Impact of different stressors on physiological and immunological variables in dairy calves

Authors: KOHL, KESLEY - Texas Tech University; Sanchez, Nicole; Broadway, Paul; Carroll, Jeffery - Jeff Carroll; LEGAKO, JERRAD - Texas Tech University; BARKER, SAMANTHA - Texas Tech University; DOBBINS, THOMAS - Texas Tech University; HERNANCEZ, SEBASTIAN - Texas Tech University; LOOMAS, KAITLYN - Texas Tech University; BRATCHER, CHRISTY - Texas Tech University

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2022
Publication Date: 5/1/2023
Citation: Kohl, K.B., Sanchez, N.C., Broadway, P.R., Carroll, J.A., Legako, J.F., Barker, S.N., Dobbins, T., Hernancez, S., Loomas, K., Bratcher, C.L. 2023. Impact of different stressors on physiological and immunological variables in dairy calves. Journal of Animal Science Supplement. 101(1):60-61.

Interpretive Summary:

Technical Abstract: This study was conducted to investigate the effects of different stressors on physiological and innate immune variables in weaned dairy calves. Dairy steers (n = 40; 110 ± 11.8 kg body weight) were transported to the USDA-ARS Livestock Issues Research Unit’s Calf Building where they were housed in individual pens in an environmentally controlled room. Calves had ad libitum access to water and a starter ration. At arrival, calves were randomly allotted to four treatment groups (n = 10 per treatment): 1) Control, 2) Transport (transported in a livestock trailer for 4 h), 3) Lipopolysaccharide (LPS; administered i.v. 0.10 µg /kg body weight), 4) Vaccine (administered a Mannheimia Haemolytica toxoid vaccine; OneShot, Zoetis). One day prior to application of stressors, indwelling jugular vein catheters and rectal temperature recording devices were placed in all calves. Whole blood was collected at -1, -0.5, 0, 1, 2, 3, and 4 h relative to application of stressors for serum, plasma, and hematology. There was a treatment × time interaction (P = 0.01) for all hematology parameters except for hemoglobin and platelets. Monocyte, lymphocyte, neutrophil, basophil, and white blood cell concentrations and the neutrophil:lymphocyte ratio were reduced (P < 0.02) in calves administered LPS compared to all other treatments. For calves administered the Vaccine treatment, white blood cell and neutrophil concentrations and the neutrophil:lymphocyte ratio increased (P < 0.04) 4 h post-challenge compared to other treatments. There was a treatment × time interaction (P < 0.01) for the change in rectal temperature relative to baseline values. The change in rectal temperature increased following administration of LPS and peaked at approximately 3 h post-challenge before decreasing to near baseline values. In contrast, rectal temperature began to increase 3 h post-challenge in calves administered the Vaccine treatment, where the greatest rectal temperature values were observed at 6 h post-challenge. There was a treatment x time interaction (P < 0.01) for cortisol concentrations, where calves administered LPS produced the greatest increase in cortisol compared to all other treatments. There was a treatment x time interaction (P < 0.01) for tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-1beta (MIP-1beta). Concentrations of TNF-alpha remained greater in LPS and vaccine calves compare to control and transport calves while MIP-1beta concentrations remained elevated for calves administered LPS compared to the other treatments. Results from this study suggest that common challenges experienced by dairy calves differentially influence physiological and immunological variables in weaned dairy calves.