The document describes the digestive systems of ruminant and non-ruminant farm animals. It discusses the parts and functions of the ruminant digestive system including the mouth, esophagus, four-compartment stomach (rumen, reticulum, omasum, abomasum), small intestine, and large intestine. It also describes the simpler digestive systems of non-ruminants like humans, dogs, cats, pigs and horses. The six major groups of nutrients - carbohydrates, fats, proteins, vitamins, minerals, and water - are identified along with their sources in animal feed.