Table 6.
Main effect of implant on liver mineral status of nonimplanted or implanted beef steers fed varying concentrations* of supplemental trace minerals
| Mineral, mg/kg DM† | No IMP, n = 18 | IMP,‡ n = 17 | SEM | P value; GS |
|---|---|---|---|---|
| Initial (day −7) | ||||
| Cu | 219 | 234 | — | — |
| Zn | 108 | 107 | — | — |
| Mn | 9.66 | 9.14 | — | — |
| Se | 1.7 | 1.7 | — | — |
| Co | 0.241 | 0.241 | — | — |
| Day 70† | ||||
| Cu | 228 | 198 | 8.2 | 0.02 |
| Zn | 95 | 98 | 3.2 | 0.53 |
| Mn | 8.59 | 7.93 | 0.228 | 0.05 |
| Se | 2.4 | 2.4 | 0.09 | 0.91 |
| Co | 0.182 | 0.170 | 0.010 | 0.36 |
| Harvest (day 125)∥ | ||||
| Cu | 246 | 237 | 15.7 | 0.67 |
| Zn | 125 | 143 | 4.0 | 0.01 |
| Mn | 8.70 | 8.94 | 0.296 | 0.59 |
| Se | 2.4 | 2.6 | 0.09 | 0.24 |
| Co | 0.174 | 0.158 | 0.007 | 0.10 |
*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.
†No GS × TM; P ≥ 0.11.
‡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.
∥Day −7 mineral concentrations were used as a covariate in analysis.
SEM, standard error of the mean.