Can I Feed my Horse Too Much Selenium?

Last Updated: | By Sarah Braithwaite, Author & Horse Health Expert

If you would like to find out about selenium for your horse then Forageplus can help answer your questions. Can you feed too much of this mineral and what is the best way to know how much is in your horse’s daily diet?

Can I feed my horse too much selenium Forageplus

Selenium for Horses

Yes you can certainly feed too much to horses.  Selenium is a trace mineral needed in minute amounts and is very easily over supplemented which could be dangerous for the health of your horse.

Although most forages in the UK do not contain enough selenium for your horse it is important to understand that you should pay careful attention to how much of this trace mineral you are supplementing each day in the form of fortified feeds and mineral supplements.

Information from the hundreds of forage analysis Forageplus carries out on grass, hay and haylage each year shows that it is safe to assume that a 500 kg horse in moderate work will need around 1-2 mg of extra selenium per day.

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Our balancers contain 1mg of selenium per 100 grams of product fed.  It is only our Performance and Young Horse balancers which contain 2mg as this is the amount shown to be needed, for these categories of horse, with reference to statistical analysis of the forage reports we have pertaining to both the UK and Europe.

Use Forage Analysis to find out Levels of Selenium to Supplement to Horses

You should be very careful not to supplement more than 2 mg per day to a 500 kg horse in light to moderate work, unless you know it is needed. Using a forage analysis to measure the amount of selenium in the grass, hay or haylage your horse eats can give you peace of mind and confirm the exact amounts of selenium to supplement.

If you can’t do analysis of the grass, hay or haylage your horse eats make sure you read the labels on any extra supplements you are feeding. Then calculate just how much of this mineral your horses is being supplemented each day.  Even better carry out a full mineral analysis and ask Forageplus to use their expertise to advise you further so you are sure.

There are pockets of the UK where our analysis reports show there are good levels of selenium. In these areas horses do not need supplementation of this mineral. In this case you would want to feed a mineral supplement either without selenium or pay careful attention to the levels in your horse’s total daily intake. This is where you can take advantage of our expertise in devising bespoke mineral plans for horses owners using separate mineral supplementation.

More about our analysis services for horses

More about our forage focused equine balancers





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