Feeding baleage to horses – the ultimate guide

The bales need to be tight to minimise the amount of air that will be sealed in with the plastic wrap.
The bales need to be tight to minimise the amount of air that will be sealed in with the plastic wrap.

Balage is an increasingly popular winter feed for horses. It’s nutritious and most horses enjoy it, but there are risks. Neil Clarkson reports on strategies to minimise them.

There’s nothing like a disastrous hay season to get horse owners thinking about their options. Some think about balage – those big plastic-wrapped bales of grass that dot the countryside in increasing numbers as the summer progresses.

Balage is grass that is baled and wrapped soon after cutting, minimising the risk of loss through rain. However, most horse owners interested in feeding it will stumble at the first hurdles.

While some contractors now offer wrapped small bales, most is made in rounds, or big or medium squares. A horse owner will need to pay a contractor to cart them in. Even if you have a tractor, you will need a special clamp to pick them up without rupturing the plastic.

They can be stored outside, which will appeal to many, but once cut open they must be fed out within a few days. Unless you have a lot of hungry horses, or some cattle on your property, you may not get through a bale before it spoils.


Balage Pros and Cons

• Your crop is far less likely to be ruined by rain.
• You can store it outside.
• It retains more food value than hay.
• It will help you achieve the rule of thumb of providing two-thirds of your horse’s diet in forage feed.

• It’s more costly than hay.
• Bales will be at least twice as heavy as their hay equivalents.
• Specialist gear is needed to move big bales, or you need to employ a contractor to do it.
• You need to check regularly for holes and repair them.
• Once open, bales need to be fed out within a few days.
• Horses can contract botulism from poor quality balage.
• Storage life can vary from bale to bale.


Unless you have specialist feeding-out gear, most horse owners will find medium squares the most convenient to feed by hand, as you can peel off the balage a slab at a time.

Balage is also more costly, but you have to weigh that against the higher food value when compared to hay.

Like hay, things can go wrong. There are also risks in feeding it to horses – mostly the danger of botulism poisoning, which we will consider later.

What is balage?

Balage, silage, and haylage are names for the same basic product: ensiled grass. It doesn’t matter whether the grass is going into a massive silage pit or a plastic-wrapped bale – the process is the same.

The grass is baled when much greener than hay. Hay is typically baled with a moisture content between 15% and 17%. Ensiled grass is typically between 30% and 60%, with the most stable balage usually made in the higher half of that range.

The grass may only be cut for a day or even less before the balers arrive.


Moisture content is critical

Correct moisture content is considered one of the most critical elements in successfully making balage, along with high sugar content. The usual range is 30% to 60% moisture, with the most stable balage usually being made in the higher half of that range. If it’s baled much above 60%, conditions tend to swing in favour of the clostridial bacteria.

Baling grass that is too dry has its problems, too. A drier bale is likely to undergo too much damaging aerobic activity before anaerobic fermentation begins. It is also less likely to drop below the desired pH of 5.0, giving clostridial bacteria yet another opportunity to multiply.

The grass needs to be good quality with a high sugar content. Coarse, stemmy grass will not only make inferior balage, it is also more likely to puncture the plastic wrap.

Grass is rowed up in preparation for baling. The best moisture range for making balage is between 40% and 60%, which may take only a day's wilting, even less.
Grass is rowed up in preparation for baling. The best moisture range for making balage is between 40% and 60%, which may take only a day’s wilting, even less.

The contractor needs to produce a good tight bale with as little air in it as possible. Loose bales are unlikely to make good balage. (When silage is being made, a digger will trundle backwards and forwards over the grass for hours, compacting the heap as much as possible.)

Soon after, the plastic wrap goes on, sealing the grass from the outside world. The ensiling process is about to begin. A combination of natural plant respiration and the action of aerobic bacteria begin to heat the bale, much as you would expect in a compost heap. But aerobic bacteria need air and, on a warm day, a wrapped bale can be all out of oxygen in 30 minutes. However, if conditions are cooler, or there is too much air in the bale, this process can take hours, sometimes even days.

A well-compacted bale may heat as little as 3degC before it runs out of air. Grass baled when drier is likely to have more air trapped in it, and the heating process can continue too long. Once temperatures of 40degC or more are reached, the grass will suffer heat damage and blacken, sometimes costing more than half the available protein.

Generally, the quicker this aerobic phase is over, the better, because the goodies you want to feed out to your horses are being used up. Bacteria are turning useful water-soluble sugars into carbon dioxide and water, with heat being a major byproduct.

Once the oxygen is gone, this aerobic heating phase will end. However, waiting in the wings are anaerobic bacteria, which function without the need for oxygen. They multiply rapidly and begin to ferment the grass, turning the plant sugars into organic acids – mainly lactic and acetic acid. As this continues, the bale becomes increasingly acidic.

Once it reaches a pH of about 3.8 to 5.0, the anaerobic bacteria find the going too tough and the fermentation process grinds to a halt. The bale has reached a stable state, ready to ride out the months until it is fed out. All should remain well unless the bale is punctured and oxygen penetrates.

Using quality grass with a high sugar content increases the chances of making good balage.
Using quality grass with a high sugar content increases the chances of making good balage.

It’s important to have enough sugar in the bale to drive the fermentation and drop the pH to a level that will result in stability. If the bale runs out of steam at a pH above 5.0, undesirable clostridial bacteria can take hold. Fermentation will be incomplete and the bale will be less stable, and its life much shorter.

This is why it’s important to use grass when it’s younger and still has high sugar levels. Some contractors will not cut the grass until after lunch. The longer the sun is on the grass, the higher its sugar content.

While the ultimate pH achieved in your balage is important, the speed at which it gets there is also critical. The longer the bale stays outside the desired pH range, the more likely that bad bacteria can take hold.

If all goes well, your wrapped bales should dip below pH 5.0 in a few days and, preferably, under a week. Fermentation will continue slowly for a few more weeks, but the critical pH has been reached.

There are ways a contractor can help things along. If they use a baler that chops the grass as it is fed into the baling chamber, this will speed the process. They can also spray the cut grass with an inoculant, containing good bacteria and enzymes, or an acid-based preservative. Some would consider one of these options essential for any cut grass that has been rained on, or for grass that is drier than desirable.


Hints for making good balage

These measures will not only improve balage quality, but reduce the risk of spoilage.

  • Use grass before it’s too mature and stalky. Younger grass will make much better balage. Poor quality grass will always make poor quality balage.
  • Cut the grass later in the day, when the sugar content will be higher.
  • Cut only when you’re confident you can get it baled and wrapped before it rains.
  • If your cut grass does get rained on, tell the contractor to use an additive which will help the fermentation.
  • Do what some farmers do: pay extra to have inoculant applied every time you make balage.
  • Wrap bales as soon as possible. Asking for extra layers of plastic will add about $3 a bale. It is good insurance against holes and your bales are likely to keep longer.
  • Do not make balage from a paddock contaminated with dung, especially one fertilised with poultry manure.
  • Move bales as soon as possible after wrapping to their final resting place, and do not move them again.
  • Check bales regularly for holes and tape them up.
  • Get the moisture content right at baling to increase your chances of good balage. Wetter balage not only runs an increased risk of clostridial spoilage, it can also be damaged through freezing. If the grass is getting too dry, make hay.
  • Never use a tedder unless it allows you to get it baled before rain strikes. Tedding usually shouldn’t be necessary – the “fluffing up” that results will only serve to put more air into the finished bale, which you don’t want.
  • Ensure the rake doesn’t contact the ground, stirring up dust which can put clostridial bacteria on the grass.
  • Avoid baling small-animal carcasses with the grass.
  • Store balage with some shelter from the sun. Fermentation is at its best in the range of 15 to 25degC. Higher temperatures favour clostridial bacteria, so avoid storing balage where its temperature is likely to exceed 30deg.
  • The more even the temperature during the fermentation and storage, the better.
  • Don’t stack the bales.
  • When feeding a bale out over several days, close the plastic back over the opening to keep air out as much as possible.


The risk with horses

Balage is a nutritious feed that many horses enjoy. Many hundreds of horse owners swear by it, saying their horses do well on it over the winter months.

However, it is important to recognise the risks and how to minimise them.

The biggest worry is botulism. Horses are very susceptible to botulism poisoning, which usually proves fatal.

Botulism poisoning causes progressive paralysis. Muscle trembling will be apparent and the horse will lie down often. If you pull their tongue out, they will have difficulty pulling it back. They can only eat with difficulty and death normally results from breathing paralysis, or complications from the amount of time spent lying down.

Poisoning results from the toxin produced by Clostridium botulinum. There are seven known kinds, each producing a slightly different botulin toxin. One variety is found in poultry manure; another thrives in the carcasses of dead animals. One is even found in fish.

Plastic fantastic: The wrap goes on, sealing off the bale from the atmosphere and getting the ensiling process under way.
Plastic fantastic: The wrap goes on, sealing off the bale from the atmosphere and getting the ensiling process under way.

Several kinds are common in soil and can gain a foothold in a bale if the ensiling process fails to drop the pH below 5.0.

The faster the bale reaches a pH of 5.0 or less, the less chance that clostridial organisms can take hold. Higher pH levels can also provide a suitable environment for listeria.

Bales made with a moisture content greater than 60 per cent also stand a greater chance of becoming badly affected by Clostridium botulinum.

Clostridial spoilage arises from the production of butyric acid. The balage will be sour and foul smelling, often like ammonia. You are likely to find evidence of slime moulds. Never feed it out. In fact, do not feed out any mouldy balage, even if it still has that distinctive balage smell.

The issue, as with most feeds for horses, comes down to quality. Most feeds have their dark side: Substandard hay can deliver dangerous moulds and trigger hay colic. Moist grain can carry dangerous mycotoxins. Badly made balage brings with it the risk of botulism poisoning.

Provided the balage is of high quality, evidence would suggest the risk is low, but each horse owner will have to make their own call. Like any feed change, it needs to be introduced gradually to a horse’s diet.

Dealing with and preventing holes

There’s little point in making balage unless you’re going to be diligent about keeping it sealed up. Farming stores sell tape for the purpose, so get some before the bales are made. Use the tape to seal up holes as soon as you find them. 

  • Set aside an area for storing the bales where no stalky material or sharp stones are likely to puncture the bottom of the bales.
  • Check them over carefully for holes once wrapped, and seal them up with tape. Check again once they’re moved off the paddock.
  • Stock will chew through balage plastic so erect temporary fencing if necessary to keep animals out.
  • Birds can puncture bales with their talons and beaks. Some farmers store their balage close to busier areas so birds don’t get free rein.
  • Heavier bales are more likely to be damaged when being moved.
  • Pay the contractor to put extra wrap on each bale. More plastic means less chance of holes. It has been suggested that two extra layers is as good as using inoculant.
  • Keep children and pets from climbing on the bales.
  • Don’t store the bales where you know porina to be a problem.


Dr Simone Hoskin, senior lecturer in ruminant and equine nutrition at Massey University’s Institute of Veterinary, Animal and Biomedical Sciences, believes pit silage is more risky than balage because of its generally higher moisture content.

“Wrapped silage (balage) can be a great feed for horses and can be very cost effective,” she says, “although once a bale has been opened it should be used within a few days unless it is very cold or snowy weather, in which case it can be fine for up to 10 days – otherwise you can get secondary fermentation.”

Dr Hoskin considers the risk of botulism poisoning low, provided the balage is of good quality.

It is hard to escape the conclusion that New Zealand appears to be a low-risk area for botulism poisoning in stock. There have been no recorded cases of it in any speciesat Massey University in at least 10 years. It is known in birds, but there do not appear to have been any cases reported in cattle in this country. Even if cattle cases have come to light here, they would certainly rate as extremely rare.

All this will no doubt provide considerable comfort to horse owners feeding balage, although it should be noted that horses are more susceptible to botulism than cattle.

Overseas, livestock have not been so lucky. Feed-related outbreaks of botulism have not only been linked to silage and balage – big-bale lucerne hay and oaten chaff have also been a source. This shows that any spoiled feed (not just balage) could potentially carry a risk of botulism and should never be fed out.

The risk for horses may be low, but remember the golden rule: never feed spoiled, mouldy, or poor quality balage to horses.

What can go wrong?

  • The cut grass can be rained on. This leaches sugar from the grass and can result in poor balage. Rain can also splash clostridial bacteria from the soil on to the grass, which can cause bad fermentation.
  • The bale plastic can be punctured, either while being transported, by birds, vermin, porina moths emerging from the ground beneath the bales, or by stalky material poking through the plastic. (see “How to prevent holes”).
  • The wrong kinds of bacteria can take hold, ruining the bale and risking botulism poisoning in horses if fed out.
  • The grass may not have enough sugar to fully ferment, resulting in an unstable bale and increasing the chances of spoilage.

Test for quality

Balage being bought should be tested for quality and the price should reflect the quality, says Massey University equine nutritionist Dr Simone Hoskin.

Most major suppliers get their product tested, she says. “If they haven’t, you are quite within your rights to ask for it to be tested, or get it tested yourself.”

A fresh 500g sample (preferably from the centre of a bale) can be sent by courier in a sealed plastic bag to a variety of labs for analysis, including the Massey University Nutrition Laboratory.

Horse owners otherwise risk paying too much for poor quality feed, she says.

Keep your friends

If you’re feeding balage out by hand, have a dedicated set of clothing for the task, including gloves. The smell of balage is quite invasive, and not everyone will enjoy Eau de Silage. It’s one of those smells that keeps on giving!

Watch for the skitters

Balage can trigger loose bowel movements in some horses, probably through finding the feed too rich or acidic. The problem is usually overcome by providing hay with the balage.

What about a vaccine?

Veterinary reports in the United States have suggested vaccinating against botulism if feeding balage to horses. However, the inoculation requires two or three shots (with annual boosters) and is certainly not foolproof, mainly because it doesn’t cover all varieties of the bacterium. Undesirable side-effects have also been reported. One vet suggested it was not a decision to take lightly. The vaccine does not appear to be available in New Zealand.


First published on Horsetalk in April, 2007
» Balage chosen by horses over hay – study
» Horse hay: how to identify the good stuff

4 thoughts on “Feeding baleage to horses – the ultimate guide

  • February 13, 2013 at 10:11 am

    How long does baleage last if you just leave it bailed? 1 year? 2 years?

    • January 19, 2017 at 2:16 pm

      It all depends on what quality it was when baled and how many layers of plastic was put on. Along with a lot of other circumstances. We do around 400 acres of it and it is a wonderful thing. I personally don’t agree with everything in this article. I hope that helps you 🙂

      • August 6, 2020 at 5:52 am

        I have a question. We ordered dry wrapped hay and upon opening one it had a smell of fermentation like a sour bar like smell
        It was bailed a day early to be considered dry hay. A little damp to the touch
        Once a flake or two was out in the air the smell went away and seemed mostly dry
        My concern is that it didn’t have enough moisture to be considered baleage and the fear of botulisim. Any input would be greatly appreciated

  • May 14, 2017 at 12:22 pm

    Usually try to use it before the second winter. Do not move it as air can get inside. It can go two full years but depends on the quality.


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