Anglo-Saxon vs French roots of English

A further and rather telling example [of difference in English word origins between Anglo-Saxon and French] is the fact that the English words for many animals (such as ‘cow’, ‘sheep’, ‘boar’, ‘deer’) refer to the living creature in the hands of the farmer or herdsman, while once slaughtered, cooked and served to the Norman barony they acquire a French-based culinary name: ‘beef’, ‘mutton’, ‘pork’, or ‘venison’.

Stephen Pollington, An Introduction to the Old English Language and its Literature, 8.