Most digestion therefore occurs in the small and large intestine. Sugars and starches are digested by enzymes to predominantly glucose and absorbed into the blood leading to the liver. Similarly proteins are digested to amino acids in the small intestine and these end products of digestion pass via the liver before being circulated throughout the body via the blood.
Naturally the horse would graze for 16 - 18hrs per day and evolved without a gall bladder; bile being secreted continuously as the food passes through the gastrointestinal tract. Bile helps to alkalise the digesta and the bile acids are required for emulsification and digestion of lipids. Most fatty acids are absorbed into the lymphatics but some of the medium chain tri-glycerides may be absorbed directly into the blood stream.