We had the opportunity to speak to Dr Emmanuelle Van Erck about sugar and horses. Emmanuelle works at the Equine Sports Medicine Practice and is author of more than 40 scientific articles and regularly lectures at international scientific meetings. She continues to collaborate on applied research projects in Equine Sports Medicine and teaches clinical training for the veterinary students and practitioners.
Let’s start by righting some
Misconceptions about sugar and horses. When horses are out in the wild, they eat grass and with the grass, they ingest high amounts of sugar. The horse therefore gains quite a large part of its energy from sugars. However, the typical sports horse does not get access too much fresh grass, so they need to be provided by other sources of carbohydrates. Not all sugars are equal, and if we can provide the horse with enough fibrous-associated sugars, such as good quality hay, or a feed containing structural carbohydrates, that is the best. The more we use refined sugars, like those found in cereals or molasses, the more we are moving away from the horse’s natural sources of sugars.
Shifting the microbiota
Refined structural sugars are digested differently by the community of bacteria inhabiting the horse’s gut – otherwise known as the ‘microbiota’. The more the diet is differs from a natural diet, the more the profile of the microbiota community will change and impoverish, and that is what we want to avoid. Just like, you would not feed a top level athlete with low quality fast foods, you should pay attention to the quality and sugar profiles of your horse’s diet if you want to feed his performance. You have to combine various sources of sugars, and not just refined sugars, to avoid deleterious shifts in the microbiota. But if you respect the microbiota by feeding non-structural sugars that are more natural, you fuel him with healthy energy. Sugars are important for the horse’s physiology and function – their brain and muscle for instance use sugars. Good sources of carbohydrates are essential to the horse’s energy metabolism.
Energy and training
Training brings change to the way the horses use energy; when you train a horse, the muscles adapt and become more efficient in using other sources of fuel. For instance, they get better at using fat and storing glycogen in their muscles and liver. The diet can be adapted according to the stage of training the horse is at. Increased levels of carbohydrates are adapted to certain types of exercise such as sprinting, whereas endurance training benefits from a fat-enriched diets. Horses have a particular digestive physiology: if sugar is an essential source of fast energy, it cannot be provided under the form of ‘energy bars’ like in humans. Owners and riders are right to be cautious about feeding too much sugar! They need to realise that sugar is already in the horse’s diet but under a different form from what they expect. Getting familiarized with the composition of your horse’s feed is an important step. It allows you to safely monitor the levels of sugars. Sugars cannot be totally excluded from a horse’s diet, they can be useful to improve the palatability of the meal for the horse, especially if he is under a high-fibre diet.
Ulcers; a tricky case
Horses that have gastric ulcers are often given feeds that are low in starch and sugar; but if they are too poor carbohydrates, it poses a number of problems. Firstly, they do not get enough energy; the horse gets tired quickly during training because in his diet lacks the necessary fuel for his muscles. Secondly, these diets are not particularly tasty to the horse, and they do not feel like eating it. Horses were made to eat regularly over the day: if they do not eat on a regular basis, they will develop more ulcers. Because they produce gastric acid throughout the day, they need to have something to digest in their stomachs at all times. And that needs to be a balanced feed.
This is another reason you need to get interested in the composition of your horse’s diet; because not all sugars are equal. The horse can digest certain types of starch very well, and other types not. Starches that are not digested completely go into the hind gut and are fermented by the local bacteria. These bacteria utilise the undigested starch to produce gases and volatile fatty acids which are detrimental to the integrity of horse’s digestive tract. So it is important to not just look at the feed label for the percentage of sugars or starch, but also its origin as not all starches are digested in the same way.
The role of the feed companies
The feed manufacturers need to help the owners understand what is in their horse’s feed and how a certain type can better for certain horses, depending on their breed, type, activity and potential health issues. Horses prone to tying-up for example, require a different diet with lower amounts of starch and sugars. The same thing goes for horses with metabolic syndrome or ulcers; they all need specific types of feed, but it does not mean these have to be completely sugarless. They just need different types of easily digestible sugars.
Things looking sunny this year?
This year, we have had particularly sunny and warm weather early on, making the grass and the hay a lot richer in sugars and energy. In addition to looking at your concentrates, it can be a good idea to have your hay analysed. Try and use the same hay provider and balance your feed accordingly.
Top sport is all about balance
In a world where in human sports, everything is about balance, we are just now gaining all the scientific knowledge to start doing the same for our equine athletes. In the past, communication has perhaps not been as efficient, but now we have the science to back up what we feed our horses. That is so important because horses are a specific type of herbivore, they do not function the same way we do, or a cow does. The more we gain knowledge from science, the more we can do to balance our horse’s diet.
The era of technology
I also think we have the means now to gain more insight on our horses’ requirements. In humans, we have smartwatches that record our heart and metabolic rates. We have quite a lot of backlogs to catch up on this in horses. We have not had these systems available for horses, but now we are starting to, we can evaluate training and see if we are under-training or over-training, for instance. We can get objective measurements as to exactly how much training a horse is doing and adapt the diet accordingly.
Behaviour; a big connection!
Of course, diet has a big impact not only on performance, but also on behaviour. Science is just now beginning to discover that by balancing a horses diet and moving away from the traditional oats, horses become much more serene and they work better. They are less nervous, and nervousness as we know can be detrimental for achieving peak performance. There is a definite correlation between a more balanced diet and less stress in the horse.
My first tip would be that you train your eye to see if your horse is losing or gaining weight; can you feel the ribs, how is his neck? Belly? Take pictures of your horse regularly, and use a measuring tape to estimate your horse’s weight more objectively. When you call an equine nutritionist, weight and body type will be the first things they look at, so if you can train yourself to look at that yourself, you will already be more precise in giving your horse what he needs and adapting it if necessary. If it is difficult for you to be objective, send a picture to someone else to have a look at, for instance your vet. They can help you determine if your horse is fit or fat. Avoid making decisions based on something you’ve read on the internet one random day, really educate yourself in the different types of feed and what they do.
My second tip is regarding sugars: with digestive problems, we tend to go for low starch, low sugar diets, and most of the time this is appropriate. But sometimes horses are starving because they do not get enough energy. It can then be better to feed a little more sugars and starch to get the appetite back and avoid secondary problems. If it is well dosed, it won’t make them fat, but keep them more healthy. ■