How to Accurately Feed Your Horse a Forage-Based Diet

have soils that are known to be deficient in selenium. This results in the forage either hay or pasture having very low levels of selenium.
By simply looking at your hay it is impossible to know what nutrients are lacking. Therefore to accurately feed a foragebased diet the crucial first step must always be a hay analysis.
Hay Analysis
When you walk into a feed store to choose a product to feed your horse you likely read the tag or label first. Maybe you specifically look at the protein content. Or does the energy content lead to your decision? There are a variety of factors that can assist the horse owner in choosing a product they deem suitable.
Now imagine walking into a feed store to choose a product for your horse only to find the nutritional information not available. This would make choosing the right product an extremely challenging task and its unlikely you would feel confident in choosing what is best. If that situation sounds scary why do we do this with hay? 
If hay comprises the majority of the horses diet it is logical to want to know the nutritional value of that forage. There is no reliable way to predict accurate nutritional information without a hay analysis.
The good news is that you can easily obtain a hay analysis yourself. I recommended asking your local feed store or equine nutritionist for the use of a hay probe to take your sample. These tools drill a core out of the bale to improve the accuracy of the sample.
Then follow these steps 
Have multiple bales available from which to take handfuls of hay. Open each bale and take a handful. A minimum of 10 bales should be used to ensure that your sample is representative of the batch of hay.
Within each bale vary the location your sample is taken from. Most of the grab samples can be taken from the interior of the bale.
Trim the ends of the handful to emulate a core. The handfuls should be trimmed to about three inches in length.
During this process be careful not to crush any leaf matter as it is nutritionally important.
Put all trimmed handfuls into one labelled Ziplock bag and mix well. Prior to shipping the sample to your nearest lab attach the laboratorys sample submission form to the bag.
In Canada there are many different labs. Ensure that you are sending your sample for an
equine analysis. For example Ontarios SGS Laboratory in Guelph and AL Canada Laboratory in London both have equinespecific analyses. But if this task seems daunting reach out to a qualified equine nutritionist in your area. They will be equipped with a forage probe to take an accurate hay sample and ship it to the nearest laboratory for you. 
Ideal Forage Amount
Most horses will consume between 1 52 5 percent of their bodyweight in forage. If your horse easily maintains body condition and becomes overconditioned it is recommended to decrease the forage intake to closer to the 1 5 percent. However if your horse is not overweight or has a difficult time maintaining weight closer to the 2 5 percent is preferable. If your horse is not overweight providing freechoice access to forage is ideal. Following an equine body condition score system to ensure accuracy in evaluating your horses condition is recommended.