If you don't slaughter the cows, how do you make them into hamburgers?

but curiously, i just read a letter to the editor of Natural History magazine about cows-- how cows set up informal baby sitting arrangements.. so the mother can graze-- and that low status cows have more babysitting chores,and less free time-- they have to eat and run. (The letter writter said this was true for Texas cows.. and i don't know enough about cows to know if its true for other cows.)