Fish Feed Formulation for Ghana Farmers

Slow fish are usually a feed problem

When a farmer tells us his tilapia have stopped growing, the first thing we ask is what he is feeding and how much. The answer is almost always in the sack. Feed takes the largest share of the cost of a fish crop, and it is the part of the business you can change in a single afternoon. Water, pond design and stocking can be wrong for months before anyone notices, but a mix with too little protein shows up in the fish within a week or two.

Many farmers in Ghana buy a bran-heavy mix from a local trader, feed it by the bucket and hope. Sometimes it works. Often the fish grow at half the pace the pond should allow, and the farmer blames the water or the seed. The alternative is not complicated. You need to know the protein you are feeding, the stage of the fish you are feeding it to, and how much of it goes into the water.

Our feed knowledge comes from the birds we hatch and sell. The principles of protein, energy and mineral balance carry over to fish, but the numbers do not. A layer ration will not grow a tilapia fingerling properly, and some poultry additives are not meant for fish at all. The rest of this article works the fish side on its own terms.

Protein by life stage, with a table to set your target

Young fish need a richer diet than older fish, because they are building muscle and bone quickly from a small body. As they grow, the share of protein in the ration can come down, and the feed becomes more about energy and cost. The table below gives typical crude protein ranges found in published tilapia and catfish guides. Treat them as a starting point, then check the target against your species and district with your feed supplier or your district fisheries officer.

A practical rule is to change the mix when the fish change size, not when the calendar says so. Weigh a sample of fish every two weeks, and move to the next mix when the average weight crosses the point your feed supplier recommends for the switch. Keeping one mix from fingerling to harvest is the most common cause of poor growth and oversized, underfed fish in the same pond.

What goes into a fish feed in Ghana

Most small mills and farmer-formulated rations use a short list of ingredients. Each one brings a job to the mix, and each one brings a risk. The list below covers the materials farmers ask us about most often, with the role each plays and the thing to watch for.

• Maize gives energy and is the bulk of most grow-out mixes. It carries little protein, and yellow maize from a clean, dry store is the usual choice.
• Processed soya bean meal is the main plant protein. Use the processed meal from a mill or a reputable trader. Raw soya beans contain compounds that fish do not digest well, so never feed them whole or unprocessed.
• Fishmeal brings high-quality protein and some minerals. Its protein and salt content vary a great deal between lots, so the analysis sheet matters more here than with any other ingredient.
• Wheat bran and rice bran add fibre, some fat and some protein at low cost. They also bring variable quality, so buy from a source you trust and check for mould.
• Groundnut cake is a good protein source, but it is the ingredient most likely to carry aflatoxin. Buy it only with a clean smell and a clear lot record, and store it carefully.
• Cassava products such as dried chips or peel meal supply energy. Use processed cassava only, since fresh cassava contains cyanogenic compounds that must be removed by drying or cooking.
• Oil, usually palm or soya, adds energy and helps the pellet hold together.
• Premix and salt supply vitamins, minerals and the sodium the fish need. Buy a premix formulated for fish and follow the supplier's inclusion rate.

Ghana's mills and agro-dealers stock most of these, and availability changes with the season. Current rates also change, so check them with your supplier. We do not publish feed input prices, and any figure you read online should be checked against what is on offer in your own market.

Reading an analysis sheet for fish feed

An analysis sheet is the only honest description of what is in a bag. Ask for it for every lot you buy, and file it with the lot number. The main figures are crude protein, crude fat, crude fibre, ash and moisture. Crude protein is what most buyers check first, and it is the figure traders most often get wrong.

Read the figures together. High ash alongside low protein in a fishmeal usually means the meal has been diluted with sand or bone. High fat in a meal that is starting to smell can mean the oil has gone rancid. High moisture is a warning sign for mould and for a stored mix that is about to heat. Fibre tells you how bulky the ration will be, which matters for a small fish with a small stomach. If a sheet is missing a figure you need, ask for it before you pay, and if the supplier cannot provide one, buy somewhere else.

A worked 30 per cent mash, step by step

A grow-out mash aimed at about 30 per cent crude protein makes a useful worked example. The percentages and the protein values are illustrative, based on typical published figures, and they do not replace the analysis sheet for each ingredient you actually buy. Substitute your own values, and check the total protein against the sheets for your lots.

The method is simple. Multiply each ingredient's share by its protein value, add the results, and check the total. If the answer is short of the target, raise the soya or the fishmeal share slightly and take the difference from the maize. If it is well over, take protein out and check that the fish still get enough energy. The Pearson square method, covered in our Pearson square guide, is a quick way to make two-ingredient adjustments, and the least-cost formulation article shows how to balance more than two ingredients at once.

Once the mix is set, weigh each ingredient on the same scale, mix the dry ingredients first, then add the oil and the premix. A batch of 100 kilograms is easy to check by hand. A batch of 1,000 kilograms needs a mixer, and a mixer that has not been cleaned can carry one batch's contamination into the next.

Adding oil, premix and salt without upsetting the balance

The smallest ingredients do the most quiet damage when they are wrong. Oil supplies energy and gives the pellet its bite, but too much makes the feed soft, greasy and prone to going rancid in a warm store. Add it at the mixing stage, and use fresh oil from a clean container. A rancid oil smells like old paint, and a mix made from it will taste wrong to the fish long before you can see the cause.

Premix is the part of the feed most farmers are tempted to guess. Use a premix formulated for fish, and follow the supplier's inclusion rate exactly. More is not better. Excess vitamins and minerals cost money and can harm the fish. Salt is needed in small amounts, but the fishmeal already contributes some, so count it in your total before you add more. If you are unsure about the premix or the salt, ask your extension officer to check the label with you.

Mash, pellet or crumble: choosing the form

Mash is the cheapest form and the easiest to make. It is a moist or dry powder that the fish take from the surface or the pond floor. Its weakness is waste: a mash breaks up in the water and drifts away before it is eaten, and it can foul a pond quickly if too much goes in at once. Pellets hold together longer, and they make it easier to see what the fish are eating.

A sinking pellet suits species that feed on the bottom, and it stays in the feed zone until the fish find it. A floating pellet suits species that feed at the surface, and it lets you watch the fish feed, which is the best check you have on appetite. For a smallholder with a hand pellet mill, a binder such as cassava starch or wheat flour holds the pellet together. Add the binder with enough water to make a stiff dough, press the dough through the die, and dry the pellets in the shade or on a clean sheet in the sun until they snap. Damp pellets go mouldy within days, and mouldy pellets make fish sick.

Crumbles are pellets broken down for small fry and fingerlings. Make them by crushing dry pellets through a fine sieve, and feed them by weight, not by volume, so each batch is consistent.

How much to feed: rates and the feeding tray

The amount you feed depends on the size of the fish, the temperature of the water and what the fish clean up. A common planning range is around 5 per cent of body weight a day for small fingerlings, falling to roughly 2 to 3 per cent for fish nearing harvest. Treat the figures as a starting point. Warm water and fast-growing fish eat more, and cool spells in the harmattan season mean they eat less.

A feeding tray placed in the pond shows you what is being eaten. Feed a measured ration each day, and check the tray an hour later. If the feed is still there, reduce the next ration. If it has gone, add a little more the following day. Feed at the same time each day, usually in the morning, and avoid heavy feeding in the late afternoon when oxygen can be falling. Write the amounts in the feed book, and the tray check will tell you more than any table.

Feed conversion: the figure that tells the truth

FCR, the feed conversion figure, tells you how many kilograms of feed went into each kilogram of fish. It is the simplest honest measure of how well your feed is working. You get it by dividing the total feed given over a cycle by the weight of fish gained in the same cycle.

Suppose you fed 120 kilograms of mash over a cycle and the fish gained 80 kilograms in weight. The FCR is 120 divided by 80, which is 1.5. The next cycle, with the same fish and the same pond, might give 2.0 if the feed was wasted or the mix changed for the worse. Many well-run tilapia units report figures in the range of about 1.5 to 2, but the number that matters is your own last cycle. Compare each cycle with the one before, and treat a rising FCR as a warning to check the feed, the tray and the oxygen before you blame the fish.

Storage and the aflatoxin trap

Aflatoxin is the most serious hidden risk in a fish feed store. It is produced by certain moulds that grow on maize, groundnuts and other grain when they are stored damp or warm. Fish that eat contaminated feed can be harmed, and the risk does not show on the outside of a bag. A musty smell, a grey or greenish bloom, or clumping in a sack are all reasons to stop using that lot.

Keep stock dry, lifted on pallets and set back from the walls. Keep the store cool and ventilated, and use the oldest stock first. Do not buy a cheap lot of groundnut cake because it is a bargain. If you are unsure about a lot, ask your extension officer about testing, and check current terms with the body that does the testing, since arrangements change. Discard any feed that you suspect, rather than trying to save it by mixing it into a fresh batch.

Swapping ingredients when a bag runs short

Every farmer meets a shortage in the middle of a cycle. A mill runs out of soya, the groundnut cake has gone mouldy, or the fishmeal lot has changed. The answer is not to improvise. Swap one ingredient at a time, recalculate the protein total with the new values, and check the result against your target before you mix.

In general, you can replace some of the soya with groundnut cake if the cake is clean and dry, or with other processed plant meals whose protein value you know from the analysis sheet. Replacing fishmeal is harder, because it brings protein of a quality that plant meals rarely match. If you must swap, expect the growth rate to fall and watch the fish closely. Write every change in the feed book, dated, so you can trace a slow cycle back to it later.

Where poultry feed know-how fits, and where it stops

Many farms keep birds and fish side by side, and it is tempting to share a store and a mill. The principles carry over: protein matters, minerals matter, dry storage matters. The numbers and the additives do not. A layer ration is built for birds that lay eggs, and it may contain additives that are meant only for poultry. Feeding it to fish without checking with the supplier and your extension officer is a risk, not a shortcut.

For the bird side of the same farm, our guides on poultry feed formulation and mixing your own poultry feed cover the basics for birds. Byproducts such as brewers grains and cassava in poultry feed can also appear in fish mixes, but their quality and inclusion rates differ between the two uses, so treat each one as a fresh decision for the species you keep.

Checklist for every fish feed batch

Use this list each time you mix. It takes a few minutes and catches most of the avoidable faults in a batch.

1. Confirm the life stage of the fish, and the protein target for that stage.
2. Check the analysis sheet for every ingredient in the batch, and file the lot numbers.
3. Work the protein sum on paper before weighing anything.
4. Smell and inspect each ingredient for mould, clumping and rancidity, and discard anything doubtful.
5. Weigh every ingredient on the same scale and mix the dry ones first.
6. Add fresh oil and the fish premix at the stated inclusion rate, and mix again.
7. Dry pellets fully in the shade or on a clean sheet until they snap, and store them dry.
8. Record the batch, the feeding amounts and the tray checks in the feed book.

If your fish or birds are also part of a wider plan, our day-old chicks range is supplied from the hatchery, and orders go through our order form. For wider partnership questions, see partner with us. Planning the pond itself? Our guide to building a fish pond in Ghana covers the water and the earthworks. Want the poultry side talked through? Send your questions on WhatsApp to +233 24 915 1503.

Questions farmers ask