Why is Fibre good and the Dangers of NSC

Why is Fibre good and the Dangers of NSC

Every horse owner is now aware that high levels of grain are bad for horses. Some of you may ask, what specifically about grain is bad? And what is this new term NSC.....?

The horse?s digestive system is built to utilise fibre. Fibre is passed through the digestive tract whole until it reaches the hindgut, where millions of bacteria break it down and utilise it as energy. This is how the horse has functioned for millions of years.

In the process of domestication, horse are grazing less, and often the amount of  digestible fibre they eat is not enough for maintenance and performance.  The solution has been to feed high energy grain based diets.

What is the relationship between grain and horse health

Feeds contain sugar and starch, which are collectively termed non structural carbohydrates (NSC).  The level of NSC can vary from less than 10, to 70% in grain. It is considered that the safe level of NSC in the feed should be less than 12%.  The following graph shows the NSC content in a range of Australian Horse feeds.   Higher NSC feeds are suitable for horses in active work.

 Are we killing our horses with kindness

The dilemma has arisen where horses have been overfed and underworked. We are now becoming increasingly aware that horses were not meant to cope with large amounts of sugar and starch (NSC).  It has not been until recently that the NSC content of horse feeds has been measured, and so the relationships between feeds and many of the metabolic problems were not identified.

Recent studies have shown that feeding high NSC feeds (>12% NSC) are one of the main causes of  many of the metabolic disorders including obesity, laminitis, equine metabolic syndrome (EMS) etc.  Since these conditions are mainly feed related, overfeeding your horse with high NSC feeds can potentially harm your horse.

When horses digest sugar and starch in the stomach and intestines, they absorb glucose. The resultant release of insulin from the pancreas is used for the uptake of glucose into cells, i.e. the cells are sensitive to insulin. Feeding a horse high levels of NSC, causes the cells become gradually resistant to insulin, i.e. the horse is insulin resistant, and blood glucose levels are too high. Insulin resistance is associated with metabolic disorders including laminitis, EMS, tying up, Cushings and colic.

Many people go by the saying that a fat horse is a happy horse. This is definitely not the case. Horses that are overweight, in most cases, have decreased sensitivity to insulin. This decreased sensitivity causes problems in the horse as their cells cannot cope with the sudden influxes of glucose and metabolic problems occur as a result. More studies have started to confirm the direct link between obesity and laminitis, with a high NSC feed being  the causative agent.

The recommended level for horses that are not in medium to heavy work is below 12%. Once the horses work load increases the level of sugars and starches can also increase without causing problems.

How does high NSC cause Laminitis

High levels of NSC are thought to contribute to Laminitis, gastric ulcers and metabolic disorder through dysbiosis of the gut. Dysbiosis refers to the disharmony in the growth and supply of the intestinal micro-organisms. Once the balance of the gut flora becomes disrupted through sugar and starch overloading, there is an overgrowth of normal organisms as a result of the increased food supply.

Microbial population upsets can cause  damage to the intestinal mucosa which allows leakage of sugar molecules, bacteria and pathogens into the bloodstream (?leaky gut syndrome?). The higher than normal circulating blood sugar causes the cells to become resistant to insulin, disrupting glucose transport into the cells. The high blood sugar also stimulates the adrenal gland to increase cortisol production, which may cause damage to the lamellar structures in the hooves. The combined effect is inflammation, laminitis and then founder.

A low NSC alone is not the answer.

In many cases, a low NSC feed is produced by diluting the sugars and starch with a low nutritional filler such as soybean hulls, sunflower hulls, rice husks.  This will reduce the NSC, but at the expense of diluting the digestible energy as well.  Some natural feeds such as copra meal naturally have a low NSC content, as well as a high DE content from the coconut oil, and are suitable for marinating condition, whilst reducing the NSC intake.

Finding suitable Feeds ? alternatives to NSC

Role of fibre

Horses should always be fed a source of long stem fibre such as hay in their diet in order to maintain normal gut functioning and their hard feed should always contain a secondary source of fibre to assist in digestion. Fibre is responsible for gut health, peristalsis of the gut and absorption of water for the horse.  Fibre is also an important source of energy.

Today, some of the best sources of fibre come from the following;

  • Hay and chaff
  • All pastures
  • Soyabean Hulls
  • Copra Meal
  • Oat hulls

Many of these fibres contain low levels of NSC, and also low levels of digestible energy.

Role of MCT

Medium chain triglycerides (MCT) which include lauric and caprylic acids are reported to have antimicrobial actions that promote gut health.  It is suggested that the MCT  in coconut oil prevents ulcers in the stomach, and dysbiosis (leaky gut) in the intestines.

MCT are an untapped resource when it comes to feeding horses. They are very   easily digested and are an excellent source of energy because, unlike Long Chain Fatty Acids (LCFA) they are absorbed directly into the portal blood and transported to the liver to be utilised as readily available energy.

Due to the easy absorption of MCT's they tend to enhance the absorption of other nutrients. Coconut oil added to the diet aids the absorption of fat soluble vitamins and magnesium and calcium. MCT's are also beneficial to growth and development in addition to protection due to antimicrobial nature of coconut oil. To attest to this MCT's are found in human breast milk.

Possible Solution

Overall it is best to feed horses a mix of high fibre and low NSC in order to maintain gut health and prevent a large number of metabolic disorders. Alternative sources of energy such as oils are the safest alternative and on average, yield more energy than grain. Oils are also filled with natural benefits such as coat conditioning and weight gain. In order to guard against metabolic disorders associated with microbial upset or ?dysbiosis?, natural oil with MCT's such as coconut oil is the most beneficial. Coconut oil can be found in adequate percentages in high quality copra meal.