If you are not breeding on a foal heat then the norn is 15 days and is more to contol when they cycle then anything. I do the 21 days so I am way past the foal heat and my mare will start to cycle. Each mare is different. Been doing this a long time and you just get a felling for it and the mares Posted via Mobile Device
I don't breed on foal heat because I just feel like they haven't had enough time to cleanse properly and finish healing any little tears or abrasions that soon. I will breed on the '30 day' heat if necessary, but the way I do it, I usually bred 1 mare this year for next year's foal and then another mare next year for the following year's foal and that way I give the mare at least 1 year off to get back in physical condition and just spend time with her foal and being a mare.