Why do cattle farmers choose different breeds of cattle?

Different breeds are good for different conditions and environments. Some grow slower but can take a harsher climate; some grow faster but need to be pampered, and vice versa. Choosing a breed also depends on market demands and personal preferences. Since there are over 900 breeds to choose from, but are limited to what he can raise according to where he lives, he can choose whatever breed or breeds he likes according to market, environment, maternal/paternal characteristics, his past experiences and his personal preferences.