Everything Explained - Can fibre really fuel a horse in hard work?
Katie Williams M.Sc. (Dist) R Nutr
If you’re taking the time to read this article then it is highly likely that you already appreciate the importance of fibre to your horse’s health and wellbeing. What you may be less certain about is how great a contribution fibre can make to a horse’s energy requirements, particularly those working at harder levels. But before we get to that, let’s start by clarifying a few terms that can cause confusion.
Forage or Fibre?
It is important to distinguish between forage and fibre. Forages are a source of fibre but they also contain other nutrients that may supply energy such as sugar – grass, for example, is often the greatest source of sugar in many horse’s diets. Fibre is a nutrient that can be found in lots of feed materials in varying levels and whilst in humans its main benefit is to promote regular bowel movements and therefore good gut health, the horse can actually extract energy from fibre.
There are different types of fibre from the very digestible pectin to the less digestible cellulose. Lignin is often referred to as fibre but although it has a structural function it is indigestible and not technically fibre. High levels of lignin significantly reduce the digestibility of a forage. The types of fibre in feed materials vary thereby determining how useful they are as an energy source to the horse.
Fibre Digestion
Fibre is often referred to as structural carbohydrate which means that although it is made up of glucose as other carbohydrates like starch are, the way in which the glucose units are linked together is different. This means that the digestive enzymes produced by the horse can not break the links and so the horse relies on bacteria and other microorganisms to break down fibre. This releases energy that the horse can then utilise. This is why it is vital that the microbial population in the gut is healthy as without the right bugs, the horse is unlikely to look or perform well.
The energy released from fibre can be utilised straight away by the horse or stored for use later. It is stored as fat which can then be broken down to provide energy. This process requires the presence of oxygen and so is most efficient for horses working at low intensities, hence why endurance riders use a lot of fibre to fuel their horses. It is important to note that some of the energy produced from fibre can be converted to glucose in the liver and so horses on high forage diets are able to create glucose from fibre. The downside to this is that it is a relatively inefficient process.
Energy levels in forages
The digestibility of a forage affects how much energy the horse can extract from it. Sugar beet that we commonly feed to horses has had most of the sugar removed leaving a fibrous residue which is very digestible. It has an energy value of between 11MJ and 12MJ DE/kg which is comparable to a medium to high energy mix. In trials carried out at the Institute of Grassland & Environmental Research, sugar beet was found to increase the digestibility of other forages fed alongside and so it makes a useful addition to fibre based diets for working horses. Alfalfa is another high fibre feed that can make a significant contribution to a horse’s energy requirements. At 10MJ DE/kg it is comparable to a low energy mix and if oil is added the energy value increases to 12.5MJ which is equivalent to a competition or conditioning mix.
There is no question that endurance work can be fuelled from fibre and oil but what about high intensity work where speed and/or power are required? Although we know fibre can be converted to glucose it is relatively inefficient and so theoretically, quick release energy sources may be required for the very highest levels of work intensity. However, it is important to consider the natural athleticism of the individual horse and it’s temperament as these factors can also influence the type and amount of dietary energy required. For example, many event horses can make the time cross country even at four star level with no problem at all and the biggest challenge is keeping them calm enough to perform a good dressage test. Fibre is recognised as a slow release energy source and so for over-excitable individuals a high fibre diet is recommended. Avoiding wasting energy on silly behaviour can help to improve performance as the horse isn’t depleting energy stores before it starts or losing electrolytes through sweat which can result in early onset of fatigue, particularly in hot conditions.
If a high fibre diet is used for a performance horse it is important to ensure the diet is balanced which can easily be achieved by using a good quality supplement or balancer formulated to meet the needs of the performance horse. A suitable diet for a 500kgs Advanced event horse would be:
- 2.5kgs Alfa-A Oil
- 0.5kgs Alfa-Beet
- Dengie Alfa-A Balancer or Performance Vits & Mins
- A good quality electrolyte supplement
- Ad lib hay/haylage
One of the common mistakes with fibre feeds is that they tend to be underfed because they are so light and fluffy. Relative to cereals a larger volume needs to be fed – think a ton of feathers versus a ton of coal, they are the same weight but the feathers take up a lot more space. This leads people to think that they are over feeding but it is not the case with fibre feeds as they don’t overload the digestive system in the same way that cereal based feeds do. In fact, more chew time is really beneficial as it helps to keep the gut functioning normally - a definite recipe for competitive success!
If you would like more information then please contact the feedline on 0845 345 5115
