Dr Tom Shurlock, Consultant Nutritionist at British Horse Feeds offers advice on the importance of fibre and forage replacement to ensure your horse gets the very best nutrition.
The Importance of Forage
Fibre is one of the essential nutrients needed when it comes to the horse’s diet and forage is the highest proportion. These fibre needs are easily met through paddock grazing and hay/haylage.
Over the years there has been a gradual uptake in fibre based feeds due to extensive research and development showing the huge benefits to all horses and ponies.
Why is fibre important?
The equines digestive system has been designed to be a hind gut fermenter, thus allowing them to graze on forage and fibre for long periods of the day.
With modern feeding practices of using cereal based feeds for high energy, particularly for performance horses, it is important that fibre is consumed to help process these feeds. Fibre acts as a buffer to the acid that is continuously produced in the stomach that breaks down feed. Without fibre to soak up this acid it can cause conditions like Equine Gastric Ulceration Syndrome and colic.
Wild horses would have grazed up to 20 hours a day, with the modern day owner now trying to mimic this type of natural behaviour by supplementing with hay or haylage, alongside time out on pasture. However in winter, some owners need to keep their horses stabled for a longer period of time and hay/haylage becomes even more important.
Fibre feeds are a good source of slow release energy and in winter the fermentation process in processing fibre actually creates thermal heat which helps to raise core body temperature.
Some studies have shown that diets lacking in fibre can cause behavioural issues including aggression and vices such as crib biting. This could be because they have the inability to fulfil their natural grazing behaviour.
There are four main components of fibre in plants: lignin, cellulose, hemicellulose and soluble fibre.
Lignin is woody material that is inherent in the structural fibre; as lignin is impervious to most microbial fermentation, increasing levels will reduce the overall digestibility of the forage.
Beyond this there is a relatively consistent ratio between cellulose and hemicellulose in forages. This is due to the basic structure of plant cell walls – designed to give rigid, yet elastic properties.
In the majority of grass, cereal, legume and various other forages there is an approximately consistent ratio between cellulose and hemicellulose. These are the structural fibres, with pectins and other soluble fibres providing the “filling”, so it is perhaps unsurprising that there is a consistent relationship.
There are differences, the makeup of individual carbohydrate molecules may vary, and these may affect the profile of slow-release energy, but in the main the structural integrity of plant cell walls and their rigidity is based on this relationship.
Although the British Horse Feeds products are generally slightly higher in hemicelluloses, and substantially higher in pectins, they are still a relatively good fit and so appropriate for replacement.
Another good reason for forage replacement with Speedi-Beet or Fibre-Beet is the presence of increased pectins. The soluble fibre is believed to act as a prebiotic, encouraging the growth of those microbes that can breakdown hemicellulose, improving the overall digestibility of fibre in the gut; in essence lower levels of these feeds can replace higher levels of forage.
However, it is not solely a matter of replacement. Using Speed-Beet or Fibre-Beet can be far more versatile.
The term forage replacer is, almost by definition, a misleading. As forage describes such a variable product then it would be difficult to replace it with another. Forage replacers are, in fact, forage alternatives and as such have a number of roles. Maybe we should be using the term ‘forage management’.
We are increasingly becoming aware of the need to supply fibre as the main source of energy as it has benefits, both physical and physiological, that are not automatically provided by other sources, and the best source of fibre is still forage. It also is the cheapest and so makes sense to optimise its use. Mediating this fibre uptake is becoming the role of the forage replacers or alternatives. And this is done in one of three ways:
Basically for horses who are at the maintenance end of the scale. They may be resting, prone to fat or who have underlying issues that require a low energy diet. Here the replacers are usually built around chaff or straw. We are supplying high levels of cellulose that is broken down only slowly in the hindgut and helps offset the faster fermentation of grass or hay that has greater levels of the more fermentable hemicellulose and soluble fibres. Additionally they are traditionally low in protein and sugars, both of which can reach surprisingly high levels in grass.
Possibly this is true forage replacement, although which type and state of forage that is being replaced is difficult to say. Here we are supplying a fibre product that is similar in profile to a reasonable quality hay or grass and is used to even out the variations that are present in the forage, whether it is changes in fibre content and profile, protein or sugars.
Here the basic forage is suitably matched to the horse and its lifestyle, all we are doing is ensuring consistency of product and, in extreme cases where our forage runs out, providing a short term alternative to that forage.
Forage alone is not sufficient to provide all the nutrients required for the more active horse. People may prefer not to rely too much on traditional hard feeds for a variety of reasons and so choose forage enhancement.
These products are based upon super fibres, which really mean sources high in soluble fibres, pectins and hemicelluloses, and low in cellulose and lignified material. Generally speaking these are usually beet pulp, soya hulls and oat fibres, though alfalfa can be another source. By providing highly fermentable fibre sources the daily energy intake of an active horse can be significantly increased without resorting to starchy feeds.
Although there are three distinct areas where forage is “replaced” they all have a common factor. They provide extra fibre without extra starch or sugars and without high levels of protein. Bearing in mind that grass, depending on the time of year, can have on a dry basis up to 25% protein and 30% sugars, diluting these levels with good quality fibre can offset potential nutritional problems of oversupply.