Table 1.
Review of literature examining steroidal implants and zinc metabolism in cattle.
| Ref. | Sex | Steroidal Implant 1 | Potency 2 | Supplemental Zn 3 | Day 4 | ∆ 5 ADG, % | ∆ 5 Plasma Zn, % | ∆ 5 Liver Zn, % |
|---|---|---|---|---|---|---|---|---|
| [1] | Steer | 200 mg TBA + 20 mg E2 | High | 0 | 69 | -- | -- | +10.6 |
| 30 a | 69 | -- | -- | +11.0 | ||||
| 100 a | 69 | -- | -- | +22.9 | ||||
| [14] | Steer | 200 mg TBA + 20 mg E2 | High | 30 a | 13/14 | +29.0 | −11.2 | −6.6 |
| [118] | Steer | 200 mg P + 20 mg EB | Moderate | 0 | 59 | +7.6 | +1.8 | −26.1 |
| 200 a | 59 | +17.4 | +3.2 | +30.7 | ||||
| 200 b | 59 | -- | −15.0 | +8.5 | ||||
| [118] | Heifer | 200 mg TP + 20 mg EB | Moderate | 0 | 50 | +11.0 | +7.0 | −38.2 |
| 200 a | 50 | +17.0 | −2.5 | +25.4 | ||||
| 200 b | 50 | −26.0 | +24.7 | −40.8 | ||||
| [119] | Steer | 80 mg TBA +16 mg E2 (Initial) | Moderate | 100 c | 14/15 | -- | −3.1 | −1.0 |
| 200 mg TBA + 20 mg E2 | High | 100 c | 14/15 | -- | −12.8 | +4.8 | ||
| [120] | Steer | 200 mg TBA + 20 mg E2 | High | 0 | 18 | +8.0 | −4.6 | -- |
| 30 a | 18 | +3.1 | −9.7 | -- | ||||
| 100 a | 18 | +4.5 | −7.0 | -- | ||||
| 150 a | 18 | +21.6 | −3.5 | -- | ||||
| [124] | Steer | 200 mg TBA | High | 55 c | 2 | -- | −4.3 | −16.2 |
| 120 mg TBA +24 mg E2 | Moderate | 55 c | 2 | -- | −8.5 | −16.2 | ||
| [125] | Steer | 200 mg P + 20 mg EB (Initial) | Moderate | 360 d mg·steer−1·d−1 | 28 | -- | −4.8 | +12.2 |
| 80 mg TBA +16 mg E2 | Moderate | 360 d mg·steer−1·d−1 | 56 | -- | −7.7 | +4.7 |
1 Steroidal implant hormone concentrations are listed using the following abbreviations: E2: estradiol, EB: estradiol benzoate, P: progesterone, TBA: trenbolone acetate, TP: testosterone propionate. All steroidal implants were given as the terminal implant, unless otherwise noted as initial implant. 2 Steroidal implant potency is arbitrarily categorized as low, moderate, or high based on hormone combination and dose. 3 Supplemental Zn is expressed as mg/kg DM, unless otherwise stated. Source of Zn supplemented is represented by superscript: a inorganic, b organic, c blend of inorganic and organic, d means of inorganic and organic Zn supplementation were combined due to no source differences. 4 Represents day relative to administration of the steroidal implant used in each study. 5 The percent delta (∆) represents the effect of steroidal implant compared to non-implanted cohorts on growth and Zn metabolism parameters on the noted day post-steroidal implant administration. Changes in plasma Zn concentrations for [118] represent changes in serum Zn concentrations.