Table 5.
Effects of nonimplanted or implanted beef steers fed varying concentrations* of supplemental trace minerals on plasma glucose and urea nitrogen concentrations
| Plasma | No IMP | IMP† | SEM | P value | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CON, n = 6 | REC, n = 6 | IND, n = 6 | CON, n = 6 | REC, n = 6 | IND, n = 5 | GS | TM | GS × TM | ||
| Glucose,‡ mg/dL | ||||||||||
| Day 0 | 105 | 99 | 98 | 101 | 94 | 114 | — | — | — | — |
| Day 70∥ | 96 | 97 | 95 | 98 | 102 | 103 | 4.4 | 0.14 | 0.88 | 0.79 |
| Day 124∥ | 94x,y | 108x | 93y | 104x,y | 98x,y | 107x,y | 5.1 | 0.29 | 0.72 | 0.06 |
| PUN,‡ mg/dL | ||||||||||
| Day 0 | 9.0 | 8.0 | 9.4 | 10.6 | 10.3 | 8.2 | — | — | — | — |
| Day 70∥ | 9.0 | 9.9 | 10.2 | 7.6 | 9.0 | 8.4 | 0.74 | 0.03 | 0.22 | 0.85 |
| Day 124∥ | 10.0 | 11.4 | 10.1 | 9.7 | 10.8 | 10.3 | 0.85 | 0.74 | 0.33 | 0.90 |
x,yWithin rows, means without a common superscript tend to differ (P ≤ 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.
†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.
‡Blood samples were collected before feeding.
∥Day 0 concentrations used as a covariate in analysis.
SEM, standard error of the mean.