Table 3.

Carcass traits of steers receiving 0 or 8.33 mg/kg zilpaterol hydrochloride (ZH) and 60 or 300 mg supplemental Zn/kg diet DM (60Zn or 300Zn, respectively) for a 24-d experiment¹

	No ZH		ZH			P-value
Item	60Zn2	300Zn2	60Zn2	300Zn2	SEM	Zn	ZH	Zn × ZH
HCW, kg	438	433	445	440	10.15	0.83	0.21	0.96
Dressed yield, %	65.2	65.8	65.7	65.9	0.47	0.37	0.52	0.72
Liver abscess, %	30.0	20.0	30.0	30.0	14.81	0.72	0.72	0.72
LM area, cm2	97.2	93.5	99.4	100.0	2.52	0.46	0.07	0.37
12th-rib s.c. fat, cm	1.32	1.37	1.22	1.35	0.10	0.37	0.48	0.76
USDA yield grade	2.7	3.0	2.4	2.4	0.22	0.50	0.05	0.50
Marbling score3	481	492	503	523	23.8	0.52	0.27	0.85
KPH, %	1.60	1.70	1.45	1.75	0.17	0.09	0.66	0.39
Select, %	20	0	10	0	8.33	0.08	0.55	0.55
Choice, %	80	100	90	100	8.33	0.08	0.55	0.55

¹Zilpaterol hydrochloride (Merck Animal Health, Millsboro, DE) was fed for 21 d followed by a 3-d withdrawal prior to harvest.

²Sixty milligrams Zn per kilogram was provided as zinc sulfate, and the remaining 240 mg Zn/kg in the 300Zn diet was fed as zinc oxide.

³Marbling scores were determined by a USDA grader: Small = 400 to 499; Modest = 500 to 599.