PSVI-2 - Economic evaluation of forage-fed vs concentrate-fed beef finishing systems

Abstract: The objective of this study was to determine the economical benefit of implanting beef steers and including a beta-agonist in the finishing diet. To accomplish this, Hereford-cross steers (450 ± 15 kg) were assigned to one of three drylot pens based on initial weight and sire so that each pen had an equal starting weight and sires were equally represented in each pen. Each drylot pen was assigned to one of three treatments: receiving a hormonal implant (IMP), consuming a beta-agonist (BAG), or receiving both of the previous treatments (AND). All steers were fed a mixed ration consisting of 30.0% rye silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement (22.0% CP, 2.90 Mcal ME/kg DM). The data were analyzed in SAS v9.4. Animals were evaluated on intake, growth, and performance measures during a 45-day feeding trial. Average daily gain (ADG) and hot carcass weight differed significantly (P < 0.05) between treatments with AND steers gaining 1.48 kg/d with a hot carcass weight of 394.8 kg, BAG steers gaining 1.28 kg/d with a hot carcass weight of 352.9 kg, and IMP steers gaining 1.26 kg/d with a hot carcass weight of 347.4 kg. The BAG treatment rendered significantly lower marbling scores than IMP and AND (P< 0.05). It was concluded based on carcass quality data that there was no difference in the IMP and AND treatments, though the AND treatment had significantly higher growth rates and feed conversion rates. Results of this trial are expected to indicate at what price point it becomes economically effective to finish animals using a beta-agonist in conjunction with a hormonal implant.