The heifers are out of black angus cows that are moderate framed girls I do not know what the bloodlines are. the sire is 7AN288 Rockin Horse Tailor Made 456. I would guess they will be in the 1100 pound range at calving time. I live in colorado they summer at about 6000 feet on dry land grass and cake. these cows have to work and work hard i do want to be able to keep replacement heifers out of these girls.What is the background of the yearling heifers. What is the breed makeup, what will they weigh at calving time, what bloodlines might they be?