Effects of early weaning on finishing feed efficiency, marbling development and retail product quality of beef steers

dc.contributor.authorSmith, Jason Kaleben
dc.contributor.committeechairMcCann, Mark A.en
dc.contributor.committeememberHanigan, Mark D.en
dc.contributor.committeememberEl-Kadi, Samer Wassimen
dc.contributor.committeememberJohnson, Sally E.en
dc.contributor.committeememberGreiner, Scott P.en
dc.contributor.departmentAnimal and Poultry Sciencesen
dc.date.accessioned2015-09-18T20:08:46Zen
dc.date.available2015-09-18T20:08:46Zen
dc.date.issued2015-09-03en
dc.description.abstractBeef cattle producers continuously search for nutritional management options that provide flexibility to production scenarios. Due to its positive effects on maternal productivity, early weaning is one such alternative strategy that has received considerable interest. To better understand the effects of early weaning on calf productivity, an extensive literature review and three experiments were conducted to evaluate the effects of early weaning on finishing feed efficiency, marbling development and retail product quality of beef steers. In experiment I, which included 90 Angus-sired steers from four calving seasons, early weaning followed by a short ad libitum concentrate-feeding and pasture-backgrounding phase reduced finishing residual feed intake (RFI) by 7 % (P < 0.0001) and increased carcass marbling score (MS) by 10 % (P < 0.01) when compared to conventionally weaned (CW) contemporaries. Similar effects were observed in experiment II, which included 28 Angus and Simmental-sired steers, as early weaning reduced RFI (P < 0.01) and increased carcass MS (P < 0.01). Lung mass of early weaned (EW) steers was greater than their CW contemporaries (P < 0.05), and was inversely related to RFI (R2 = 0.17; P < 0.05). Finishing treatments in this experiment included a high corn ration and an alternative low corn ration that iso-calorically replaced 50 % of the DM from corn with dried corn gluten feed. Iso-caloric replacement of corn reduced lung mass (P < 0.01), and when combined with the observed increase of EW steers suggests that lung development is affected by dietary energy type at various stages of growth. In experiment III, objective analyses of ribeye steaks obtained from steers included in experiment two revealed that early weaning increased cross-sectional muscle fiber area by 28 % (P < 0.001) and tended to increase (P = 0.08) Warner-Bratzler shear force by 36 %. Nonetheless, these effects were not great enough to alter un-trained consumer perception of texture (P ≥ 0.65), juiciness (P ≥ 0.55), flavor (P ≥ 0.25) or overall acceptability (P ≥ 0.34). Collectively, these results indicate that early weaning enhances finishing feed efficiency and carcass marbling without affecting un-trained consumer sensory perception.en
dc.description.degreePh. D.en
dc.format.mediumETDen
dc.identifier.othervt_gsexam:6261en
dc.identifier.urihttp://hdl.handle.net/10919/56596en
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectearly weaningen
dc.subjectfeed efficiencyen
dc.subjectmarbling developmenten
dc.titleEffects of early weaning on finishing feed efficiency, marbling development and retail product quality of beef steersen
dc.typeDissertationen
thesis.degree.disciplineAnimal and Poultry Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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