Cornish Cross · day old chicks · May 26, 2026

How to Raise Cornish Cross Broilers: Complete Week-by-Week Guide

by Tyler Chastain

Flock of day-old Cornish Cross broiler chicks from Stumphouse Farms hatchery in Anderson, South Carolina

Your Cornish Cross chicks will reach processing weight in 8 weeks if you feed them correctly and prevent the three health problems that kill most meat birds. We've shipped thousands of Cornish Cross chicks from our Anderson, South Carolina hatchery to backyard growers and small farms, and the growers who follow this week-by-week feeding schedule consistently harvest 5-6 pound birds without leg problems or sudden death syndrome.

Cornish Cross broilers are the fastest-growing meat chickens available. They convert feed to meat more efficiently than any heritage breed. A Cornish Cross chick weighing 1.5 ounces at hatch will reach 6 pounds live weight in 8 weeks on 12-15 pounds of feed. No other meat bird comes close to that feed conversion rate.

This guide covers the exact feeding schedule, brooder setup, common health issues, and processing decisions we share with customers who order Cornish Cross chicks from Stumphouse Farms.

Should You Raise Cornish Cross Broilers?

Choose Cornish Cross if:

You want maximum meat in minimum time (8 weeks to harvest)
You prioritize feed efficiency over free-range behavior
You're comfortable managing rapid growth and accepting 2-5% mortality
You have adequate space (2 square feet per bird by week 8)
You can process birds at exactly 8 weeks

Avoid Cornish Cross if:

You want chickens that free range and forage actively
You expect zero mortality or perfect health outcomes
You want dual-purpose birds that lay eggs
You prefer slower-growing heritage breeds
You lack proper brooding equipment or space

If the "avoid" list describes your operation, consider Red Ranger broilers instead. They take 12-14 weeks but remain healthy and active throughout the growing period.

Cornish Cross vs Red Ranger: Which Meat Bird Should You Raise?

Factor	Cornish Cross	Red Ranger
Time to harvest	8 weeks	12-14 weeks
Dressed weight	4-5 lbs	4-6 lbs
Feed per bird	12-15 lbs	20-25 lbs
Feed efficiency	Excellent (2.0:1 conversion)	Good (3.0:1 conversion)
Health issues	Leg problems, sudden death common	Minimal health problems
Activity level	Low, cannot free range well	High, excellent foragers
Heat tolerance	Poor	Good
Mortality rate	5-10% typical	1-3% typical
Best for	Fast, efficient meat production	Pasture-based, free-range systems
Cost per bird	$9-10 total	$12-15 total

Bottom line: If your priority is speed and feed efficiency, choose Cornish Cross chicks. If you want a more forgiving bird that free ranges well, choose Red Rangers.

What Makes Cornish Cross Different from Other Meat Chickens

Cornish Cross broilers are a hybrid cross between Cornish and White Rock breeds developed for commercial meat production. They grow three times faster than heritage meat breeds.

Key differences:

Cornish Cross: 6 pounds at 8 weeks on 12-15 lbs feed
Red Ranger: 5 pounds at 12 weeks on 20-25 lbs feed
Heritage breeds: 4 pounds at 16+ weeks on 30+ lbs feed

The rapid growth creates specific management challenges. Cornish Cross cannot free range like heritage breeds because their legs cannot support sustained walking at heavy weights. They need high-protein feed constantly available, or they become aggressive and stressed. Their fast metabolism makes them sensitive to heat and requires careful brooder temperature management.

These birds were bred for one purpose: efficient meat production. They're meat production specialists, not backyard pets or dual-purpose birds.

Week-by-Week Broiler Growing Schedule

Week 1: Brooder Setup and Initial Feeding

Temperature: 95°F under heat lamp
Feed: 24% protein starter, available 24 hours
Space: 0.5 square feet per chick
Bedding: 3-4 inches of pine shavings

Start chicks at 95°F under the heat lamp. Use a 24% protein starter feed and provide feed 24 hours per day. Chicks should eat and sleep in cycles, never going more than 2 hours without eating or sleeping.

For 25 chicks, provide a minimum of 12.5 square feet of brooder space. Use pine shavings bedding on a chick brooder floor mat to prevent leg splay. Never use newspaper or slick surfaces.

Water consumption at this age is roughly double feed consumption by weight. Check chicks every 4-6 hours. They should be active, eating frequently, and spreading out under the heat. Huddling means they're cold. Panting means they're too hot.

Week 2: Temperature Drop and Feed Increase

Temperature: 90°F
Feed: 24% protein starter, 24-hour access
Space: 0.75 square feet per chick
Feed consumption: ~25 lbs total for 25 chicks this week

Drop brooder temperature to 90°F. Chicks will be noticeably larger and eating aggressively. You'll see a clear size difference between the largest and smallest birds by day 10. This is normal genetic variation.

Each chick now needs 0.75 square feet. Move to a larger brooder or reduce flock size if you see crowding. Overcrowded broilers develop leg problems and respiratory issues due to ammonia buildup in the litter.

Refill feeders at least once a day, morning and evening. Never let feeders go empty or birds will panic and pile.

Week 3: Move to Grower Feed

Temperature: 85°F
Feed: 20% protein grower, 24-hour access
Space: 1 square foot per bird
Target weight: 1-1.5 pounds at day 21

Switch from 24% starter to 20% grower feed. Birds should weigh 1-1.5 pounds at day 21.

Critical week for leg health: This is when leg problems start appearing if brooder management was poor in weeks one and two. Watch for birds limping, sitting instead of standing, or avoiding movement. These are early signs of leg weakness that will worsen if not addressed.

Increase space to 1 square foot per bird minimum. Provide multiple feed and water stations to prevent competition and ensure smaller birds can access resources.

Week 4: Watch for Heat Stress

Temperature: 80°F
Feed: 20% protein grower
Space: 1.5 square feet per bird
Feed per bird: ~1 pound daily from this point forward

Birds are large enough that they generate significant body heat. Heat stress becomes a major risk at this age, especially in warm weather.

Heat stress warning signs:

Panting with open beaks
Wings held away from the body
Reduced feed intake
Birds lying down instead of standing

If ambient temperature exceeds 85°F, provide fans, shade, and cool water. Some growers switch to night feeding during hot weather to reduce daytime metabolic heat.

Week 5-6: Decide on Feed Restriction

Temperature: 75-80°F
Space: 1.5-2 square feet per bird
Target weight: 4-5 pounds live weight
Feed restriction option: 12 hours on, 12 hours off

Birds are approaching 4-5 pounds live weight. This is when sudden death syndrome and leg collapse become serious risks if you push growth too hard.

Feed restriction schedule (if needed):

Remove feed at 8 PM
Provide feed at 8 AM
12 hours on, 12 hours off daily
Reduces sudden death syndrome by 50%
Extends processing time by 3-5 days

We recommend feed restriction if you're experiencing sudden deaths or severe leg problems. If your birds are active, healthy, and gaining steadily, continue 24-hour feed access to maximize growth.

Week 7-8: Final Growth and Processing Prep

Temperature: 70-75°F
Space: 2 square feet per bird
Target weight: 5.5-6.5 pounds live at day 56
Dressed weight: 70-75% of live weight

Birds should hit 5.5-6.5 pounds live weight by day 56. This is the prime processing age for most backyard growers. Dressed weight will be 70-75% of live weight after processing.

Processing at 8 weeks produces:

4-4.5 pound dressed birds (perfect roasters)
Less than 5% mortality is typical
Birds are still active and healthy
Excellent feed conversion maintained

Processing equipment matters at this stage. Without proper tools, processing 25 birds can take an entire day. A quality chicken plucker machine reduces hand plucking from 20-30 minutes per bird to under 60 seconds. For backyard operations processing 25-50 birds at once, the time savings from a single batch pay for the equipment.

If you choose to grow past 8 weeks, implement strict feed restriction (12 hours on, 12 hours off) and increase space to 2 square feet per bird. Monitor daily for sudden deaths and leg collapse. Process immediately if you see widespread health issues.

Three Health Problems That Kill Cornish Cross (And How to Prevent Them)

Sudden death syndrome, leg problems, and heat stress kill more Cornish Cross than predators and disease combined. All three stem from the breed's rapid growth rate and heavy body weight.

1. Sudden Death Syndrome (Flip-Over Disease)

What it is: Birds grow so fast that their heart cannot keep up with their body mass. They suddenly flip onto their backs and die, often after eating.

When it happens: Most common weeks 4-8

Prevention:

Feed restriction starting week 4 (12 hours on, 12 hours off)
Avoid excessive protein (don't exceed 24% in starter)
Process at 8 weeks, not later
Accept that 2-5% mortality is genetically normal

No cure exists once it happens. Some mortality from sudden death syndrome is inevitable with this breed.

2. Leg Problems (Twisted Leg, Leg Weakness)

What it is: Heavy breast weight stresses immature leg bones and joints. Birds that grow too fast or lack proper nutrition develop permanent leg deformities.

Warning signs:

Limping or favoring one leg
Sitting instead of standing
Reluctance to move to feed/water
Twisted or bowed legs

Prevention:

Use proper starter feed with correct calcium/phosphorus ratios
Provide adequate space (prevents overcrowding stress)
Use brooder floor mats in weeks 1-2 to prevent leg splay
Avoid slick floors that cause early leg injuries
Process at 8 weeks before severe problems develop

3. Heat Stress and Respiratory Failure

What it is: Cornish Cross generates enormous metabolic heat. At 6 pounds live weight in 80°F+ weather, they cannot cool themselves adequately.

Symptoms:

Panting with an open mouth
Wings held away from the body
Lying down, refusing to stand
Reduced or stopped feed intake
Sudden death during hot afternoons

Prevention:

Provide shade and ventilation after week 4
Use fans when temperature exceeds 85°F
Offer cool water (change frequently in hot weather)
Consider night feeding during heat waves
Process before the summer heat if possible

Real data from our South Carolina operation: Growers who maintain proper ventilation and process at 8 weeks see 3-5% mortality. Growers who push birds past 10 weeks in summer heat see 15-20% losses. The difference is entirely in management and timing.

Housing Requirements: Space and Equipment

Cornish Cross needs more space than you think. The standard 4 square feet per bird cited for heritage breeds will cause problems for Cornish Cross due to overcrowding, stress, and ammonia buildup.

Space requirements by age:

Age	Square Feet Per Bird	Example (25 birds)
Week 1-2	0.5-0.75 sq ft	12.5-18.75 sq ft total
Week 3-4	1-1.5 sq ft	25-37.5 sq ft total
Week 5-8	2 sq ft minimum	50 sq ft total

For 25 birds, that means 50 square feet total space by processing age. Most backyard brooder setups are undersized. Plan accordingly.

Feeder and waterer requirements:

Feeder space: 2 linear inches per bird (50 inches total for 25 birds)
Waterer space: 1 inch per bird (25 inches total for 25 birds)
Multiple feeding stations prevent competition stress

Litter management:

Start with 3-4 inches of pine shavings
Add fresh shavings weekly to absorb moisture
Never let litter become caked or wet
Wet litter causes breast blisters and respiratory problems

Outdoor access: Cornish Cross can go outside after week 3 if weather permits, but they will not free range effectively. Their heavy weight makes sustained walking difficult. Provide shade, protection from predators, and easy access back to shelter. Many growers keep Cornish Cross in tractors or confined outdoor pens rather than free-ranging.

Feed Costs and Return on Investment

Feed is your largest expense when raising Cornish Cross. A bird processed at 8 weeks consumes 12-15 pounds of feed from hatch to processing. Current feed prices in South Carolina run $18-22 per 50-pound bag for quality broiler feed.

Cost breakdown for one bird raised to 8 weeks:

Chick cost: $2.95 (Cornish Cross from Stumphouse Farms)
Feed cost (14 lbs @ $0.40/lb): $5.60
Bedding, heat, misc: $1.00
Total cost per bird: $9.55

Value returned per bird:

Live weight at 8 weeks: 6 pounds
Dressed weight (75%): 4.5 pounds
Retail chicken price: $4-6 per pound
Value of meat: $18-27

Your savings per bird: $8-17
Savings for 25-bird batch: $200-425

This assumes you process birds yourself. Custom processing at $3-5 per bird adds to costs but saves significant time. For growers processing their first few batches, custom processing while you learn is worth the cost.

The economics improve significantly if you grow larger batches. Fixed costs like brooder heat and equipment amortize across more birds. Many growers find that 50-100 birds per batch hits the sweet spot for backyard meat production.

Processing at 8 Weeks vs Waiting to 12 Weeks: The Data

Most backyard growers process Cornish Cross at 8 weeks for good reason. Birds are healthy, active, and growing efficiently at this age.

8-Week Processing Results:

Dressed weight: 4-5 pounds (perfect roasters)
Mortality rate: 3-5% typical
Feed conversion: Excellent (2.0:1)
Bird health: Active, mobile, healthy
Processing ease: Clean feathers, firm skin

10-12 Week Processing Results:

Dressed weight: 6-8 pounds
Mortality rate: 10-15% common (some operations see 20%+)
Feed conversion: Declining (2.5:1 or worse)
Bird health: Leg problems are frequent, many cannot walk
Processing difficulty: Skin tears, heavy birds are harder to handle

Case study from a Georgia customer: Runs 200 Cornish Cross twice a year. Processes at exactly 56 days for every batch. Dressed weights average 4.2 pounds with 2% mortality. Feed cost per pound of meat: $1.28. His consistency comes from never deviating from the 8-week harvest window.

Case study from a North Carolina customer: First batch pushed to 10 weeks for bigger birds. Lost 30% to sudden death syndrome and leg collapse. The second batch was processed at 8 weeks with feed restriction starting week 4. Lost only 3%. Lesson learned: Don't fight the breed's genetics.

We recommend 8-week processing for first-time growers. Once you master the basics, you can experiment with longer growth periods to get larger birds. But understand that you're pushing these birds past their optimal harvest window.

What We've Learned from 20+ Years Shipping Cornish Cross

Stumphouse Farms ships Cornish Cross chicks every week from mid-March through November. Tyler and Lydia have seen every mistake new growers make and every management practice that works.

The pattern among successful growers:

Provide 2x the space they initially think necessary
Maintain strict temperature control (95°F week 1, drop 5°F weekly)
Process at exactly 8 weeks, not "when they look big enough"
Use feed restriction if any sudden deaths occur
Have processing equipment ready before the birds reach weight

The pattern among struggling growers:

Underestimate space requirements (try to use 1 sq ft per bird at week 8)
Attempt free ranging like heritage breeds
Wait for 10-12 weeks, hoping for bigger birds
Blame the chicks instead of management
Process by hand without proper equipment

Growers who treat Cornish Cross as specialized meat-production birds succeed. The growers who expect them to behave like backyard chickens struggle.

If you want chickens that free range, forage, and remain healthy past 8 weeks, order Red Rangers instead. If you want maximum meat from minimum feed in minimum time, Cornish Cross is unmatched.

Frequently Asked Questions About Cornish Cross Broilers

Can Cornish Cross free range like other chickens?
No. Their heavy weight and rapid growth make sustained walking difficult. They can go outside in confined pens or tractors, but will not forage effectively like heritage breeds. Most successful growers keep Cornish Cross in stationary or mobile pens with easy access to feed and water.

Why do some Cornish Cross die suddenly with no warning?
Sudden death syndrome (flip-over disease) results from heart failure as the bird's cardiovascular system cannot keep pace with explosive muscle growth. It typically happens after eating. Feed restriction reduces the incidence, but 2-5% mortality is within the normal range for this breed.

Should I feed Cornish Cross medicated or non-medicated starter?
Use a medicated starter containing amprolium to prevent coccidiosis unless you're growing certified organic birds. Coccidiosis stress combined with rapid growth increases sudden death syndrome risk. Switch to non-medicated grower feed at week 3.

How much does it cost to raise one Cornish Cross to processing weight?
Approximately $9-10 per bird, including chick cost, 12-15 pounds of feed, and bedding. This produces a 4-5 pound dressed chicken worth $18-27 at grocery store prices, saving $8-17 per bird.

Can I keep some Cornish Cross as laying hens?
No. Cornish Cross are bred solely for meat production and have severe health problems if kept past 12 weeks. They do not lay well and typically die from leg problems or heart failure before reaching laying age. Order layer chicks for egg production instead.

What's the best age to process Cornish Cross?
8 weeks (56 days) produces the best combination of bird health, feed efficiency, and meat quality. Waiting beyond 8 weeks significantly increases mortality and reduces feed conversion efficiency.

Start Your Meat Bird Operation Right

Raising Cornish Cross broilers successfully requires planning, proper equipment, and realistic expectations about this breed's strengths and limitations. They're not backyard pets or dual-purpose birds. They're meat production specialists that convert feed to meat faster than any other chicken breed available.

Order your Cornish Cross chicks from Stumphouse Farms and receive healthy, vaccinated chicks shipped directly from our Anderson, South Carolina hatchery. We ship weekly from March through November with confirmed hatch dates you choose at checkout.

Before chicks arrive:

Set up the brooder two days early
Have 24% starter feed, pine shavings, and heat lamp ready
Prepare feeders and waterers (2 inches feeder space per bird)
Test brooder temperature at 95°F

Processing equipment saves massive time: Hand plucking 25 birds takes 8-12 hours. A quality chicken plucker reduces total processing time to 2-3 hours. View our complete poultry processing supplies for everything you need.

Process at 8 weeks for the best combination of bird health, feed efficiency, and meat quality.

Legal Disclaimer: This guide provides general information on raising Cornish Cross broiler chickens based on Stumphouse Farms' experience as a hatchery. It is not professional agricultural or veterinary advice. Poultry health, growth rates, and feed conversion can vary based on genetics, environment, management practices, and other factors. Consult with a licensed veterinarian or agricultural extension agent for specific guidance on poultry health issues or mortality problems. Local regulations regarding backyard poultry keeping and home processing vary by jurisdiction. Always follow USDA guidelines for safe poultry processing and handling.

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