Select guard animals from other goat producers and give them a test period before depending on them totally. (articles.extension.org)
Talk to other goat owners in your area before taking them in, so you're prepared for these unique animals. (petsinthecitymagazine.com)
That said, during my playthrough the game threw out different level - based challenges such as defeating a boss and using X number of certain attacks on other goats. (thatvideogameblog.com)