The natural aging process causes older horses to become less active, less efficient in digesting foodstuffs and have a reduced appetite. Aged horses also are stressed more easily. Palatability of the ration is important. Horses prefer immature pasture forages rather than stemmy, mature grass. Similarly, different grain formulations and the physical form of grain mixes influence the desire to eat.
Many older horses prefer pelleted or extruded forms of grain mixes rather than whole grain diets.
Also, older horses may not want to eat as much at one time as younger animals. Since depressed appetite may affect the adequate intake of nutrients, it is recommended that total rations provide at least 12 percent protein, 0.3 percent calcium, and 0.25 percent phosphorus. The inclusion of fat-added grain mixes is another popular way to increase energy intake without feeding large amounts of ration. Some horse managers who do not use commercial grain products designed for older horses meet additional nutrient needs by feeding more legume hay as a portion of the forage, or by switching to a grain mix formulated for horses in heavy states of production or growth. Younger horses may drive them away from feed, or they many not eat as readily as other horses.