Abstract

A pasture/feedlot field study was conducted to evaluate the effects of a single Ralgro® implant during the stocker phase on steer grazing performance and subsequent feedlot performance and carcass merit. A total of 2,764 steers of Mexican origin averaging 449 lb were assembled in Texas and shipped to Kansas, where they grazed on three intensively-early-stocked Flint Hills pastures. At initial processing, the steers were individually weighed and randomly assigned to either a non-implanted control group or a Ralgro implant group. Ralgro steers gained more (23 lb; P<0.01) than controls during the 82- to 93-day grazing phase. Following the grazing phase, all steers were shipped to a commercial feedlot in southwestern Kansas where steers from each pasture were individually weighed and given a single Component E-S® implant. Immediately after processing, steers from each pasture were sorted into either a light- or heavy-weight pen, regardless of pasture implant treatment, resulting in six feedlot pens. Days on feed ranged from 127 to 197. Control steers gained faster (P<0.01) during the feedlot phase; however, Ralgro steers had higher cumulative weight gains across the combined pasture and feedlot phases (P<0.01) and averaged three fewer days on feed (P<0.05). There were no significant differences for marbling, fat thickness, ribeye area, KPH fat, or yield grade. Ralgro steers had lower (P<0.05) quality grades because of a higher incidence (P<0.001) of steers with B and C carcass maturities.

Keywords: Cattlemen's Day, 2001, Kansas Agricultural Experiment Station contribution, no. 01-318-S, Report of progress (Kansas State University. Agricultural Experiment Station and Cooperative Extension Service), 873, Beef, Growth implant, Ralgro, Steers, Pasture, Feedlot, Carcass traits

How to Cite:

Paisley, S., Kuhl, G. L., Higgins, J. J., Huck, G., Farran, T., Sindt, J., Montgomery, S. P., Birkelo, C., Blasi, D. A. & Dikeman, M. E., (2001) “Evaluation of Ralgro® on pasture and subsequent feedlot performance and carcass merit of Mexican crossbred steers”, Kansas Agricultural Experiment Station Research Reports 1(1), 26-28. doi: https://doi.org/10.4148/2378-5977.1756