The maize arrived on a Friday in the middle of the June rains. The trader from Techiman had given a good price, the bags looked full, and the farmer stacked them straight onto the floor of his feed room in Kasoa because the pallets were being used for something else. Three weeks later his broilers had stopped growing, a few had yellow, swollen livers at post-mortem, and the layers next door were laying 15 percent fewer eggs than the week before. Nothing in the flock was infectious. The problem was in the sacks.
Aflatoxin is a poison produced by moulds, mainly Aspergillus, that grow on maize, groundnuts and other feed ingredients when they are damp and warm. Ghana has both in abundance for half the year. The toxin is invisible, tasteless and heat-stable, so cooking does not remove it, and a bag of maize can look reasonably clean and still carry enough to damage a flock. This guide explains what it does, how to detect trouble early, and the storage habits that keep feed safe from harvest to feeder.
What aflatoxin does inside a chicken
The toxin attacks the liver first. In a young broiler the liver is working hard to build muscle, and aflatoxin slows protein synthesis, so growth stalls and feed conversion worsens. It also suppresses the immune system, which is why flocks eating contaminated feed break with Gumboro, coccidiosis or Newcastle more easily even when properly vaccinated. In layers it reduces egg production, lowers egg weight, and can cause pale yolks and weaker shells. Ducks and turkeys are even more sensitive than chickens.
There is no single "safe" dose because effects build up over weeks. A low level with no visible symptoms can still cost two or three points of feed conversion, which on a batch of 1,000 broilers is real money. High levels kill outright, with livers enlarged and yellowish and kidneys swollen.
Signs in the flock that point to bad feed
- Broilers uneven in size at three to four weeks, with some birds clearly stunted, despite good brooding.
- Feed consumption dropping, or birds picking through the feed and leaving parts of it.
- Pale combs, ruffled feathers and dullness without fever or respiratory signs.
- Sudden fall in egg numbers with no disease pattern, especially after a new delivery of feed or maize.
- Increased leg weakness, bruising and slow healing of small wounds because clotting is affected.
- Post-mortem: enlarged, pale or yellow-brown liver, sometimes with small haemorrhages; swollen kidneys.
- Vaccination failures, with disease breaking in flocks that should have been protected.
None of these is proof on its own. The link most farmers miss is timing. If trouble started 7 to 14 days after a new batch of feed or maize came in, suspect the feed before anything else. Our guide on how to know a sick chicken helps separate feed problems from infection.
Where mould starts: moisture, heat and time
Mould needs three things: grain moisture above about 13 to 14 percent, warmth, and time. Ghana supplies the warmth all year. Moisture comes from grain sold before it is properly dried, from bags absorbing damp through a concrete floor, from rain blowing into a store, and from condensation between cool nights and hot days. Time is the factor you control most easily, because feed used within three weeks has little chance to spoil.
The rainy season, from roughly April to July in the south and later in the north, is the danger period. Humidity sits above 80 percent for weeks, maize harvested in the minor season is often sold damp, and feed rooms with poor ventilation become incubators. Our article on rainy season poultry management covers the wider farm; here we focus on the feed store.
The bottom bag problem
Bags stacked directly on a concrete floor draw moisture up from below. The bottom layer moulds first and is often the last to be used. When you open the store after a wet week and smell mustiness, check the bottom bags before the top ones.
Inspecting maize before you pay
We buy maize in bulk for our own birds and this is the routine we use at the lorry. Push a hand deep into several bags, not just the top one; grain that is warm inside or feels slightly damp is not dry enough. Take a handful and smell it. Sound maize smells faintly sweet; mouldy maize smells musty or sour. Look for kernels that are blue-green, black, shrivelled or dusty. Bite one; dry maize cracks sharply, damp maize is chewy. A cheap grain moisture meter pays for itself in one avoided bad load. Never accept a lower price for questionable grain thinking you can sort it. The toxin is in the kernels that look fine too. If you mix your own feed, our guide to local feed ingredients in Ghana pairs with this one.
A storage routine that works in Ghana
The table below is the checklist we follow. None of it is expensive; most of it is discipline.
| Practice | How to do it | Why it matters |
|---|---|---|
| Raise bags off the floor | Wooden pallets or timber rails at least 10 cm high | Stops floor moisture wicking into bags |
| Keep bags off the walls | Leave a 30 – 50 cm gap all round | Walls sweat during rains; gap allows airflow and rodent checks |
| Stack low and loose | No more than 8 – 10 bags high, with gaps between rows | Heat builds in the middle of tight, tall stacks |
| First in, first out | Date each delivery; use oldest bags first | Prevents forgotten bags from spoiling at the back |
| Limit stock time | Mixed feed used within 3 – 4 weeks; whole maize within 3 – 4 months if dry | Mould and vitamin loss both increase with time |
| Ventilate and shade | Vents high on opposite walls, roof that does not leak, no direct sun on bags | Keeps store cool and dry |
| Control rodents and insects | Bait stations, sealed doors, no spilled feed | Rats and weevils bring moisture and open bags |
| Add a mould inhibitor or binder | Propionic acid product or clay-based toxin binder at the label rate | Extra protection in the wet season or for grain of doubtful quality |
These are practical orientation guidelines drawn from our own farm and dealers we trust. Confirm product rates on the label and adjust storage times to your local humidity.
What to do if you suspect contaminated feed
Stop feeding the suspect batch immediately and switch to a fresh, trusted source. Do not "dilute" bad feed with good; the toxin is still going into the bird. Give the flock a liver support product and extra vitamins, particularly A, E and K, in the water for five to seven days. A clay-based toxin binder in the new feed helps mop up residual toxin in the gut. Broilers usually recover growth within a week or two if caught early; layers take longer. Keep a sealed, labelled sample of the suspect feed in case you need to raise the matter with the seller or have it tested. Our guide to vitamins and supplements for poultry lists what supports recovery.
A weekly feed store walk
Every Monday, open the store, smell the air, lift a bottom bag, check for rodent droppings, and look at the roof for leaks. Five minutes a week catches most problems before they reach the flock.
Frequently asked questions
Can I still feed maize that has a few mouldy grains?
Does sun-drying mouldy maize make it safe?
How long can I store poultry feed in Ghana?
What does a toxin binder do and is it worth it?
Are eggs and meat from affected birds safe to eat?
Healthy chicks need clean feed from day one
Agro Prime supplies vaccinated day-old chicks from Kasoa and shares the same feed handling practices we use on our own farm with every customer. WhatsApp or call +233 24 915 1503, email support@halaalfarmsghana.com, or book a visit to see how we store feed and raise chicks.
