Dairy friend of ours beds the cattle in it, that is standard pulverized lime. keeps the mastitis cases way down.
We of course use it for spreading on our fields before we fertilze as we need to sweeten our high acidic ground , other wise we are throwing ferterlizer on it for naught.
We have heard of feed additive, but have never tried. perhaps gypsum does the same?
We use hydrated lime to spread over the 'footprints' left over after we move our calf hutches, ( we bleach also) works wonders killing so many pathogins left behind, we also dust our barns often with it, especially after cleaning, or we get a sick cow in there. JUST DON"T TOUCH IT WITH BARE HANDS... and it does get caustic when contacted with moisture, can get pretty nasty on your skin, wear a dust mask if you handle it alot as well.