Summer Feeding of Horses

Ahh, the joys of summer. Hot days mean early morning rides, the smell of fresh horse sweat in your nose and the warm sun on your back (not to mention the steady hum of flies around your head!).

Owning horses can be an absolute pleasure in the summertime, but just like the other seasons, summer feeding has its own problems to contend with.

Horses have a bit of a hard time in the Australian summer, especially in the hotter and more humid regions of the country where the weather puts special demands on your diet formulation skills! Here is a guide to what is important, and how to deal with that sticky weather and maintain a well fed healthy horse as well as a healthy rider’s T-shirt tan!


Hot weather means hot horses, and that means sweat, and if you like to ride your horse every day – lots of it! Horses sweat in a different way to us humans, when we sweat (or for the ladies amongst us, when we ‘perspire’!) we lose mainly water, with a small amount of salt, but when horses sweat, they are much more ‘leaky’ and lose a lot more salt and some protein too.

The ‘salt’ is really made up of a number of electrolytes. Electrolytes are salts that are vital in maintaining water balance and muscle function amongst other important body processes. When a horse sweats a lot and doesn’t get the lost electrolytes replaced, he may lose the stimulation to drink and will have tired and sore muscles. We also know with all the research that has been done, that horses that do not get the right amount of electrolytes are more likely to tie up than those who have their diet balanced.

The major electrolytes to be concerned about that horses lose in sweat are sodium (Na), potassium (K), chloride (Cl) and magnesium (Mg), with sodium and chloride being the major ones in horse sweat. For everyday purposes, it is important to make sure that your horse has regular salt in his diet (the same kind you put on your chips is fine! – you can buy it in bulk at your produce store). Either put it into his feed, or make a salt block available to him in the paddock, or do both, just to be sure. Salt only replaces the sodium and chloride that the horse has lost, but if he hasn’t sweated much, the others are less important.

On days where your horse sweats a bit as you work him it is a good idea to replace all of the electrolytes he has lost with an electrolyte supplement such as Equivit Restore, which is formulated to be the same as horse sweat and so replaces exactly what the horse has lost. If you live in one of the humid areas of Australia, then you will notice that your horse sweats more because the sweat doesn’t evaporate and cool him down very well, so the stuff just keeps pouring out! Electrolytes are very important for these horses and should be given every day after you’ve ridden, with a salt block always available in the pasture.

Remember with all horses that it is very important to cool them down after work before they are fed. This is especially important in the summer, as horses take longer to cool down in the hot weather. Walking the last few kilometres of the ride and hosing off your sweaty horse on your return will help, as well as hand walking for up to half an hour if he is still puffing after that. Only when he is completely cool and his breathing has returned to normal should you give him any food, including hay.

If you plan on doing lots of competitions this summer, you will need to take electrolytes with you, both for the competition and for the journey to get there. Lots of horses sweat during travelling, and need an electrolyte top-up when they get to the comp before they even get a saddle on! You can give the electrolyte in a syringe over the tongue mixed with water, yoghurt or apple sauce.

Feed Storage

Would you like to eat your dinner if it had been left outside in the heat all day? Your horse will give you the same answer. Hot weather makes feed go ‘off’ a lot sooner than it does in the winter, specially prepared feeds with molasses and oil added. Pelleted feeds usually store longer than sweetfeeds, and whole straight grains also have a longer shelf life in summer than sticky molasses sweetfeeds.

In the summertime, buy only enough feed to last you for 10-14 days. Don’t buy in bulk to save money, because you will probably end up throwing half of it out after it has gone sour. Keep your feed in a cool dry place, preferably in a shady feed room with plenty of ventilation. When you buy your feed, if the feed room is nice and cool, transfer it into sealable containers such as large rubbish bins with lids or purpose made feed bins to prevent flies and rodents getting into it.

If the feed room is warm as most are in summer, keep the feed in the bags to help air circulation and prevent ‘sweating’ (yes, your feed sweats too!) and consider using an air conditioner or dehumidifier in the feed room during the day if it is sealable. If you store your feed in bags, put them on a pallet rather than directly on the floor to allow air to circulate around them and prevent moisture from soaking into the bag and spoiling the last four or five scoops of feed.

It can help to shake the bag up a little to get air into the feed and prevent clumps. Make sure you remove shrink wrap or plastic bags from around the feed, as this will encourage them to sweat and go rancid more quickly, but do roll the tops of the bags closed enough to keep out flies. Keep your feed out of direct sunlight. If you feed oil, it’s a good idea to store it in a fridge (move over your dad’s beer stockpile, your horses are much more important!), the same goes for molasses.

If you feed straight grains, remember that cracked and rolled grains go off quickly in the heat, so inspect all your grains and feeds carefully every day for signs of mould, or musty smells – if they smell bad to you, you can be sure your horse will turn his nose up at them too. Also be sure to check your hay and forage as these can also mould much more easily in the summertime, a musty, mouldy smell will give them away every time. If your feed does go off, throw it out. Trying to make your horse eat feed that is off is dangerous, and could make him very sick.

If your horse has eaten some spoiled feed by mistake, he might show signs of diarrhoea, loss of appetite or even colic, so watch for these symptoms throughout the summer months with more vigilance.

Feed types

Some types of feed will make your horse’s body temperature increase which is bad news when the outside temperature means that they can’t get rid of the excess heat easily – it’s a bit like us drinking a hot drink and putting on a sweater whilst sitting on the beach! Those feeds that are high in protein are the main culprits; things like soybean meal, lupins and lots of lucerne will contribute to a high protein intake.

Look at the label on your feed bag for the protein content – mature horses only need a feed with about 10-11% protein so unless your horse is a racehorse, or is young and growing, or a pregnant mare, be sure to minimise excess protein in the diet in summer months. Feeding lots of hay will also increase body heat slightly, but hay and forage are essential for a healthy gut, and should not be reduced to less than 1.5% of the horse’s body weight where hay is the only forage source (about 7.5kg for a 500kg horse). Grass is best, but is no good when it has burnt off! So feed supplementary hay and chaff depending on the quality of your pasture.

On the subject of overheating, many people will use light cotton rugs to avoid sun-bleaching in the summer. Make sure they are fully breathable and do not use synthetic materials, or your horse could get seriously overheated.


Probably the most important part of summer horse care is the provision of water. Your horse should always have access to fresh clean water and on long rides stop for a rest and a drink at any rivers or streams that you pass. Feeding electrolytes to take care of sweat losses makes your horse thirsty, just as eating a pack of salted peanuts makes you reach for the soft drinks, so be sure to give him a drink after he’s had his electrolytes.

Horses can drink up to 50 litres of water a day in the summertime, so make sure he has a constant clean fresh supply. Algae in water troughs can build up quickly in the summertime, so check regularly, and thoroughly clean the trough often. This means that yes, you do have to get up close and personal with that slimy green stuff. Scrub it thoroughly away, you can even use cleaning products as long as you make sure that the trough is rinsed thoroughly three or four times so that all traces of the suds and chemicals are gone before your horse gets anywhere near it. If you use buckets for water, you will need to refill them regularly and clean them daily to avoid algae build up.

Make hay while the sun shines!

Get out there and enjoy the summer months, compete, play around, go for rides with friends and be confident that your horse is getting the best of care.

By Kentucky Equine Research – Last updated 16 November 2012
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