Actually, Berkshire does not refer to way it is raised, it is a hog breed that is known for deep red meat and more marbling. Berks may or may not be free range, though typically they are raised that way.
http://www.americanberkshire.com/Con...nichepork.html
1. WHAT DO YOU MEAN BY NICHE PORK?
Pork that has certain attributes preferred and valued by some groups of customers. These attributes include: pork raised without antibiotics, growth promotants, or animal by-products in the feed; heirloom breeds such as Berkshire pork (also known as Kurobota pork); organic pork; and locally grown or farm direct pork. These attributes typically require unique production practices, which can limit supply and availability, making them niche products. .