(I know, I know, Shepherds specifically herd sheep. I just can't think of a better name)
Shepherds would be Merchants that allow you to purchase domesticated farm animals such as pigs, cows, sheep, chickens, etc (not the "wild" versions like aurochs, elk, boars, and such) for a good amount of money. The purchased animals wouldn't follow you, so you'd need leads or their desired food at hand if you wanted to herd them somewhere.
I could see The Shire, Bree, the Dunedain, the Rhudaur Hillmen(?), the Dunlendings, Rohan, Dale(?), Gondor, Dorwinion, and Rhudel having Shepherds.
Thoughts?