Pig

Pig (family Suidae, the most common species is Sus scrofa) also called hog or swine, is a large, omnivorous ungulate whose rapid breeding and growth make it an efficient food source for humans. Pig meat is called pork in general, and specific pork-based foodstuffs are called ham and bacon. Pork was popular in ancient times in the cooler regions of Europe and Asia. However, in the very hot climate of the Middle East, pig meat was difficult to maintain without refrigeration, and thus often caused food poisoning. Ergo, many cultures of that region have traditional taboos against eating pig meat, which is regarded as unclean. The Bible of Judaism and the Koran of Islam have famous passages describing such taboos.

Pigs in "The R-Strain"
The Jewish cultural prohibition on eating pork is based on a text which condemns the pig as an animal which has a split hoof but does not chew cud. Rabbi Aaron Kaplan, a Conservative Jewish scholar, set himself a task to determine whether this old stricture applied to the unprecedented, genetically engineered new species of cud-chewing pig.

{The R-strain}