Table 3.

The effects of implant^a and zinc source^b on carcass characteristics and carcass-adjusted performance in finishing feedlot steers

Implant treatments	NoIMP			IS/200				P-values
Zinc treatments	ZnB	ZnG	ZnS	ZnB	ZnG	ZnS	SEM	IMP	Zn	IMP × Zn
Steer (n)	12	11	12	11	11	9
Hot carcass weight, kg	385	380	380	408	410	424	5.6	<0.001	0.33	0.12
Dress, %	63.8	63.9	64.2	64.6	64.8	64.8	0.37	0.01	0.72	0.85
Ribeye area, cm2	80.0	81.2	80.2	86.8	83.4	83.9	2.23	0.01	0.76	0.51
Rib fat, cm	1.69	1.71	1.80	1.80	1.87	1.81	0.125	0.31	0.86	0.79
KPHc, %	2.6	2.6	2.6	2.6	2.6	2.7	0.09	0.63	0.77	0.96
Marblingd	530	511	572	546	517	515	35.7	0.66	0.63	0.50
Yield grade	3.94	3.85	4.00	3.90	4.17	4.21	0.181	0.23	0.53	0.55

^a Cattle were either non-implanted (NoIMP) or received a Component TE-IS (IS/200; 80 mg trenbolone acetate + 16 mg estradiol; Elanco Animal Health, Greenfield, IN) on day 0 followed by a Component TE-200 (200 mg trenbolone acetate + 20 mg estradiol; Elanco Animal Health) on day 57.

^b Cattle received 70 mg Zn/kg DM from ZnSO4 + 30 mg Zn/kg DM from basic ZnCl, Zn glycinate, or ZnSO₄ (ZnB, ZnG, or ZnS, respectively). Total Zn supplementation was targeted at 100 mg Zn/kg DM to meet industry consultant recommendations (Samuelson et al., 2016).

^c Kidney, pelvic, and heart fat.

^d Marbling scores: slight = 300, small = 400, modest = 500, moderate = 600, slightly abundant = 700, moderately abundant = 800.