Traditionally, feeding straw to horses was common place and a key part of many horses’ diets, but it’s less heard of these days not least because of the rumoured risk of it causing impaction colic and gastric ulcers. In our grandparents’ day, the main option for bedding would have been a straw-based bed, and it was a given that some of the bed would be eaten. This in turn reduced the forage bill and was a regular ‘filler’ to go alongside the hay ration. The question here is did our ‘elders know best’, allowing their horses access to eating straw, and if so, what could our horses be missing out on today?

It is important to understand that straw has a low nutritional value. In instances where you are struggling to find a lower calorie hay, you know you can reduce the calorie content by using this method. Straw will also extend eating times for those horses who are not already overweight but who you have to monitor carefully, enabling you to feed a certain amount ‘on top of’ the hay ration you are already giving.

The longer horses eat and therefore chew, the healthier it is from a digestive and behavioural point of view. The fact we can do it in such a low-calorie format by feeding straw to horses is overlooked by many. As with changing or introducing any feed, it’s important to get it right. It is also important to note that feeding straw isn’t suitable for every horse or pony, especially if they struggle to hold condition, are young or old or have poor teeth. Seek advice from your vet first.

How to feed straw safely

1. Check your horse’s teeth

Ensure your horse’s teeth are in good order. Horses with poor teeth will find straw more difficult to manage than hay or haylage. If the teeth are okay, then gradually introduce the straw to comprise up to 30% of the forage ration.

2. Choose the type of straw

I tend to recommend either barley or oat straw. Check that it hasn’t been sprayed with chemicals, which it can be if being sold as bedding because these chemicals are used to discourage eating.

3. Calculate how much to feed

Straw shouldn’t make up your horse’s whole forage ration — it can replace up to 30%, effectively reducing the calories your horse consumes without taking away the amount of food he or she has access to. Straw has a low nutritional value, being high in fibre and low in calories. It is much less digestible than hay or haylage as it contains a higher level of lignin (indigestible material). As a result of this, where feeding straw to horses becomes particularly useful is for good-doer types or those who are already overweight.

4. Gradually introduce it

As with any new forage or feedstuff, straw should be introduced gradually, to allow your horse’s digestive tract time to adjust and maintain positive digestive health.

5. Keep hydrated

Always ensure that your horse has access to clean drinking water. There’s no real need to soak straw, as on average it has a water-soluble carbohydrate level between 6% and 7%.

6. Mix straw in with your horse’s hay

There will not be any harm caused if you mix the straw in with your current hay and, because you soak your hay, then you end up also soaking the straw. Ultimately, however, while the nutritional value of straw will vary by type and growth conditions, average straw has a water soluble carbohydrate (WSC) level of between 6% and 7%, so there is no real need to soak it.

How much straw can a horse eat?

An alternative to buying straw bales from your hay or haylage supplier would be to use readily available straw-based forage replacers, which are produced by many feed manufacturers. The major benefit of this is you will know its nutritional analysis.

When introducing it, first check if it is suitable as a complete or partial forage replacer; this may influence your choice. If it has a very high inclusion rate of straw, then it will be listed as a partial forage replacer. Some, however, include straw at a much lower inclusion rate, so many are suitable as a complete replacer. Typically, the lowest calorie options will be the ones with the highest levels of straw, which would be fed alongside your hay or haylage to replace up to 30% of it.

Once you have established the ideal amount for your horse — which tends to be around 1kg to 3kg if acting as a partial forage replacer — gradually introduce 500g of it every other day, in a separate bucket in your horse’s stable. Follow any manufacturer guidance, such as soaking. If you are unsure, call the feed company’s helpline.

Do horses like eating straw?

Don’t be surprised if your horse eats their hard feed and then starts on their hay, appearing as though they have ‘shunned’ their bucket of straw-based forage replacer. As owners we love seeing our horses ‘eat up’, but the reality is horses typically turn to the straw when their sweeter forage sources have depleted. Straw tends not to be as palatable, but really this is another of its major advantages, particularly for the good doer. Rather than eating rapidly the horse will go back and forth, reducing the length of time he goes without access to forage.

Do I need to add any supplements when feeding a horse straw?

As with all forage sources in the UK, your horse’s diet will require the addition of vitamins and minerals, either from a suitable hard feed fed at the correct rate, or a balancer/vitamin and mineral supplement, to ensure it is balanced. This will correct the low level of calcium (which can actually be low in hay too) and also the low protein content found in straw, while also providing a complete blend of required vitamins and minerals. Some manufacturer straw-based forage replacers are fortified with calcium to support this further.

Can feeding a horse straw cause gastric ulcers?

Straw has been a worry for owners of horses with gastric ulcers. A study in Denmark found that a horse eating straw as the only source of forage was more likely to have gastric ulcers. However, here in the UK we would not feed straw as the sole source of forage, or recommend you do so. A further study was then published which looked at feeding 50% of a haylage ration as wheat straw. The risk of gastric ulcers in this situation did not increase.

While straw does not buffer the stomach particularly, it does need to be chewed. This in turn produces saliva, which contains bicarbonate and helps to buffer acidity. Therefore, when fed in the correct way, straw can help to promote positive digestive health.

Can eating straw cause impaction colic?

There have also been concerns in the past that feeding straw is linked with impaction colic. A study undertaken by Redwings and veterinary researchers at the University of Edinburgh looked at feeding 50% straw and 50% hay to a group of overweight ponies and compared them to a group fed with normal hay throughout winter.

Those who were on the mixed ration lost a significantly greater amount of weight than those who were fed only hay. What is useful to note too is that none of these ponies suffered from impaction colic. In turn, it highlighted that the inclusion of straw is a really positive way to help owners manage their horse’s weight and thereby help to reduce the risk of laminitis.

Have you heard about Your Horse’s #FitNotFat campaign, which is supported by Spillers? Equine obesity is an enormous welfare problem and we’re on a mission to provide owners and riders with the knowledge, skills and information you need to keep your horse in tip-top health. It could be life saving! Find out more