Table 4.
Effect of zinc1 supplementation and implant2 strategy on liver mineral concentrations of finishing heifers
| NRC | IND | SEM | P-value | |||||
|---|---|---|---|---|---|---|---|---|
| REV-XH | REV-200 | REV-XH | REV-200 | Zn | IMP | Zn × IMP | ||
| Heifers (n) | 9 | 9 | 9 | 9 | ||||
| Trace mineral concentrations3 | ||||||||
| Liver, mg/kg DM4,5 | ||||||||
| Cu | 350 | 371 | 353 | 321 | 26.8 | 0.28 | 0.85 | 0.24 |
| Fe | 172 | 167 | 167 | 171 | 9.5 | 0.97 | 0.99 | 0.61 |
| Mn6 | 8.32a | 7.94ab | 8.71a | 7.40b | 0.217 | 0.70 | 0.0007 | 0.03 |
| Zn | 113 | 117 | 115 | 121 | 4.1 | 0.47 | 0.13 | 0.81 |
1The NRC treatment received 30 mg Zn/kg DM from ZnSO4 and IND treatment received 100 mg Zn/kg DM from ZnSO4.
2Implant strategies included either a single Revalor-XH implant (REV-XH; 20 mg estradiol + 200 mg TBA; Merck Animal Health, Madison, NJ) on day 0 or a Revalor-200 on day 0 and again on day 91 (REV-200; 20 mg estradiol + 200 mg TBA; Merck Animal Heath, Madison, NJ).
3Data were analyzed using repeated measures of the mixed procedure of SAS and represent overall treatment means.
4No Zn × IMP × Day (P ≥ 0.25) effect was observed. Day (P ≤ 0.0002); IMP × Day (P ≥ 0.12) except for Mn (Figure 2; P = 0.02).
5Liver samples were collected on days −5, 14, 105, and 164.
6Unlike superscripts indicate differences in treatment means (P≤ 0.05).