the bird is at its heaviest, but the feed cost per kilo of gain has climbed, and the birds take longer to clear the house.
Pick the age that matches your buyer. A trader who wants a heavy bird for a festive order will pay for weight. A household that buys one bird for a family pot may prefer a slightly lighter, younger carcass. Write down what each batch weighed and what it sold for, and within three batches you will know your own best age.
Withdraw feed for a few hours before processing so the gut is clear, following the timing your processor or your vet advises. Never withdraw water.
Heat and the dry season in Central Region
A heavy white bird does not handle heat well, and a Cornish Cross in the hottest weeks of the dry season will eat less in the afternoon and pant more at night. From week four the birds are generating a lot of heat themselves, so the house needs to get rid of it. Open the side curtains early, keep the water cool and check the drinkers twice a day.
Dusty harmattan air in December and January can also irritate the airways of heavy birds. Keep the litter damp enough to hold the dust down, but not wet, and sweep the walkways rather than pushing dust into the house. A bird that breathes through an open beak for a long time is telling you the house is too hot or too dry.
For the signs of heat stress in a heavy flock, our heat stress article lists what to look for, and the heavy broilers guide covers the feed and house steps that matter most for a bird this size.
Checklist for a Cornish batch from arrival to processing
Print this list and keep it in the house. Each step is something we have seen a farmer skip, and each one costs weight or birds when it is missed.
- Count the chicks at the gate, and photograph any doubtful bird for us that same day.
- Brood at the right temperature and check the chicks' spread within the first hour.
- Start the starter ration and clean water before the chicks settle, and keep both topped up.
- Step to the grower at day 15 once the birds are eating the starter cleanly.
- Walk the house every morning from week four and remove any bird that cannot get up.
- Weigh a sample of ten birds each Monday and compare with the target table.
- Step to the finisher at day 29 and keep the trough space at the target level.
- Withdraw feed for the time your processor advises, and record the weight and sale price.
Our poultry vaccination schedule lists the typical timings for the programme we give at the hatchery, and your vet's advice sets the dates for your own house.
Questions farmers ask
What is a Cornish Cross broiler?
It is a white, heavy-breasted meat bird, a cross of a Cornish male line with a White Plymouth Rock female line. Most small and medium farms finish it at six to eight weeks, at roughly 2.5 to 3.5 kilograms. It is a meat bird only, and it is not kept for eggs.
How heavy does a Cornish Cross get?
In a well-managed batch, birds typically reach around 3.25 kilograms by seven weeks, with heavier birds at eight weeks. The weight depends on feed, space, light and heat, so use the breeder's guide and your own weighings rather than any single figure.
How much feed does a Cornish Cross need?
By week seven, a bird on a planning table of this kind has eaten about 7.3 kilograms of feed, with a cumulative conversion near 2.3. Feed cost is most of your expense, so track feed per kilo of live gain and compare batches on that basis.
Why do Cornish Cross birds struggle to walk?
The deep breast puts weight forward, and by weeks four and five the hocks and feet carry a lot of load. Damp or caked litter, high stocking density and a feed balance that is off for calcium and phosphorus all make it worse. Walk the house every morning and remove birds that cannot rise.
Should I use long light or short light for Cornish birds?
Many small producers start with long, dim light in the first week so chicks find feed and water, then reduce to about 18 hours. A long light programme pushes early growth and can make leg problems and heart strain more likely in a heavy bird.
Is the Cornish Cross the same as the Ross 308?
No. The Ross 308 and the Cobb 500 are faster commercial lines with better feed conversion at the same age. The Cornish Cross is slower and heavier in the breast, and its conversion is higher at the same weight. Compare the tables and the feed bills before you choose.
Can I keep Cornish Cross birds for breeding?
Not with any useful result. The cross is designed for meat, and the breeding stock is kept under strict management that a small flock cannot reproduce. If you want to breed, keep a separate flock of suitable hens and cockerels and speak to a vet or an experienced breeder first.
