Feed efficiency, carcass, and temperament traits in F2 Nellore-Angus steers

dc.contributor.advisorGill, Clare A.
dc.contributor.advisorHerring, Andy D.
dc.contributor.committeeMemberDerr, James
dc.contributor.committeeMemberSanders, James O.
dc.contributor.committeeMemberSawyer, Jason E.
dc.creatorAmen, Tonya Sue
dc.date.accessioned2010-01-15T00:04:22Z
dc.date.accessioned2010-01-16T00:04:02Z
dc.date.available2010-01-15T00:04:22Z
dc.date.available2010-01-16T00:04:02Z
dc.date.created2007-12
dc.date.issued2009-05-15
dc.description.abstractFeed efficiency in fed F2 Nellore-Angus steers produced through embryo transfer was evaluated using two methods: residual feed intake (RFI) and NRC-based model predicted residual consumption (MPRC). Sire and family(sire) both contributed to differences in model predicted residual consumption (P = 0.036 and P < 0.001, respectively), but not in RFI (P = 0.117 and 0.455, respectively). This indicates that variation exists among the sires and families studied, and the opportunity exists to improve MPRC through selection; it also indicates these 2 evaluation methods could result in different conclusions about feed efficiency. Five aspects of temperament were also evaluated (aggressiveness, nervousness, flightiness, gregariousness, and overall temperament) on a 9-point scale shortly after weaning. Sire had a significant effect on all 5 aspects of temperament evaluated, but family was only responsible for variation in aggressiveness, nervousness, and overall temperament. Contemporary group had no effect on aggressiveness, but did contribute significantly to variation in all other temperament traits. All temperament traits were highly correlated with one another (r = 0.81 to 0.98). Recipient dam temperament was lowly correlated with gregariousness and overall temperament (r = 0.16 and 0.15, respectively), and the correlations with recipient dam temperament approached significance for aggressiveness, nervousness and flightiness. This suggests that the temperament of the recipient female may have a small effect on the temperament of the calf. This population was structured to identify QTL for economically important traits and appears to be useful to identify genetic markers for feed efficiency and animal temperament.en
dc.format.digitalOriginborn digitalen
dc.format.mediumelectronicen
dc.format.mimetypeapplication/pdf
dc.identifier.urihttps://hdl.handle.net/1969.1/ETD-TAMU-2009
dc.language.isoen_US
dc.relation.urihttps://hdl.handle.net/1969.1/85776
dc.subjectfeed efficiencyen
dc.subjecttemperamenten
dc.subjectcattleen
dc.titleFeed efficiency, carcass, and temperament traits in F2 Nellore-Angus steersen
dc.typeBooken
dc.typeThesisen
dc.type.genreElectronic Dissertationen
dc.type.materialtexten
thesis.degree.departmentAnimal Scienceen
thesis.degree.disciplineAnimal Breedingen
thesis.degree.grantorTexas A&M Universityen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen

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