The cows drop a variety of items but they are not typically used for magic finding the best rare's and uniques. In fact, it is sometimes better to run LESS magic find. That is because they drop a lot of bases for runewords to be made so finding them Normal or Socketed quality is best! Runewords for most characters can literally change the quality of life in a drastically positive way so finding a nice piece of armor or a nice superior weapon is a big deal. The Secret Cow Level is quite a decent place for Runes to drop as well. In Hell difficulty, the Hell Bovines can drop runes all the way up to Zod Rune! If you are playing Solo Self-Found through the game, this is your best opportunity to find Superior Bases for your Runewords. I do not recommend magic finding this area for other items. Although the monster level in Hell difficulty is level 81, there are better places to find better items. Listed below are some of the high-tier items that can drop in both difficulties