- just put an dlc pet with food in animal pen
They don’t produce anything so be careful turning your Gold-Veil Rocknose! I don’t like this skin anyway. Turan Elephant rulezzzz!
It’s a current known issue.
So in the meantime avoid to turn them if you wish replace them in the pen.
Read the Wiki and you know more than others. 
Greetings
SirBowen