The effects of grazing, liquid supplements, and implants on feedlot performance and carcass traits of Holstein steers

In each of 2 yr, 20 Holstein steers (185 +/- 7 kg initial BW) were allocate d to each of three treatments: pastured for 4.5 mo on grass/legume pastures and then fed 80% corn diets (DM basis) until slaughter; pastured for 4.5 m o on grass/legume pastures with ad libitum access to molasses-based protein supplements and fed 80% corn diets until slaughter; and placed in a feedlo t and fed only 80% corn diets until slaughter (FEEDLOT). Half of the steers in each treatment were initially implanted with Revalor-S and not reimplan ted. Supplemented steers on pasture had greater (P < 0.05) ADG than unsuppl emented steers, and FEEDLOT steers gained faster and were fatter (P < 0.05) after 4.5 mo. Implanted steers had greater (P < 0.05) ADG with no signific ant treatment x implant status effect. Supplement intake was variable and r elated to ambient temperature. During the feedlot phase, steers previously on pasture had greater DMI and ADG (P < 0.05) but were not more efficient t han FEEDLOT steers. Percentage of USDA Choice carcasses, fat thickness, dre ssing percentage, yield grade, and final weight were greater (P < 0.05) for FEEDLOT steers than for steers on other treatments. Implanting increased A DG of all steers but did not affect carcass traits, carcass composition, or feedlot performance during the finishing phase. Holstein steers consuming supplemented and unsupplemented pasture before slaughter will be leaner, ha ve lower carcass weights, and have generally lower quality grades than thos e fed exclusively in a feedlot when slaughtered at similar ages.