Table 4.
Implant treatments | NoIMP | IS/200 | P-values | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Zinc treatments | ZnB | ZnG | ZnS | ZnB | ZnG | ZnS | SEM | IMP | Zn | IMP × Zn |
Steer (n)a | 12 | 11 | 12 | 11 | 11 | 9 | ||||
Liver, mg/kg DMe | ||||||||||
Znf | 103 | 102 | 101 | 105 | 106 | 112 | 2.9 | 0.02 | 0.62 | 0.21 |
Cu | 303a | 314a | 240b | 298a | 278ab | 301a | 18.3 | 0.62 | 0.19 | 0.02 |
Mne | 9.0 | 8.5 | 9.1 | 8.5 | 8.3 | 8.8 | 0.30 | 0.19 | 0.19 | 0.86 |
Fe | 167 | 153 | 156 | 164 | 147 | 155 | 6.3 | 0.53 | 0.04 | 0.92 |
Muscle, mg/kg DMe,g | ||||||||||
Zn | 118y | 122y | 123xy | 124xy | 133x | 119y | 3.7 | 0.16 | 0.14 | 0.09 |
Plasma, mg/Le | ||||||||||
Cu | 0.99 | 1.05 | 1.02 | 1.00 | 1.07 | 1.03 | 0.046 | 0.76 | 0.34 | 0.99 |
Fef | 1.92 | 2.24 | 2.13 | 1.97 | 2.25 | 2.15 | 0.107 | 0.79 | 0.02 | 0.98 |
PUN, mg/dLe,f | 8.20 | 9.02 | 9.12 | 7.96 | 7.83 | 7.37 | 0.485 | 0.01 | 0.78 | 0.30 |
a Implant strategies included no implant (NoIMP) or a Component TE-IS (IS/200; 80 mg trenbolone acetate + 16 mg estradiol; Elanco Animal Health, Greenfield, IN) on day 0 followed by a Component TE-200 (200 mg trenbolone acetate + 20 mg estradiol; Elanco Animal Health) on day 57.
b Cattle received 70 mg Zn/kg DM from ZnSO4 + 30 mg Zn/kg DM from basic ZnCl, Zn glycinate, or ZnSO4 (ZnB, ZnG, or ZnS, respectively). Total Zn supplementation was targeted at 100 mg Zn/kg DM to meet industry consultant recommendations (Samuelson et al., 2016).
c Liver and muscle samples were taken on days −5/−4, 14/15, 71/72, and 120/121, whereas blood for plasma trace mineral and PUN analysis was collected on days −1, 14, 56, 71/72, and 125.
d Unlike superscripts indicate differences between treatment means; a,b,c represent P ≤ 0.05 and x,y,z represent 0.05 < P ≤ 0.10.
e Data were analyzed using repeated measures of the mixed procedure of SAS and represent treatment means. No IMP × Zn × Day or Zn × Day interactions were observed (P ≥ 0.15) for all measurements except plasma Zn (IMP × Zn × Day; P = 0.06; Figure 1).
f An IMP × Day effect (P ≤ 0.01) for liver Zn (Figure 2A), plasma Fe (Figure 2B), liver Mn (Figure 3A), and plasma urea nitrogen (PUN; Figure 3B). No other IMP × Day effects were observed (P ≥ 0.27).
g A Day effect was observed (P < 0.0001; Figure 3).