What is Grain-Free for Horses?

it as a base for supplemental product decisions. For example if you have a senior horse being maintained on a vitamin and mineral supplement mixed with beet pulp but new hay is much lower in protein compared to previous hay you may need to add a quality protein source such as alfalfa cubes or pellets.
EasyKeepers
If you have a horse that readily maintains weight on hay it is easy to source a grainfree ration balancer. These products are designed to provide vitamins minerals and often supplemental protein as well to the horse without adding a significant number of calories. When investigating the ingredient list on pelleted ration balancers the hulls of grains are commonly included. This should not be a concern even for your easykeeper as they are fibrous and not high in starch or sugar.
If you are looking to curate a ration that does not have any grain or even grain parts in it a vitamin and mineral powdered supplement at a minimum is what you would need to feed your easykeeper. These products work well for balancing a ration as long as the hay is meeting your horses protein requirements. For palatability they are typically mixed with a soaked fibre source such as hay cubes or beet pulp. 
Active Horses 
Active and hardworking horses generally need additional nutritional supplementation above and beyond hay and a ration balancer. In these cases a fortified performance feed that includes vitamins minerals protein and additional carbohydrates and fats is fed. These products are often pelleted or extruded and contain an array of various ingredients.
As previously mentioned it is important to understand that just because a product is pelleted does not mean that it is high in starch or contains large amounts of grains. In fact many of these products include fibrebased ingredients such as alfalfa meal oat hulls beet pulp and fat sources like oils and rice bran. Of course often there will also be grain ingredients such as steamrolled oats or cracked corn to list a couple of the many examples. Therefore if you are beginning to investigate grainfree due to concerns over starch intake or gastrointestinal upset consulting an equine nutritionist to critically review the ingredient list of various performance products is recommended. To reiterate just because a product is pelleted or processed does not mean it is high in starch and sugar. Lowstarch feeds will generally rely on fat and
fibre as the primary energy source instead of NSCs.