Table 8.

Effects of nonimplanted or implanted beef steers fed varying concentrations* of supplemental trace minerals on carcass characteristics and QG distribution

	No IMP			IMP†			SEM	P value
Item	CON, n = 12	REC, n = 11	IND, n = 12	CON, n = 12	REC, n = 12	IND, n = 12		GS	TM	GS × TM
Dress,‡ %	63.4	64.7	64.8	64.5	64.4	65.9	5.8	0.26	0.13	0.50
KPH, %	2.21	2.00	2.13	2.00	1.96	2.13	0.69	0.24	0.20	0.44
Backfat, cm	1.52	1.34	1.69	1.16	1.46	1.46	0.126	0.13	0.16	0.17
REA, cm2	77.8c	79.8c	81.1c	91.9a	86.6a,b	85.1b	1.87	<0.01	0.58	0.02
YG∥	3.60a,b	3.31a,b	3.70a	2.84c	3.44a,b	3.63a,b	0.163	0.09	0.03	0.02
MS$	494	541	550	486	539	483	39.5	0.43	0.46	0.66
% QG distribution¶
Average choice or higher	41.7	58.3	66.7	33.3	58.3	33.3	—	0.23	0.34	0.48
Low choice	41.7	16.7	25.0	50.0	25.0	41.7	—	0.31	0.18	0.94
Select	16.6	25.0	8.3	16.7	16.7	25.0	—	0.68	0.88	0.49

^a,b,cWithin rows, means without a common superscript differ (P ≤ 0.05).

^*Supplemental trace mineral treatments: CON (no additional supplemental trace minerals), REC (2016 NASEM recommendations: 10 Cu, 30 Zn, 20 Mn, 0.10 Se, 0.15 Co, and 0.50 I; mg/kg), and IND (feedlot consultant recommendations from Samuelson et al. (2016) of 20 Cu, 100 Zn, 50 Mn, 0.30 Se, 0.20 Co, and 0.50 I; mg/kg). Sources of trace mineral included copper sulfate, zinc sulfate, manganese sulfate, calcium iodate, sodium selenite, and cobalt carbonate.

^†Growth-stimulated implanted steers (IMP) received Component TE-IS (16 mg estradiol + 80 mg TBA) on day 0 and were reimplanted with Component TE-200 (20 mg estradiol + 200 mg TBA) on day 56, whereas NoIMP received no implants.

^‡Dressing percent.

^∥Yield grade.

^$MS: small = 400, modest = 500, moderate = 600.

^¶Percentage of steers in each treatment by QG within treatment total is 100%.

SEM, standard error of the mean.