Feeding horses well is both art and science. If you’ve ever had a horse too fat, too skinny or jumping out of their skin with playfulness then you’ve probably experienced the effects of a diet mismatched to your horse’s energy requirements. “Overfed and underworked” and “He needs more wet saddlecloths” are terms you might hear when horses are fed more than they need for the level of work they perform.
The amount and type of food your horse requires is determined by his or her size (weight), workload, age, breeding status and whether you are aiming for weight loss, maintenance or gain.
To feed your horse correctly, at any point in time you need to accurately answer the following question: “Does my horse need to lose, gain or maintain bodyweight?”
Determine Body Condition Score (BCS)
Body Condition Scoring is a useful tool for monitoring the balance between dietary energy (calories consumed) compared to the amount of energy your horse is using (for repairs, keeping warm, working, etc).
There are various body scoring systems available, ranging from 5 point to 9 point scales. They all rely on estimating body fat using a combination of visual assessment and feeling the horse. Check out this great online tutorial on Horse Body Condition Scoring from the University of Minnesota.
The harder your horse works, the more calories his or her body will need to perform the work and maintain body condition.
The NRC (National Research Council) defines weekly workloads to help owners and nutritionists ensure that horses are fed appropriately, according to their daily nutritional needs for their work level. The definitions are:
A horse not being ridden or lunged can be defined as a horse at ‘maintenance.’ You might sometimes see this referred to as being at ‘rest’ or ‘spelling’. Some nutritionists even define whether the unworked horse has a high or low level of activity (depending on the paddock size and temperament of the horse).
A horse in light work performs 1 – 3 hours per week: 40% walk, 50% trot, 10% canter with an average heart rate of 80 beats per minute (bpm) over the ride. Light work could include horses used for recreational (trail or pleasure) riding, working ponies, horses during the early stages of training or beginning breaking in or show horses given occasional work.
A horse in moderate work is performs 3 – 5 hours per week: 30% walk, 55% trot, 10% canter, 5% low jumps or other skill work with an average heart rate of 90 bpm over each ride. This typically includes horses used for more regular recreational (trail) riding, beginning training/breaking, show horses, dressage, campdraft, polo or polocrosse, stock work, cutting horses, showjumpers and low level eventers.
Hard (or Heavy) work is defined when a horse performs 4-5 hours per week: 20% walk, 50% trot, 10% canter, 15% gallop, jumping or other skill work with an average heart rate of 110 bpm over the session. Hard working horses may be performing stock work, polo, high level dressage or show jumping, medium level eventing, race training.
Very Heavy Work
Very Heavy (or Intense) work is performed by racehorses, elite 3 day eventers and endurance horses. Their work varies – it can be 1 hour per week speed work or 6 – 12 hours per week of slow work. Their average heartbeat will be in the range 110 – 150 bpm.
Once you have identified how hard your horse works, you can use this information to calculate how much food (total intake) is needed each day, and whether hard feed and supplements are required to provide the right levels of energy (calories), protein, vitamins and minerals.
How much should be feeding my horses?
Many horses (especially ponies, easy-keepers and horses at rest or in light work) consume all the calories they need from their forage source (that’s the pasture, hay and chaff they eat). DO NOT give a hard feed to an overweight horse – only feed forage and a token feed to carry supplements. If you need to reduce weight further, remove from pasture and limit hay intake to 1.5% of bodyweight, choosing hay with a low sugar and starch content (or soak it to remove water soluble carbohydrates).
Hard keepers, breeding, growing and hard-working horses often need a concentrate feed to provide enough calories to maintain body condition or gain weight. Selecting the right hard feed to suit an individual horse is where experience and art come into play.
The most reliable way to assess whether your horse is getting enough concentrate feed is to carefully observe changes in body condition PROVIDED enough forage is available. If you are feeding plenty of forage and your horse starts to lose weight, increase the size of the hard feed.
It’s normal to need to adjust the amount you feed on a regular basis in response to changes in forage quality or workload. Changes in grass quality are often hard to detect by looking at the plants, but your horse’s body condition tells you all you need to know! Your horse will often need more hard feed the regular workload increases, and usually need some changes to vitamin and mineral supplementation.
Feeding Horses Nutritional Supplements
The vitamin and mineral requirements of a performance horse kept in a yard or stable and subject to the stresses of intense exercise are higher than when the same horse is spelling at pasture.
Green grass is rich in vitamins and omega-3 oils which are lost as the grass is cut, dried and stored as hay. Hard working horses need more vitamins than resting horses, but their natural vitamin intake is often low because they eat more hard feed and hay and less green pasture. As your horse’s access to green grass declines and workload increases, make sure you provide enough additional vitamins and omega-3 oils as a supplement or ingredient in pre-mixed hard feed.
Performance horses need to be fed optimal levels of minerals to enable their bodies to function efficiently, allowing them to perform to their physical potential. When diets lack essential minerals, or the critical mineral ratios are not balanced, sub-optimal performance is to be expected.
All horses, even those grazing very healthy pasture, will be mineral deficient unless supplemented with zinc, copper, iodine and often selenium.
Many pastures also lack enough calcium, phosphorous and magnesium to meet even the lower requirements of horses out of work. The type and degree of mineral shortages will depend on the nutrient status of the plants which is not always closely aligned to soil mineral status.
When a critical mineral ratio is out of balance it can create an induced deficiency of other minerals even if those minerals are supplied at 100% or more of the recommended daily intake (RDI).
The harder a horse works, the higher its need for minerals. For example, a 500 kg horse at rest needs 20 g of calcium a day compared to a 30 g/day requirement for a light workload. The same horse in very hard work needs double his maintenance calcium requirement taking it to 40 g/day.
Similar trends exist for other key minerals such as phosphorous, magnesium, potassium, sodium and chloride. The requirement for sulphur, copper, cobalt, iodine, iron, manganese, selenium and zinc increases with work, but not to the same extent. For example, a resting 500 kg horse needs 100 mg of copper compared to the need for 125 mg when in heavy work.
Read more about the best mineral supplement for New Zealand pastures here.
Electrolytes, the minerals used to balance the body’s hydration, are very important for working horses and those kept in hot climates. Salt provides two of the most important electrolytes: sodium and chloride, and should be fed every day. Feed salt at the rate of 7 to 12 grams per 100kg of horse bodyweight daily, counting the salt added into premixed feeds. Grass and hay are naturally high in potassium, another major electrolyte. Give extra salt or a commercial electrolyte replacer during very hot weather and after heavy work to replace the electrolytes lost in sweat.
A correctly balanced diet will add the vitamins, minerals and omega-3 fatty acids necessary to top the levels in the diet up to at least daily minimum requirements. It must also balance critical ratios across the whole diet, taking the mineral levels of roughage, hard feeds and supplements into consideration.
Performance horse owners are often pleasantly surprised that a few changes in the mineral balance of the diet can lead to an increase in feed-use efficiency and a smaller feed bill!
However, adding too many of the wrong supplements can cause an imbalance, possibly leading to deficiencies, poor performance and money wasted. A small investment in the services of a qualified equine nutritionist will often pay for itself very quickly by reducing waste whilst improving your horse’s health and nutrition.
You can get a free diet analysis from qualified nutritionists at Farmalogic! As a part of our strong commitment to customer service, and to help save you money, we offer a free diet analysis to fine-tune your horse’s diet and calculate the level of supplementation your horse requires. To access this service, please weigh your horse’s feeds then fill in a diet analysis request form here.