I researched the different nutrients each caries and they are a little bit different but not much. Ratio wise theyre basically the same. I mainly feed rat pups about the same size as mice since the pups wont bite back. Ive had both my balls bite the wrong end of a mouse and get bit back. Seeing as balls are from africa, ASF rats are probably the healthiest for them but there is no evidence to prove this. Whatever your ball feels like eating whether it be rats/mice/ASF rats it should be be fine health wise.