title: Enhancement of the acute phase response to a lipopolysaccharide challenge in steers supplemented with chromium.
abstract: The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Steers received a premix that added 0 (control; n = 10) or 0.2 mg/kg of chromium (n = 10) to the total diet on a dry matter basis for 56 d. Steers were fitted with jugular catheters and rectal temperature (RT) recording devices on d 52. Blood samples were collected and sickness behavior scores assigned to each steer relative to an LPS challenge (0.5 µg/kg) on d 55. Pre-LPS RT were greater in chromium-supplemented than in control steers. Post-LPS RT increased in both treatments, with control steers producing a greater change in RT than chromium-supplemented steers. Sickness behavior scores were greater in control than in chromium-supplemented steers post-LPS (P = 0.03). Cortisol concentrations did not differ between treatments pre-LPS. Post-LPS cortisol concentrations increased but did not differ due to treatment. Concentrations of IL-4 increased post-LPS but were not affected by treatment pre- or post-LPS. Treatment did not affect pre-LPS TNF-α or IFN-γ. Post-LPS TNF-α and IFN-γ increased in both treatments, with chromium-supplemented steers producing greater TNF-α (P = 0.005) and IFN-γ (P = 0.004) than control steers. Pre-LPS IL-6 was greater (P = 0.027) in chromium-supplemented steers than in control steers. Post-LPS IL-6 increased in both treatments and was greater (P < 0.001) in chromium-supplemented than in control steers. These data suggest that chromium supplementation enhances the acute phase response of steers to an LPS challenge, which may expedite recovery.
authors.affiliation: USDA ARS Livestock Issues Research Unit, Lubbock, TX 79403, USA.
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Burdick
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Bernhard
authors.forename: Jeffery A
authors.initials: JA
authors.lastname: Carroll
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Rathmann
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Johnson
mesh_terms: D000210:Acute-Phase Reaction / Q000276:immunology* / Q000662:veterinary; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004032:Diet; D019587:Dietary Supplements; D018450:Disease Progression; D019446:Endotoxemia / Q000276:immunology* / Q000662:veterinary; D005786:Gene Expression Regulation; D056747:Immunomodulation; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D011422:Propionates / Q000008:administration & dosage*
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides; D011422:Propionates; C029658:propionic acid