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Evaluation of Weaning Stress in Beef Calves

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dc.contributor.authorLanda, Chelsea E.en
dc.contributor.committeechairSwecker, William S. Jr.en
dc.contributor.committeememberWahlberg, Mark L.en
dc.contributor.committeememberTracy, Benjamin F.en
dc.contributor.departmentBiomedical and Veterinary Sciencesen
dc.date.accessioned2014-03-14T20:41:27Zen
dc.date.adate2011-07-19en
dc.date.available2014-03-14T20:41:27Zen
dc.date.issued2011-06-30en
dc.date.rdate2011-07-19en
dc.date.sdate2011-07-14en
dc.description.abstractConventional techniques within the beef cattle industry involve weaning the calf from the dam when the calf is about 205 days of age. Weaning induces a stress-response that is implicated in reducing the health and productivity of newly weaned calves. Our goal was to evaluate the impact of weaning on the stress immune responses of beef calves. To that end, we 1) evaluated novel methods to quantify physiological markers of stress, 2) compared immune function and growth of calves grazing legume versus grass forages, and 3) compared the effects of abrupt versus two-stage weaning on calves. In study 1, calf, yearling, and adult beef cattle were used to assess the accuracy and precision of handheld glucometers in quantifying bovine blood glucose concentration. Precision Xtra® and ReliOn® glucometers were used chute side to quantify blood glucose concentrations in cattle and were compared to an accepted plasma glucose analysis on the same samples for validation. The Precision Xtra® glucometer was more accurate and precise than the ReliOn® glucometer. In study 2, weaned heifers were used to compare the immunomodulatory effects of grazing alfalfa versus fescue over a 30 day grazing period. No differences were detected in the interferon gamma (IFNγ) production and weight gain between the heifers on alfalfa and fescue. In study 3, effects of two-stage (fenceline) and abrupt weaning were compared. Calf weights, immune cell function, antibody production, blood glucose concentrations, fecal cortisol concentrations, and gene expression (FAS, IL-4,IL-10, and IFNγ) were measured pre- and post-weaning. On the day after weaning, the abruptly weaned calves had higher blood glucose concentrations than fenceline weaned calves. Fecal cortisol concentration and gene expression of FAS and IL-4 increased in both groups after weaning, but no differences were detected between the weaning treatments. Gene expression of IL-10 and IFNγ did not change over time. No date, treatment or treatment*date effect was detected for total weight gain or IFNγ production within the non-stimulated and the mitogen-stimulated whole blood samples.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-07142011-082442en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07142011-082442/en
dc.identifier.urihttp://hdl.handle.net/10919/34009en
dc.publisherVirginia Techen
dc.relation.haspartLanda_CL_T_2011.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectIgG2en
dc.subjectIgG1en
dc.subjectIFN-γen
dc.subjectblood glucoseen
dc.subjectqPCRen
dc.subjectforage-finished beefen
dc.subjectcalvesen
dc.subjectweaningen
dc.subjectfencelineen
dc.subjectcattleen
dc.titleEvaluation of Weaning Stress in Beef Calvesen
dc.typeThesisen
thesis.degree.disciplineBiomedical and Veterinary Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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