Importance of Fibre for Digestive Health (Elementary Level)

Read the following information and then complete the quiz questions at the end of the page to test your knowledge and earn AMTRA points.

This resource will introduce you to the following topics:

• A guide to the horse’s digestive system
• The importance of fibre for maintaining the health of the digestive system

Problems associated with a low fibre diet

• Increased risk of gastric ulcers
• Increased risk of colic
• Loose droppings
• Behavioural stereotypies, e.g., wood chewing

Benefits of fibre for the digestive system

The mouth

• Chewing is vital for saliva production – which keeps other parts of the digestive system healthy, particularly the stomach.
• 10-12 litres of saliva is produced daily and this contains bicarbonate which buffers acidity.
• Horses chew 800-1200 times per kilogram of concentrates and 3000-3500 per kilogram of forage.

Effect of diet on chewing

• Eating forage like hay and haylage requires more intense activity of the cheek muscle compared to mixes and cubes.
• More intense action = more saliva produced
• Using fibre feeds instead of cereals is therefore going to increase the amount of saliva produced and this will help to manage the level of acidity in the stomach due to the natural bicarbonates in saliva.
• Feeding high levels of mixes and cubes increases the likelihood of dental irregularities such as enamel overgrowths or sharp edges.
• In contrast, high fibre diets have been shown to encourage the horse to use slower, larger movements when chewing, so that chewing not only takes longer but is more effective.

The stomach

• The stomach is rarely empty if horse allowed to eat almost continuously.
• Saliva production helps to buffer acidity in the stomach.
• Important for reducing risk of Equine Gastric Ulcer Syndrome (EGUS) in the squamous region of the stomach.
• This region has no built in protection against acid.
• Instead it relies on buffering support and the presence of food which acts as a physical barrier.
• Feeding a double handful of chopped fibre about 20-25 minutes before work produces a fibrous mat that stops acid splashing around when the horse exercises.

The small intestine

• Horses are not well adapted to high starch diets.
• Villi in the small intestine significantly increase the surface area for absorption. A human small intestine, if rolled out flat, would cover a whole tennis court!
• Research has shown that absorption capacity is reduced as villi shrink in more acidic conditions produced by high starch diets.
• For digestive health, keep intake of starch low – no more than 2g of starch per kilogram of bodyweight per day.
• Using fibre as an energy source instead of cereals potentially helps to improve absorption capacity.

Cross section of a small intestine. The most prominent feature of the mucosal layer is the abundance of villi extending into the lumen.

The hindgut

• Microbial population digest fibre by fermentation.
• Fibre is important to push gas (a by-product of fermentation) out of the digestive system.
• Fibre fermentation also produces heat, so this can act as the horse’s personal central heating system.
• ‘Bugs’ that break down fibre also produce B vitamins such as biotin.
• Sudden changes in diet and starch overflow into the large intestine may both result in digestive disturbance including problems like laminitis, colic and loose droppings.

Watch our video on the digestive system

Summary

• The type of feed the horse consumes can influence gut health.
• Insufficient fibre in the horse’s diet can increase the risk of digestive and behavioural problems.
• High starch diets can increase the risk of problems such as laminitis, colic and EGUS.

Test your Nutrition Knowledge!

It’s now time to put into practice what you have learnt about fibre and the horse’s digestive system. Answer all the questions below correctly to receive your Dengie Nutrition Certificate, plus you can earn TWO AMTRA Suitably Qualified Person (SQP) points. To ensure your points are awarded please make sure that you include your unique AMTRA number in the box provided with your details.