Table 5.
Effect of supplemental vitamin E (VE) on plasma cortisol and malondialdehyde (MDA) concentrations of beef steers
| Supplemental VE treatment1 | Contrast P-value | |||||||
|---|---|---|---|---|---|---|---|---|
| CON | LOW | MED | HIGH | SEM | Linear | Quadratic | Cubic | |
| Cortisol, ng/mL | ||||||||
| Day −12 | 28.9 | 29.4 | 25.0 | 26.2 | – | – | – | – |
| Day 26 | 20.0 | 18.2 | 19.0 | 21.1 | 3.32 | 0.68 | 0.67 | 0.78 |
| Day 283 | 25.5 | 19.6 | 24.0 | 20.6 | 2.73 | 0.49 | 0.98 | 0.11 |
| MDA, µM | ||||||||
| Day -12 | 7.7 | 7.1 | 6.8 | 6.6 | – | – | – | – |
| Day 26 | 7.1 | 7.6 | 8.5 | 7.5 | 0.61 | 0.65 | 0.10 | 0.86 |
| Day 283 | 5.0 | 6.7 | 7.4 | 7.2 | 0.45 | 0.01 | 0.01 | 0.18 |
1VE = vitamin E (ROVIMIX E-50 Adsorbate, DSM Nutritional Products, Heerlen, The Netherlands); CON = control (no supplemental VE); LOW = VE at 25 IU/kg DM; MED = VE at 500 IU per steer daily; HIGH = VE at 1,000 IU per steer daily.
2Values from day −1 (prior to treatment initiation) were utilized as a covariate in analysis.
3Blood collected after steers were restricted from feed for 24 h.