Horses are herd animals by nature that once lived on the Eurasian Steppe. They are creatures of habit that must always have the opportunity to flee. Horses are also herbivores that are accustomed to movement through grazing. Originally, they would graze practically day and night, spending as much as 16 hours a day nibbling on grasses and herbs that were low in nutrients. For a gastrointestinal tract to work properly, a horse must eat fibre every day.
Dietary FibreWhen we talk about fibre, we mean dietary fibre. Dietary fibre consists of carbohydrates that are fermented by bacteria. A horse needs fibre not only for energy, but also for healthy bowel movements and a strong immune system. Fibre is actually an essential “multi-tool” in the horse’s body, ensuring a well-functioning gastrointestinal tract which in turn ensures proper absorption of nutrients and good immunity. Forage has a high proportion of fibre that a horse can easily digest. A horse’s daily supply of forage provides its basic fibre requirements. Concentrates may also contain fibre.
Different kinds of fibreFibre sources may vary, but generally it all comes from plants: grass, but also lucerne, beet pulp, wheat, spelt and even (to a lesser degree) in concentrates. In short, you can divide fibre into two types: fermentable and non-fermentable fibre. Bacteria break down fermentable fibre in the caecum and large intestine. It is then converted into volatile fatty acids that provide energy for the horse’s body. Non-fermentable fibre does not provide energy but has another important function. It provides intestinal content that stimulates kneading of the intestinal wall. This process moves feed along through the bowel. The speed of passage is also important, as the right speed allows the contents to mix well and ensures longer contact of the chyme with the intestinal wall, promoting nutrient absorption.
In this video, you’ll learn all about a horse’s digestive system:
The importance of prebioticsThe gut microbiome is something you often encounter in relation to fibre. Many microorganisms, such as bacteria, viruses and yeasts, live in and on the body. Collectively, these are called the microbiome. A predominance of good microorganisms means that the gut microbiome has a positive influence on the horse’s health. High-fibre feeds support the development of a stable and healthy microbiome. Prebiotics feed “good” bacteria and fibre is a natural prebiotic.
Do horses get enough fibre on average?Horses get most of the fibre they need from forage. You could say that if the horse eats enough forage, the horse is getting enough fibre. In principle, a horse can never consume too much fibre. However, fibre absorption is more complicated than it may seem. Too much fibre from forage is not possible, but forage does not consist of fibre alone. It also supplies the horse with protein and energy. Unlimited forage is therefore not healthy for every horse because a horse may consume more energy than it needs, with all the associated consequences. Always adjust the type and amount of daily forage according to your horse’s needs.
Provide sufficient dry hay. Normally, the recommended minimum amount of body weight in dry matter from forage is 1.25%. The recommended amount for horses that need to lose weight is 1%. This may be supplemented by 1–2 kg of straw (to add fibre and prevent boredom)
Too much fibre is not possible, but too much energy is. In fact, horses meet their basic energy needs through forage. Horses in work will not get enough energy from forage alone. In an earlier article we discussed sugar intake in horses.
Fibre qualityIt is difficult to make a 100% accurate estimate of a horse’s fibre intake. You can learn a lot about it, though, from a horse’s manure droppings. They should be nice and round, not watery, stalky, or dry. A very coarse texture can tell you something about the horse’s teeth as well as the health of its intestinal flora. A disrupted gut microbiome cannot digest fibre adequately. Pre- or probiotics can help. Colic and diarrhoea are also often related to fibre intake. The solution is a ration with adequate fibre. The quantity of fibre cannot be determined with the naked eye; fortunately, a comprehensive analysis offers a solution. You can use this to determine the digestibility of the crude cellulose and the quality of the fibre. In general, forage analyses are only useful if you feed hay or haylage from a large batch all originating in the same country.
An analysis provides insight into the quality of the raw celluloseThe longer the fibres (>2 centimetres), the longer the horse has to chew, and the more saliva is produced. This is good for neutralising stomach acid. Long fibres also stimulate intestinal motility which ensures proper digestion and less chance of colic. Saliva isn’t the only benefit of long chewing. It also causes the teeth to wear down and helps the feed to be absorbed more slowly.
Fibre first and foremostHorses are herbivores. The equine digestive system is designed for this from beginning to end. Horses need lots of forage. The dry matter percentage can then be used to calculate the amount of forage needed. The more fibre in the feed, the longer the horse must chew it, and longer chewing will produce more saliva. That’s healthy for the horse. The micro-organisms in the gut also need roughage. Adequate fibre is essential to maintaining healthy microflora. A healthy intestinal system ensures a healthy immune system, the foundation for equine health.
Tips from the specialistFibre is important for overall health. A horse will get most of the fibre it needs from forage, but you can supplement the feed ration with concentrates to provide extra support. Concentrates with fibre are an ideal addition to the ration.
Veterinary surgeon Erica Reijerkerk knows all about the internal equine health. She has some tips:
- Always feed adequate fibre through forage and concentrates. An unlimited supply is not always better. A horse benefits more from multiple servings in a day tailored to its energy needs.
- The teeth are the first step in the digestive process. Have your horse’s teeth checked annually!
- Exercise affects digestion. Match the ration to your horse’s level of physical activity
- Do a daily screening to get a good overview of your horse’s health