FEEDING A RACEHORSE

Horses have evolved to eat poor quality roughage, such as grass, shrubs and herbs.  However, for most of the time, wild horses move at a slow pace with only occasional short bursts of speed when danger is suspected.  Energy requirements are therefore low.

Racehorses, however, exercise daily and are expected to travel at top speeds over distance.  For example the Melbourne Cup  is a gruelling 3200m long race where a good amount of energy is needed to be reserved for the final 100 metres, as reported on Henry’s Melbourne Cup racing pages.

Horse also carry weight, which wild horses are not subjected to.  Their energy needs are much higher and it is thought that roughage alone cannot meet these needs.

However, due to the design of the digestive system, feeding high levels of starchy grain can lead to issues such as colic, gastric ulcers, azoturia, laminitis and over excitability.  Achieving the correct balance between performance and welfare should be every racehorse trainers’ ultimate end result.

Some basic needs exist which trainers interpret in their own way, tweaking to suit different animals.  An average thoroughbred weighs about 550k and he requires roughly 2 ½ percent of his body weight in food every day.  This equates to 13.75kg of feed per day.  This needs to be balanced with the energy requirements of a racehorse, which is double of a horse at rest.  The average racehorse requires about 34Mcal of digestible energy a day.

A horse at maintenance (ie, not working) can obtain all its energy, protein and vitamin needs from a good quality forage source, such as good grazing or hay/haylage.  However, a racehorse in hard work will struggle to meet its requirements through fodder alone.  According to Kentucky Equine Research staff, 7-9kg of quality forage such as Timothy hay, will only provide enough energy to meet its maintenance requirements. 

It is recommended for gut health that the forage ration should not fall beneath 50 percent of the total diet, but this is not always adhered to within racing stables.  Trainers feel the energy present in forage is not adequate for the job, and therefore more concentrate is fed, often up to levels of 70 percent of the diet.  The other reason given for this in the publication by Huntingdon & Jenkinson ⁽¹⁾ is that roughage is bulky and it can be hard to get racehorses to eat the necessary concentrates if they are full of bulk feeds.

The concentrate ration differs across different regions of the world, due often to climatic variations and crop availability.  According to a discussion by Huntingdon & Jenkinson published by Kentucky Equine Research,  Australians feed more straights, such as oats, rather than compound feeds such as mixes or pellets.  However, it is also thought that this is changing as manufactured feed develops.  Oats, maize, barley, bran and rice pollard are all mentioned in the study as energy feeds used in Australia.  In the UK, oats and hay are the primary diet.

Compound feeds, if fed as instructed on the bag, will provide adequate levels of vitamins and minerals and the trainer knows exactly how much energy and protein is being consumed.   The exact composition of straight feeds such as oats (the most common starch feed given to racehorses) is not always known as accurately.

Lucerne, or alfalfa, is a commonly fed hay within racing stables.  As part of the legume family, it produces its own nitrogen in nodules beneath the soil and is therefore high in protein.  It is also rich in calcium, an important mineral for growth and development .  In general, the protein needs of racehorses do not increase at the same rate as energy requirements, even when working hard.  However, many horses are raced at an early age when they are still growing, and protein is an important nutrient in their development.  Older racehorses do not need nearly as much protein as is often fed.

According to Gibbs, Potter and Scott ⁽²⁾, fat can also be safely used as an energy source.  Fat does not have the same effect on the digestive system as an overload of starch (which can lead to health issues mentioned earlier).  However, the short duration of high sprinting requires the horse to work anaerobically, relying on blood glucose, and liver and muscle glycogen.  This form of energy is formed mostly from carbohydrate, therefore fat can not be relied on for a racehorse’s energy requirements.  However, Potter and Scott do state that studies have shown fat increases the ability of muscles to store glycogen so it is being included more and more, up to a level of 10 percent of their concentrate ration.

In conclusion, horses in race training are fed a good quality forage source, such as a lucerne/Timothy hay, a high energy carbohydrate, often in the form of oats or racing pellets, and a fat source such as soya oil or cod liver oil.  Many trainers also supplement with vitamins and minerals if a compound pellet is not being fed to ensure the horse receives all the necessary nutrients.   However, feeding horses has always been an art mixed with science, and a good trainer will consider all variables when devising the rations.  And keeping the feed as simple and as close to nature as performance needs allow will also ensure a much healthier horse.

This article was written by Chrissie M. for iMedia Group P/L

Citations

1. ^ Huntingdon, P.J, and Jenkinson, G.J.  Feeding Practices in Australia and New Zealand.  http://www.ker.com/library/advances/142.pdf

2. ^ Gibbs, P.G, Potter, G.D, and Scott, B.D. Feeding Race Prospects and Racehorses in Training.  Agrilife Extension Texas A & M System. http://animalscience.tamu.edu/files/2012/04/equine-feeding-race-prospects2.pdf