Modulation of the metabolic response using dexamethasone in beef steers vaccinated with a multivalent respiratory vaccine

Authors: Sanchez, Nicole; Carroll, Jeffery - Jeff Carroll; MAY, NATHAN - West Texas A & M University; HUGHES, HEATHER - West Texas A & M University; ROBERTS, SHELBY - West Texas A & M University; Broadway, Paul; BALLOU, MICHAEL - Texas Tech University; RICHESON, JOHN - West Texas A & M University

Submitted to: Translational Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2019
Publication Date: 10/19/2019
Citation: Sanchez, N.C., Carroll, J.A., May, N.D., Hughes, H.D., Roberts, S.L., Broadway, P.R., Ballou, M.A., Richeson, J.T. 2019. Modulation of the metabolic response using dexamethasone in beef steers vaccinated with a multivalent respiratory vaccine. Translational Animal Science. 4:324-330. https://doi.org/10.1093/tas/txz165.
DOI: https://doi.org/10.1093/tas/txz165

Interpretive Summary: Vaccination is a common management practice used by producers to prevent or reduce the negative effects of disease. However, vaccination is often done at the same time as other management procedures such as weaning, transportation, mixing of unfamiliar cattle, and exposure to new diseases, which can cause stress and negatively affect how well the vaccine works. Additionally, stress can reduce the amount of energy available for the immune system to fight off an infection. A study was conducted by scientists from the Livestock Issues Research Unit, West Texas A&M University, and Texas Tech University to mimic the effects of acute (short-duration) and chronic (long-duration) stress on the metabolic responses to vaccination. Data from this study show that both the acute and chronic stress treatments increased biomarkers in the blood that are indicators of energy breakdown. Results from this study suggest that the increase in the breakdown of energy in the body due to the stress treatment may affect the energy available to the immune system in order to adequately respond to vaccination and protect the calf against disease. This information will be of interest to cattle producers, veterinarians, and scientists interested in the effects of stress on vaccine effectiveness.

Technical Abstract: Available energy plays a critical role in the initiation and maintenance of an immune response to a pathogen, a process that is further altered by activation of the stress system. This study was designed to determine the effect of an acute versus chronic stress model on the metabolic response to vaccination in naïve beef steers. Steers (n = 32; 209 ± 8 kg) were blocked by BW and assigned to 1 of 3 treatments: 1) Chronic stress (CHR), 0.5 mg/kg BW dexamethasone (DEX) administered i.v. at 1000 h on d 3 to d 6; 2) Acute stress (ACU), 0.5 mg/kg BW DEX administered i.v. at 1000 h on d 6 only; or 3) Control (CON), no DEX. On d 2, steers were fitted with jugular vein catheters and moved into individual bleeding stalls in an environmentally-controlled facility. Blood samples were collected at -74, -50, and -26 h, at 0.5-h intervals from -4 to 6 h, and at 12, 24, 36, 48, and 72 h relative to vaccination with Pyramid 5 + Presponse SQ at 1200 h on d 6. Data were analyzed by the MIXED procedure of SAS specific for repeated measures. There was a treatment x time interaction (P < 0.001) for serum glucose concentrations. Specifically, glucose concentrations increased at -50 h in CHR steers and at 12 h in ACU steers and remained elevated through 72 h post-vaccination period in these two treatments compared to CON steers. The change in NEFA concentrations relative to baseline values was affected by treatment and time (P < 0.001) such that the change in NEFA was greater in CHR (0.06 ± 0.01 mmol/L), followed by CON (-0.01 ± 0.01 mmol/L) and ACU steers (-0.04 ± 0.01 mmol/L). Serum urea nitrogen (SUN) was affected by treatment and time (P < 0.001) such that SUN concentrations were greatest in CHR (12.0 ± 0.1 mg/dL) followed by ACU (10.4 ± 0.1 mg/dL) and CON steers (9.6 ± 0.1 mg/dL). These data demonstrate that activation of the stress and immune axes using an acute or chronic stress model can increase energy mobilization prior to and following vaccination in naïve steers, potentially affecting available energy needed to mount an adequate antibody response to vaccination.