title: Effects of supplemental chromium on antibody responses of newly weaned feedlot calves to immunization with infectious bovine rhinotracheitis and parainfluenza 3 virus.
abstract: The objective of this study was to determine the effect of supplemental dietary chromium (Cr) on antibody responses of feedlot calves. Fifty-five newly weaned calves were divided into two groups, 28 that received supplemental Cr and 27 that did not, and were immunized with a commercial vaccine against bovine infectious rhinotracheitis virus (IBR) and bovine parainfluenza virus type 3(PI-3). Sera harvested from blood sampled preimmunization, and at days 14 and 28 postimmunization (PI), were assayed for anti-IBR and anti-PI-3 antibody titers. Individual calves were also scored as seroconverters if day 14 or 28 PI titers were > or = 3 times the value of the preimmunization titer. Thirty-five calves did not seroconvert to either antigen. Of 20 IBR seroconverters, 15 calves were from the Cr-supplemented group while only five calves were controls (p = 0.007). There was no treatment difference in the number of PI-3 seroconverters. Least squares analysis of actual antibody titers revealed that Cr supplementation increased the magnitude of the peak antibody response to the IBR (p = 0.003), but had no effect on anti-PI-3 antibody titers. These data confirmed and extended our previous observations that supplemental Cr can be immunomodulatory in cattle.
authors.affiliation: Department of Veterinary Microbiology and Immunology, University of Guelph, Ontario.
authors.forename: J L
authors.initials: JL
authors.lastname: Burton
authors.forename: B A
authors.initials: BA
authors.lastname: Mallard
authors.forename: D N
authors.initials: DN
authors.lastname: Mowat
mesh_terms: D000704:Analysis of Variance; D000821:Animal Feed; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D002417:Cattle / Q000276:immunology*; D002857:Chromium / Q000008:administration & dosage*; D004032:Diet; D005527:Food, Fortified; D007242:Herpesvirus 1, Bovine / Q000276:immunology*; D007114:Immunization / Q000662:veterinary; D010224:Parainfluenza Virus 3, Human / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D014886:Weaning
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines; D002857:Chromium