Methionine and Lysine in Ghana Poultry Feed

Why the second bag of feed went flat

The question we hear most often about feed is some version of this: the first bag grew the birds well, the second bag did not, and nothing else on the farm changed. The brand was the same. The price was the same. The label still said the same protein figure.

The label is usually right about protein and silent about the things that matter more to the bird. Protein is a bundle of amino acids, and two of them, lysine and methionine, are the ones a maize and soya ration most often leaves short. When the maize came from a different store, or the soya from a different lot, the amount of each amino acid can shift even when the crude protein figure stays put.

This article is about those two amino acids. We will look at where they come from, how to work out a shortfall with real numbers, and how to add the synthetic forms without guessing.

What lysine and methionine do inside the bird

Birds build muscle, feathers and egg protein from amino acids, and some of those they cannot make fast enough on their own. Lysine drives lean muscle, which is why it matters most in a broiler from the second week onward. In a ration built around maize, it is also the amino acid a fast grower is most likely to run short of.

Methionine does two jobs. It is needed for protein building in general, and it is the main sulphur source the bird uses to make cysteine, the amino acid that forms much of the feather keratin. That second job is why poor feather cover shows up early when methionine runs short. The feed still goes in, but feather growth lags behind body weight.

In a laying flock, both amino acids feed into the protein of the egg itself. A short ration shows up in egg size and feather condition at the same time, so it is worth looking at both together rather than one at a time.

Why maize and soya leave methionine behind lysine

Maize is a good energy source and a weak protein source. Soya brings plenty of lysine but relatively little methionine. Put the two together with nothing else and methionine ends up low. The table gives the typical figures we use when we talk a ration through with a farmer. They are rounded values from common feed tables, not the analysis of any particular bag.

Read the table with the mix in mind. Most of a grower ration is maize, so the maize figures count for more than the soya figures, even though the soya numbers look bigger. Soya brings the lysine to the table. Maize brings the energy and very little of anything else.

Fishmeal fixes both amino acids at once, which is why it shows up in so many formulas. It is also the ingredient most open to adulteration and variation, so it needs a sample check before you rely on it. Our article on protein sources for poultry feed compares the options by cost per kilo of usable protein.

Why the ratio matters more than the total

Birds use amino acids in fixed proportions. If lysine is the reference point, methionine has to sit at a set fraction of it. The working range in most tropical broiler and layer guides is about 0.35 to 0.40 of lysine. Your breeder guide or nutritionist will give the exact target for your strain and stage, and that target is the number to use, not ours.

Here is the consequence people miss. Once lysine is fixed, methionine has to follow it. Add more lysine, perhaps by adding more soya, and the methionine target rises with it. A ration with 0.75 per cent lysine and 0.30 per cent methionine sits at a ratio of 0.40, which is comfortable. Push lysine up to 0.90 per cent without touching the methionine, and the ratio falls to about 0.33. Nothing in the bag changed, but the ration is now short.

A flock of layers on this ration is a good test case for the arithmetic, because the target sits on the egg protein and not on muscle. If you are bringing in layer day-old chicks, plan the amino acid check before the first lay rather than after the first dip.

Lysine above what the methionine can support is paid for and not used. That is the real cost of the ratio problem: it is spent money with no return.

Working out the shortfall in a 250 kg batch

Here is a worked example for a 250 kg batch of layer ration. We picked a simple mix on purpose: 62 parts ground maize and 30 parts soya. The remaining 8 parts are limestone, salt, oil and premix. Those 8 parts carry little lysine or methionine for this sum, so we leave them out.

1. Lysine: (0.62 × 0.25) + (0.30 × 2.70) = 0.155 + 0.810 = 0.965 per cent.
2. Methionine: (0.62 × 0.18) + (0.30 × 0.60) = 0.112 + 0.180 = 0.292 per cent.
3. Ratio: 0.292 ÷ 0.965 = 0.30. Our working target is 0.38, so the ration is short.
4. Methionine needed at target: 0.38 × 0.965 = 0.367 per cent.
5. Shortfall: 0.367 − 0.292 = 0.075 per cent of the mix.
6. DL-methionine is about 99% active, so 0.075 ÷ 0.99 = 0.076 per cent of the batch is the synthetic product.
7. On 250 kg, 0.076 per cent is about 0.19 kg, or roughly 190 grams.

About 190 grams in a quarter tonne. At an illustrative GH₵55 per kilogram, that is around GH₵10.40 for the batch. Check the price with your own supplier, because it moves. The figure is there to show the scale. A shortfall that looks serious on paper is a small, weighable amount, and that is good news for a farmer working to a budget.

DL-methionine, L-lysine and the liquid alternatives

DL-methionine at 99% is the powder most feed mills use. L-lysine is usually sold as lysine hydrochloride at around 78% lysine, so a 1 kg bag holds about 780 grams of active lysine. Liquid methionine is a different product, a hydroxy analogue that the bird converts to active methionine. It works, but the active content per kilogram is lower, so you need more of it to deliver the same methionine.

Compare the cost per gram of active amino acid, never the price on the label. A product with a lower active share can cost more per gram delivered than its shelf price suggests, and the label has the numbers you need to work that out.

Two handling points matter in Ghana. These products are dry powders that clump in damp store rooms, which is a problem in the rains. Keep them sealed, away from fertiliser and open feed, and reseal after every use. Second, weigh them properly. A kitchen scale that reads in 10 grams is too coarse for a batch that needs 190 grams. A scale that reads to 1 gram is the minimum.

Blend the synthetic amino acid into a cup or two of maize first, then mix that into the batch in stages, the same way you would handle premix. A pinch sprinkled over the top of the bag is how one part of the flock gets a bigger share than the rest.

What a short ration looks like in the flock

Signs of a methionine or lysine shortfall are slow and easy to blame on something else, so we list them as things to check, not as diagnoses. A short ration usually shows up as a pattern of several signs together, and one sign on its own rarely proves anything.

If the signs continue after a feed check, follow your vet's advice before you change medicines or add supplements to the water. A vet can rule out disease. Feed is one part of the picture, and changing three things at once makes it impossible to see which one helped.

Heat-damaged soya and the lysine you cannot see

Soya is cooked during processing so the anti-nutrients break down. Cook it too hard and the sugars in the meal react with lysine, binding part of it so the bird cannot absorb it. The total lysine on a laboratory report can look reasonable while the lysine the bird can use is lower. The bag does not show the difference, and the crude protein barely moves.

Overheated soya is darker and toasted in colour, smells sweetish or burnt, and feels gritty and dry. Colour alone is not proof, because some lots are dark for other reasons. Ask for the digestible or available lysine figure on the analysis, or send a sample to a laboratory that runs amino acid profiles.

If your flock slips after you change soya supplier, the ratio on paper is not enough. Check the soya itself. Our guide on soya and groundnut cake for poultry explains how to judge a lot before it goes into the mix.

Questions to put to a feed supplier

A supplier who answers these questions plainly is one you can work with. A supplier who answers with the crude protein figure alone is telling you what the bag can show, not what the bird will use.

• Is the lysine figure total lysine or digestible lysine?
• Is the methionine figure methionine alone, or methionine plus cystine?
• Which form of methionine is in the premix, DL-methionine or a liquid hydroxy analogue?
• When was this batch tested, and can you send the report with the batch number?
• How much of this batch is left, so I can test the same lot if the birds slip?

Prices for our chicks are listed on the day-old chicks prices page, and the feed is usually the largest cost after the birds, so it pays to get it right. If you want a second opinion, a feed mill technician or a poultry nutritionist can run the numbers from the supplier's analysis in an afternoon. Bring the bag label and the batch number. Our broader guide to feed formulation basics shows where the amino acid figures fit into a full ration.

What we tell farmers who ask us about amino acids

We hatch and import day-old chicks. We do not sell feed, so we have no reason to push one bag over another. What we can do is tell you what the birds we send are built to need. A Ross 308 broiler grows fast and needs its lysine and methionine on schedule. A Sasso takes longer to finish, and its ration timing is different. The breeder guide sets the targets, and that is where we send farmers first.

Check the breed you are raising before you change the feed. Our broiler day-old chicks and Sasso day-old chicks pages list what each line is good for, and the breeds section compares them side by side.

Our advice on synthetic amino acids is blunt. Do not add them to a ration you have not checked. A small shortfall is cheap to fix, and a large unknown is not. If you are unsure, send a message on WhatsApp to +233 24 915 1503 with the feed label and the batch number, and we will point you to the right breed page and the right people to ask. You can also visit our frequently asked questions for how we handle orders and delivery.

A checklist before you add synthetic methionine

1. Get the lysine and methionine figures from a recent analysis, not from the protein figure on the bag.
2. Confirm your target ratio with your breeder guide or nutritionist, and write it down.
3. Calculate the shortfall from the mix you actually made, not the recipe you intended.
4. Choose the synthetic form and check its active content on the label.
5. Weigh the product on a scale that reads to 1 gram, and record the batch date.
6. Blend it in stages, then store the product sealed and dry.
7. Watch weight gain, feather cover and egg size for two weeks, and write each one down.

If you can tick every line, you have a fair test. If you cannot, the shortfall you are trying to fix may be the least of your problems.

Questions farmers ask