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.
April 10, 2011. The cow starts as a calf when she's born, grows into a heifer and then earns her cow stripes -- or spots -- when she's fully grown. A cow's weight depends on her breed and ranges between 800 and 2,400 pounds. There are variety of types of cows, some born and raised as dairy cows and some suited for beef production.