Written by Malcolm Green, Technical Director, EquiFeast

Magnesium is an essential nutrient for horses, but the enthusiasm with which it is added to horse feeds defies all the science. Here is a link to a really easy-to-read review article that supports all of our research, trials and monitoring of horses over the past years. I have highlighted the key points so you can skip through to the important bits in seconds :)


A horse’s Recommended Daily Allowance (RDA) of magnesium can depend on a range of factors. We have summarized these below:

Weight of mature horse in work

Light work (grams per day)

Moderate work

(grams per day)

Heavy work

(grams per day)

Very Heavy Work

(grams per day)





















If this table does not apply to your horse, further information can be found in Nutrient Requirement of the Horses, 6th Edition, published by the National Research Council, 2007.

Grass, Lucerne and grass hay almost always contain excess of the recommended amount of magnesium for horses whatever their work load.

There are a number of reasons why we believe that the vast majority of horses do better with no added magnesium in their diet. For more information about our research you can access our magnesium articles here.


In this article, Malcolm Green describes how to create a diet with little or no added magnesium in an Australian market.


Making your own diet from “straights”

The only real benefit of formulated feeds is that they contain supplementary vitamins, minerals and sometimes other key nutrients. It is these premixes that nearly always contain artificial sources of magnesium. They may also contain other minerals generally not needed and possibly counter-productive in North America such as iron and manganese.

Formulated feeds are designed to be fed at a certain rate – often 6-10 lbs a day for a 1200 lb horse. Feed less and you under-supplement, feed more and you over-supplement. In the UK this has led to a dramatic increase in the use of “feed balancers”. These may take the form of a “feed” that is fed at 1/2 - 1 lb per day. Or a supplement that may be in the region of 1 - 2 ounces per day.

Formulated feed options

I have really struggled to find American feeds with no added magnesium. If you find a brand please let me know. Don't just believe the label or web site though. Many don't list the magnesium they add.

Balancer options

In America most balancers are of the supplement variety. They enable you to make up your own diet from pasture, hay (various options) and various other ingredients we will discuss below.

At EquiFeast, our main feed balancer is called Essential Daily Care. It contains no added magnesium, iron or manganese. But does contain the amino acids lysine and methionine, sulphur (MSM), zinc, copper, iodine, selenium, cobalt (racing legal quantities). Vitamins include A, D3, E, K, C, B1, B2, B6, B12 niacin, pantothenic acid, folic acid, biotin and carnitine. 

From April 2021 Essential Daily Care is available in USA pre-blended with Cool, Calm & Collected under the brand name Sensible Essentials. These are packed in our UK packaging and each pack contains enough for 5 weeks for a 1,200lb horse.

We also have other balancers combined with different ingredients for different purposes like hooves, performance and Kissing Spines.

So what can you make the rest of the diet up with?

Our primary objective is to turn your pasture and grass hays into good horse feed. So unless your horse has a problem with these feeds, they will make the foundation of the diet. Hay rich in ryegrass, clover and even Lucerne are fine if your pasture is made of native grasses or meadow grasses. Even oxalate pastures will be fine so long as they are not too rich and fast growing. But if your paddocks are rich and growing fast you may need to be sourcing some low carbohydrate, high fibre hay to dilute it with. Or some of the “super fibre” options below.

Hays from grasses like Timothy, Rhodes and “meadow hay” are probably the safest you can get. Good native grasses are also excellent.

Lucerne is a hay that people either love or hate. Generally it is intensively produced so can be very high protein and potassium. For most horses it is fine as a supplementary feed.

Oaten Hay will normally have a lot of the oat grain left on it. That makes it higher in starch. But oats have been a traditional feed for horses for centuries and there is evidence that, compared to other cereal grains, it is much safer and indeed may have some physiological benefits.

For more concentrated fibre sources consider beet pulp and Copra. Both contain what are becoming known as “super fibres” which are more digestible than grass fibre but also appear to boost the digestibility of the fibre in pasture and hay. So they provide a double whammy. A few people report their horses going a bit loopy on copra so test it out gently.  UPDATE FEBRUARY 2021 - There is some anecdotal evidence that the relatively high level of oxalate that some beet pulp products contain is contra-indicated if pastures or hay are also high in oxalates. 

Rice bran is also becoming quite popular.

Sunflower seeds are also high in slow release energy as well as protein and make excellent components of the diet. Balancing the omega 3 and omega 6 oils with some micronized linseed is a good idea.

Another protein boosting option is from pulses. I’m not a great fan of soya (quite starchy and too many phyto-oestrogens) but lupins claim to have a much better non-starch energy component. Again it is wise to test out how your horse responds to lupins.

The feeds above offer a broad range of fibre, energy and protein options enabling horse owners to adjust their diet whether their objective is to build condition or muscle or just provide energy and protein to maintain horses for work.

They also provide plenty of low starch, high fibre options to help manage horses with EMS, PSSM, Cushing’s or at risk of laminitis, ulcers, colic etc.


Formulating a diet using a variety of different “straights” supplemented with a balancer (like EquiFeast’s Essential Daily Care) will provide all the options you need to formulate a feeding routine suitable for your horse.

If you need further help you can use a nutritionist.

A list of USA and Canada feed forms that apparently don't add magnesium to their grains (not verified by EquiFeast). Please let us know if you find more companies but don't rely on labels or websites. There is no legal obligation to list added magnesium on those and most firms don't:

Standlee Premium Products (a large range of chaffs and pellet forages)
22349 Kimberly Road, Suite E
Kimberly, ID 83341

208-825-5117 Office
800-398-0819 Toll Free
208-825-5119 Fax


Coolstance (for Copra): https://stanceequitec.com/

Renew Gold Equine (for Rice Bran): https://renewgold.com/products/renew-gold-equine-products/

New York:
Narrowsburg Feed and Grain, NY Tel: +1 845-252-3936

In the West:
LMF Feeds https://lmffeeds.com/

llenbass Feeds https://www.elenbaasco.com/product-category/equine/

Haystack Farm & Feed, 541 475-2319. https://haystackfeeds.com/