i personally think is very important that the mare is moved to her new field a good few weeks before, to make sure that she prepares for foaling immunity wise...the foal will then have the neccessary immunity for its new environment through the colostrum (first milk)
make sure that she has all the vits and mins she needs. i give ours a gesture of balancer and some haylage.
There are many signs that you can look out for, but can differ from mare to mare.
bagging up and waxing up - does usually mean mare is ready, but some mares can do this over and over again.
slackening of muscles on haunches
some mares can go lame,dont be alarmed if she seems to as this can mean that baby is lying on nerves
if in doubt have vets number to hand. also it would be advisable if owner is there at foaling, i know i would....
theres plenty more and i m sure others will elaborate x
