The Scoop on Grains and Concentrates

the nutrients of the feed. It often has a higher fat concentration than pellets. Texture wise it is typically softer and less dusty as well.
Complete Feed
Complete describes a feed that contains everything the horse needs in his diet including the forage.  Complete feeds can be fed as the sole ration.  Senior horses that have lost the ability to chew hay will benefit from a complete feed.  Medical conditions may require the use of complete feed for example when dust or hay irritate the airway. Complete feeds can serve as an alternative option when good hay quality is limited in your area as well.  
Ration Balancers
Ration balancers are designed to be fed along with forages to horses that do not need additional energy calories from concentrates but do need additional protein vitamins and minerals.  Ration balancers are a pelleted feed. They typically have low crude fiber and fat. The first ingredient is often soybean meal making them high in protein. It is a heavily fortified feed with small daily recommended feedings. The purpose of a ration balancer is to provide your horse with the essential nutrients that are insufficient in a foragebased diet. Ration balancers provide a good amount of calcium and other key macrominerals trace minerals and fatsoluble vitamins.  They are not intended to be fed for extra calories. They often have a high percentage of protein but this is because such small amounts are fed 12 pounds per day. If your horse needs additional vitamins and minerals but not protein then a vitaminmineral supplement would be a more appropriate option.
Tips on Feeding Concentrates
When feeding commercial concentrates make sure to follow the feeding instructions on the label. They are carefully formulated to meet your horses needs but only if you feed the right amount. The label will specify how much

to feed based on your horses body weight. If you only feed half the recommended amount or dilute it by adding whole grains or mixing in another feed then the benefit of a carefully balanced feed is gone. You may notice that the feeding instructions are in pounds not quarts or scoops. If you feed by scoop use a kitchen scale to figure out how much one scoop of each feed weighs then figure out how many scoops are required to meet the recommended feeding amount. A scoop of pellets will not weigh the same as a scoop of sweet
feed so do this for each different product in your feed room. Lastly if you have to cut back a horses grain to below the recommended amount because it is gaining too much weight then consider switching it to a ration balancer instead.
Providing a properly balanced diet for your horse is the most significant part of horse ownership and is a key part of keeping your horse healthy. If you rely on a boarding facility or if you are the sole caregiver for your horse it is important to understand how to properly feed them.  Your veterinarian extension specialist or an equine nutritionist are great resources to aid in developing a diet that meets your horses nutrient needs.