
BY ANDREA D. ELLIS FROM ANIVADO
Does a feed or supplement really affect horses’ behaviour?
Can supplements or feed affect behaviour? If the horse is on well balanced, species specific diet and receives the correct amount of nutrients it requires then, the short answer is – no, there is no real scientific evidence so far.
There is some limited research showing that incorrect feeding and certain nutrient deficiencies however may have an effect on horse behaviour. This is often intertwined with other management factors, such as housing and pasture access as well as exercise, training and stressful situations. When we talk about ‘unwanted’ behaviour in horses, this is often ‘unwanted’ or ‘inconvenient’ to us humans, while for the horse it is part of a behavioural repertoire they have developed in order to survive in their natural environment. For example, what we deem as ‘distracted’ behaviour or ‘lack of attention’ for the horse is a matter of being ‘alert’ and ‘reactive’ to any possible attack from predators. We need to be aware of this and ensure our own ‘reactions’ do not make these behaviours worse by creating stressful situations.
Author’s Tip: Always consider behaviour from the ‘horses’ point of view, avoiding putting ‘human’ motives or interpretations behind it (e.g. put yourself into ‘your horse’s hooves’) – why does it behave or react in a certain manner. What may be the trigger or purpose of the behaviour? Remember the horse is a flight animal and a herd animal and a herbivore – these three characteristics are behind most behavioural motivations in the horse.
But let’s look closer at feedstuffs and the myths and truths about these and behaviour. The motivation for food intake behaviour can be linked to lack of foraging opportunity. Here studies have shown that horses require to spend around 12/24 hours per day on food intake related behaviours – and that these are distributed evenly in a 2-3 hour feeding resting pattern throughout 24 hours. So, no, our horses do not go to ‘sleep’ at night. If they have restricted foraging opportunities they will eat their bedding (straw, hemp, peat, wood shavings), they may chew wood or rugs.
Author’s Tip: Providing enough turnout and forage opportunities can prevent unwanted related behaviours and can prevent stereotypic behaviours from developing. It will also make the horse calmer, especially if it has more social contact with other horses. In ‘easy doers’ finding ways of slowing down feed intake (strip grazing, muzzles, slow feeders, hay nets) will help to still keep them busy while restricting feed intake.
When we look closer at nutrient composition of feedstuffs, it is generally believed that concentrated feed (with higher starch and sugar content) will make horses ‘flightier’ or ‘faster’. There is no scientific evidence to support this at all. In fact, if they put on weight from the high energy feed, which is not natural to their metabolism, they will become sluggish and slower. One study has shown that feeding high concentrate feed to foals after weaning versus high forage and fat feed let to increased stress behaviour in the high concentrate group.

Author’s Tip: Replacing 1 kg of grain/concentrates, which may take 10 minutes to eat, with 1 kg of good quality forage, which takes 40 minutes to eat will result in a ‘calmer’ horse, because it is ‘happy’ when it is chewing. So it links back into fulfilling feeding requirements.
Other nutrients which may be lacking in the diet can affect behaviour, but only if the horse is deficient in these in the first place. Magnesium has been shown to cause animals to be more excitable and easily stressed when deficient. There are several studies in pigs, calves and also one in horses. Therefore, unless your horse is deficient in the first place, buying a supplement to ‘calm’ the horse down may be a waste of money, therefore it is best to first to a ration evaluation and feed analysis to check if a supplement is required.
A lack of essential amino acids has been implicated in behavioural problems but there is very little evidence out there. Herbal supplements which have shown some calming effects in humans and may possibly work in horses are camomile and hops. But in the end nothing will calm a horse down more than the removal of the stressor or good training which allows it to habituate to certain stressful situations we put the horse in.

Author’s Tip: If your horse displays ‘unwanted’ behaviours, check that there is no underlying pain with a veterinarian, then consult with a good certified equine behaviourist and a nutritionist, approaching things from a ‘holistic’ – multi-angle point of view. Always ask yourself – what am I doing that may be making the situation worse – we are often not aware of our own actions, and a good trainer can see these. There are plenty of ‘not so good ones’ out there, so beware, get references and do a little research yourself. There are some good courses available online, if you want to learn more about this. Every behaviour has a ‘reason’ or motivation behind it!
This column was brought to you by nutritional experts from ANIVADO. ANIVADO is a platform for online courses on equine nutrition, behaviour, health and performance. If you want to learn more about us please visit: www.ANIVADO.com