Calcium Supplementation for Horses

Calcium Supplementation for Horses
Authored By AmacronEquine Admin

In Australia, the pasture and the feeds available, generally have enough calcium supplied for your horses. However there are certain grasses that provide very little calcium, there are also certain growth stages of horses where an adequate level of Calcium is crucial. There are also certain conditions that can occur, eg Nutritional Secondary Hyperparathyroidism (or Big Head) if a horse has a deficiency in Calcium. Furthermore, it is important that the correct ratio of 2:1 (Calcium: Phosphorus) is maintained.

Calphormin by TRM is known worldwide to provide a balanced ratio of these all-important minerals. It is very important the ratio is right otherwise the horse might not be able to absorb these minerals. (Eg. if you have too much phosphorus it can block the absorption of calcium, if there is too much potassium it can block the absorption of magnesium, and too much zinc can block the copper absorption

We recommend FeedXL which is a program that allows you to make sure that the mineral requirements are being met for your horse, and that they are in the correct ratio.

Unlike vitamins, which are produced by the horse, these macro minerals, like Calcium & Phorphorus need to be supplied in the diet and they play an important role in the formation of bones, teeth, and other structural components.

When breeding horses, no matter what you are breeding the horse for, the priority is to have a foal develop with healthy strong bones and clean legs - free of defects and developmental disease. There are multiple reasons why foals have bone defects, genetics and nutritional are the most common causes. Overfeeding has been linked with conditions like DOD or OCD, however, mineral deficiencies can have a similar effect so it is important to get the balance right. It is well recognized that an unbalanced mineral diet can lead to developmental issues, Calphormin contains the correct ratio of Calcium: Phosphorus ratio, so adding this to your feed will not throw out the ratio.

ALSO READ: Calphormin Trial Results


Pastures where calcium is unavailable

Sub-tropical pastures contain oxalates, this chemical binds to calcium during digestion which means that the calcium cannot be absorbed into the body, or very little of it can be. 

types of grasses for horses


Here are some examples of sub-tropical grasses.

  • Buffel Grass
  • Green Panic Grass
  • Kikuyu Grass
  • Pangola Grass
  • Para Grass
  • Setaria Grass
  • Signal Grass
  • Pigweed

This points out the need to carefully consider if your horse needs a calcium supplement. You might have a mixture of these grasses in your pasture resulting in lower available calcium content.


At what stage of growth does your horse have a greater demand for Calcium?

horse and foal health

Unborn or newborn foals have a much greater demand for calcium because their bone structure is growing at such a rapid rate. 76% of your horse’s skeletal growth occurs during the last 3 months of pregnancy and the first 8 months of life, so it is incredibly important to make sure they have an adequate supply of available calcium during those periods. This means that a large part of the minerals required for bone formation must be supplied by the dam. Feeding a calcium supplement like Calphormin, during the last 3 months of pregnancy and during lactation and then continuing to feed the foal after weaning, can be very beneficial.

For the broodmare - (during her last 3 months of pregnancy) - it is important to supply a calcium supplement for your horse, to ensure she can pass on this critical mineral to the unborn foal. Calphormin from TRM was specifically designed for supplementing the broodmare and unborn foal. Calphormin contains a unique and balanced combination of Calcium, Phosphorous, Sodium Zeolite, Lysine, Zinc, Copper, Manganese, and MSM. You will find that by supplementing a broodmare with the Calphormin, she maintains her condition and weight much better during pregnancy, as she is not required to use her own calcium reserves to feed her unborn foal.

For the young racehorse that is put under pressure during training at a young age, this can be very demanding for the bone structure as the bones are still growing and need to sustain the rigors of racing, by using a calcium supplement for horses it can really help to increase bone density, this will lead to tougher bones and fewer problems during training. A common problem is shin soreness, the risk of this can be reduced by the method of training, ie - more gradual slower training, but you can also supplement with something like Calphormin, which contains a perfectly balanced ratio of all the needed minerals.

Mature horses that are not working or pregnant and do not get the correct amount of calcium and phosphorus per day will have a weakened skeleton and will be susceptible to lameness and bone injury. The bones of all horses are being constantly remodeled to an extent, so the need for Calcium and Phosphorus is life long.

What is Big Head? (Nutritional Secondary Hyperparathyroidism)

Big Head is a condition that can occur if a horse is grazing on fast-growing pastures, high in oxalates, over a prolonged period, as these grasses are low in available Calcium and therefore these horses need calcium supplementation. This condition occurs when the horse continues to be deficient in calcium, parathyroid hormone is released which starts the process of resorption of calcium stored in the horse’s bones. The resorption normally starts in non-weight-bearing bones, as the calcium is removed from the bones, they become weak and become deformed, this often affects facial bones and they begin to protrude, hence the term “Big Head”. Bones act as a storage facility for calcium when nutritional availability in the diet is deficient, the body starts taking calcium from the skeletal structure.

Can you feed too much Calcium?

It has not been too well established as yet, but it does seem likely that excessively high levels of calcium in the diet can interfere with the absorption of other minerals like iron, zinc and copper. Also, extremely high calcium intake has been associated with developmental orthopaedic disorder (DOD), this includes osteochondritis dissecans (OCD) and epiphysitis.

Many commercially available horse feeds contain the correct levels and balance of Calcium, however, due to climate variations in pastures and if farms mix their own feed, you should always perform an analysis to make sure quantity and ratios of these essential minerals are correct.

Should I use a calcium supplement for horses?

There are many supplements on the market today, offering calcium and other key bone minerals. It is important, however, to make sure you are adding these supplements to a well-balanced diet. The supplements cannot “fix everything” on its own, you need a correctly balanced diet to start off with, then supplementation to further improve your horse’s mineral intake. Calphormin is a great supplement known worldwide.


Calphormin AUS:

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