Fibre - on the line

Next to water, Fibre is arguably the most important nutrient to the horse. Fibre is the ‘leafy’ plant-based material of the horses’ diet, be that grasses, hay, haylage, or chaffs. The importance of fibre is rooted in the evolution of the horse. It has a digestive system that developed to ingest large volumes of tough plant-based material, in an almost constant or trickle manner. Bacteria in the hindgut can then digest and convert this fibre to Volatile Fatty Acids, which are absorbed and used for energy.

Fibre is critical for the digestive system, including gastric (stomach) health. The horse’s stomach can be divided into two sections.

1. Glandular Region – a mucous layered area, protected against acid

2. Non-Glandular Region – non-mucous layered area, unprotected against acid

Atonomy of the equine stomach (today's veterinary nurse)

The area between these two regions (Margo plicatus) is a common site for the development of gastric ulcers. Symptoms of ga stric ulcers include poor appetite, abdominal discomfort, weight loss, diarrhoea, colic, nervous or aggressive behaviour and poor performance. Rese arc h has rep orted 63% of performance horses experience Equine Gastr ic Ulcera tion Syndrome (EGUS). Changes to management, ensuring appropriate fibre intake can minimise the risk and impact of EGUS.

As horses chew, they produce saliva, which contains bicarbonate ions, capable of neutralising gastric acid. This protects t he vulnerable, n on- glandular region of the stomach. Chewing forage results in twice the saliva than when chewing straights or a concentrate. As previously stated, horses have a di ges tive system designed for an almost continuous s upply of forage to chew and ingest. Horses need to receive 1.5-2% b ody weight in fibre per day, that’s 7.5-10 kilogram s (KG) for the average 500kg horse. In situations where horses go without forage for a period (which can be as little as a few hours), the stomach acid levels rise, as does the risk of EGUS. Ideally forage should be fed ad lib.

A possible explanation for the higher prevalence of EGUS in polo ponies (compared to those seen in leisure horses), may be due to their management. Time spent in stables, travelling or being on the line waiting to play can all interrupt feeding. Timing of fibre provision is also a major consideration for supporting gastric health. Hay/haylage should be available in stables, with haynets ensuring it’s still available during travel and while standing at events. Hand grazing when away will also reduce the extent of interrupted eating that can occur from competing.

Another explanation for the higher prevalence of EGUS in polo ponies could be the ‘splash effect’. This is the when acid is forced to splash up into the sensitive area of the stomach by more intensive exercise. Fibre in the form of chaff can be used to lessen this splash effect. As little as a stubbs scoop of a chaff (such as Alfalfa) fed just prior to exercise has been shown to form a ‘raft’ on top of the acid. This raft limits the splash effect and has been shown an effective method of managing EGUS and supporting gastric health.

In lower work (as is currently likely due to events being on hold) fibre should, as always, form the base of the diet. Changing the hard feed may be required to manage body condition and energy levels. Using a feed that’s higher in fibre and lower in energy than full competition diets can be a suitable alternative, such as Classic Fibre Cubes.

5 Top Tips

1. Ensure 1.5-2% bodyweight forage per day is provided

2. Provide forage ad lib

3. Prevent periods where forage is not available

4. Utilise haynets to ensure fibre intake while traveling

5. Provide a chaff e.g. Alfalfa Oil Plus prior to exercise or travel