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Full-Text Articles in Life Sciences
Effects Of Ractopamine (Optaflexx) Fed In Combination With Melengestrol Acetate On Feedlot Heifer Performance, W. A. Griffin, G. E. Erickson, B. D. Dicke, T. J. Klopfenstein, R. J. Cooper, D. J. Jordon, R. S. Swingle, W. M. Moseley, G. E. Sides, D. J. Weigel
Effects Of Ractopamine (Optaflexx) Fed In Combination With Melengestrol Acetate On Feedlot Heifer Performance, W. A. Griffin, G. E. Erickson, B. D. Dicke, T. J. Klopfenstein, R. J. Cooper, D. J. Jordon, R. S. Swingle, W. M. Moseley, G. E. Sides, D. J. Weigel
Department of Animal Science: Faculty Publications
Two commercial feedlot experiments were conducted to determine the effects of feeding melengestrol acetate (MGA) or MGA plus ractopamine (MGA+OPT) on the performance and carcass characteristics of finishing heifers. In Nebraska (Exp. 1), 1,807 heifers (337.3 ± 20.0 kg) and in Texas (Exp. 2), 1,964 heifers (331.5 ± 6.1 kg) were fed 0.4 mg of MGA daily. For heifers fed MGA+OPT, 200 mg of ractopamine was fed daily the last 29 (Exp. 2) or 36 d (Exp. 1). Live and carcass-adjusted performance data were collected. On a carcass-adjusted basis, G:F for the entire feeding period was improved (P < 0.01) by 1.7 and 3.7% in Exp. 1 and 2, respectively, for heifers fed MGA+OPT compared with MGA. For the last 29 to 36 d, G:F was increased (P < 0.02) by 8.1% (Exp. 1) or 27.2% (Exp. 2) on a carcass-adjusted basis for heifers fed MGA+OPT compared with MGA. Fat thickness, USDA YG, marbling score, LM area, and percentage USDA Choice were not different (P > 0.47) between …
Effect Of Sorting And Optaflexx Supplementation On Feedlot Performance And Profitability Of Long Yearling Steers, W. A. Griffin, T. J. Klopfenstein, G. E. Erickson, D. M. Feuz, K. J. Vander Pol, Matthew A. Greenquist
Effect Of Sorting And Optaflexx Supplementation On Feedlot Performance And Profitability Of Long Yearling Steers, W. A. Griffin, T. J. Klopfenstein, G. E. Erickson, D. M. Feuz, K. J. Vander Pol, Matthew A. Greenquist
Department of Animal Science: Faculty Publications
A 2-yr study was conducted using 200 long yearling steers/yr (436 ± 30 kg) to determine the effect on performance and economics of sorting by BW at feedlot entry and feeding 200 mg/steer of Optaflexx (OPT) daily for the last 28 d. At feedlot entry, steers were allotted into 1 of 4 treatments in a 2 × 2 factorial arrangement: sorted or unsorted with or without OPT. Sorted steers were placed into 1 of 3 groups—1) heavy steers (32%; 468 kg), 2) medium steers (44%; 432 kg), or 3) light steers (24%; 399 kg)—and were fed for 97, 118, or …