Cassava in Poultry Feed in Ghana: How Much Is Safe

The question farmers ask us about cassava

Farmers ask us this more than almost anything else about feed. Maize keeps going up, somebody at the market says dried cassava will do the same job for less, and the question reaches us as a chick buyer: is it safe to put cassava in the bird's feed?

The honest answer is yes, in a narrow way. Cassava is one of the cheapest energy sources you can put into a poultry ration in this country, and it grows across most of the forest and transition zones. But energy is only one part of what a bird eats. We are a hatchery, so the mix is your decision. What we see is the result when that decision goes wrong: birds that look full and grow slowly, layers whose eggs get a little smaller, and chicks that never catch up with their batch.

Our guide to cheaper feed alternatives compares cassava with the other options, and this article sets out what cassava gives a bird, what it takes away, the cyanide question, and the highest share we would put in each stage. The numbers are ceilings for good, processed product. A lower share is always the safer choice.

What cassava gives the bird, and what it does not

Cassava is mostly starch. Dried chips and meal are carbohydrate, which the bird turns into energy quickly, and that is why they work as a partial replacement for maize. Maize is also mainly starch (our maize in poultry feed article covers it in depth), but it carries more protein, more fat and more of the minerals a bird needs. Set the two side by side and the gaps show.

These figures move with the sample, so ask your supplier for the analysis of the batch you are actually buying. The pattern does not move. A bird on a high-cassava, low-protein ration tends to eat more while it searches for the protein it lacks. You pay for that extra feed and get very little bodyweight back.

Cyanide: the part that can kill birds

Cassava contains compounds called cyanogenic glucosides. They stay inert while the root is whole. When the tissue is cut, chewed, crushed or soaked, an enzyme breaks them down and releases hydrogen cyanide. That release is what makes raw cassava dangerous. Bitter varieties carry more of the compound than sweet ones, and the peel and skin carry more than the flesh. How the product was handled matters more than which variety it came from.

Drying and processing bring the level down a long way. Thin slices dried fully in the sun, or properly processed chips, leave very little behind. Damp chips are a separate problem. A sack that sits wet can keep active enzyme and start releasing cyanide again, and it will mould as well. Chips dried badly during the rains are the batch to refuse.

Poisoning is uncommon when cassava is handled properly, but when it does happen it is fast. Birds that gasp, stagger, convulse or die within minutes or hours of a new feed need your vet straight away. Take the feed out of the trough while you call. Do not wait to see whether the flock recovers on its own.

Why protein has to come back in

Here is the sum most farmers skip. Take 10 kg of maize out of 100 kg of layer mash and put in 10 kg of dried cassava. Maize at 8.5 per cent protein gives 0.85 kg of protein from that 10 kg. Cassava at 2.5 per cent gives 0.25 kg. The mash has just lost 0.6 kg of protein, which means the crude protein has dropped by 0.6 percentage points, from 16 per cent to 15.4 per cent.

Six-tenths of a point sounds small. In a layer that is working for its feed, it is the difference between a hen with enough amino acids for a full egg and one without. Work it the other way and the rule is simple: each 1 per cent of cassava that replaces maize takes about 0.06 points of protein out of the mash. An 8 per cent share needs roughly half a point of protein put back.

The cheapest way to do that is usually a small share of soya meal, which is high in both protein and lysine. Our protein sources guide sets out the other options. About 1 per cent of soya covers an 8 per cent cassava share on protein alone. Soya does not balance everything, though, so have your nutritionist recheck lysine and methionine before the change goes into a whole shed. A mix short of amino acids does not look wrong until the egg size falls, and by then the feed is already paid for.

Broilers show a protein shortfall faster than layers do. Weigh a sample of birds every week for the first month of any change. A flock that slows down in week two has told you what it needs, and the answer is to put the protein back or take the cassava out.

Safe maximums by stage

These are the highest shares we would consider for dried, processed cassava, with a protein supplement in place. They are ceilings for good product, not targets. If you are unsure, start at the lower figure and move up only after a clean trial.

Note the word ceiling. A bird on a ration at the top of a range is one bad batch of chips away from trouble, so keep your share well below these numbers, especially through the rains when chip quality changes from week to week.

Drying and storing the chips at home or in the store

If you dry your own cassava, the work is in the first two days. Slice the roots thin, lay them flat in full sun on clean mats or raised trays, and turn them until they are hard all the way through. A chip still soft in the middle will mould in the sack within weeks. Harmattan air dries chips quickly, but its dust settles on them, so cover the trays overnight. In the rainy months the same job can take a week, and backyard drying usually loses the race against damp air.

Once dry, chips need to stay dry. Store them in clean sacks on wooden pallets, clear of the wall and clear of any drip from a roof. Check every fortnight for warmth, smell and mould. A sack that feels warm has started to heat, and that is the one to use first or throw out. Our feed storage and aflatoxin guide covers the mould side in more detail.

Do not mix damp chips into a fresh batch to make up the weight. The wet ones spread their mould and their enzyme into the whole lot, and you will not see the damage until the birds show it.

Reading a cassava sack before you buy

You cannot see cyanide, and a chip that looks clean can still be wrong. Buy on paper as well as by eye, and treat any supplier who will not write the figures down as a supplier to walk away from.

1. Ask for the production date and whether the chips were dried in the sun or by machine.
2. Ask for the hydrocyanic acid result for the batch, in milligrams per kilogram, and compare it with the limit your nutritionist uses.
3. Ask for the protein figure. Dried chips usually sit in the low single digits.
4. Bend a chip from the middle of the sack. It should snap clean. A chip that bends is too wet.
5. Smell the sack. Dry cassava smells plain. Sour, vinegary or musty means reject.
6. Look inside a handful. The colour should be even, with no grey or black patches, no webbing and no insects.
7. Buy one sack first, run it through a trial, and only then buy in bulk.

Where to buy in Ghana and how to compare prices

Cassava is grown across the forest and transition zones, including the Central, Eastern and Volta regions. Processed chips travel from those areas to feed sellers in Accra, Kasoa and beyond. The journey takes time, and time is when chips take on damp in a truck or a warm store. Buy from a processor who dries on clean surfaces in open sun, and ask how long the stock has been waiting before it reached you.

Compare cost by energy, not by sack. A sack of chips can look cheaper than maize per kilogram and still cost more per unit of energy, once you add the soya needed to restore protein and the lower share you are allowed to use. Write the sum on paper before you buy. Take the price per kilogram of cassava, add the protein you must buy back, divide by the energy it supplies, and set that against the same sum for maize.

A simple test: if the sum only favours cassava when you forget the protein, it is not a saving. The same arithmetic applies to palm kernel cake and cottonseed cake, which are often sold as cheap protein.

Trying cassava without losing a flock

Change the share in steps. Start at about half the ceiling for your stage, run it for seven days, and move up only if the birds are doing well. A week is too short to show a change in shell strength or a chick's final weight, so keep the trial going for the full phase, not just the first week.

Record a few things every day: feed given, feed left, the number of eggs, and the droppings. Weigh 20 birds at the start and end of each week and compare the average with the week before. In layers, weigh a fixed sample of eggs on two days out of every seven. If weight drops, eggs get smaller, or droppings turn watery and sticky, return to the old mash and call your vet before you change anything else.

The mistakes we see most often

Most of the trouble with cassava comes from a short list of habits. None of them is hard to avoid.

• Swapping maize for cassava and changing nothing else. The protein falls and the flock shows it within weeks.
• Feeding cassava to chicks because it is cheap. Starter feed is the wrong place to save money.
• Using a sack that has been wet. Damp chips mould and can release cyanide again.
• Adding peel or kitchen cassava to the mash. Household peel is untested, and it is often the most toxic part of the root.
• Trusting the seller's word. Ask for the number. A seller who cannot give you one has not tested the product.

When we would leave cassava out

We would leave cassava out of a flock that is already behind on growth, because a struggling bird needs protein and amino acids more than it needs cheap energy. We would also leave it out if the farm cannot weigh feed, birds or eggs in any consistent way. Cassava only saves money when it is measured, mixed and tested. Without a scale and a sample to weigh, the saving slips away unnoticed.

If you are starting a new flock and want the feed plan worked out alongside your chicks, WhatsApp us on +233 24 915 1503 or place your order through the order form. Choosing the breed first helps too. Our layer chicks and broiler chicks pages list what each line needs. If you are mixing your own feed, read our guide to mixing your own poultry feed before you buy a single sack of chips. Questions about getting chicks to your region are answered on our delivery page, and the FAQ covers the rest.

Questions farmers ask