January 15, 2020

Interpretive Summary: Metabolic response in steers exposed to dexamethasone

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

By: Jackie Walling

Vaccine efficacy and immune response are affected by stress and available energy. Stress alters available energy, which is critical to immune response. Exposing cattle to dexamethasone (DEX) is thought to alter antibody response to a multivalent respiratory vaccine. This 2019 December Translation Animal Science article determines the metabolic response steers have when acutely or chronically exposed to DEX.

Thirty-two steers were divided into three treatments: Acute (ACU, DEX day 0), Chronic (CHR, DEX day 0-3), and Control (CON, no DEX). Serum glucose, nonesterified fatty acid (NEFA), and serum urea nitrogen (SUN) concentrations were analyzed.

Acute stress may result in an increase in glucose and metabolites that stimulate the immune system. Chronic stress may cause more susceptibility to infections. Continued release of glucocorticoids negatively affects energy metabolism and results in insulin resistance. 

The vaccination did not affect serum glucose concentration, but there was a treatment by time interaction to DEX administration. Glucose levels rose immediately following a dose of DEX. CHR steers often had higher levels. This response was likely due to glucose redistribution rather than production.

Serum NEFA differed among treatments before DEX administration for unknown reasons. Results were based on changes. NEFA concentrations were affected by treatment and time. There was also a treatment by time interaction. CHR steers showed the most significant changes overall and for several time periods measured.

SUN was influenced by treatment and time but did not have a treatment by time interaction. All treatments differed from one another, with CHR having the highest levels and CON the lowest.

Overall, the vaccination did not change metabolic parameters measured. This study showed increases in all three parameters measured when ACU or CHR stress was induced by DEX. The metabolic parameters altered by DEX may influence the immune response to the vaccination because the changes in glucose affect energy availability.

To view the full article, visit Translational Animal Science