I use 300 days as a "cut off" period....now, if I can just get the mares to read this, somehow
I have had preemie foals born at 295 and perfectly normal, ready to be born foals born at 283.
Then I have had a late term abortion at 296.
All mares were hand bred, so dates are correct.
There is just no rhyme or reason to it, a foal is born when it is ready, or it is in trouble, but the length of the gestation does not seem to matter.
I always remember a friend, a fellow horse breeder, expecting her first child, was told by her doctor to pack a bag and report to maternity as they were going to induce her.
She refused, went a full MONTH (brave lass) more, and gave birth to a perfectly normal, 9lbs baby boy.
As she said, had he been induced he would have been a month premature.
Sometimes Mother really does know best!!