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.
Some farmers give a hormone called recombinant bovine somatotropin (rbST). Cows already make bovine somatotropin (bST). The rbST is made with the same techniques that are used to make insulin to treat diabetics.rbST is the same hormone as the naturally-occurring form that is already in the cows.ows already make bovine somatotropin (bST). The rbST is made with the same techniques that are used to make insulin to treat diabetics. rbST is the same hormone as the naturally-occurring form that is already in the cows.