Items required in the digestive system

In general, the animals are divided into three categories: herbivores, carnivores and omnivores.  Herbivores are those mainly feed on algae and plants.  Carnivores are all animals that eat other animals. Omnivores are those that eat other animals, algae and plants also. In conclusion, all animals feed on different food sources. It's important to have on mind, foods are consumed for the collection of nutrients, minerals, vitamins, etc.  

The diet of an animal provides chemical energy, organic molecules and essential nutrients.  Animals require 20 amino acids which are obtained from meat, eggs, cheese, etc.  All essential amino acids are complete proteins.  Also, animals can synthesize fatty acids most needed.  As well, like the 20 amino acids we need also need 13 essential vitamins.  These vitamins are classified as soluble or fat soluble.  The soluble vitamins: B complex and vitamin C.    Fat-soluble vitamins are vitamin A, D, E and K.  Furthermore, minerals usually required in small quantities. Minerals should be consumed in small amounts due to ingestion of large amounts can alter the homeostatic balance.