Abstract
The carcass traits of 229 F[] steers sired by 15 Brahman bulls and 1 Nellore bull and out of Angus and Hereford dams were evaluated. The first calves were born in the Spring of 1994 and the last calves were born in the Spring of 1998. Of the steers already slaughtered, 169 have been Brahman-Angus, 41 Brahman-Hereford, and 19 Nellore-Angus. The F[] steers averaged 427 d of age at slaughter. The carcass traits analyzed in this study include mutability, quality, and tenderness traits. The curability traits evaluated include actual fat thickness, preliminary yield grade, hot carcass weight, longissimus muscle area (ribeye area), ribeye area/100 kg of hot carcass weight, estimated internal fat percentage, and yield grade. The quality traits include lean maturity, skeletal maturity, and marbling score. The tenderness traits evaluated were Wamer-Bratzler shear force values for the postmortem aging periods of 0, 7, 14, 21, 28, and 35 d. The curability traits averaged 1.08 [] .37 cm, 3.17 [] .34, 312.75 [] 32.31 kg, 77.11 [] 6.87 cmz, 24.83 [] 2.19 cmz, 2.31 [] .51%, and 2.92 [] .56, respectively, for actual fat thickness, preliminary yield grade, hot carcass weight, longissimus muscle area, longissimus muscle area 100 Kg of hot carcass weight, estimated internal fat percentage, and yield grade. The quality traits of lean maturity and skeletal maturity averaged 166.72 [] 14.93 and 156.81 [] 7.50, respectively, and marbling score averaged 365.94 [] 48.75. Warner-Bratzler shear force averages for 0, 7, 14, 21, 28, and 35 d of postmortem aging were 3.66 [] .84, 3.32 [] .72, 2.87 [] .63, 3.08 [] .69, 3.00 [] .66, and 3.03 [] .70 kg, respectively. The average Warner-Bratzler shear force value across all steers and all aging periods was 3.16 [] .7 kg. Breed of dam differences were also evaluated. Angus dams produced steers with heavier hot carcass weights, more external fat, higher preliminary yield grades, larger ribeye areas, more KPH, higher yield grades, higher skeletal maturity, and more marbling than steers produced in the same years out of Hereford dams.
Fry, Cody Allen (1999). Evaluation of carcass traits of F₁ calves sired by Bos indicus bulls. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1999 -THESIS -F79.