Genetic parameter estimates for finished steer carcass and yearling bull ultrasound measurements

dc.contributor.advisorWilton, J.W.
dc.contributor.authorDevitt, Crosby Jordan Blake
dc.date.accessioned2020-08-24T15:56:06Z
dc.date.available2020-08-24T15:56:06Z
dc.date.copyright2000
dc.degree.departmentDepartment of Animal and Poultry Scienceen_US
dc.degree.grantorUniversity of Guelphen_US
dc.degree.nameMaster of Scienceen_US
dc.description.abstractCarcass and growth measurements of finished crossbred steers (n = 843) of multiple breeds and yearling ultrasound and growth measurements of purebred bulls (n = 5654) of 11 breeds were an analyzed to estimate genetic parameters. Multiple trait restricted maximum likelihood (REML) was used to estimate heritabilities and genetic correlations between steer hot carcass weight (SHCW), steer carcass ribeye area (SREA), steer carcass backfat (SBFAT), steer carcass marbling score (SMAR), steer average daily feedlot gain (SADG), bull ultrasound ribeye area (BREA), bull ultrasound backfat (BBFAT), bull ultrasound percent intramuscular fat (BIMF), and bull average daily post weaning gain (BADG). Three end-points were considered: backfat, age and weight at measurement. Backfat constant genetic correlations between SREA and BREA, SMAR and BIMF, and SADG and BADG were .57, .68, and .87, respectively. Age constant genetic correlations between SREA and BREA, SBFAT and BBFAT, SMAR and BIMF, and SADG and BADG were .66, .80, .88 and .72, respectively. Weight constant genetic correlations between SREA and BREA, SBFAT and BBFAT, SMAR and BIMF, and SADG and BADG were .82, .75, .90 and .46, respectively. The strong, positive genetic correlation estimates between steer carcass measurements and corresponding bull ultrasound measurements suggest that genetic improvement for steer carcass traits can be achieved by using yearling bull ultrasound measurements as selection criteria.en_US
dc.identifier.urihttps://hdl.handle.net/10214/20634
dc.language.isoen
dc.publisherUniversity of Guelphen_US
dc.rights.licenseAll items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectcarcassen_US
dc.subjectgrowth measurementsen_US
dc.subjectcrossbred steersen_US
dc.subjectbreedsen_US
dc.subjectyearling ultrasounden_US
dc.subjectpurebred bullsen_US
dc.subjectgenetic parametersen_US
dc.subjectmultiple trait restricted maximum likelihooden_US
dc.subjectheritabilitiesen_US
dc.subjectgenetic correlationen_US
dc.subjectsteer carcass traitsen_US
dc.titleGenetic parameter estimates for finished steer carcass and yearling bull ultrasound measurementsen_US
dc.typeThesisen_US

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Devitt_CrosbyJB_MSc.pdf
Size:
4.57 MB
Format:
Adobe Portable Document Format