The Importance of Feeding Extra Salt.Danny licks a salt lick

Adding salt to feeds is turning out to be the 'nutritional tip of the century'!!

Horses grazing green, growing, over-grazed or otherwise stressed grass can be ingesting many times the amount of potassium per day than they require.

As potassium is involved in cell division it is always in the tips of the leaves so in this respect short grass is worse. Also high in potassium are lucerne, molasses, protein meals and many herbs.

As grasses become higher in potassium they do not correspondingly become higher in sodium.

Lucerne and clover, being legumes store sodium in their roots while the leafy part is very high in potassium.
Spring grass has a higher water content which exacerbates the lack of sodium.

Danny (in the photograph at right) is busy licking the salt lick but this alone is NOT ENOUGH salt!




All the literature says that excess potassium shouldn't be a problem as it is normally easily excreted in urine, but the fact is that it is a problem.

Horses, like us, have efficient self-regulating mechanisms involving various glands and hormones which are designed to correct temporary spikes of potassium in the diet but our domestic horses are subject to permanent high potassium, low sodium diets and the self-regulating mechanisms are eventually overwhelmed.

Significant improvements can be observed for the list of symptoms (right) when salt is added to the diet. How simple and cheap!! 

Salt stimulates thirst and the resulting increased water consumption facilitates the excretion of excess potassium.

The supplying of sodium and chloride (salt) goes a long way towards correcting crucial electrolyte imbalances and restoring normal nerve and muscle function.

When horses chew on rails, wood or trees, eat dirt or manure, or lick your hands they are exhibiting a craving for salt.

When feeding salt the feedback from horse owners so far includes:
  • The threshold at which their horse sweats with exercise goes up.
  • No more 'nervous' sweating (eg in the float)
  • No more sweating despite no exertion
  • Clear, rather than white, lathery sweats  
  • More ‘good’ energy
  • Better movement
  • No more uncharacteristic ‘stopping’ at jumps
  • No more 'falling asleep' (like narcilepsy)

We feed all our 14 horses approx 10gms per 100kgs live-weight of salt/per day. That is at least 2 tablespoons.


Symptom List...

This ‘Zonked’ Look is a classic sign of a lack of salt and is often associated
with Staggers

Signs of an excess potassium/lack of sodium imbalance include:  

  • Loss of appetite, weight loss, no top-line
  • Dry, staring hair-coat
  • Pinning their ears when asked to go
  • Having absolutely 'no go’
  • Excessive yawning
  • Sweating with little exertion
  • Sweating in odd places (on top of the neck or rump)
  • ‘Stiff’, short movement (often precedes laminitis)
  • Not able to canter properly, bunny-hopping, swapping leads behind
  • Showing inflammation of muscles in Thermograph pictures (polymyositis)
  • Saddle-fitting problems (because of above)
  • Getting the shakes
  • Being prone to laminitis & head-flicking
  • Reproductive problems
  • Retarded growth and bone development
  • Standing base wide
  • Wobbly especially in the hind-quarters
  • Difficulty backing up
  • Difficulty walking downhill
  • Apathy
  • Head-ache
  • Abdominal bloating
  • Allergies (salt is an excellent anti-histamine)
  • Staggering

swollen legs from salt deficiency
Same leg, 3 days apart after adding 60gms of salt / day

click on image for bigger picture.


Is all this salt going to 'harden their arteries'?

It is not actually salt that hardens arteries, rather it is a build up of calcium plaque which occurs because of giving calcium without magnesium.

Horses are large animals and have a relatively large requirement for salt especially when green pasture or lucerne make up a high proportion of their daily forage intake, working hard, or it is hot.

When increasing salt intake it is vital to ensure access to plenty of clean water. Clean troughs regularly.

What about salt licks?

Two things:

  • When the diet is high in potassium the body doesn’t always register the need for a higher salt intake.
  • Horses have smooth tongues and are not inclined to lick nearly enough to cover requirements.

Best to add the basic requirement to the daily feed and have a salt lick available if they want more.

Can I offer it ‘free choice’?

Making loose salt available is an option in situations where there are multiple horses not being hard-fed. However it needs to be kept dry which is a challenge.

What about hay-fed horses?

The less green grass or lucerne in the diet, the less the potassium intake and therefore the less need to add salt to feed.

Should it be iodised salt?

Unrefined sea-salt is best but many people feed plain ‘sodium chloride’ without added iodine.

Iodine is usually supplied in Vitamin and Mineral supplements or in prepared feeds. Excess iodine intake can be a problem for broodmares.

How do I know if I am feeding too much salt?

The body will excrete it via the manure and urine so you may observe water with the stools and excessive urination.

Can you feed too much salt?

 Absolutely. But it is equally harmful to feed to little. So how much is too much?

According to the latest “Nutrient Requirements of horses” a 500kg horse at rest requires 50gms (that is the 10gms per 100kg Live-Weight that we recommend) Lactating mares and horses in heavy work need more. Dr Julia Getty an eminent equine vet recommends 2oz/day, this is the equivalent of 56 gms.

A horse that consumes 10kgs of cool season pasture grass will get about less than one gram of salt from that grass. Remember grass has NO requirement for salt so doesn’t bother to uptake it. Grass has no interest in the health of your horse or whether you and your horse have a terrible time or not!

From the same amount of grass the horse will get about 300gms of potassium.

It is crucial for life that the horse’s blood and body fluids maintain about twice, no more than 5 x the amount of potassium as sodium. This is the job of the adrenal glands and the kidneys.

It is not rocket science that if the horse is subject to this chronic imbalance every day of his life that he will cope for awhile (sometimes they appear to cope for years) but eventually the adrenals and the kidneys can’t keep up and horses show the outward signs of being grass-affected that most of us are very familiar with.

As soon as you add salt to the feed this takes the pressure off his adrenals and kidneys and eases the situation for him.

The thing to understand about salt (the sodium component in particular) is that it has to be at a certain concentration in the blood and body fluids. If you eat too much salt you  trigger the thirst response and you will go and drink some water. This maintains the correct concentration. If you drink lots and lots of water without increasing salt intake you will be in metabolic trouble and can have seizures and die!

 So while horses have a good tolerance for a good intake of salt,  so long as they have access to clean drinking water (that isn’t too cold) it is best not to go overboard with it either.