The experts I use advise me to stick to the label. If it says IM or IV or SC, that is how it is intended to be absorbed and metabolized. Otherwise, you are either throwing your money away or risking the animal because you cause it to attempt to digest/absorb a drug/med/vaccine/toxin in a way that the organs are not capable of handling.
I know people have tried. I don't wanna name names, but even "experts" that have tried. There are alot of variables when adding it to the feed. I couldn't tell you how much to give, but it may be appropriate for a pen full of older bucks that you couldn't give the the vaccination any other way.
