Meeting Energy Requirements of Yearling and Two-Year-Old Horses

Normal weight gains in yearling horses ranges from 0.75 to 1.25 lb (0.33 to 0.66 kg) per day, depending on prior feeding and development history. If young horses have been fed for rapid gains during the suckling and weanling phases and this program is continued when the horses become yearlings, they will probably become obese, especially in the case of fillies. Yearlings that have been underfed previously may need to be fed for rapid growth similar to weanlings according to body weight rather than age. This should be done carefully to avoid developmental orthopedic disorders.

In addition to differences in previous feeding and growth histories, managers should take into account individual differences in gender, metabolism, and exercise patterns. These young horses are still growing, and most tend to be quite active if they are turned out with same-age peers. Data from breeding farms and experimental results show that colts and fillies grow at similar rates up to about a year of age but colts appear to continue to grow into their yearling year at slightly higher rates than fillies. Colts need to be fed enough additional feed to account for higher gains of 0.2 to 0.3 lb (0.09 to 0.14 kg) per day as well as any higher maintenance requirement due to the large amount of voluntary activity in yearling colts which are kept in groups or are allowed to exercise in groups.

Similar to yearlings, amounts to feed two-year-olds depend on how close they are to reaching mature weights, which in turn depends on previous feeding and development history. A gain of 0.25 lb (0.11 kg) per day will add 100 lb (45 kg) of weight a year, and that should be adequate under most practical conditions. This will need to be modified if horses are put in training. Regular weighing and measuring of young horses will help managers plan a feeding program that will lead to a steady weight gain.