As evolution of the horse progressed through the stages of the Mesohippus, Merychippus, and Pliohippus to today's Equus, the horse remained a forager. Thousands of years of foraging has resulted in a rather unique digestive system that bears resemblance to only the rabbit and guinea pig. Placement of a rather small stomach immediately prior to the small intestines where most of the starch, fat, and protein digestion occurs in the horse very much like other monogastric animals. But just beyond the small intestines is the cecum, a blind gut compartment that harbors the microbial flora similar to the microbial population in the rumen of cattle.
Horses are best able to digest higher quality forages when compared to ruminants.
For a more in depth look at forage utilization by the horse, grazing patterns, preferences, digestibility values, and definite reasons to consider forages the first step in the balancing the diet for horses will be discussed. Behavior Associated With Food Consumption Grazing clocks and extended observation watches have been utilized by researchers to determine what a horse does during the day. The relatively small stomach and energy needs of a large horse necessitates extended grazing periods. Presumably, enhanced bite size of the forage decreased grazing time of ryegrass. From the above data, one may conclude that horses tend to be more continuous consumers of forage than ruminants.