Oats have been the traditional feed for horses until the introduction of mixes and pelleted feeds approximately 40 years ago . This was because they are easy to feed, oats can be fed whole ' unlike other cereals they do not need to be micronised (cooked) before feeding. Oats are the highest in fibre and contain the least amount of energy when compared to other cereals such as barley and maize and because of this are not as likely to make horses and ponies fizzy or hyper as we commonly believe that they do. Nowadays oats are most likely to be fed to horses that are working hard such as racehorses and eventers, although they are often in small quantities to a horse's existing feed to give a little more 'oomph'. The disadvantage of oats is that they tend to be very low in calcium but high in phosphorous. Calcium is needed by all horses, especially youngsters and brood mares, to maintain healthy bones, but too much phosphorous in the diet will prevent the horse from absorbing calcium. This is why oats should not be fed on their own to youngsters and brood mares, but if oats are fed with other feed stuffs that are high in calcium such as alfalfa, sugar beet pulp or a specially designed supplement these problems can be avoided.