Influence of prenatal transportation stress on innate immune response to an endotoxin challenge in weaned Brahman bulls calves

Authors: LITTLEJOHN, BRITTNI - Texas A&M Agrilife; Sanchez, Nicole; Carroll, Jeffery - Jeff Carroll; PRICE, DEBORAH - Texas A&M Agrilife; VANN, RHONDA - Mississippi State University; WELSH, THOMAS - Texas A&M Agrilife; RANDEL, RONALD - Texas A&M Agrilife

Submitted to: Stress: The International Journal on Biology of Stress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2018
Publication Date: 1/24/2019
Citation: Littlejohn, B.P., Sanchez, N.C., Carroll, J.A., Price, D.M., Vann, R.C., Welsh, T.H., Randel, R.D. 2019. Influence of prenatal transportation stress on innate immune response to an endotoxin challenge in weaned Brahman bulls calves. Stress: The International Journal on Biology of Stress. 22:2, 236-247. https://doi.org/10.1080/10253890.2018.1523895.
DOI: https://doi.org/10.1080/10253890.2018.1523895

Interpretive Summary: Elevated maternal cortisol may alter the fetal environment, thereby altering fetal development. Fetal programming is defined as the fetal response to a specific insult during a critical period that alters the trajectory of development. Alterations in the fetal environment program the fetal hypothalamic-pituitary-adrenal axis to prepare the neonate to survive in a stressful postnatal environment. Such programming may include mechanisms that lead to alterations in the temperament of an animal. Therefore, a collaborative study was conducted with scientists from Texas A&M University, Mississippi State University, and the USDA-ARS Livestock Issues Research Unit to determine if exposing gestating calves to a prenatal transportation event would affect the postnatal innate immune response of Brahman calves to an endotoxin challenge. To test this hypotheses, an experiment was conducted that evaluated the effects of a repeated transportation event during five time periods of gestation. Specifically, ninety-six pregnant Brahman cows were assigned to either a transportation group or control group. The transported cows were transported for two hours at 60, 80, 100, 120, and 140 ± 5 days of gestation. The control cows were maintained in the same manner as stressed cows with the exception of being transported. Results from this study demonstrated an altered physiological response to an acute immune challenge in weaned prenatally stressed bulls, suggesting an impact on the body’s capacity to respond to an immunological insult. Because one’s health begins in utero, this model can provide insight into the genetic and/or epigenetic effects of prenatal stress on postnatal health and performance of animals and humans. This information will be of specific interest to both beef cattle and dairy cattle producers, and veterinarians working with these producers.

Technical Abstract: The objective of this study was to assess the influence of prenatal stress (PNS) on innate immune response to an endotoxin challenge in weaned bull calves. Temperament [Calm (C); Intermediate (I), or Temperamental (T)] was also assessed. Brahman cows (n=96; 48 stressed by transportation at 5 stages of gestation and 48 Controls) produced 85 calves, from which 16 uncastrated male (bull) calves from each PNS and Control treatment were selected for an LPS challenge period. The transported cows were transported for two hours at 60, 80, 100, 120, and 140 ± 5 days of gestation. Rectal temperature (RT), sickness behavior score (SBS), cortisol, interferon-gamma (IFN), tumor necrosis factor-alpha (TNF), interleukin-6 (IL-6), and complete blood count (CBC) variables were assessed in response to i.v. LPS (0.25 micrograms/kg BW) administration. All variables increased following LPS (P<0.01). During both pre- and post-LPS periods, PNS had greater (P<0.01) RT than Control bulls, and T had greater (P<0.01) RT than C and I bulls. Post-LPS SBS was greatest (P<0.01) in C-PNS bulls. Post-LPS cortisol was lowest (P<0.01) in T bulls. Pre-LPS IFN was reduced (P<0.01) and post-LPS was greater (P<0.01) in PNS compared with Control bulls. Post-LPS IFN was greatest (P<0.01) in I-PNS bulls. Pre- and post-LPS TNF was greater (P=0.03 and P<0.01, respectively) in PNS than Control bulls. Post-LPS TNF was greatest (P<0.01) in T-PNS bulls. Pre-LPS IL-6 was greater (P=0.02) and post-LPS IL-6 was reduced (P=0.04) in PNS compared with Control bulls. Prenatal transportation altered the innate immune response to an LPS challenge within temperament groups before and after LPS, suggesting an impact on the body’s capacity to respond to an immunological insult.