I think that it was reduced a few years ago to 8.5in but i did hear something along the lines that they are now trying to go back to the more traditional with more bone, it really does very from draught to draught I know both mares and stallions with 8.5'' and then I also know mares with 10.5'' so its all relative to each horse!!
Theoretically, there is now no 'minimum' - but you'd struggle to get a mare through grading in the UK with less than 8.75" - she'd lose marks on 'type' as well as on the front leg. And I hope I NEVER see the day when a stallion grades with less than 9".
This chap is a biggish ID (17hh at 5yo) and he has 10.25" of bone already. (He'd look silly with less! )
This chap is barely 4, and currently 16.1 (a full brother to the one above but without his tackle), and he currently measures 9.5" of bone.
Unfortunately Janet some stallions have graded with less than 9'' of bone in Ireland, there are quite a few measured at under 23cm(9'') and there are a few with only 8.3''
!! However i do think that this is not the 'norm' and personally would not use an RID with such a small amount of bone.
my lad is described as "irish" on his passport, and we suspect he's IDx something. He's got 9 and a bit inches of bone. excuse the bandages on his back legs keeping his socks clean!
Taken from the IDHS Ireland website
Bone
Good, strong, clean, flat bone. The bone is proportionate to the height of the horse and is not round or coarse; a minimum of 8.5 inches (21.5cms) of bone, increasing in proportion to height
I find this quite funny as on the same website in the stallion list there are stallions listed with less than the required minimum
I have a ID mare who has 9 1/4 bone, a rising 3 y o gelding who has 10.5 and another rising 3 yo gelding who has 9.5, so i think must be over 9" really