Im not trying to argue- biotin is for hair growth too though- I agree too many supliments will be peed out but can cause a horses hair to be coarse and can cause too hard of feet if it aint needed.
unless your new farrier aint putting the bevel to your horses feet like your old one was I don't see why an extra two weeks would make your horses feet chip up in pasture or soft moist ground?
I thought it was weird because sometimes I trim ours every six weeks or sometimes they go eight- (depending on how lazy I get) but they don't chip up on moist pasture-- is there lots of rocky spots in your pasture?
Im wanting to see the bottoms of his feet now, lol.
Id like to know what happened if you took him off the biotin and gave him a grass hay- just a couple flakes if he's on pasture turn out 24/7 can't hurt.. no alfalfa- orchard.