Relationships among lifetime measures of growth and frame size for commercial beef females in a pasture-based production system in the Appalachian region of the United States

dc.contributor.authorEchols, Allison Clareen
dc.contributor.committeecochairGreiner, Scott P.en
dc.contributor.committeecochairWahlberg, Mark L.en
dc.contributor.committeememberSwecker, William S. Jr.en
dc.contributor.departmentAnimal and Poultry Sciencesen
dc.date.accessioned2014-03-14T20:45:27Zen
dc.date.adate2011-10-10en
dc.date.available2014-03-14T20:45:27Zen
dc.date.issued2011-09-09en
dc.date.rdate2011-10-10en
dc.date.sdate2011-09-16en
dc.description.abstractThe beef cattle industry has placed increased focus on mature cow size as a result of its influence on production efficiency and profitability. The objectives of this study were to evaluate relationships among lifetime measures of body weight (BW) and frame score (FS) in commercial beef females, and to assess the value of immature measures as predictors of mature cow size. Measurements of BW, hip height (HH), body condition score (BCS), and calculated FS were recorded at weaning (WN), breeding at 13 mo age (BR), and 8 subsequent periods, ceasing at approximately 5 yr of age for 232 Angus-cross females born 2004 through 2008. Correlation analysis revealed significant (P < 0.001) relationships among BW taken at WN and BR with BW measurements taken at 2.5, 3.8, and 4.8 yr of age (WN r = 0.70, 0.51, 0.61; BR r = 0.65, 0.57, 0.64, respectively). Significant relationships (P < 0.001) existed between FS collected at WN and BR, and FS at 2.5 and 3.8 yr (WN= 0.70, 0.72; BR= 0.79, 0.82, respectively). Repeatability of lifetime FS measures was 0.73. BCS was a significant (P < 0.001) source of variation in mature BW, with a unit change in BCS accounting for 41 kg BW change at 4.8 yr (P < 0.001). BW and FS were moderately to strongly related (P < 0.001) at WN, BR, 2.5, 3.8, and 4.8 yr (r = 0.62, 0.49, 0.62, 0.62, and 0.47 respectively). Prediction models for BW at 4.8 yr were similar using weaning BW alone, or with inclusion of both weaning BW and HH (R2 = 0.57 and 0.56). Similarly, breeding BW and HH were non-additive for prediction of 4.8 yr BW (R2 = 0.68, 0.58, and 0.68 for BW, HH, and BW +HH respectively). Performance at immature ages proves to be a satisfactory indicator of mature size, supporting continued incorporation of immature BW and HH and/or FS measurements into selection practices.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-09162011-210222en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-09162011-210222/en
dc.identifier.urihttp://hdl.handle.net/10919/35076en
dc.publisherVirginia Techen
dc.relation.haspartEchols_AllisonC_T_2011.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectframe scoreen
dc.subjectmature sizeen
dc.subjectbeef cowen
dc.subjectbody weighten
dc.titleRelationships among lifetime measures of growth and frame size for commercial beef females in a pasture-based production system in the Appalachian region of the United Statesen
dc.typeThesisen
thesis.degree.disciplineAnimal and Poultry Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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