Suffolk

As a proper noun referring to a specific English county, this word is always capitalized. When used as a modifier for livestock breeds, such as in "Suffolk sheep" or "Suffolk punch," it functions as a proper adjective, maintaining its capitalization to denote the geographic origin of the breed.

In the context of animal husbandry, the term is used as a classifier rather than a countable noun. You would refer to "Suffolk sheep" (plural) or "a Suffolk sheep" (singular), but you would not pluralize the word "Suffolk" itself to describe multiple animals.