What is "ranch mink"

Mink \Mink\ (m[i^][ng]k), n. [Cf. 2d Minx.]

1. (Zo["o]l.) A carnivorous mammal of the genus Mustela (foremrly Putorius), allied to the weasel. The European mink is Mustela lutreola. The common American mink ( Mustela vison) varies from yellowish brown to black. Its fur is highly valued. Called also minx, nurik, and vison.

2. The fur of the mink[1]. Together with sable, it is one of the most expensive furs not taken from endangerd species. When the fur is taken from animals grown on a farm, it called ranch mink.