Horses have been domesticated for about 5,500 years. By domesticating them, we have changed their way of living (habitat, reproductive management, “physical exploitation”) and consequently their eating behavior. But looking at the way horses are used in sports nowadays, how can we be sure that their ration is adapted to their nutritional needs? And how can we objectify their training intensity in order to evaluate more accurately their nutritional needs? What a challenge…
Wild horse versus domesticated horse 🐴
We’ve discovered that since 2018 there was no more wild horse left on Earth! And yes, a team of researchers has sequenced the genome of the mythical Przewalski horse. They realized (not without surprise) that those horses were not the descendant of wild horses but of domesticated horses having escaped from their owners … As “sad” as it may seem, modern horses come 100% out of human domestication.
Why did I share that with you? Because it impacts horses’ lifestyles and diets.
In the wild, horses spend most of its time eating: around 15h to 16h per day! How? Well, you’ve probably seen your horse in the meadow: he slowly moves while grazing. He will spend about 1 to 2 hours a day moving from pasture to another and find water (he can walk up to 30 km / day). If the grass becomes scarce or its nutritional quality is poor, he can increase its grazing time and cover long distances (up to 80 km).
But you have understood, this “natural” behavior doesn’t apply to our horses 😞. Indeed, our domesticated horses live at best 100% in fenced meadows and are therefore limited in their movements and in their choice of pasture.
But then, in the context of current domestication, how do we evaluate their nutritional needs and feed them adapted rations?
Maintenance needs of domesticated horses 🍽🐴
To quantify what a horse needs nutritionally speaking, one needs to understand the concepts of maintenance and production needs. Let’s see what they correspond to.
⏩ Maintenance needs are the energy expenditures of the body to maintain life. It ensures all the vital functions: breathing, digestion, waste disposal, thermoregulation, activities of different organs etc. They depend on the horse’s weight but also on his body condition, sex, temperament, health or even environmental factors such as climate.
⏩ When the body is in great demand (muscle demands, growth, pregnancy and lactation of the broodmare), the nutritional needs increase. We are then talking about production needs. They add up to maintenance needs.
📚Read more: overweight horses
It is because of these production needs that, historically, humans started feeding horses. Working horse and war horses had intense activities!
As a result, cereals were used to meet a dual purpose. First increase the energy intake. Then, limit the time of food intake. You can imagine that one could not wait for his war horse to quietly ingest his hay in order to meet his nutritional needs before a battle.
Where things get complicated is that the basic metabolism (and therefore the needs) varies according to the breed. For example, ponies have a relatively low metabolism and therefore have relatively low energy requirements. In short, they can be satisfied with a frugal diet. On the other hand, horses have a higher metabolism with extra maintenance needs.
Let’s also remember that we are not all the same… There are also variations related to the genetic characteristics of individuals. Do not tell me you’ve never been annoyed by this guy, you know, the one who nonchalantly swallows tons of food and does not take a gram while you get fat just by looking at your dessert! Well, it’s the same for horses.
Did someone talk about UFC and MADC? 🧐
To quantify our energy needs as well as our food intake, we humans use calories. For the horse, another system has been established by the INRA: L’unité fourragère Cheval (UFC). The UFC is the energy value of one kilogram of standard barley (ie, 2250 kcal of net energy in the maintenance horse). This is the French system.
When talking about proteins, they must first be digestible in order to be metabolically useful. This is why INRA has given a system of needs assessment and protein intake called “Matières Azotées Digestibles Cheval” (MADC). The mention “raw proteins” appearing on the labels of the feed bags is therefore insufficient! This includes all proteins, including the ones that are not metabolically useful to the horse!
UFC and MADC can be linked to the intensity of the exercise: for each level of work there is a level of recommendation. Here are the feed intakes recommended by INRA for a 500 kg horse:
What about the ingestion capacity? 🍟
Another important aspect to consider is the ingestions abilities of your horse. This is called the ingestion capacity, which actually corresponds to the horse’s voluntary consumption level.
This is very important because it defines the overall volume of the ration and therefore determines the nutrient concentration needed to meet his requirements. To give you an idea, for an adult horse of 500 kg, it can vary from 8 to 12 kg DM (= dry matter) per day depending on the intensity of work (10 kg DM equivalence in spring grass= 50 kg and equivalence in hay = 12 kg!).
This is why sport horses with high nutritional requirements, will need specific feed including specific nutrients (energy, proteins, fats, micronutrients) in a good amount.
💡Link between ration and nutritional needs: mistakes not to commit
1) Underestimate roughage:
roughage is indispensable to horses! It also helps reaching their nutritional needs. The difficulty? Quantify it! It is essential to weigh the hay in order to be able to integrate the ration calculation. Often, we feed less than we think … In addition, the quality of the roughage (grass) and the way it is being stored (hay) is very heterogeneous (and fluctuating during the year), as you can see (INRA values):
|Low quality hay||0,45||13|
A forage analysis makes it possible to obtain these values and then to use them to determine the most suitable forage supplement. Destrier technicians are equipped to make you benefit from these analyzes.
2) Choose your feed according to the ingredients label:
When energy, protein, vitamin and mineral requirements are not fully covered by roughage, choose the most suitable feed. Often, our first reflex is to look at the ingredients and especially the grains being fed. Yet, this information is only really useful if you do not want to feed your horse a specific ingredient. The second reflex is to look at the label which actually contains more regulatory information than useful nutritional information. Often you will not see UFC and MADC appear! You will have to refer to the data sheets that manufacturers make available on the internet. To make an optimal ration calculation, do not hesitate to ask your local technician.
3) Divert the feed use:
Keep in mind that a certain feed has been formulated for a specific situation. Feed with adulte horses will not be rich enough in protein for a lactating mare and vice versa for breeding feed. Conversely, sports feed will be too energetic for a leisure horse. Finally, a complementary feed to roughage AND cereals supposes a contribution of cereals in the ration etc. In short, respecting the instructions is the best to do from a nutritional point of view!
Heart rate, an important factor!
The last difficulty when trying to go into more precision when it comes to ration calculations lies in the measurement of the effort intensity. You have probably noticed, the INRA table specifies only 4 levels of effort: very light, light, moderate and intense. It’s good but it’s not enough. 😅
By Equisense, we’ve been working on this for a long time. How to tell if your horse’s work is light, moderate or intense?
We could estimate it depending on the number of sessions per week, but that is of course not enough. We could say that it’s equal to the canter time per session, but for some horses, canter is no effort. And then on equal time, the intensity is not the same between a normal canter and a cross canter. We could continue down the list…
The fact is, estimating the horse’s energy expenditure can only be measured through: the heart rate. ❤️
Indeed, a formula developed by researchers made it easy to go from the heart rate to VO2 (the volume of oxygen consumed) and finally to the expended energy. Not in UFC but in Calories.
By measuring the daily heart rate during training, one can monitor the energy expenditure of his horse thus, categorize more precisely the intensity level of the training, to adapt the ration accordingly!
That’s exactly why we developed our new product: Equisense Motion S, which measures, among other things, your horse’s heart rate and energy expenditure!
Food is 80% invisible
Setting up a feeding program calculated as closely as possible to the nutritional requirements of a horse, taking into account his level of work, is a guarantee of sporting vitals and longevity. As for us, horses’ diet is 20% visible (coat shine and hair, hoofs, body score) but especially 80% of invisible (immunity, integrity of the digestive system, fertility, osteo status -articular etc.).
Marine Slove & Camille Saute,
Veterinarian and Nutritionist at Destrier and R & D Director at Equisense