The first week don't give tomuch food but feed her 4-5 times per day if she stay at stable. Becouse her stomach become smaller and if you will give tomuch food in one moment,she can all eat if she is hungry and then can be problems. My friend bought before too horse and he saw that horse long time didn't eat well. For night he gived oats and tomuch hay to be enough till morning. When he come at morning he found his new horse died(( so tack care of your new horse! Good luck!
Ad lib forage and high calorie feed. Make sure any feed changes are slow and gradual. This might help for tips and pointers: https://lookaside.fbsbx.com/file/UCDrefeedingCEHpubs-July2012-bkm-sec.pdf?token=AWyqzpWOMeQbnuiN1ysssydsuk8eCBvdKhtnPLhV99blAhKn2lf8dkyc37XaGRMKY22TOLMlvatyMSuT-__Wnb8mjXFZ5rhBAC67YgBjKTR5Y3Bb3Ju-pk52-xyXuDTrrDQOaAh3o76yOJ14pwmm0OE42gXqtH3U9jb0jPo8xkIejQ