Any differences on timing of heats using estrumate vs. lutalyse? I used estrumate with CIDRs on 4 recips this past week and had one standing at 72 hours, 2 standing at 96 hours, and other one didn't respond at all. Tried to time them with my donor cow for direct transfer. My embryologist uses lutalyse and needless to say I only had one recip ready to transfer fresh eggs from the donor. Other two needed to be frozen for a day. Kinda defeated the purpose of me timing them with the donor. Don't get me wrong I will continue to use estrumate but has anyone else had experiences like this? Is this a rare occurance or is it common for them to show heat past 72 hours? Tough to gauge if they should be time bred at 72 hours or wait on them and risk being too late. Also, ideally I would like a tighter window for them to respond especially with setting up recips. Thanks.