Because excess iron cannot be excreted, there is concern that many horses suffer from iron over-load.
When you have pasture analysed, iron readings tend to be high; usually made higher by soil contamination on the sample. This is virtually impossible to avoid, as is the ingestion of excess iron by the horse whilst he is grazing short grass.
Although it varies regionally, soil is inherently high in iron** so the shorter the grass, the higher the iron intake because of the close proximity of the mouth to the ground.
The iron levels in the graph below, have been obtained from Forage Analyses done by Calm Healthy Horses and clearly shows how short grass (< 2”) contains the highest iron levels by far. Long grass (> 8”) has lower iron levels and hay even lower.
The Daily Requirement, for a 500kg horse, according to the NRC Nutrient Requirements of Horses, is 400mgs/day (500 for horses in intense work, 625 for lactating mares. Horses living on short grass have an iron intake which far higher than the Daily Requirement. Water which is high in iron can also be another underestimated source.
The GOOD NEWS is that, because this iron isn’t in a bio-available form, most of it does not get absorbed anyway. Around 80-85% goes through the digestive system and out with the manure.
The iron that is absorbed by the horse is particularly important for optimal health. It is an essential element for the production of blood, for the transport of oxygen plus other roles such as assisting enzymes to perform the trillions of chemical reactions needed for life to go on.
If you are concerned about iron overload, the most effective remedial action you can take is to manage your horse’s grazing in such a way they are not living 24/7 on short grass. Having a high hay diet reduces iron intake substantially.
It is also essential to ensure optimal copper levels because copper is required for iron to perform its functions. And you need 3 x as much zinc as copper (Premium NZ Horse Minerals and Premium MVA are ideal options and take care of these ratios and everything else for your horse)
** Iron, chemical symbol Fe, is the fourth most abundant element available on Earth, according to the University of Wisconsin.
“I have added Himalayan salt to my EMS pony’s feed for nearly two years, but recently someone said that it is high in iron, is this correct?”
A good question.
Even though it is the iron in the salt that gives Himalayan salt its ‘pink’ colour it contains only 0.0369mgs per gram (there are 1,000mgs in a gram) – certainly nothing to worry about. Doing the sums: in 20gms (approx. a tablespoon) there is 0.738mgs which is still less than 1mg - a truly miniscule amount.
It would be therefore be misleading to say that it is 'high' in iron.
(Table salt contains less iron at 0.0101mgs per gram. 20 gms contains 0.202 mgs of iron)
Himalayan salt used to be sea salt hundreds of millions of years ago. Himalayan salt appeals because it is subjected to minimal processing, a comparatively unrefined product with no additives. The natural harvesting process leaves the pink Himalayan salt with many other minerals and trace elements that are not found in regular table salt (99 % NaCl). These very minerals, especially the iron, that give Himalayan salt its characteristic pink colour.
The important point is that none of these trace minerals are present in large enough quantities to be of any use at all for physiological processes.
What about Table Salt?
This salt is usually highly refined — meaning that it’s finely ground, with most of its impurities and trace minerals removed. The problem is that once ground to such tiny crystals, it becomes ‘hygroscopic’ - it tends to absorb moisture from the air and clump (cake) together. For this reason, anti-caking agents, included at extremely low levels are added so that it flows freely.
Sea Salt is naturally produced when shallow ponds and bays dry up in dry, low rainfall regions, leaving the salt crystals behind where the salty water once was.
Table Salt is made via salt ‘brines’. Water is pumped into salt deposits below the earth’s surface to dissolve the salt and make a brine. The brine is pumped back up to the surface where it is processed to remove impurities.
This is how the very white free-flowing very clean ‘table salt’ is produced.
Salt mined on a very large scale (using dynamite) is destined for industrial purposes
• Table salt is ‘purified’ but contains anti-caking agents.
• Himalayan, other Gourmet, salts and sea-salts do not contain anti-caking agents but may contain impurities`
• They all contain minute, negligible traces of iron
Remember salt is best added to the horses feed rather than relying on a salt lick from which they do not lick sufficient quantities to meet daily requirements.