Nursing mares may also need grain to help them maintain body condition. Hard-working horses have a higher energy demand than others, especially if they are in poor body condition to start with. These animals may benefit from the extra energy that corn adds to the diet. Proper mineral balance is also very important in the horse's diet at all stages of life. Once the foal is growing, properly balanced minerals in its diet will help prevent joint diseases.
Horses are nibblers.
They have a relatively small stomach and need frequent smaller meals to avoid problems like colic. If grain is necessary, provide a maximum of one-half pound of grain per 100 pounds of body weight at a time. Good quality hay should be available free choice. When temperatures dip and horses are outside, give the animals more forage. The heat of fermentation will keep the horse warm.