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 The optimum bull-to-cow ratio is 1 bull per 10 to 30 cows, depending on the size of the pasture, and the bull's age, promiscuity/libido and experience. 2  Some bulls, depending on the fertility rate of the cows and how many cows are in heat at one time, can breed over 50 cows in one season. Some bulls, depending on the fertility rate of the cows and how many cows are in heat at one time, can breed over 50 cows in one season. 2  Body condition score your cows and heifers 30 days before breeding season.