Performance and Carcass Traits of Early Weaned Steers Receiving Either a Pasture Growing Period or a Finishing Ration at Weaning

A 2-yr study was conducted to evaluate 1) steers fed ad libitum high concentrate after weaning (CONC), or 2) steers grown on pasture for 82 d, followed by high concentrate finishing (PAST) on the performance and carcass traits of 74 early weaned (117 d of age) steers. Potential breed differences were evaluated using steers of three different breed types: 1) 3⁄4 Angus x 1⁄4 Simmental (BRI), 2) 3⁄4 Simmental x 1⁄4 Angus (CON), and 3) 1⁄2 Wagyu x 1⁄4 Angus x 1⁄4 Simmental (WAG) crossbred. Steers were randomly assigned within breed to the two treatments. There was no interactions (P > .10), so the data were pooled over years. The CONC steers had .17 kg/d higher ADG (P = .0001), 1.09 kg/d lower intake (P = .0001), and .013 units better gain:feed (.190 vs .177, P = .008) than PAST steers overall. Growing treatment did not affect total concentrate consumed (P = .97). The BRI steers required 31 fewer d than CON steers (P = .008), and 23 fewer d than WAG steers (P = .05) when fed to a constant fat endpoint (1.1 cm). The BRI steers exhibited .16 kg/d higher ADG (P = .0003), tended (P = .07) to have .49 kg/d higher intake, and exhibited .01 units better gain:feed (.189 vs 180) than WAG steers. When compared to CON steers, BRI steers consumed 310 kg less total concentrate (P = .0003). No differences (P > .38) were observed between growing treatments for carcass characteristics or sensory attributes except, CONC steers tended (P = .11) to improve percentage of steers grading Average Choice or higher by 47% over PAST steers. The WAG steers had a 76 unit higher marbling score (1,000 = Small, 1,100 = Modest)(P = .006) than BRI steers resulting in 19% more (P = .09) steers grading 3 to Choice, and 82% more (P = .03) grading ≥ to Average Choice. Liver (P = .15) and rumen (P = .01) weights as a percentage of hot carcass weight were reduced for CONC steers. The CONC steers had higher gain, lower intake, better efficiency, reduced liver and rumen weights, and consumed the same amount of total concentrate when compared to PAST steers. The BRI steers had less finishing days and lower daily intake compared to CON steers. The WAG steers had more days finishing, lower gain, lower intake, more undesirable efficiencies, consumed the same amount of total concentrate, and improved quality grades compared to BRI steers.