Most form pairs during the breeding season, but in some species, such as fur seals, the gray seal (Halichoerus grypus), and elephant seals, males (bulls) take possession of harems of cows and drive rival bulls away from their territory.
Look for the crooked tail. This is probably the best ways to tell if a cow has been bred: A cow or heifer will have a crooked tail or a tail that is held out in an odd angle than usual for 24 to 48 hours after being serviced by the bull. 1  4 Edit step.
1. A cow should be bred back after she has had a calf. The optimum time to breed her is 45 to 60 days after she has had a calf. In order to get her to calve on the same date as the previous years, allow for 80 to 90 days of rest before getting her bred again.epending on the breed of the heifer, most heifers will start to show the first signs of heat when they are between 9 and 22 months of age. 1  The rate of sexual maturity or puberty is determinate of genes and breeding.