Should You Feed More to a Horse That Feels Tired and Lazy?

Well… it depends! If your horse is light in condition and possibly losing some weight and feels tired and lazy then yes, feeding more is probably the solution. Light condition and/or weight loss are both symptoms of note quite enough calories in the diet. Feeding more and increasing calorie intake should help with energy levels when being ridden.

BUT! If your horse is overweight or gaining weight, more feed is not the answer to overcoming your horse feeling tired or lazy when being ridden. This feeling/behaviour could be caused by multiple things, including just a lack of fitness or even a lack of education in the ‘go forward’ area.

But, overwhelmingly when we work with horses like this, more often than not the horse is tying up. But tying up on such a mild level that the only real symptom is this feeling of being tired and lazy when ridden.

Because changing diets to a diet suitable for a horse with tying up is simple and safe, it is worth a shot to see if your horse’s level of energy improves with a change in diet. Most horses that feel like this are warmblood or warmblood crosses or heavy horse or heavy horse crosses, which means the most likely form of tying up will be PSSM (polysaccharide storage myopathy).

If you eliminate all grain and grain by-product from the diet of a horse with PSSM and keep starch and sugar levels as low as possible, you should see an improvement in energy levels within 2 to 3 weeks (provided the horse is fit enough to do the work you are asking).

FeedXL can help you with this. You simply tick ‘Tying Up (PSSM)’ in your horses details and then FeedXL will colour code the ingredients in its database according to whether they are suitable for a horse with tying up or not.

Makes it much easier than trying to sift through the unfortunately sometimes misleading marketing information from manufacturers to work out what feed ingredients might be suitable or not.

For more information on feeding a horse that ties up, read our article Feeding Horses that Tie Up.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Gut Bacteria, Vitamin B1, and Behaviour: Are They Linked?

The short answer is yes! Here is how:

Vitamin B1 has been observed to have an influence on behaviour in multiple animal species, including horses. A horse will meet its vitamin B1 requirements via the vitamin B1 it eats in its diet and from vitamin B1 produced by the bacteria in its hindgut.

There are two main families of bacteria living in your horse’s hindgut:

1. The fiber fermenting bacteria who love to ferment fibre from the forage your horse eats. These little critters are the ones we consider the ‘good bacteria’; and
2. The starch and sugar fermenting bacteria who prefer to ferment starch and sugars. These we generally consider to be the ‘bad bacteria’.

The good bacteria PRODUCE vitamin B1 that your horse can then absorb and use.

On the other hand, the bad bacteria produce a compound called ‘Thiaminase’ that actually destroys vitamin B1 (also known as thiamine) that is in the gut, making it useless to your horse.

If your horse has too many bad bacteria, and not enough of the good ones your horse may not get enough vitamin B1 and behavioural changes may occur.

How do you avoid this? Keep your horse’s hindgut healthy with an abundant population of good bacteria. The main two things you should do to achieve this are:

1. Feed lots of forage!; and
2. Never feed uncooked grains (with the exception of oats for some horses)

For more tips on caring for your horse’s hindgut, read our article Keeping the Hindgut Healthy.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Feeding the ‘Pony Club’ Mount

A good Pony Club mount is a precious commodity and they often require special care to keep them fit, healthy and active for as many years as possible. Sound nutrition should form the basis of this care. Pony Club mounts are also carrying an even more precious load, your children; and in this respect, temperament is everything. The following article gives you some tips on how to feed your Pony Club mount to keep them healthy and calm without costing yourself a fortune.

Tip #1 – Base the diet on forage

Diets that are based on good quality hay or pasture have many advantages. They keep horses calm, healthy and content, they are cost effective and they reduce the risk of major diseases like colic. As a rule your Pony Club mount should be fed a minimum of 2 kg/100 kg of bodyweight/day of hay or given free access to pasture (provided excess weight isn’t an issue).

If your Pony Club mounts are able to hold their condition on pasture or hay alone all you need to do is provide them with a good quality vitamin and mineral supplement and you will have a diet that keeps them happy, healthy and calm on a shoestring. FeedXL can help you to work out which supplement to use and what dose rate will work best.

If you find they can’t hold their weight on grass based pasture or hay alone even when they are being fed as much as they can eat, try adding some lucerne/alfalfa hay to the diet. If this still isn’t enough you will need to add a complete feed suitable for Pony Club mounts to their diet.

Tip #2 – Use suitable complete feeds

Some feeds can affect a horse’s temperament, so if you do need to use a complete feed for your Pony Club mount choose carefully. If you have a mount that tends to get hot when fed higher energy feeds, look for a non-grain complete feed that provides cooler energy from fat and fiber sources (Tip: to make it easy to find these feeds when using FeedXL, tick ‘Grain Intolerant’ when filling in your horses details and the unsuitable feeds will be in red in the feeds list). Likewise if your horse or pony is prone to laminitis, select feeds that contain no grain or grain by-product with a sugar and starch (NSC) content of less than 10 – 12% (again by ticking ‘Laminitis’ in your horse’s details in FeedXL, unsuitable feeds will be ‘red listed’ to help you steer clear of them).

If you have older mounts that are having trouble holding their weight or young horses that need extra energy, look for feeds that contain cooked and easy to digest grains and good quality protein.

Tip #3 – Don’t overfeed

Overfeeding will result either in an overweight horse or a hyperactive horse. One isn’t good for the horse, the other is certainly not good for its rider. When feeding your Pony Club mounts, feed them according to the work they are doing and their current body condition. Don’t be afraid to adjust the amount you feed on a daily basis according to if and how hard they were ridden that day and what their temperament or body condition is like.

For example, you might feed 2 kg of a complete feed on days your mount is ridden for at least an hour with 50% or more of this time being solid trot and canter work. On days that horse is not ridden, it might only be fed 0.5 kg of feed plus its hay or pasture. Condition score your mounts regularly and assess their temperament and adjust their feed according to whether they are gaining, holding or losing weight or whether they are feeling flat or a little hyperactive.

Tip #4 – Feed a balanced diet

Making sure all nutrient requirements including those for minerals and vitamins are met will keep your Pony Club mounts as healthy as possible. Common deficiencies of minerals like selenium can compromise a horse’s immune function, copper deficiency will lead to bleached coat colour and joint issues while a zinc deficiency will eventually lead to hoof problems. These nutrients are easily supplied in good quality vitamin and mineral supplements or well formulated complete feeds. Use FeedXL to assess if your mount’s requirements for these important nutrients are being met.

In Summary

Feeding the Pony Club mount should focus on keeping them healthy and active, yet calm. Feeding balanced diets based on forage and only using suitable feeds when needed will go a long way to achieving this goal. Adjusting the amount of any high energy feeds fed according to the horse’s workload, temperament and body condition will help to avoid excessive weight gain and hyperactive behaviour, while being sure to meet all vitamin and mineral requirements will keep hooves, skin, coats, muscles and joints healthy for as long as possible.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Pasture: Is it Affecting Behaviour?

Is Pasture Affecting Your Horse’s Behaviour?

During times of the year when pasture is young, lush, very green and growing quickly it is common to find horse owners having problems with their horse and particularly their behaviour. Normally quiet, calm horses can become ‘spooky’, behave erratically and become excited easily, show signs of incoordination, muscle tenseness, soreness or twitching and in severe cases may become dangerously aggressive and exhibit unusual herding behaviour.

Until recently, the spookiness and excitability was often assumed to be due to the high energy content of the lush grasses. This may indeed still be a contributor, but when looking at all of the symptoms together it becomes clear that another underlying problem exists. The problem is, it is not very clear what this underlying issue is.

Magnesium deficiency has been proposed several times, but most horse nutrition texts give no reference to pasture having the ability to cause a magnesium deficiency, much less that magnesium deficiency is capable of causing all of the symptoms seen.

While this is a topic that one could easily spend years researching without answering many of the questions we now have, the following is my take on pasture induced magnesium deficiency and how it may be affecting your horse.

Can a magnesium deficiency really cause all of these problems?

The NRC 2007 publication reports that magnesium deficiency may cause ‘nervousness, muscle tremors and ataxia (incoordination), with the potential for collapse, hyperpnea (deep breathing) and death’. It goes on to say that ‘while uncommon, tetany in transported horses has been attributed to hypocalcaemia and potentially hypomagnesemia’. The NRC 1989 publication also stated that ‘pastures that are conducive to magnesium deficiency, tetany and death in ruminants do not affect horses similarly’. It then goes on to say that ‘no evidence was found in the literature to support this claim’. I am pointing this out only to demonstrate how little is known about this condition in horses. On reading this information about magnesium it would be easy to assume that a pasture induced magnesium deficiency in horses would be a rare occurrence.

The fact is, many horse people are reporting strange behaviour in horses during the times of year pasture is young, green, lush and rapidly growing so something is going on. With such little information available in horses on magnesium deficiency, we must again look to other animal species for clues.

It is quite well documented in ruminant animals that during phases of grass tetany (magnesium deficiency, most commonly seen in high producing dairy cows during early lactation grazing lush pastures) that affected animals are nervous with an overly alert appearance, they may lose coordination and ‘stagger’ and they may also become aggressive. Humans are also reported to suffer with cramps and muscle weakness as well as become confused, delusional, disoriented, suffer hallucinations and become aggressive during periods of magnesium deficiency. Hypocalcaemia (low plasma calcium) is also frequently observed in both humans and ruminants with magnesium deficiency. So while we don’t have direct, documented evidence in horses (yet), certainly the symptoms we are seeing in horses relate well to symptoms seen in other animal species under conditions of magnesium deficiency.

(The effects of magnesium deficiency in humans are far more extensive than listed above.)


The Science – why are these symptoms present?

OK, so here we go with some of the underlying science to these problems that will help to explain why a magnesium deficiency can cause the symptoms seen in horses.

Magnesium is essential for the functioning of a magnesium dependent enzyme called acetylcholine esterase. Acetylcholine esterase is needed for the breakdown of the neurotransmitter acetylcholine. During periods of magnesium deficiency, acetylcholine esterase does not function as it should and acetylcholine accumulates at the motor end plates causing neuromuscular excitability. This accumulation of acetylcholine is likely to contribute to the tense muscles, incoordination, muscle twitches and spookiness seen in magnesium deficient animals.

Magnesium is also needed for the adenyl cyclase enzyme which is involved in the action of parathyroid hormone. This compromised function of the parathyroid hormone (PTH) is thought to be the main cause of hypocalcemia which is commonly observed in magnesium deficient animal species including ruminants, humans and rats as PTH is needed for calcium absorption. PTH is also needed for magnesium absorption so magnesium deficiency predisposes an animal to a more severe magnesium deficiency by altering the function of the hormone needed for its absorption.

Magnesium is required for the phosphorylation of vitamin B1 (thiamine) into the biologically active thiamine pyrophosphate, so in effect a magnesium deficiency will cause a vitamin B1 deficiency, even when there is ample vitamin B1 in the diet. In humans, a vitamin B1 deficiency can cause confusion, and disorientation with sufferers reportedly becoming delusional and even hallucinating (maybe your horse really does see goblins hiding behind the tree!). Vitamin B1 deficiency can also lead to aggression. In horses, vitamin B1 deficiency is known to cause loss of appetite, incoordination, muscle twitching, tremors or stiffness, overflexing of the hindlegs, unnatural extension of the forelegs and hypothermia (low temperature) of the bodies extremities like the legs, muzzle and ears. Thiamine deficiency may also result in missed heart beats and lactate accumulation in the muscles.

Finally a magnesium deficiency affects nitric oxide production by motor neurons. In situations of low extracellular nitric oxide but high intracellular nitric oxide in humans, aggression can result.

This by no means is a complete review of how a magnesium deficiency may affect horses and again it is a subject I would need to research for years to fully understand (as there is some serious biochemistry involved). This mini review should however serve to demonstrate that should a magnesium deficiency occur, it is certainly capable of producing the varied symptoms being observed in horses by their owners.


So, now that we know a magnesium deficiency could be the root cause of the unusual symptoms and behaviours observed in horses grazing lush, green and rapidly growing pastures, let’s look at what it is about these pastures that can cause a magnesium deficiency.

Reduced Magnesium Absorption

Lush, young, rapidly growing pastures are well known to have high potassium and low magnesium levels. While direct evidence for horses is not available to my knowledge, in ruminant animals it is well known that excessive potassium can reduce the absorption of magnesium from the rumen. High dietary potassium is also reported to reduce magnesium absorption in humans. While it is only through extrapolating from data in other animal species, it is likely that excessive potassium in the equine diet also reduces the absorption of magnesium in horses. This reduced absorption, coupled with an already low magnesium concentration in the diet could possibly result in an induced magnesium deficiency, even if there appears to be enough magnesium in the diet to meet requirements.

The acid base balance of the body can also affect parathyroid hormone (PTH) release, with an alkaline body pH, which commonly occurs on high potassium diets, suppressing the release of PTH in some animal species … so maybe this is also playing a role … and maybe even supplementing magnesium help as the horse may not be able to absorb it due to low PTH levels.

Other dietary factors than can reduce magnesium deficiency include excess calcium (high dietary calcium reduces parathyroid hormone (PTH) release. As discussed above, PTH is needed for magnesium absorption), excess phosphorus (phosphorus can block the absorption of magnesium as it can calcium) or a vitamin D deficiency (also needed for magnesium absorption), vitamin B1 deficiency (affects magnesium absorption by altering the pH environment of the stomach) or vitamin B6 deficiency.

Increased Magnesium excretion from the body

High dietary potassium in lush green pastures not only reduces magnesium absorption in animals, but it can also increase the amount of magnesium excreted from the body, giving it a ‘double-whammy’ effect in causing magnesium deficiency.

In addition, under the right environmental conditions lush green pastures can also have large amounts of nitrate accumulated in their leaves, especially when plants are very young and in the one or two leaf stage. In order to remove nitrate from the body, ruminants and horses bond the nitrate to a cation (a positively charged ion which includes calcium, magnesium, sodium and potassium) to form an ionic complex which is then excreted. Professor T.W. Swerczek, a researcher with the Department of Veterinary Science at the University of Kentucky, USA has reported that when a sodium deficiency exists (which is common in grass based pastures) nitrate is more likely to bond with calcium or magnesium, so under high nitrate conditions, a magnesium deficiency can occur.

Other factors that may increase magnesium excretion from the body include excess oestrogen (possibly putting mare’s or horses grazing estrogenic forages like some clovers at higher risk) and a dietary selenium deficiency (again this is not confirmed in horses but is taken from human data).

So with the combination of factors that reduce magnesium absorption and increase magnesium excretion from the body, a magnesium deficiency is certainly possible under the right conditions for horses grazing lush, green, rapidly growing pastures.

Do endophyte mycotoxins play a role?

They certainly could, though they need not be present for the symptoms of magnesium deficiency to appear. Ryegrass and fescue pastures that are infected with endophyte fungi may be more likely to contain higher concentrations of the problematic mycotoxins under high pasture potassium conditions (Swerczek 2003). Knowing whether or not they are involved is however going to be tricky as many of the symptoms of endophyte mycotoxicosis are very similar to those that could be caused by magnesium deficiency. Mycotoxicosis is however reported to be most likely when pastures are grazed down to the ground or when they are tall and rank, so it is less likely when the pastures are green, lush and growing rapidly.


Laminitis is often seen in horses during spring and autumn seasons when pastures are green, lush and growing rapidly. It is now known that insulin resistance and high levels of circulating insulin are the most likely cause for most pasture based cases of laminitis and this certainly does help to explain most cases. However, rapidly growing pastures and particularly rapidly growing pastures in warmer climates are unlikely to have large amounts of accumulated sugars and starches and yet laminitis can still be found on these pastures. So if it isn’t sugar and starch causing the laminitis, what is?

Insulin is used as a signal to cells to take in potassium from the blood. A really interesting study in cows and calves by Lentz et al (1976) found that high levels of potassium (infused as potassium chloride) caused significant elevations in plasma insulin and in the calves, this response was further exaggerated in magnesium deficient animals. So it is quite possible that the high potassium content of lush pastures coupled with an induced magnesium deficiency is causing laminitis by causing prolonged elevations of insulin, which presumably would be worse in insulin resistant animals. This would certainly make a very worthy avenue of research.

It is also possible that the high nitrate levels that can accumulate under the right environmental conditions in young, lush, green pastures leads to laminitis. There is gathering anecdotal evidence to support this theory but as yet no science to actually prove it.

Further, research by Paolisso et al, published in the American Journal of Clinical Nutrition (1992) showed that administering magnesium to elderly patients at a rate of 4.5 g/day improved their glucose handling and insulin sensitivity. This finding begs the question of whether a transient magnesium deficiency that may occur in horses when grazing rapidly growing spring or autumn pastures increases the risk of laminitis for already insulin resistant horses during these periods by exacerbating their insulin resistant status.

What can you do about it?

While there may not be much published equine evidence to prove all of this is happening with your horse, if your horse is showing symptoms that could be related to a pasture induced magnesium deficiency there are some things you can do to help, including:

  • Seek veterinary advice if your horse is showing symptoms – magnesium deficiency to the point where an animal is showing symptoms is a serious medical condition and you should always consult your veterinarian for advice. Your horse may be deficient to the point where magnesium and calcium need to be administered parenterally to restore blood levels back to a point that will alleviate the most severe symptoms and also allow magnesium and calcium to be absorbed from the gastrointestinal tract again (as very low magnesium levels turn down parathyroid hormone levels which then reduces magnesium and calcium absorption). It may be a good idea to discuss testing your horse’s level of parathyroid hormone as part of your vets overall assessment of your horse’s condition.
  • Remove animals from problem pasture – if it is possible you should remove your horse from the problem pasture as soon as any signs are evident. Or if you know your pastures are problematic at certain times of the year, plan in advance and have them off the pastures before the symptoms appear.
    If you are unable to remove your horse from the pasture completely you should somehow try to restrict intake of the pasture by using a grazing muzzle during certain periods of the day (if laminitis due to sugars isn’t a concern then muzzling overnight and early in the morning is suggested as this is when nitrate levels are highest) or by strip grazing the pasture in small amounts each day and providing a low potassium forage like a mature grass/meadow hay.
  • Use a low potassium forage as the base of the diet – mature grass hay will provide you with a lower potassium alternative to the lush pasture. If your horse is already suffering symptoms you should also soak the hay for 30 minutes to remove as much potassium from the diet as you can.
  • Supplement with magnesium, calcium, sodium and vitamin B1 – This is where it gets tricky as while we know you should supplement with these nutrients it is hard to say how much more you should add to the diet. Luckily though, all of these nutrients have a wide safety margin so we are afforded a nice big safety net.
    For a horse suffering with symptoms of magnesium deficiency, I would provide the following: Magnesium, sodium and vitamin B1 – an additional 100% of the recommended daily intake for your horse.
    Calcium – in theory, once you have corrected the magnesium deficiency and get the parathyroid hormone functioning as it should again you shouldn’t need to add additional calcium to the diet if the amount in the diet is already adequate. However, if your calcium to magnesium ratio in the diet is less than 2 parts calcium to one part magnesium on addition of the extra magnesium you should add enough calcium to bring this ratio back up to 2: 1.
  • Correct any deficiency of vitamin B6 and selenium that may exist in the diet – A deficiency of these nutrients leads to reduced magnesium absorption and increased magnesium excretion so it makes sense to ensure your horse’s requirements are met according to the FeedXL recommended daily intakes for these nutrients.
  • Avoid pastures, feeds and conserved forages that may contain oestrogens – Excess oestrogen reportedly increases magnesium excretion from the body so it would make sense to keep the dietary intake of plant derived phytoestrogens to a minimum during high risk periods of pasture induced magnesium deficiency. This includes avoiding clover, alfalfa/lucerne and feeds that contain soybean or soybean meal. These feed ingredients also tend to contain large amounts of potassium so avoiding them provides a double benefit (please note though that under normal circumstances all of these ingredients can play a valuable role in a horses diet so don’t go overboard in avoiding them all the time).
  • Learn to recognise high risk periods and either remove your horse from the pasture or begin magnesium, sodium and vitamin B1 supplementation early – Pastures are high in potassium and nitrates during rapid, early stages of growth which can be seen during any time of the year depending on the climate where your horse lives. Particularly high risk periods include pasture growth associated with drought breaking rains, frost periods, cloudy days, hot dry winds and cold weather. Any of these (very varied) climatic conditions can induce high potassium levels, high nitrate levels or both in pasture where soil potassium and nitrate is plentiful
  • PLEASE don’t ride your horse – if your horse is showing symptoms of magnesium deficiency please don’t try to ride. Your horse in this condition is both physically and mentally unstable and trying to ride would be the safety equivalent of getting into a car with a seriously drunk person and going for a drive – it really isn’t worth the risk and it won’t be enjoyable for you or your horse.

A very real, but not very well recognised syndrome

Having seen some severe cases over the last few years there is no doubting that this condition exists, but as yet it isn’t recognised in nutrition texts. While it may seem like a simple matter of adding extra magnesium to the diet to correct the issue it isn’t that easy as the various factors discussed above may be contributing to low magnesium absorption or high magnesium excretion rates. If your horse is exhibiting these symptoms or other unusual behaviour that you think may be linked to your pasture you should have your pasture analysed to determine mineral levels you are working with and work closely with your vet and FeedXL to get your horse’s diet rebalanced and your horse’s magnesium levels restored.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Feeding for Calm Behaviour

There is nothing quite as unnerving or unenjoyable as riding a horse that is completely full of itself and constantly reacting before thinking. On a more subtle level a horse that won’t concentrate or continually overreacts to aids is frustrating. While education plays a major role in determining a horse’s behaviour under saddle, feeding can also have an impact.

What you feed, how much you feed and when you feed it can make a big difference. Here are some tips for feeding to assist your horse to maintain a calm and responsive attitude under saddle.

6 Feeding Tips for Calm Behaviour in Your Horse

1. Feed a forage based diet

Forage is soooo important when it comes to thinking about how to feed for calm behaviour! Here is why!

  • Chewing forage keeps a horse more mentally relaxed and calm. If they have a forage based diet, with an absolute minimum of 1.5% of their bodyweight in forage per day (7.5kg for a 500kg horse) they spend more time chewing and mentally content which is then reflected in their behaviour.
  • Forage encourages the production of large amounts of saliva which buffers the acidity of the stomach fluid, keeping a horse more comfortable and calm.
  • Forage provides the fibre that is able to stop acid splashing around in the stomach. If a horse’s stomach is empty because there is not enough forage in the diet, the gastric acid can splash up onto the unprotected upper (squamous) region of the stomach, ‘burning it’ and causing discomfort. This discomfort can potentially lead to changes in behaviour.
  • Forages feeds the ‘good bacteria’ in a horse’s gastrointestinal tract. These bacteria then produce B-vitamins and hormones that are crucial for maintaining normal behaviour.
  • A high forage diet is also typically low in grain and therefore starch. Research has shown that these low starch diets are less likely to cause changes in behaviour.
  • Low starch diets are also less likely to result in starch overload to the hindgut. When starch overload does occur, bacterial populations shift toward the ‘bad’ starch fermenting bacteria and hindgut acidosis can result. Shifting bacterial populations and hindgut acidosis will both cause unwanted changes in behaviour.

2. Don’t feed too much

Horses that are fed more than they need for the work they do can become hyperactive and difficult to control. When feeding your horse, be careful to define your horse’s workload carefully and feed it accordingly. FeedXL defines light, moderate and heavy work as follows:

Light Work: 1 to 3 hours per week of walking (40%), trotting (50%) and cantering (10%).

Moderate Work: 3 to 5 hours per week of walking (30%), trotting (55%), cantering (10%) and skill work such as low grade jumping, dressage or cutting (5%).

Heavy Work: 4 to 5 hours per week of walking (20%), trotting (50%), cantering (15%) and galloping or skill work such as high level jumping, dressage or cutting (15%).

So not only does the total number of hours of work need to be considered, but the type and speed of work must be taken into account as well. Classifying your horse in a workload higher than they actually are and overfeeding is possibly the most common cause of hyperactivity (and equine obesity). Once you classify your horse’s workload correctly, use the Digestible Energy requirement calculated by FeedXL as a guide to how much you need to feed.

3. Alter feeding according to daily workload

If your horse tends to become hyperactive, especially following a day off, reducing the amount you feed from a working ration back to a maintenance ration on days off can help to solve this issue. Developing one diet for days your horse is ridden and another with similar ingredients but smaller portions for days off means your horse is only being fed what he needs on any given day.

To take this one step further, if you work your horse at varying intensities on different days you may develop a couple of different working diets. For example, if you lunge your horse for 30 minutes two days a week (light work), trail ride for 1.5 hours mainly at the walk and trot with some cantering 2 days per week (moderate work) and have dressage and show jump lessons or competitions 2 days per week for 1.5 to 2 hours each with mostly trotting and cantering as well as skill work (heavy work) and your horse has 1 day off you could have a maintenance diet for the day off, a light work diet for the lunging days, a moderate work diet for the trail days and a heavy work ration for the lesson and competition days. That way you are constantly adjusting feeding to suit workload and avoiding overfeeding.

4. Feed ‘cool’ feeds

Fibrous feeds that are fermented in the hindgut to release energy are the most natural and also the ‘coolest’ sources of energy for horses. Using forages like pasture, hay, and chaff to provide the majority of the energy in your horse’s diet will help to keep your horse calm and responsive.

Horses in light work should be able to happily exist on a diet made up almost entirely of forages with supplements added if and when needed (use FeedXL to determine when supplements are needed and which fit the diet best). So if your horse is in light work, don’t be too quick to reach for ‘hard feeds’, stick with forages, especially if your horse’s temperament is an issue.

However, horses in moderate to heavy work often need higher energy feeds added to their diet as most physically can’t eat enough forage to meet energy requirements. In these situations where energy requirements can’t be met by forage alone, cool energy sources such as high energy fibres (sugarbeet pulp, soybean hulls, lupin hulls and copra meal), oils and high oil feeds like rice bran can be used to boost energy intake without impacting on a horse’s behaviour (though there is no guarantee).

5. Avoid ‘hot’ feeds

Grains and grain based feeds, molasses and forages like alfalfa/lucerne hay tend to be commonly blamed for making horses ‘hot’. Whether this is because they do actually make horses hyperactive, or because they are energy dense feeds that are easy to overfeed and therefore by default make horses hot is hard to determine. In any case, if your horse reacts to grains, grain based feeds or forages like alfalfa, avoid using these in the diet.

To make it easy to avoid any feeds that contain grains or molasses, simply tick the ‘Grain Intolerant’ box when entering your horse’s details in FeedXL and any feeds or supplements containing grain, grain by‐ product or molasses will be marked in RED.

6. Feed a balanced diet

Some deficiencies like vitamin B1 (thiamine) and magnesium can have an impact on your horse’s behaviour. Use FeedXL to make sure your horse’s requirements for these and other important nutrients are met and avoid nutrient deficiencies that can alter your horse’s behaviour. If you’re not yet a member, click here to learn more.

A note on calming supplements

There are a plethora of ‘calming’ supplements on the market aimed at helping to calm a hyperactive horse. Whether these supplements work or not is difficult to establish. Many studies have been conducted to assess their effectiveness with contradicting results. Most however are safe supplements, commonly containing large amounts of the water soluble (and hence virtually non‐toxic) vitamin B1. Some also contain magnesium and an amino acid called tryptophan.

If you are fine tuning your horse’s feeding regime to ensure you are not overfeeding, adjusting feeding according to daily workload, feeding a diet based on forage, using cool energy sources when needed and feeding a balanced diet PLUS have your horse well educated and its behaviour is still a problem, then trying calming supplements to see if they have a positive impact is a feasible option. If they work, keep using your chosen supplement. If they don’t, keep adjusting the diet and working on education until the right balance is struck.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


© FeedXL