| Type of Document |
Master's Thesis |
| Author |
Shank, Alba Maria Montana
|
| Author's Email Address |
ashank@vt.edu |
| URN |
etd-09032002-091440 |
| Title |
Effects of Stress on Several Immune and Health Responses of Weanling Calves |
| Degree |
Master of Science |
| Department |
Veterinary Medical Sciences |
| Advisory Committee |
| Advisor Name |
Title |
| Swecker, William S. Jr. |
Committee Chair |
| Eversole, Dan E. |
Committee Member |
| Fontenot, Joseph P. |
Committee Member |
| Saker, Korinn E. |
Committee Member |
|
| Keywords |
- Glutatione peroxidase
- Weaning
- Selenium
- Stress
- Bovine
|
| Date of Defense |
2002-07-02 |
| Availability |
unrestricted |
Abstract
The effects of weaning stressors on several immune and health responses were measured in three experiments. Sixty-four beef calves from 2 sources were bled on d - 7 (pre-weaning), 0 (weaning), 7, 14, and 21 (post-weaning). Serum selenium (Se), neutrophil and lymphocyte counts, and glutathione peroxidase (GSH-Px) activity for erythrocytes and leukocytes were measured for each calf at each date. Erythrocyte GSH-Px activity remained constant over time, while leukocyte GSH-Px and serum Se increased on d 7 (P<0.0001). Effects of single mineral vs. multi-mineral supplementation were measured for several immune and health responses in 2 trials. Trial 1: 36 heifers weaned on-site at SVAREC were randomly assigned 1 of 2 dietary supplements: 1) no supplement; 2) 15% CP at 0.5% BW; and 1 of 3 injection treatments: 1) no treatment (control); 2) Mu-Se injection; 3) Multi-Min injection. Whole blood Se and serum Cu increased post-weaning and serum Zn decreased post-weaning. Mu-Se-supplemented heifers gained weight faster between d 14-28 vs. Multi-Min-supplemented (P=0.01) or control heifers (P=0.02). Trial 2: 48 steers purchased at auction and transported to SVAREC were randomly assigned to 1 of 4 pasture management systems: 1) control (no treatment); 2) litter fed; 3) litter applied; 4) inorganic fertilizer; and 1 of 3 injection treatments (same as Trial 1). Whole blood Se and serum Cu increased post-stress and serum Zn decreased post-stress. Oxidative burst activity decreased in Mu-Se and Multi-min supplemented steers between d 0-4 vs. control steers (P<0.01). Multi-min-supplemented steers had higher phagocytic activity vs. steers in either Mu-Se or control groups (P=0.04).
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