The Jewish diet is made up of Kosher (Kashrut) food. "Kashrut" comes from the Hebrew root Kaf-Shin-Reish, meaning fit, proper or correct. It is the same root as the more commonly known word "kosher,"...
In order for an animal to be considered fit for food, it must both chew its cud and have split hooves. Any animal that does not meet both requirements is not a food animal according to Jewish law.