Adaptive cow breed types such as F-1 Brahman x English breeds and terminal sires can result in calf gains in excess of 1000 lbs per acre.  Cows with fall-born calves stocked on clover or ryegrass can exceed 850 lbs at weaning and have direct harvest potential.  Heavy-weight calves at weaning require reduced feedlot residence and demand premium prices.  Efficiency of animal production using forage mass and nutritive value parameters has major implications on beef cattle industry sustainability.  Fall- and winter-calving cow herds comprise the birth-to-harvest dataset for BeefSys which can enhance biological and economic strategies for beef production.