I haven't fed anything with probiotics that I know of. We have been feeding a 50/50 blend of Record Rack Sportsman and Golden Deer Nugget. The Sportsman has a higher protein(20%) and lower fat(3%) than the Golden Deer Nugget(13% protein and 12% fat). It gives us roughly 16% protein and 7% fat. We have seen the difference in the health of the deer in how they look compared to when we first started feeding. The look fat(no ribs showing) than previous years, their coats are shiny in photos, bigger bodies, thicker fat when we field dress them and we seem to have healthier fawns that are surviving their first year.