The endurance horse works by a different mechanism. Muscular activity is not as extreme, rather it is prolonged, and energy derived from the fermentation activities in the hindgut is sufficient to generate ATP. Although glucose breakdown is also involved the intensity of exercise means that there is unlikely to be a shortage of oxygen and the debilitating effects of lactic acid build up, and activity is not restricted by a lack of muscular activity.
In simple terms one uses “instantly available” energy, whilst the other uses a constant stream of lower energy (VFA) to power activity.
So where does the polo pony lie? As with the footballer it is a mix between the two.
A polo pony needs to be fed for both speed and stamina. Agility is not a factor we can feed for, but the others we can. What is important is to get the mix right without depriving the animal of “instant energy” but avoiding the risk of tying up or of Monday Morning Sickness. These conditions are linked with the generation of ATP, and its possible oversupply. Most biochemical reactions are reversible. That is for example ATP can be changed to ADP and back again and it is this mechanism that contracts and relaxes the muscle strands. However, if there is too much ATP being generated then the reaction to ADP dominates, and the muscle strands may lock. With all mechanisms in the body it is a matter of balance.
To achieve the balance, we need to look at the requirements of the pony. He will be exercised and trained to maintain peak activity and then, during the season will be expected to perform at a higher rate. However, feeding an animal where the level of activity is not always the same can present problems.
So we start with the basis that horses eat grass. For an animal on maintenance or light exercise this is probably sufficient if the grass is of reasonable quantity. If we increase the activity, we must increase the input, and this has been traditionally achieved by feeding compound or cereal based feeds. However, if we increase and then decrease there is a danger that unutilised glucose (stored as glycogen) can lead to several disorders, including those mentioned earlier.
A more favourable alternative is to use a fibre source that is highly fermentable and provides more “slow release” energy (VFA) than grass or hay. Such a product is Fibre-Beet, which has been formulated not only to provide more available energy, but also to “smooth out” variation that occurs in forage.
The nutrition of using a Fibre-Beet/Forage base allows us to maintain the pony on a higher level of nutrition, and when extra activity is required cereal base feeds can be added; this has the added advantage of being able to feed less concentrate, supplying only as much “instant energy” as is needed for the task in hand.
There is another aspect. After a chukka the pony needs to recover, possible in a relatively short time. It will be dehydrated but may not want to drink. Speedi-Beet, an ingredient of Fibre-Beet, has been shown to help re-hydrate horses by the simple expedient of offering it soaked in the proportion of 1:10 with water. The palatability of the Speedi-Beet encourages intake more so than offering water alone. Also, if electrolytes are offered these will be more readily accepted when incorporated in the Speedi-Beet. Again, a small amount of Fibre-Beet, added to water makes an attractive and palatable drink.
The above regime means that for a pony undergoing reasonable levels of exercise, Fibre-Beet can replace some of the forage and allow most of the energy required to come from hindgut fermentation VFA’s. When training is increased concentrates can be added, but at lower levels than traditionally used. Instant energy is available but in moderation and only for the period required. Intensifying activity can be accompanied by increase in the concentrate, again only for the period required. As the level of activity decreases (rest days etc.) the concentrate can be reduced. An important effect is that, throughout the different activity cycles, there are not large changes in diet, which in itself can avoid serious impact on the microflora activity in the hindgut.
In addition, recovery and re-hydration can be aided with Speedi-Beet and, as this is also a component of Fibre-Beet, again there is no conflict with rapid diet change and negative effects on digestion.