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dc.contributor.authorHay, El Hamidi Abdel
dc.date.accessioned2014-03-04T20:02:43Z
dc.date.available2014-03-04T20:02:43Z
dc.date.issued2011-08
dc.identifier.otherhay_el-hamidi_a_201108_ms
dc.identifier.urihttp://purl.galileo.usg.edu/uga_etd/hay_el-hamidi_a_201108_ms
dc.identifier.urihttp://hdl.handle.net/10724/27471
dc.description.abstractDays on feed (DOF) is an essential component in the profitability of feedlot industry. Several equations have been developed to predict DOF that include multiple animal and environmental factors. More recently, molecular information (molecular breeding values) for several traits is available to add to the calculation of DOF, with the advantage that this information is readily available as soon as the animal is genotyped for a set of single nucleotide polymorphisms (SNPs). In this study, a data set of 10,209 feedlot animals were used to establish a prediction equation for DOF based on arrival weight, sex, growth, genotypes (for 200 SNP markers), and an imputed Zilmax status. Three models were compared in their prediction ability of DOF. The first model (M1) included the following effects (sex, HCW, initial weight, marbling score, backfat, ribeye area, and 36 SNPs selected out of the available 200 SNPs). The second model, M2, included all the effects in M1 plus Zilmax status (case/control) based on the predicted probabilities using 0.5 as a threshold value. The third model, M3, included all effects in M1 and the uncertain or unknown Zilmax status. Several analyses were conducted where a joint crisp and soft classification of Zilmax status was adopted.
dc.languageeng
dc.publisheruga
dc.rightspublic
dc.subjectZilmax
dc.subjectPrediction
dc.subjectDays on feed
dc.subjectSNP
dc.titleBayesian analysis in the presence of missing explanatory variables
dc.title.alternativeapplication to days on feed in feedlot cattle
dc.typeThesis
dc.description.degreeMS
dc.description.departmentAnimal and Dairy Science
dc.description.majorAnimal Science
dc.description.advisorRomdhane Rekaya
dc.description.committeeRomdhane Rekaya
dc.description.committeeBrent Woodward
dc.description.committeeIgnacy Misztal
dc.description.committeeJ. Keith Bertrand


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