Location: Livestock Issues ResearchTitle: Exogenous administration of lipids to steers alters aspects of the innate immune response to endotoxin challenge Author
|Carroll, Jeffery - Jeff Carroll|
|Donaldson, Janet - Mississippi State University|
|Buntyn, Joe - University Of Nebraska|
|Schmidt, Ty - University Of Nebraska|
Submitted to: Innate Immunity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2014
Publication Date: 1/15/2015
Citation: Sanchez, N.C., Carroll, J.A., Donaldson, J.R., Buntyn, J.O., Schmidt, T.B. 2015. Exogenous administration of lipids to steers alters aspects of the innate immune response to endotoxin challenge. Innate Immunity. 21(5):512-522.
Interpretive Summary: This study is a collaborative effort from scientists within the USDA-ARS Livestock Issues Research Unit and from Mississippi State University and the University of Nebraska-Lincoln. Previous data has indicated that changes in energy availability, such as greater circulating concentrations of free fatty acids observed in temperamental (or excitable) cattle may benefit the innate immune response. For example, previous research has demonstrated that temperamental cattle exhibit greater non-esterified fatty acid concentrations while producing a reduced rectal temperature, sickness behavior, cortisol, and glucose response to an immune challenge. Therefore, this study was designed to determine if increasing available energy, either through a continuous lipid infusion or through a one-time administration of glucose, would alter the immune response of dairy steers. The results of the study demonstrate that indeed, providing additional energy prior to and during the immune challenge was able to reduce various aspects of the innate immune response, including rectal temperature, cortisol, and the pro-inflammatory cytokine response. These data support the conclusions that increasing energy availability can alter the innate immune response to an immune challenge, and support the results observed in temperamental cattle. Results from this study will be of interest to researchers in the areas of immunology, animal health and animal nutrition.
Technical Abstract: Limitations in energy availability are known to impede the efficiency of the immune response to endotoxemia. Therefore, this study examined the effects of increasing energy availability on the pro-inflammatory response to LPS in Holstein steers. Steers were randomly assigned to 1 of 3 groups (n = 7 per group): saline at 0.5 mL/kg BW (Control) or 50% dextrose (0.5 mL/kg BW; Dextrose) administered immediately prior to LPS (0.5 µg/kg BW at 0 h), or continuous lipid emulsion infusion from -1 to 6 h (Intralipid 20%; 0.5 mL/kg/h; Lipid). Concentrations of non-esterified fatty acids (NEFA) were greater (P<0.001) in steers provided the lipid infusion compared to Control and Dextrose steers. A greater decrease (P=0.02) in the change in rectal temperature, relative to baseline, was observed in response to LPS in Dextrose in comparison to Control and Lipid steers. Cortisol was greater (P=0.002) in Lipid than Dextrose and Control steers from -0.5 to 0 h, yet decreased (P=0.002) from 0.5 to 5.5 h relative to LPS challenge. Concentrations of IL-6 were decreased (P<0.001) in Lipid steers in comparison to Dextrose and Control steers, and were decreased (P<0.001) in Dextrose than Control steers post LPS challenge. Together, these data suggest that increasing circulating NEFA may modulate the pro-inflammatory response in steers.