They start nibbling at moms alot sooner then 6 months. I think ideal weaning time is 4 months. Mare's milk after that time isn't that good anymore anyway, because naturally the grass by that time has lost it's nurtional value for the year.
Becky
I agree, my vet said 4-5 months to wean. Its not fair on Mom or foal to keep that going longer. It takes too much out of the mare.