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Three-Year Summary Of Preconditioning Effects On Pre- And Postshipment Performance Of Feeder Calves, R.H. Pritchard, J.K. Swann, M.A. Robbins

South Dakota Beef Report, 1987

Production efficiencies associated with preconditioning feeder calves have been evaluated using 600 calves obtained from four ranches over a 3-year period. Nonpreconditioned calves remained with their dams during preconditioning and all calves were shipped to a research feedlot on the same dates each year. Average daily gains of nonpreconditioned calves for 28 days prior to shipment were variable over years and related t o range conditions. ADG of nonpreconditioned calves during each year were 1.39, .2 and 2.12 b and differed (P< .001) from preconditioned c a l f gains of 2.18, 1.81 and .91 lb for the 39 days prior to shipment. Preconditioning responses interacted with ranch and year, indicating ranch conditions will have a significant impact on results. By weaning 30 days earlier, dams of preconditioned calves lost less weight during this same period. This effect was more pronounced when range conditions were poor. Preconditioning did not affect feed lot morbidity or mortality. During the initial 56 days in the feedlot, preconditioned calves consumed more dry matter each year but gains were similar. There was no effect of preshipment management on ADG after 56 days on feed and in the initial 2 years feed efficiency was better for nonpreconditioned calves. This advantage in feed efficiency carried through to slaughter at about 240 days.