Abstract
Production and carcass data from 241 calves sired by 34 bulls of the Hereford, Brahman, Santa Gertrudis, Charolais, Charbray, and Brown Swiss breeds were analyzed to estimate phenotypic and genetic parameters for fourteen production and carcass traits and to develop regression equations to predict carcass cutability. Separate estimates and regression equations were calculated from records of 76 Hereford calves. The traits studied were birth weight, 180-day weight, average daily gain in the feedlot, final weight off test, carcass weight, weight of boneless steak and roast meat, rib eye area, fat thickness at the 12th rib, kidney fat weight, carcass grade, shear force, length of leg, length of body, and width of round. Least-square s analyses of variance and covariance were computed for each trait for all breeds combined and for Herefords only. Constants for nongenetic factors for all breeds combined were obtained from a model which included a sire-breed subclass and were used to adjust the data before estimating heritabilities and genetic and phenotypic correlations from intra-breed and sire analyses of variance and covariance. The data for Hereford cattle were analyzed from a statistical model which included sire as a main effect, and heritabilities were estimated from the sire and error components of variance. ...
Dubose, Leo Edwin (1965). Genetic and phenotypic relationships among production and carcass characteristics in beef cattle. Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -174744.