I am new to raising some for-home-consumption-beef, and bought 2 black Angus heifers in November. At the time, the 2 combined weighed 1000 lbs between the 2 of them (I figured 450 and 550). At the time they were a couple months old. What live weight can I expect/(should I shoot for) at about 16/18 months old? They will be pastured this summer, and will be given a daily ration of chop, plus any hay they want. Thanks.