I have little or no experience with Shorthorn, but they are a British breed. Any breed is affected by environment, feed and forage conditions, and differences between particular bloodlines. I think it would be safe to say that the typical British cattle will have mature cows weighing from 1,000 to 1,500 pounds, with the mature bulls weighing from 1,600 to 3,200 pounds, again depending on the bloodline and breeding selection within the bloodline. The oldtimers tell me that bulls grow until they are four or five years old, but they will be pretty close to their mature weight by three years, and I'd say a cow that is two to two and a half years old is probably pretty close to mature weight as well.
I don't know what you are trying to develop for, but in the U.S. we want the steers to finish around 1,200 pounds in the feedlot. A 1,100 to 1,300 pound mature cow bred to an 1,800-2,200 pound bull is the ideal combination to achieve this goal.
