I just purchased 4 angus heifers, about 650 lbs. The guy I bought them from could only tell me they where 12 to 15 months old. He claims they are ready to breed now, but I think its a little early. I am going to put them with our angus bull, he will be 3yrs in March. What is the best way to know they are ready? Should I consult a vet to be sure? I have pictures I could send if someone could give me their opinion, it would be greatly appreciated.