Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/22/2002
Publication Date: 4/1/2003
Citation: Casas, E., Cundiff, L.V. 2003. Maternal grandsire, granddam, and sire breed effects on growth and carcass traits of crossbred cattle. Journal of Animal Science. 81:904-911. Interpretive Summary: The beef industry is under increasing pressure to improve the consistency of beef by reducing fat while improving palatability of beef products. One way to accomplish this is to utilize breeds of cattle that will more closely meet product targets. This project was designed to determine differences among beef breeds for carcass traits evaluating carcasses of steers and heifers produced by mating crossbred cows, obtained by crossing British breed (Hereford or Angus), Brahman, Boran, Tuli, or Belgian Blue bulls to Hereford, Angus and MARC II cows, with Charolais or crossbred (Belgian blue x British breed ) bulls. Animals with Belgian Blue maternal grandsire breed produced the leanest, heaviest muscled carcasses. Carcasses of animals with British breed grandsire breed were the fattest and least muscular. Tuli, as a tropically adapted breed, appear to provide heat tolerance without a detrimental effect on meat tenderness. No one grandsire breed excelled in every trait. Sire and maternal grandsire breed differences allow optimization of postweaning growth and carcass traits by incorporating these breeds in selection and crossbreeding schemes.
Technical Abstract: Postweaning growth, feed efficiency, and carcass traits were analyzed on 1422 animals obtained by mating F1 cows to F1 (Belgian Blue X British breeds) or Charolais sires. Cows were obtained from mating Hereford, Angus and MARC III dams to Hereford or Angus (British breeds), Tuli, Boran, Brahman or Belgian Blue sires. Breed groups were fed in replicated pens and slaughtered serially in each of two years. Postweaning average daily gain (PWADG; kg/d), live weight (LWT; kg), hot carcass weight (HCW; kg), fat depth (FAT; cm), longissimus area (LMA; cm2), estimated kidney, pelvic and heart fat (KPH; %), percentage choice (CH; %), marbling score (MA), USDA yield grade (YG), retail product yield (RPYD; %), retail product weight (RPWT; kg), fat yield (FATYD; %), fat weight (FATWT; kg), bone yield (BONEYD; %), and bone weight (BONEWT; kg), were analyzed in this population. Quadratic regressions of pen mean weight on days fed and of cumulative metabolizable energy consumption (ME) on days fed were used to estimate gain, ME consumption and efficiency (Mcal ME/kg gain) over time (0 to 200 d on feed) and weight (300 to 550 kg) intervals. Maternal grandsire breed was significant (P < 0.01) for all traits. Maternal granddam breed (Hereford, Angus, or MARC III) was significant only (P < 0.05) for FAT, YG, RPYD, FATYD, FATWT, and BONEYD. Sire breed was significant (P < 0.05) for all traits except KPH, RPYD, FATYD, and FATWT. Sex class was a significant source of variation for all traits except CH, MA, RPYD, and FATYD. Sire and grandsire breed effects can be optimized by selection and use of appropriate crossbreeding systems.