Impact of Days Fed on Holstein Bull and Steer Performance and Cutability of Cattle Pen- Fed Organic Diets

Performance, carcass characteristics, and total meat yield of Holstein bulls and steers were compared in a simulated organic production system with the goal of producing ground beef. Holstein bulls (n = 120, initial BW = 487 lb) and steers (n = 120, initial BW = 471 lb) of the same age were blocked by BW and assigned randomly to be harvested at 308, 343, 378, and 413 days on feed. After harvest, all meat o the carcass was considered trim and was collected and weighed to calculate total trim yield. Bulls gained faster and had greater live body weight, carcass weight, and trim yield than steers. Steers showed greater linear increases in marbling scores and fat composition of trim yield as days on feed increased than bulls. Increasing days on feed linearly increased feed intake, live body weight, carcass weight, and trim yield. Bulls had greater feed costs per animal than steers but castration had no effect on feed cost of gain. Feed cost per pound of trim yield increased linearly as days on feed increased. Feeding bulls may increase profitability in a ground beef production system that is not penalized for low quality beef