fescue and mare
Whle endophyte-infected fescue does cause lack of milk production, and unless you planted endophyte free fescue, the potential is there, at 2 1/2 months the foal has passed the 'critical' time of need for milk. And, the effect on milk production at that stage will be variable, so you might not encounter a problem. To help, feed a textured or pelleted grain to the mare that the foal likes to eat so grain becomes part of its nutrition soon. If you notice an adrupt decrease in milk production of the mare, you can go to the trouble of creep feeding the foal separate from the mare.