Digestion is the process of breaking down the feed into simple substances that can be absorbed into the bloodstream.The four basic type of digestive systems in the animals are monogastric, avian, ruminant, pseudo-ruminant.monogastric animals such as swine, eat rations high in concentrates. The avian digestive system found in poultry,is competely dfferent from other three digestive systemd.A poultry animal does not teeth but has a crop,a proventriculus,a gizzard, and a colaca.The ruminant digestive system is found in cattle, sheep, and goats.Ruminants eat feed rations that are high in roughages.The ruminant digestive system has a large stomach that are divided into four compartments - the rumen, recticulum,omasum and the abomasum.A pseudo-ruminant is an animal that eat large amount of roughages but do not have a four compartment stomach.A pseudo-ruminant animal can utilise roughages because of an enlarged cecum and large intestine.
Thus different digestive system performs different functions to break down feed.