Cytokine and haptoglobin profiles from shipping through sickness and recovery in metaphylaxis- or un-treated cattle

Authors: Chitko-Mckown, Carol; Bennett, Gary; Kuehn, Larry; DEDONDER, KEITH - Kansas State University; APLEY, MICHAEL - Kansas State University; Harhay, Gregory; Clawson, Michael - Mike; Workman, Aspen; WHITE, BRADLEY - Kansas State University; LARSON, ROBERT - Kansas State University; CAPIK, SARAH - Texas A&M Agrilife; LUBBERS, BRIAN - Kansas State University

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2021
Publication Date: 3/19/2021
Citation: Chitko-McKown, C.G., Bennett, G.L., Kuehn, L.A., DeDonder, K.D., Apley, M.D., Harhay, G.P., Clawson, M.L., Workman, A.M., White, B.J., Larson, R.L., Capik, S.F., Lubbers, B.V. 2021. Cytokine and haptoglobin profiles from shipping through sickness and recovery in metaphylaxis- or un-treated cattle. Frontiers in Veterinary Science. 8. Article 611927. https://doi.org/10.3389/fvets.2021.611927.
DOI: https://doi.org/10.3389/fvets.2021.611927

Interpretive Summary: Respiratory disease accounts for the highest percentage of disease deaths in cattle, with the costs of these losses approaching $1B annually. APHIS reports that the average cost of treating a single case of BRDC is $23.60. Therefore, decreasing the mortality and morbidity of BRDC in U.S. cattle herds would reduce the need for antibiotic treatment and mass medication and result in substantial cost savings for producers. Variables that may contribute to BRDC are stress, the environment, and exposure of the host to pathogens. Cattle are shipped from the farm of origin to the sale barn and eventually a feedlot. Throughout these movements they are exposed to the stress of shipping and mixing with strange animals, and are exposed to new physical environments as well as to both bacterial and viral pathogens that they may be naïve to, and may or may not be vaccinated against. In many cases, This perfect storm results in an outbreak of BRDC. We studied a set of 28 cattle that had become sick with bovine respiratory disease after going through mixing and shipping from Day 0 at the sale barn through Day 28 at the feedlot. These animals were matched with animals that had also undergone similar stresses but remained healthy. We then compared concentrations of a panel of blood proteins called cytokines (IFN-g IL-1b, IL-4, IL-6, and TNF-a), which are part of the immune response, and a stress protein (haptoglobin), to see if we could measure differences between the sick and healthy animals. Some of the animals had been mass-medicated upon arrival at the feedlot and we also compared differences in their cytokine and haptoglobin profiles with non-medicated animals. There was no overall difference between the treated animals and their non-treated counterparts for any of the analytes measured. State of origin tended to affect TNF-a concentration. Differences for all analytes changed over days, and on specific days was associated with state of origin. The Treatment by Day by Case interaction was significant for HPT. Concentrations of IFN-g, IL-1b and IL-6 were higher in healthy cattle than their matched BRDC counterparts, but concentrations of TNF-a and Haptoglobin were higher in animals with BRDC.

Technical Abstract: Fifty-six head of cattle, 28 animals with bovine respiratory disease complex (BRDC), and 28 healthy animals that were matched by treatment, sale barn of origin, day, and interactions among these variables, were identified from a population of 180 animals (60 each purchased at three sale barns located in Missouri, Tennessee, and Kentucky) enrolled in a study comparing animals receiving metaphylaxis to saline-treated controls. Cattle were transported to a feedlot in KS and assigned to treatment group. Blood samples were collected at Day 0 (at sale barn), Day 1, Day 9, and Day 28 (at KS feedlot), and transported to the US Meat Animal Research Center in Clay Center, NE where plasma was harvested and stored at -80°C until assayed for the cytokines IFN-', IL-1ß, IL-6, and TNF-a, and the acute stress protein haptoglobin (HPT). Our objectives were to determine if cytokine and haptoglobin profiles differed between control and metaphylaxis treatment groups over time, and if profiles differed between animals presenting with BRDC and those that remained healthy. There was no difference between the treated animals and their non-treated counterparts for any of the analytes measured. Sale barn of origin tended to affect TNF-a concentration. Differences for all analytes changed over days, and on specific days was associated with state of origin and treatment. The Treatment by Day by Case interaction was significant for HPT. The analyte most associated with BRDC was HPT on D9, possibly indicating that many of the cattle were not exposed to respiratory pathogens prior to entering the feedlot.