If your chicks are dying during brooding, the first thing to do is not to start changing drugs or feed at random. Start by looking at when the deaths began, how the chicks are behaving, and whether the problem is affecting the whole brooder or only a few birds.
Use this approach to investigate high brooding mortality on a farm. A chick that dies because it was chilled, dehydrated or trampled needs a different correction from a chick dying from yolk sac infection, respiratory disease or another infection.
This guide will help you work through the likely causes in a practical order. If the flock is also panting, huddling, growing unevenly or showing other management problems, use our Common Chicken Problems guide alongside this one.
What Is High Brooding Mortality?
Brooding mortality simply means chicks are dying during the period when they still depend heavily on the farmer for warmth, easy access to feed and water, good air, dry litter and protection.
The first week deserves special attention because a lot can go wrong very quickly. Day old chicks have just been hatched, handled, transported and placed into a completely new environment. If they arrive weak, stay too long without water, become too hot or too cold, or cannot find feed, you can lose birds before the real cause becomes obvious.
There is no single mortality percentage that diagnoses the problem on every farm. What matters is the pattern. A sudden jump in deaths, deaths continuing every day, or mortality accompanied by weakness, diarrhoea, swollen navels, gasping, tremors or poor feed and water intake should be investigated promptly.
Before Anything Else: Check the Pattern of Deaths
When chicks are dying, check three things immediately.
- What age are the chicks?
- When did mortality start?
- What were the chicks doing before they died?
Deaths that begin within the first day or two can point you towards chick quality, transport stress, dehydration, placement conditions or severe temperature problems. Deaths building over the first week can also involve poor feed or water access, brooder conditions, navel or yolk sac infection and other early infections. Mortality that begins later may shift the investigation towards disease challenge, litter, ventilation, coccidiosis risk, feed problems and wider flock management.
Do not use age alone to diagnose a disease. Use it as a clue.
The 10-Minute Brooding Mortality Check
Before you open a drug cabinet, walk the brooder and check these points:
- Chick distribution: Are they spread comfortably, packed under the heat, pushed to the edge or piled in corners?
- Water: Is clean water actually reaching every drinker? Can the smallest chicks reach it?
- Feed: Is starter feed available and easy to find? Are crops filling after placement?
- Heat: Is the temperature appropriate for the chick age, humidity and production system?
- Air: Is the house fresh, or is it smoky, stuffy or smelling strongly of ammonia?
- Litter: Is it dry and comfortable, or wet, mouldy, cold or badly caked?
- Chick quality: Are navels closed? Are chicks bright and active, or weak with wet or swollen navels?
- Space and equipment: Are chicks crowding because there are too few drinkers, feeders or warm areas?
- Predators and accidents: Any rat attack, trampling, drowning, piling or equipment failure?
- Records: How many died today, yesterday and the day before?
For the complete setup side of brooding: before mortality begins: see our Guide to Chicks Brooding. For broilers specifically, use Broiler Chicks Brooding: What You Should Know.
Why Are My Chicks Dying During Brooding?
1. Chilling: The Chicks Are Too Cold
Cold chicks usually tell you before they die. They crowd tightly around the heat source, make more noise, pile on one another and may stop moving around normally to eat and drink.
The danger is not only “cold” itself. Once chicks huddle, weaker birds can be smothered or trampled, feed and water intake falls, and the whole flock gets off to a poor start.
Do not judge the brooder by the thermometer alone. Watch the chicks. The current Ross Broiler Management Handbook also emphasises bird behaviour, feed and water access, brooding conditions and crop fill when troubleshooting problems in the first seven days.
2. Overheating and Dehydration
The opposite problem can kill chicks too.
If they are avoiding the heat source, spreading far away from it, panting or lying flat and inactive, check for excessive heat. Also check the water immediately. Chicks left too long in transport boxes or in a hot brooder can dehydrate quickly.
In hot Nigerian weather, do not assume that because chicks are young they always need “more heat.” What they need is the right environment. Our Heat Stress in Poultry guide explains the warning signs and cooling priorities.
3. The Chicks Cannot Find Enough Water
A water tank can be full while chicks are still short of water.
Walk the line. Touch the nipples. Check every drinker. Look for drinkers that are too high, empty, leaking or blocked. Watch the smallest chicks and see whether they can actually drink.
After placement, feed and water need to be easy to find. Aviagen’s 2025 guidance specifically recommends checking that chicks have found both feed and water after they settle and using crop fill as one of the practical checks of a good start.
If water stops even for a short time during hot weather, the effect can be much worse because thirsty chicks also reduce feed intake and crowd around the first water point that comes back on.
4. Poor Feed Access or a Poor Start
Do not blame “bad feed” before checking whether the chicks are eating it.
Is starter feed available immediately? Is it fresh? Is it easy for chicks to find? Are there enough feeding points? Are weaker chicks being pushed away?
A chick that does not start eating properly can become weak very quickly. Birds that survive a poor start may later appear as the small, uneven birds we discussed in our Stunted Growth in Chickens guide.
Do not respond by adding random protein, salt, vitamins or medication to a complete ration. First identify whether the problem is feed quality, feed access, chick health or another management issue.
5. Poor Chick Quality Before the Birds Reached Your Farm
Sometimes the problem started before you opened the chick boxes.
Look at the chicks on arrival. Are they active and alert? Are many very small? Are navels properly closed? Are there red hocks, wet abdomens, abnormal legs or a bad smell around the navel?
This is one reason records from the first hour matter. If many chicks arrive weak or dead on arrival, document it immediately and contact the hatchery.
Historical Nigerian evidence supports taking hatchery quality seriously. A 2009 survey of three hatcheries around Jos reported weak chicks, dead chicks, omphalitis and physical abnormalities among the reasons for culling, and highlighted hygiene and sanitation problems as important concerns. That study is old and should not be treated as today’s national prevalence, but it remains useful Nigerian evidence about how hatchery conditions can affect chick quality. Read the study.
6. Omphalitis or Yolk Sac Infection
If chicks are dying in the first days and you are seeing unhealed, swollen, wet or dark navels, a bad smell, weakness and poor weight gain, yolk sac infection needs veterinary attention.
The MSD Veterinary Manual explains that omphalitis is an infection of the navel or yolk sac in young poultry and is associated with contamination, unhealed navels and hatchery or incubation problems. Chilling or overheating during transport or early placement can worsen losses.
Do not give antibiotics to the whole flock blindly. Severely affected chicks may respond poorly, and the underlying hatchery, sanitation or brooding problem still needs to be identified.
7. Poor Ventilation, Smoke and Harmful Gases
A brooder can be warm and still be dangerous.
This is especially important where charcoal, kerosene or gas is used. If the brooder is sealed too tightly to “keep heat inside,” smoke and combustion gases can build up while oxygen and air quality worsen.
Good brooding is a balance: keep chicks warm without turning the house into a closed box. If you smell ammonia strongly at chick level, the environment is already poor.
Wet litter makes that worse. Use our Poultry Litter Management guide and Wet Litter troubleshooting guide if litter or ammonia is part of the problem.
8. Wet, Mouldy or Contaminated Litter
Chicks spend their whole day close to the floor, so litter quality matters a lot.
Wet litter chills chicks, dirties them, increases ammonia and creates conditions that favour disease. Mouldy brooder material can also create serious respiratory problems.
If young chicks are gasping and mouldy litter, feed or brooder material is involved, our Aspergillosis or Brooder Pneumonia guide explains what to look for.
9. Overcrowding, Piling and Trampling
Early chick mortality can be a simple physical management problem.
If chicks all rush into one corner because of cold, a sudden noise, poor brooder design or uneven heat, the birds at the bottom can suffocate or be crushed.
Watch where the dead chicks are found. Several chicks dead in one corner tells a different story from chicks dying one by one across the house.
Make sure the brooder guard, heaters, feeders and drinkers are arranged so chicks can move freely without creating dangerous bottlenecks.
10. Infectious Disease
Not every brooding death is management related.
Diseases and infections can cause mortality, but the signs overlap. Weakness, diarrhoea, respiratory noise, swollen navels, tremors, paralysis, sudden mortality or abnormal droppings all need proper investigation.
Use our Signs of a Sick Chicken guide and the Poultry Diseases and Symptoms in Nigeria guide to organise the signs you are seeing, but do not diagnose a disease from one symptom.
When mortality is climbing, a fresh dead bird submitted promptly for post mortem examination can tell you far more than guessing from photographs or trying several drugs one after another.
What Does the Timing of Chick Deaths Tell You?
Deaths on Arrival or Within the First 24 Hours
Think first about transport, dehydration, chick quality, hatchery problems, extreme brooder temperature and whether placement was delayed.
Deaths Building Through Days 2 to 7
Recheck feed and water access, temperature, crop fill, navel quality, litter, ventilation, sanitation and early bacterial infection.
Deaths Beginning After the First Week
The list widens. Brooding management still matters, but disease challenge, litter deterioration, feed problems, respiratory disease and intestinal disease become more important possibilities.
This timing approach is only a troubleshooting tool. It is not a laboratory diagnosis.
Vaccination: Important, but Do Not Copy a Schedule from Another Country
Vaccination is part of flock protection, but this article will not give you one universal broiler vaccination calendar.
Vaccination programmes depend on local disease pressure, maternal antibodies, hatchery vaccination, vaccine type, farm history and veterinary recommendations. A schedule copied from Europe, South Africa or another Nigerian farm may not be appropriate for your flock.
For Nigerian farmers, confirm the programme with the hatchery, veterinarian or a competent local animal health authority. Also remember that vaccination does not correct cold stress, dehydration, poor ventilation, dirty water or poor chick quality.
What Should You Do When Brooding Mortality Starts Rising?
- Count and record the dead chicks. Do not rely on memory.
- Check the brooder before changing treatment. Temperature, chick distribution, water, feed, ventilation and litter come first.
- Remove dead chicks promptly. Keep them away from live birds and feed/water areas.
- Inspect several sick chicks, not just one. Look for common signs.
- Document chick quality. Especially navels, deformities and dead on arrival chicks.
- Check equipment. Heater failure, empty water lines and blocked drinkers can affect many chicks at once.
- Call for veterinary help early when mortality continues. Do not wait until a large part of the flock is gone.
- Use post mortem or laboratory diagnosis when indicated. This is especially important when disease is suspected or losses continue despite correcting management.
What Not to Do
- Do not keep adding heat because the chicks are young. Too much heat can be as damaging as too little.
- Do not close every opening in the brooder to preserve heat. Chicks still need fresh air.
- Do not start antibiotics simply because chicks are dying. Mortality is a sign, not a diagnosis.
- Do not copy another farm’s vaccination or medication programme.
- Do not ignore water because the drinkers “look full.” Check that chicks can actually drink.
- Do not leave dead chicks lying in the brooder.
- Do not throw away your records. Daily mortality patterns can reveal when the problem started.
Frequently Asked Questions
Why are my day old chicks dying one after another?
Start with chick quality, transport stress, dehydration, brooder temperature, water access and navel condition. If mortality continues after those are corrected, get veterinary investigation rather than assuming one cause.
Why do chicks huddle and then die?
Huddling commonly points to cold, draughts or an uneven brooder environment, but frightened chicks can also pile. Check the temperature at chick level and watch whether the birds spread out normally after correction.
Can too much heat kill chicks?
Yes. Chicks that are too hot may avoid the heat source, pant, become inactive and drink more. Severe overheating and dehydration can be fatal.
Should I give antibiotics when chicks start dying?
Not automatically. If the cause is cold, dehydration, smoke, poor water access or trampling, antibiotics will not correct it. If bacterial disease is suspected, diagnosis and veterinary guidance are much more useful than blind medication.
That caution is also supported by Nigerian field evidence. A 2010 study of early chick mortality on small scale farms in Jos found that most affected farms self diagnosed and treated birds without veterinary consultation. The authors warned about antibiotic misuse and recommended better management, hygiene and sanitation alongside proper diagnosis.
Can poor hatchery quality cause brooding mortality?
Yes. Weak chicks, unhealed navels, dehydration, incubation problems and hatchery contamination can affect early survival. Record chick condition immediately on arrival so you can separate farm problems from problems that were already present.
When should I call a veterinarian?
Call promptly if mortality is increasing, several chicks show the same disease signs, you see swollen or foul smelling navels, severe diarrhoea, respiratory distress, tremors or paralysis, or mortality continues after correcting obvious brooder problems.
Bottom Line
High brooding mortality is not one disease. It is a warning that something has gone wrong with the chicks, the brooder, the environment, management or health.
Start with the pattern. Check heat, water, feed, air, litter and chick quality before you reach for treatment. Then use the age of the chicks and the signs you are seeing to decide whether you are dealing mainly with a management problem, a hatchery/chick quality problem or a disease problem.
The faster you identify the real cause, the better your chance of protecting the rest of the flock: and avoiding the same loss in the next batch.
Veterinary disclaimer: This guide provides general poultry management and animal health information. It does not replace flock examination, post mortem diagnosis, laboratory testing or treatment advice from a qualified veterinarian or animal health professional.
