|Carroll, Jeffery - Jeff Carroll|
|MAY, NATHAN - West Texas A & M University|
|ROBERTS, SHELBY - West Texas A & M University|
|HUGHES, HEATHER - West Texas A & M University|
|SHARON, KATE - West Texas A & M University|
|BALLOU, MICHAEL - West Texas A & M University|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2015
Publication Date: 7/10/2015
Citation: Carroll, J.A., Sanchez, N.C., May, N.D., Roberts, S.L., Hughes, H.D., Broadway, P.R., Sharon, K.P., Ballou, M.A. 2015. Mimicking acute and chronic stress exposure in naive beef steers alters the acute phase response (APR) associated with vaccination. Journal of Animal Science Supplement. 93(E-Supplement 3):597.
Technical Abstract: This study was designed to determine the effect of an acute versus chronic stress model on the APR associated with vaccination in naïve beef steers. Steers (n=32; 209 +/- 8 kg) were blocked by body weight and assigned to 1 of 3 treatments: 1) Chronic stress (CHR), 0.5 mg/kg body weight dexamethasone (DEX) administered intravenously at 1000h on day 3 - day 6; 2) Acute stress (ACU), 0.5 mg/kg body weight DEX administered intraveneously at 1000h on day 6 only; or 3) Control (CON), no DEX. On day 2, steers were fitted with indwelling rectal temperature (RT) devices and jugular catheters, and then moved into individual stanchions in an environmentally-controlled barn. Blood samples were collected at -74, -50, and -26h, at 0.5h intervals from -4h to 6h, and at 12, 24, 36, 48, and 72h relative to vaccination with Pyramid 5 + Presponse SQ at 1200h on day 6. Serum was isolated and stored at -80C until analyzed for cytokines (tumor necrosis factor-alpha, TNF-alpha; interferon-gamma, IFN-gamma), and a second blood sample was used to measure complete blood cell counts. There was a treatment x time interaction (P<0.01) for RT such that DEX treatment in CHR and ACU steers decreased RT on day 3 and day 6, respectively, compared to CON steers. Vaccination on day 6 increased RT in CON but not in CHR or ACU steers with RT remaining elevated in CON for the remainder of the study. There was a treatment x time interaction (P<0.01) for total white blood cells (WBC), neutrophils, lymphocytes, and monocytes. Specifically, DEX increased WBC and neutrophils in CHR and ACU steers, yet decreased lymphocytes in CHR steers. Monocytes initially increased in response to DEX treatment in CHR and ACU steers. Also, eosinophils were greater (P<0.01) in CON than ACU and CHR steers. There was a treatment x time interaction (P<0.01) for IFN-gamma such that IFN-gamma was greater in CON and CHR than ACU steers. Concentrations of TNF-alpha were elevated (P<0.01) in CHR compared to ACU and CON steers. These data suggest that ACU stress may prime, while CHR stress may cause hyper-activation, of the APR associated with vaccination in naïve beef calves, thus potentially negatively affecting the overall immunological response to vaccination.