Need better pics to give much feedback. Check out the link in my signature for tips on that. It looks more like peeling than chipping. Also some trimmers(inc me) like to do a bare minimum of trimming when first removing shoes & do a proper trim a week or 2 later, as this seems to work better & they generally need it 2 weeks later anyway. I would definitely put a good 'roll' on those walls ASAP.
What's his story & how do you manage him & have you prepared him? What do you ride on & do you use boots at all?
There is a lot of flaring in those feet, which need to be addressed - can't tell if they weren't 2 weeks ago, but need more now. It could be nutritional or just mechanical probs that has caused this, but a well balanced diet is important, to provide the necessary 'ingredients'. Perhaps they may be a little dry, tho they look OK to me, but I would address this by including essential fatties in his diet(ground linseed for eg, methionine) rather than painting on topical goop, as that doesn't really do anything.
FeedXL.com is a great source of nutritional info & makes balancing diets easy. Generally, if the horse's diet is balanced, that's the jist of it & it's important not to OD on things either, as some nutrients are just as unhelpful as deficiencies & also can be harmful in excess. Minerals particularly important for hoof health include copper, zinc, iodine, magnesium.
Biotin is generally supplied in sufficient amounts from pasture, so pasture kept horses normally won't benefit from biotin only.
I used to think that WS, but it seems, from studies done on Spanish Riding School horses(sure there are a couple other studies too that I can't think of now) that show that while well balanced nutrition is important, biotin can indeed help regardless. It can also help & is harmless if fed in excess of dietary requirements.