Table 3.
Main effect of implant status on live animal performance and carcass-adjusted performance of nonimplanted or implanted* beef steers fed varying concentrations† of supplemental trace minerals
| Item | NoIMP, n = 36 | IMP, n = 35 | SEM | P value |
|---|---|---|---|---|
| Live animal performance‡ | ||||
| BW, kg | ||||
| Day 0 | 388 | 389 | 1.8 | 0.82 |
| Day 124 | 559 | 617 | 5.9 | <0.01 |
| DMI, kg/d | ||||
| Days 0–56 | 9.70 | 10.27 | 0.158 | 0.01 |
| Days 56–124 | 9.22 | 10.91 | 0.162 | <0.01 |
| Overall days 0–124 | 9.46 | 10.59 | 0.143 | <0.01 |
| ADG, kg | ||||
| Days 56–124 | 1.19 | 1.59 | 0.055 | <0.01 |
| Overall days 0–124 | 1.38 | 1.84 | 0.038 | <0.01 |
| G:F, kg/kg | ||||
| Days 0–56 | 0.157 | 0.203 | 0.0036 | <0.01 |
| Days 56–124 | 0.129 | 0.146 | 0.0053 | 0.03 |
| Overall G:F | 0.146 | 0.174 | 0.0032 | <0.01 |
| Carcass-adjusted performance | ||||
| Final BW∥ | 555 | 619 | 5.2 | <0.01 |
| Overall ADG∥ | 1.33 | 1.84 | 0.036 | <0.01 |
| Overall G:F∥ | 0.141 | 0.174 | 0.0030 | 0.07 |
*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.
†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 ≥ 0.13.
∥Adjusted overall live performance parameters were carcass adjusted with a common 64.66% dress.
SEM, standard error of the mean.