Foundations of Good Nutrition, Horse Health, Nutrition

Horse Nutrition Explained: the ABC and 1234 of correct diet balance!

Have you set up a spreadsheet or bought a license for an online ration calculator but after an hour of fiddling with feeds, the diet still won’t balance? Sound familiar? Are you confused? Frustrated? Ready to give up? Hang in there, because once you understand the right order to plan your horses diet, balancing it becomes much simpler.

Feeding horses well is not rocket science, but the results (in horse appearance, performance and long-term health) can blow you out of this world! And it is as simple as ABC and 1234!

Farmalogic nutritionist, Larissa Bilston, explains the simple and logical process she uses to perfect every horse’s ration, whether the diet is for a beginner’s pony, a pleasure horse, an Olympic mount or a retired and much-loved companion horse.


Energy in horse nutrition refers to the kilojoule/calorie content of the diet. Consume more energy than the body needs to maintain itself, and weight gain occurs. Consume less and the body will lose condition.

The first step in formulating a horse ration is to define your pastures and estimate how much your horse is consuming per day. Add in grass or meadow hay to the diet if pasture is sparse to bring intake up to 2% of the horse’s bodyweight. Once you’ve completed steps B,C and 1,2,3,4 come back and re-adjust pasture intake so that the total daily intake in your diet calculator is 2% of bodyweight.

In many cases, forage (pasture and hay) contains enough calories to sustain a horse. Sometimes (especially during spring) the pasture is too high in energy and horses gain too much weight. Larger and hard working horses often have an energy deficit if only fed pasture or hay. If your horse needs more energy than the pasture provides, add a cereal grain (e.g. barley, oats, millrun), a legume grain (e.g. lupins), a ‘superfibre’ (like beet pulp or soy hulls) &/or oil until the dietary energy intake matches the horse’s requirements.

When choosing your grain or energy source, consider how much time and energy you are willing to put into preparation.  Whole oats can be fed raw, but other cereal grains such as barley, oats, and sorghum should only ever be fed in a cooked form. You can boil them or buy steam flaked, pelletised, extruded or micronised. Pre-mixed hard feeds such as pellets and mueslis are usually fortified with vitamins and minerals but you should read the list of ingredients carefully so you understand what is in them. You may wish to avoid the cooked grains with added molasses – just check the labelling on the bag. Some super fibres require soaking and raw lupins are also best soaked to soften the seed coat.

The amounts of energy food required depend on horse size, level of activity or breeding status, amount of energy provided by the roughage you’re using and the individual’s metabolism. Over time, your best guide as to whether your horse is getting enough calories is to regularly observe and record changes in body condition, then adjust energy intake accordingly.


Most adult horses have all their daily amino acid requirements met by the pasture and hay they eat. Breeding and growing horses usually need a quality protein source added to their roughage to meet their basic needs for essential amino acids. Lysine, methionine and sometimes threonine are the most limiting essential amino acids. Full fat soybean meal and lucerne are often all that’s needed to top up these requirements.


Horses fed all the roughage, energy and protein they needs to grow, work, play, repair and maintain their body can still lack vitamins and minerals.

All horses need supplementary vitamin E, but won’t always need additional A, D, K or B-group vitamins. Vitamin shortages are most common when hay or grains form a large part of the diet because vitamins are most abundant in fresh plants. By the time hay has been stored 12 months, it will have lost virtually all of its vitamins.

Horses in hard work often need multi-vitamin supplementation because their requirements can exceed the levels produced by their body and gut microbes (while at the same time, their vitamin-producing gut microbes are disadvantaged by stress and lower fibre intakes).

Horses often need a vitamin boost after transport, sudden dietary change, illness or separation anxiety for a week or so while their gut microbe population recovers enough to provide adequate vitamins again.

Adding prebiotics and probiotics, especially live yeast, provides additional benefits for gut health during heavy work and during times of stress.

Mineral shortages will depend on the nutrient status of the pasture plants. Zinc, copper, iodine and selenium are almost always deficient in an unfortified diet, even when horses are grazing high quality pastures.

The friendliest vitamin and mineral supplements on the market will list their ingredients “per serve” rather than “per kilogram” to make your calculations easier. Don’t be fooled into thinking that the product with 360 mg of zinc per 60 g serve contains less zinc than the product with a label that reads:  Zinc 2020 mg/kg (this is only 121 mg of zinc in a 60 g serve or 202 mg in a 100 g serve which will not meet most horse’s needs).

Sometimes even the best supplement might be a little bit short on one of the minerals your horse requires. In this case it might be more cost effective to add a single mineral separately than to increase the dosage of a quality supplement. For example, limestone is a cheap, well-utilised source of calcium and magnesium oxide is a good option where more magnesium is needed. An equine nutritionist will be able to advise which form of minerals are the most concentrated and have the best uptake into the bloodstream.

Remember that the minimum daily requirement is almost certainly not the OPTIMUM level of minerals for your horse, it is the amount you must provide to avoid a deficiency.

Even when a diet provides the recommended daily intake of every mineral, if the ratios between them are incorrect, your horse’s body won’t be able to get enough to satisfy all requirements and will remain deficient.

Some nutritionists believe that the optimum level for many minerals in the diet is around 150% of the recommended daily intake (RDI), but up to 300 or 400% can be necessary to balance ratios correctly (more on this under heading 3, Mineral Ratios, below).

The aim of balancing the minerals in the diet is NOT to achieve 100% of RDI – it is to meet or exceed this level for all the minerals recognised as being essential for good health but without providing so much as to risk toxicity.

Once you’ve got the ABC of the diet right, it’s time to fine-tune the details with steps 1 to 4.


The more work your horse does, the higher the dietary intake is likely to be, and the more grain or concentrated energy sources the horse needs to consume enough energy. Idle horses or those in light to moderate work may zero to 25% of their intake as a hard feed (concentrate) whereas a horse in intense work may need 50 – 60% of the diet as concentrate and the remainder roughage.


This is a final check that the diet provides the essential amino acids without adding too much extra protein to the diet. For instance, it can be better to substitute one protein meal for another richer in the missing amino acid (e.g. soybean protein is relatively rich in lysine) rather than feed a lot of high protein, low lysine feed. Protein meals are relatively expensive to buy and are harder for the horse to metabolise, so keeping the protein content of the diet at the lower end of adequate is healthier for your horse and your pocket!


It’s not enough to simply provide more than 100% of RDI of all the minerals, they have to be fed in balanced ratios across the whole diet. This is because some minerals interfere with the absorption of others, so that too much of one can cause a deficiency in another EVEN IF YOU SUPPLY 100% of the horse’s daily needs.

Mineral ratios need to be balanced across the whole diet, so don’t look for a supplement that contains the ratios listed below. The Equine Vit&Min range has been designed to provide the minerals most often required to achieve optimal mineral ratios.

Guidelines for some of the most critical mineral ratios include:

  • The calcium to phosphorous ratio needs to be between 1-3 to 1 for growing horses and between 1-6 to 1 for a mature horse, leaning towards the high end for a horse grazing moderate/high oxalate pastures.  (Hint: feeding additional limestone can be a cheap solution to boost the calcium content of a diet).
  • Keep the total calcium intake below 5 times dietary requirement.
  • Calcium to magnesium should lie in the range of 1-2 parts of calcium for every part of magnesium (Hint: Magnesium oxide is an affordable and effective ingredient to boost magnesium levels in the diet).
  • Zinc to copper should be between 2-3 parts zinc for every part copper.
  • Iron to copper should be between 5-10 parts iron for every part zinc.

Avoid Toxicity

You also need to check that you are not feeding too high a level of any nutrients. Most vitamins and minerals have a very high safety margin but two to be aware of are selenium and iodine.

  • Keep iodine levels below 5 mg/kg of dry matter fed
  • Keep selenium levels below 0.5 mg/kg of dry matter fed.

Many Australian soils are selenium deficient, so this mineral is often added to horse feeds. Be careful not to double dose on selenium through different feed sources as this is one mineral where toxicity levels are relatively low.


Scientists believe that the omega 3 to omega 6 fatty levels in fresh grass provides the optimum ratio for managing inflammatory responses in the body. Omega 3 oils are very fragile, and do not survive exposure to light, heat and air. This means that when grass is dried to make hay, the omega 3 oils are lost, but the omega 6 oils which are more resilient, remain in the hay. Many of the grains fed for energy, and protein meals and oils added to horse diets are much higher in omega 6 fatty acids than omega 3.

Linseeds and marine-sourced algae or fish oil based omega 3 supplements can be utilised to bring the overall balance of the diet to around 2 to 4 times as much omega 3 as omega 6 oil.

Farmalogic Omega Balancer is a palatable and stable omega-3 supplement which is even more potent than linseeds or oils to balance a diet high in omega-6 fats due to the DHA/EPA content from marine-sourced omega-3. Omega Balancer is a dry meal that stores safely without need for refrigeration. It can be added to feeds ahead of time to suit the needs of owners working late or relying on others to feed. With a standard serve as low as 30g/day, it’s never been cheaper or easier to give your horses enough omega-3 oil to balance their omega-6 intake.


When you are considering what supplement to feed your horse, rather than think about how much each product costs, or even how they compare, you first need to know what your horse NEEDS from a supplement. Once you know how many grams or milligrams of each vitamin and mineral you need to add to your horses daily intake, the selection of the most appropriate supplement becomes a logical process.

What if I change my horse’s diet?

If you change your horse’s feeds you will need to review the vitamin and mineral balance. Be aware that the dietary gaps can vary significantly if you normally feed high levels of a fortified grain blend or pellet reduce the amount fed if grass quality and availability increases, your horse puts on too much weight or you reduce the work load. A diet that was well balanced on 4 kg of pellets per day can be very deficient when cut back to 0.5 kg of pellets per day.

The process of choosing a good base diet to meet your horse’s needs for roughage, protein and energy, then supplementing with vitamins and minerals is well worth the effort. Your time and energy will be rewarded with the knowledge that the diet you feed is giving your horses everything required to look and feel their very best!

Need an expert helping hand?

As a part of our strong commitment to customer service, and to help save you money, our team of university qualified equine nutritionists offer a free diet analysis to fine-tune your horse’s diet and calculate the type and level of supplementation your horse requires. To access this complementary service, please weigh your horse’s feeds then visit

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