In any catalog or feed store today you’ll find a variety of bagged feeds labeled for specific types of horses–growing youngsters, hardworking adults, broodmares, senior citizens, etc. All are formulated to provide the exact amount of calories and nutrition those animals need, and giving the wrong feed to the wrong horse can result in imbalances that can be harmful. “The biggest consequence is that adult rations don’t have the mineral levels young horses need,” says Sarah Ralston, VMD, PhD, Dipl. ACVN, associate professor at Rutgers University. “The result can be abnormal growth and developmental orthopedic disease.”
Also, once you’ve determined the amount of concentrates your horse needs for extra calories, be sure to choose a feed that provides the optimum nutrition in that serving size. “The most common mistake I see is feeding below rate,” says Crandell–that is, feeding a horse less than the recommended serving size. “When formulating feed, you can’t make it work for every horse,” she explains. “You can’t balance the vitamins and minerals for a horse getting one pound of feed without poisoning the horse getting 10 pounds.” Conversely, if the recommended serving size is five pounds, the horse who is getting only one pound is getting only a fifth of the added vitamins and minerals.
“If the minimum serving is too much, it’s not the right feed for your horse,” Crandell says.
Sources: Equisearch, Purina Mills Horse Health