Sweet Potato Vines as Livestock Feed

Why the vines are worth keeping after the tubers are out

Many farmers pull up sweet potato tubers and leave the vines lying in the field to rot. That is a waste of feed you have already paid to grow. A sweet potato field produces a large mass of leafy vine, and much of it can be used by the same animals you keep for meat or eggs. For a small farm, that is a free source of forage in the middle of a season when grass has gone off.

The vines are most useful to people who keep rabbits, grasscutters, goats or sheep, and they can make a modest contribution to a poultry diet. They will not replace grain or a complete mash, so think of them as a bulk ingredient. If you already grow sweet potato for the market or the house, the vines are an extra return on the same work.

If you are thinking about the wider picture of a mixed farm, the guide to starting poultry farming in Ghana covers how feed, housing and labour fit together. Our blog has other articles on crops and feed that sit well alongside this one.

What is in a sweet potato vine, and what is not

Fresh sweet potato vine is mostly water, often well over three quarters of its weight, so a bundle that looks big may contain surprisingly little dry feed. On a dry matter basis, young leaves and tender tips carry a useful amount of protein, commonly in the region of 10 to 15 percent. Older vines are tougher, higher in fibre and lower in protein, and their value falls as they age.

The energy in vines is moderate. They are a good source of fibre and minerals in some cases, but they are not a concentrated energy feed like maize or cassava meal. That matters most for birds, which need energy-dense rations to grow and lay. For rabbits and ruminants that are good at using fibre, the picture is much better.

These are typical ranges, not guarantees. Variety, soil fertility and the stage of growth all change the figures. If a ration depends on the vine, send a sample for analysis rather than trusting a table in a book.

Picking healthy vines: green, clean and free of virus signs

Not every vine is worth feeding. Pick vines from plants that look green and vigorous, with no curled, mottled or yellow leaves. Those symptoms can point to virus problems in the crop, which may not harm your animals directly but can make the material less useful. If an entire field looks stunted or yellow, feed the vines with caution and ask your extension officer what is happening.

Also check the vines for insect damage, rot at the stem base and soil contamination. A vine that has been lying in wet soil for weeks is already spoiling, and it should not go into the feed trough. Shake the cut material and remove any stones or soil before you bundle it.

Do not use vines from fields treated with herbicide until you have confirmed the product label and the waiting period. Many herbicides are not designed for feed crops, and you should ask the seller or your extension officer before feeding any material from a treated field.

Harvesting the vines without losing the tubers

The biggest risk in using vines is cutting so much leaf that the plant cannot make enough food for the tubers. The leaves are the factory that feeds the root, and a plant stripped bare will give smaller tubers. A sensible approach is to cut only part of the vine at a time, leaving the most leaf on the plant, and to stop cutting a few weeks before you expect to lift the tubers.

Harvest in the cool of the morning, when the vines hold the most water and wilt less in the cutting. Cut the stems and leaves into manageable lengths, and carry them to shade quickly. Leave the stem base in the ground, so the plant can keep growing. Some farmers grow a short block of sweet potato purely for vines, cutting it several times, and this is a sound way to get feed without sacrificing the tuber crop on the main plot.

Plan the harvest around your feed schedule. If you know you will need feed through the dry season, cut and dry vines during the rains while they are green and plentiful. That is much easier than trying to find good material in the middle of a dry spell.

Wilting and drying: the step that makes vines usable

Wilting means letting the cut material lose some of its water in shade before feeding. Spread it thinly on a clean surface, turn it once or twice, and leave it for several hours or overnight, depending on the weather and how much you cut. The vines should lose their wet, glossy shine and become limp but not brittle. Wilting makes the material easier for animals to eat and lowers the risk of heating and spoilage in the store.

Drying goes further. Lay the vines on clean raised mats or mesh in the sun for one to three days, turning them so they dry evenly. Bring them in at night or when rain threatens. The finished material should be crisp and should snap rather than bend. If it still feels cool or damp at the centre of a bundle, it is not ready and will go mouldy in storage.

Chopping the dried vine into shorter lengths before storage makes it easier to handle, and it reduces waste when you feed. Keep chopped and whole material separate, so you know what you have.

Oxalates and other limits you should respect

Sweet potato leaves contain oxalates, natural compounds that can bind calcium in the gut. In moderate amounts, within a balanced diet, most healthy animals cope well. Problems are more likely when a diet is heavy in vine, low in calcium, and fed to young or sick animals. If you feed a lot of vine, make sure the rest of the ration supplies calcium, through a proper mineral supplement or a suitable feed.

Wilting and drying reduce the moisture in the vine, but they do not remove oxalates. Do not assume that drying makes the vine safe to feed in large amounts. The sensible rule is to treat vine as one part of the diet, not the whole diet, and to watch the animals for weakness, poor appetite or unusual droppings.

Limits also apply to quantity. Vine is bulky, so an animal may fill up on it and eat less of the concentrate it needs. For birds, that means lower energy intake and slower growth. For a feed plan, the poultry feed calculator can help you see how much energy and protein each share of the ration is supplying.

Rabbits and grasscutters: steady feeding and small changes

Rabbits do very well on sweet potato vine when it is introduced gradually. Start with a small handful beside their usual feed and increase over one to two weeks. Fresh wet vine given in sudden large amounts can cause loose droppings and digestive upset. Dried or wilted vine avoids most of that trouble, and it can be kept in the hutch as a steady supplement. Always remove any uneaten green material before it rots.

Grasscutters are keen feeders on vine and will strip a heap quickly. That is useful, but it also means over-supply is wasteful. Put in what they will finish within a few hours, and keep the pen clean. A clean, dry feeding area matters more than the exact type of vine, because wet, dirty feed is the common route to illness.

Whatever you feed rabbits or grasscutters, keep fresh water available and watch how the animals eat and what the droppings look like. Changes in both are the first signs that something is wrong.

Goats and sheep: vines as one part of the forage mix

Goats and sheep handle vine well as part of a mixed forage. Offer wilted or dried vine alongside grass hay, so the animals get fibre from the grass and feed value from the vine. Chop the material so they do not pull out and trample the long stems. Small, regular servings are better than one large heap that they will sort through and waste.

Very lush fresh vine, given in large amounts after a long period on dry grass, can change the balance in the gut and cause loose droppings. The fix is the same as with rabbits: build up gradually, and keep the animals on a steady routine. A mineral lick is valuable on any vine-based diet, because it covers the calcium and other minerals that the vine may not supply in the right ratio.

Concentrates still have a role. Goats fed mostly on vine and no grain may grow slowly, especially young kids and lambs. A small daily amount of concentrate, adjusted for the animal's age and condition, keeps them on track. A vet or livestock officer can help set the right amounts for your herd.

Poultry: small shares of dried vine meal, not a grain replacement

Birds can use dried sweet potato vine meal, but only as a small share of the diet. The meal is bulky and low in energy, so a large share will reduce growth in broilers and egg output in layers. Growers and laying hens can take a modest amount in the mash, usually a low single-digit percentage as a starting point. Increase only after watching the birds' intake, droppings and output for two weeks.

For free-range or scavenging birds, freshly cut or wilted vine can be scattered for them to peck. That is a cheap form of enrichment and a little extra green feed. It does not replace a complete ration, and it should be removed if it turns wet or mouldy. Keep the feeding area clean to prevent the spread of disease.

If you keep a mixed flock, decide which birds are your priority. Broilers need dense feed to hit their weight targets, while layers need calcium and energy for eggshell and lay. The broiler chicks for sale in Ghana page and the layer chicks for sale page describe the two types, and the difference in feed needs is why a single vine-based ration will not suit both.

Storing dried vines so they do not turn mouldy

Dried vine is only as good as its storage. Keep the dried material in a dry, covered place off the ground, on a raised platform or pallet, with air passing through. Stack it in loose bales rather than packing it tight in a sack, because tight packing traps moisture and encourages mould. Check the stock every few weeks, especially in the rainy season, when humidity rises.

Mould on dried vine can produce toxins that harm animals, so do not feed a bale that smells musty, feels damp or shows white, grey or black growth. Pull out and discard the affected part, and check the rest before you use it. If in doubt, throw it out. A lost bale is a small cost compared with a sick herd.

Label the store with the harvest date. Feed the oldest material first. Vines dried in the late rains will often last well into the dry season, but a bale stored in a damp corner can spoil within weeks.

When vines are not enough, and what to buy alongside them

Vines are a useful supplement, not a complete feed. For a serious goat or rabbit enterprise, plan for grain or a commercial concentrate, a mineral supplement and a steady supply of clean water. For poultry, the energy needs of growing and laying birds are high, and they rely on dense feed ingredients that vines cannot supply. Be honest about what your vines can and cannot do before you cut back on purchased feed.

The table below summarises how vines fit each type of animal. Treat it as a starting point and adjust it to what you see on your own farm.

The cost case is usually strongest when labour is available and the vine is already growing on the farm. If you need to buy in planting material or spend heavily on labour to cut and dry large quantities, the saving may be smaller than it looks. Count the hours, not just the cedis.

If you are planning a flock and want to check the numbers, the poultry calculators set out feed, chick and running costs in one place. For current starting prices of chicks, see the day-old chicks prices page, and for delivery questions, the delivery page explains how orders are dispatched.

Questions farmers ask