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Identifying a non-invasive measure of bone status in dairy cattle

dc.contributor.authorKeene, Beth E.en
dc.contributor.committeechairKnowlton, Katharine F.en
dc.contributor.committeememberWilson, James H.en
dc.contributor.committeememberMcGilliard, Michael L.en
dc.contributor.committeememberNickols-Richardson, Sharon M.en
dc.contributor.departmentDairy Scienceen
dc.date.accessioned2011-08-06T14:40:10Zen
dc.date.adate2003-10-09en
dc.date.available2011-08-06T14:40:10Zen
dc.date.issued2003-08-01en
dc.date.rdate2004-10-09en
dc.date.sdate2003-08-13en
dc.description.abstractThe objectives of this research were to evaluate non-invasive measures of bone mineral content (BMC) and bone mineral density (BMD) as rapid, on-farm tools to assess phosphorus (P) status in dairy cows. In addition, the effects of parity and stage of lactation on measures of BMC of the fused 3rd and 4th metacarpal bone and of caudal vertebrae 14 and 15 were assessed. The caudal vertebrae and right front metacarpal (sample pairs) were excised from 107 Holstein cull cows following slaughter. Parity, age, and days in milk (DIM) of the donor animal were obtained for 43 pairs of samples. Samples were grouped by parity (1, 2, 3, and >4) and stage of lactation (Stage 1 = < 90 DIM, Stage 2 = > 90 and < 150 DIM, Stage 3 = >150 and < 250 DIM and Stage 4 = > 250 DIM). Samples were analyzed for BMC and BMD with dual energy X-ray absorptiometry (DXA), BMC with radiographic photometry (RP), breaking strength with mechanical methods, and mineral content with chemical procedures. Estimates of BMC obtained with RP and DXA were poorly related to chemical measures of actual BMC and to measures of breaking strength. In caudal vertebrae 14 and 15, increasing stage of lactation decreased energy to peak load with the lowest values observed in late lactation. Stage of lactation had no effect on BMC measured chemically in the caudal vertebrae or metacarpal. Parity did not affect breaking strength of the metacarpal or caudal vertebrae or total ash or P content of any bone. Results indicated that imaging techniques are not useful measures of BMC in mature dairy cattle.en
dc.description.degreeMaster of Scienceen
dc.format.mediumETDen
dc.identifier.otheretd-08132003-074329en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08132003-074329en
dc.identifier.urihttp://hdl.handle.net/10919/9599en
dc.publisherVirginia Techen
dc.relation.haspartFinalthesis.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectbone strengthen
dc.subjectradiographic photometryen
dc.subjectBone mineral contenten
dc.subjectDXAen
dc.titleIdentifying a non-invasive measure of bone status in dairy cattleen
dc.typeThesisen
thesis.degree.disciplineDairy Scienceen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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