We shave ours for the reasons backwoodsnanny stated.. Preggo mares shed like crazy prior to foaling and many are not shed out slick (especially the ones due early Jan-May), so many of us will shave up around the flank and lower belly to remove the long, shedding hair to prevent the baby from ingesting it when he/she goes hunting for the milk bar and nursing.. We also clip up around the tail head/vulva and butt cheeks of our girls to keep the long hair off the baby during delivery, don't want the mare ingesting the loose hairs either when she goes to clean off the newborn.. Also clipping around the flank makes it a lot easier for me to check udders daily with out all the extra hair in the way..