My Bellisimo M x Michelangelo colt is here and now 4.5 weeks old
He was tall enough that he couldn't go under momma (who is 16.2/16.3hh) at 8hrs old
He's now in a 40" blanket and his withers are higher than the waistband of my breeches (I'm 5'7" and mostly leg)
I'm terrified he will be 18hh! How soon can I string test him?
Anyone else have tales of big foals that grew into average sized horses? (I know puppies are often like that)
How closely related is foal size to mature height?
No. Some of my smallest foals ended up my largest at maturation, and some of the largest stopped growing earlier and ended up average height. Much more can be predicted by parents and grandparents, full siblings, and what the youngster looks like as a long yearling (gangly, unfinished may be tall, starting to look finished will probably stop growing sooner).
Another no. I've had it go both ways. Huge foals that topped out at 15.3, huge foals that ended up big. I haven't yet had a tiny foal turn into a huge adult, but I suspect it goes all ways. I don't breed for size - so I consider anything over 16.2 to be pretty big.