Feeding and Behaviour

We are all interested in the behaviour of our horses. Whether it is curiosity about what they get up to in the field with their companions, or trying to understand why they react at a bag flapping in a hedge – our horse’s behaviour is often the main talking point.

Behaviour is defined as ‘an animal’s reaction to a stimulus’. A stimulus can be anything from a loud bang causing the horse to startle, or the noise of feed buckets stimulating the horse to kick the stable door. Every action a horse makes is part of its behavioural range – the startle response is instinctive, whilst behaviour such as the horse kicking the stable door from hearing feed buckets, is a ‘learned behaviour’ – a result of a previous combination of stimulus and response.

Learned Behaviours

An understanding of learned behaviours is beneficial for the training and welfare of horses. There are three types of learned behaviours that the horse may show:
• Habituation
• Classical conditioning
• Operant behaviour
(See below for descriptions of these behaviours)

Feed and Behaviour – the link

It often comes as a surprise to owners that their horse’s behaviour can be linked to feed. There are numerous names for unwanted behaviour shown by our horses: bolshy, hotting up, fizzy and excitable to name but a few. Although many of these types of behaviour have a root in natural instinctive behaviours used for survival (the flight response), the damaging effects that develop mean that such behaviour is undesirable.

Although feeding cannot change the natural character of the horse, or alter instinctive behaviour, incorrect feeding can often cause exaggerated responses to harmless, everyday situations.

In order to fully appreciate the impact feeding has on a horse’s behaviour, it is important to understand what happens when a horse digests certain food types.

The horse evolved as a trickle feeding herbivore that ate small, but frequent meals of high fibre forage. Today, many horses are fed diets rich in starch and soluble sugars, with forage just being viewed as a bulk food.

Just as in humans, when a horse eats, the food is broken down in the intestines and absorbed. When the food is absorbed it enters the blood stream and causes the blood sugar to rise. This happens after every meal, but diets high in sugar and starch bring out a much higher response than fibre. When blood sugar reaches a certain level, the hormone insulin is produced which causes the sugar in the blood stream to be stored in the cells of the body – blood sugar usually peaks around 2 hours after a meal.

Sugar circulating in the blood is the most accessible form of fuel for the horse, however, there is not enough in the circulatory system to sustain exercise for long periods. The sugar contained in the blood can cause excitable behaviour and the bigger the blood sugar peak, the more chance there is of your horse showing unwanted behaviour.

When we feed our horses limited forage and meals in buckets, the peak in blood sugar can be exaggerated. Insulin is then released and the blood sugar levels fall. If we compare the peaks and troughs in blood sugar that high starch diets cause to the blood sugar levels of a horse fed a high fibre diet, we can see that there is a very big difference between the two.

Unlike the high starch diet, a diet high in fibre causes less extreme peaks and troughs in blood sugar, which means that there is less excess sugar circulating for the horse to become fizzy on. The reason for this is that fibre is broken down much more slowly in the hind gut by bacteria. The fibre is fermented by the bacteria which then releases volatile fatty acids – compounds that the horse can use as slow release energy.

If the horse does react in a negative way after eating high starch and sugar meals then it is usually operant behaviours that are seen with the horse being ‘naughty’ or ‘acting up’. The horse will learn that if he drops his shoulder or bucks, his rider may come off! Sometimes this unwanted behaviour may have a root in the flight response – horses are naturally very vigilant and so if a bag is flapping in a hedge his natural response is to run away. However, just as he will learn that the bag will do him no harm, if the rider’s response to the behaviour is to get off, or turn  round and go home, then the horse will also learn that his startle response will produce this outcome, and he will therefore carry on spooking at the bag in the hope of the same reaction.

To minimise the chance of unwanted behaviour, it is essential that a diet high in fibre is fed. Highly digestible fibre sources, such as those found in the Barley & Molasses Free Range of feeds may help to prevent fizzy behaviour, as they are broken down more slowly than traditional cereal-rich feeds. Being lower in both starch and sugar than many other feeds, the Barley & Molasses Free Range feeds will not cause excessive blood sugar peaks, meaning that both you and your horse can have fun without the fizz!

Habituation

A habituation response happens with continued exposure to a certain situation. If this occurs often enough then the horse will stop reacting. Habituation is often used when breaking a horse in. Initially, the horse will react negatively to the saddle on his back, as this is his instinctive flight response telling him he could be in danger and therefore he must run away. But as the saddle is repeatedly placed on his back and nothing hurts him, he will eventually accept the saddle and stop reacting. In a very different example, habituation often happens in riding school ponies that are used to carrying novice riders who constantly kick at their flanks. The ponies eventually stop responding to the kicking and it is this lack of reaction that we call ‘dead to the leg’.

Classical Conditioning

Classical conditioning refers to an involuntary behavioural response that results when the horse links two forms of stimuli together. For example, if a horse receives an injection from a vet wearing green overalls and the injection hurts, the green overalls have been associated with the arrival of pain. Due to this association, the horse may show a quickening of heart rate next time the green overalls appear again. The heart rate elevation is involuntary – the horse does not have to think about it to respond, it happens automatically – this is typical of a classically conditioned response. However, there will most probably also be a voluntary behavioural result from this association, such as rapid movement away from the vet. This voluntary element is referred to as the operant response.

Operant Behaviour

Operant behaviour happens when a horse learns to perform a voluntary behaviour in order to achieve reward or avoid punishment – such behaviours are commonly seen around feed time. The horse learns that if he kicks his door long enough he will get his feed first! How does he do this? The horse initially learns to recognise that certain sounds mean that he will soon be fed. In anticipation of his feed, he may start to kick the stable door.