Equus Feeds Newsletter

Is my horse working hard or hardly working?

It is important to establish how hard your horse is working because the optimal feeding of each individual depends
to a large extent on the specific workload expected from the horse.
Various classification systems for work intensity exist and it is important to take into account not only the work
intensity but also the duration of exercise, for example:

1) high-intensity and short-duration work e.g. racehorses
2) moderate-intensity and medium-duration work e.g. show jumping
3) low-intensity and long-duration work e.g. endurance type events.
There are also more scientific methods of determining work intensity which express the level of effort as a
percentage of VO2 max. With this system heart rate is closely measured and a clear distinction between the
aerobic and anaerobic phases of exercise can be established. This is, however, a very complicated and costly
measurement and not practical for everyday use.

As a guideline, a more simplistic system of classification can be set out as follows:

TYPES OF EXCERCISES

Why is the specific workload important for feeding my horse?

The specific work intensity will largely determine how much energy your horse will require from his diet. It is
important to remember that up to two thirds of the total available energy from the diet will be required for maintenance
i.e. to maintain normal bodily functions like digestive metabolism, temperature control, breathing, eating, standing
upright etc. Only the excess energy after maintenance requirements will be available for either exercise or building
body condition.

How scientific do I need to be in determining the exact work intensity?

Not at all! The scientific methods are important for research.
It is important, however, to be aware that both the work intensity and also the duration of exercise will affect the
amount of energy required and ultimately the condition and performance ability of your horse.
Anaerobic exercise, like fast sprinting, might be of short duration but requires a lot of energy because it is a more
energy expensive metabolic process than aerobic type exercises (long and slow) which utilize less energy per
minute, but over a longer period.

How should I adapt what I feed according to the work intensity?

As the intensity or duration of exercise increases, more energy will be required from the feed in order to fuel the
muscles with glycogen. When this happens you have to provide more energy otherwise the horse will start using
his bodily reserves for maintenance and both condition and ability to perform will deteriorate.

Available energy can be increased by either feeding more per day, or alternatively, by feeding a ration with a higher
energy density. For small adjustments in workload it might be adequate simply to increase the quantity fed by 15
to 25% (e.g. feed 5kg instead of 4kg). In theory, the required increase could be calculated, but best practice is to
use good horsemanship and adjust the amount based on your observations regarding the horse's condition and
ability to perform. Make the adjustments slowly and allow a few days to evaluate the difference. Horses in good
condition will react quicker than horses in unsatisfactory condition.

For bigger adjustments in workload, however, rather change to a ration with a higher energy density designed for
competition and performance horses because simply increasing the quantity of a lower energy ration will eventually
disturb the protein balance as well as that of all other nutrients.

Does the type of work or exercise affect the specific feed required?

Yes, absolutely!

This is a complicated subject and will be dealt with in a separate article, but, in essence, it is always better to use a feed which specifies the composition in terms of:

   1)Gradual release of energy compared to very quick energy release.
   2)The use of super fibres.
   3)The amount of energy derived from non carbohydrate sources like fats and oils.
   4)A "fat" specification on the bag tag other than the minimum of 25g/kg required by law which is certainly not ideal.
   5)The use of heat processed carbohydrates.
   6) The amount of different energy sources used with a limit on energy derived from molasses.
   7)The digestibility of the fibres used.
   8)A specified energy level in MJ/kg or at least a low, medium and high classification.

For more information on the composition of all Equus products see www.equusfeeds.co.za