Table 3.

Effects of zinc¹ supplementation within non-steroidal implanted and steroidal implanted² beef steers on carcass characteristics

	NoIMP				TE200					Contrasts3
	Zn0	Zn30	Zn100	Zn150	Zn0	Zn30	Zn100	Zn150	SEM	L-NoIMP	Q-NoIMP	L- TE200	Q- TE200	NoIMP vs. TE200
Steer (n)4	17	15	16	16	15	16	16	16
Hot carcass weight, kg	370	369	373	369	376	377	380	381	2.5	0.80	0.39	0.09	0.98	<0.0001
Dress, %	62.2	62.0	61.9	62.0	62.3	62.1	62.4	63.2	0.30	0.62	0.65	0.01	0.13	0.02
Ribeye area, cm2	84.4	81.7	86.5	83.1	89.4	88.8	87.9	87.6	1.96	0.76	0.56	0.48	0.91	0.001
12thrib fat, cm	1.61	1.67	1.43	1.69	1.50	1.44	1.52	1.56	0.086	0.87	0.09	0.43	0.67	0.12
Marbling5	491	470	483	495	472	460	452	472	22.0	0.70	0.52	0.96	0.43	0.17
Yield grade6	3.6	3.6	3.4	3.7	3.5	3.4	3.5	3.5	0.08	0.87	0.09	0.43	0.67	0.12

¹Zinc was supplemented to cattle at 0, 30, 100, or 150 mg Zn/kg DM from ZnSO₄ (Zn0, Zn30, Zn100, or Zn150, respectively).

²Steroidal implant strategies included no steroidal implant (NoIMP) or a Component TE-200 (TE-200; 200 mg trenbolone acetate + 20 mg estradiol; Elanco Animal Health, Greenfield, IN) on day 0.

³Contrast statements were formed to test for linear (L) and quadratic (Q) effects of Zn supplementation within non-steroidal implanted (L-NoIMP and Q-NoIMP) or steroidal implanted (L-TE200 or Q-TE200) steers. A separate contrast statement was formed to test for differences between non-steroidal implanted steers and all steroidal implanted steers (NoIMP vs. TE200).

⁴Intial body weight was utilized as a covariate for carcass characteristics.

⁵Marbling scores: slight = 300, small = 400, modest = 500, moderate = 600, slightly abundant = 700, moderately abundant = 800.

⁶Yield grade was assigned by personnel of the commercial abattoir.