Never synchronized cows before. This is my first attempt. Vet told me to use Lutalyse and turn the bull out with them. I have ten cows that had a calf no less than a month ago. Is it to soon ? Also a couple open cows that were maybe to thin, but have put the weight back on thanks. Should I sync them on different days ? Or all at once? Can a bull handle all of them in heat at once ? Thanks a million.