"Transition" is a word regularly bandied about amongst barefoot horse owners, and horse owners who are considering taking horses out of shoes. "How long will it take to transition him from shoes?" is the sort of question that I will be asked by new owners, for instance.
The Collins dictionary definition is:
"The period of time during which something changes from one state to another"
I don't know who coined the phrase, or why it was applied to barefoot horses coming out of shoes, but the more horses I take barefoot, the more misleading I think it is.
There is an assumption that once you take shoes off a horse, you need to wait, and if you wait long enough, it will "transition". There is an assumption that while you wait, your horse will be footy or uncomfortable, but that, with time, this too will improve. Of course, while you are waiting for your horse to "transition", your riding will be limited or possibly be stopped altogether.
The problem with this view is that it doesn't recognise that the hoof is a dynamic part of the horse's body which, like any other living structure, requires nutrition, stimulus and correct function in order to be healthy. A weak hoof cannot improve overnight, so time is a factor, but time alone will not turn unhealthy hooves into healthy hooves.
If you take the shoes off a "sound" horse which has weak, unhealthy hooves and is footy on hard ground then after 6 months of "transition" you will most likely have a horse with weak, unhealthy hooves which is footy on hard ground. Its hooves will be a little bit stronger and will have better circulation, but transition time alone will usually not make that much difference.
On the other hand, if you address the horse's diet before it even comes out of shoes, work it consistently on surfaces on which it can land correctly and put as many comfortable miles as you can on those hooves, then in 6 months you will generally have a horse with hooves which have strengthened dramatically, both internally and externally, and which is capable of high levels of barefoot performance.
Its more about rehabilitation and fittening than "transitioning", in my opinion.
PS: Hunting season finished yesterday, Felix, Hector and Charlie were out and had a lovely day, ending up at kennels (Charlie's spiritual home!). Charlie has hunted 3 times this week, and still went out up the field last night with the other boys at a flat out gallop and came in as sound as a pound this morning. What a little star!
Hector behaved beautifully nearly all day (!) and was ridden by a friend who had great fun with him - Hex went up the field last night standing on his head, but fortunately doesn't do anything of the sort when ridden :-)
Felix and Charlie will now have a thoroughly well-deserved holiday, at least until they get bored :-)