Farmers also operate on a thin budget, so if it increases their expenses they're likely to give it a pass, even if they approve of the idea.
OTOH, if this is cheap and easy to add, then it may be successful. Depending. How many farmers still grow their own feed? How many buy commercial feed? (OTOH, why are dairy cattle being fed corn? That's generally a bad idea. It's usually reserved for beef cattle being held in feed lots to put on fat.)
That said, my grandfather often added molasses to the alfalfa he fed his dairy cattle while milking them. So if it could be mixed into a formula of molasses, this stuff, and various other minerals it could easily be added, if not too expensive.
OTOH, my grandfather was operating on quite a small scale. (3 cows is the most I remember.) Perhaps the problems/benefits are different for larger operations.