Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 28, 2003
Publication Date: December 1, 2003
Citation: CASAS, E., SHACKELFORD, S.D., KEELE, J.W., KOOHMARAIE, M., SMITH, T.P., STONE, R.T. DETECTION OF QUANTITATIVE TRAIT LOCI FOR GROWTH AND CARCASS COMPOSITION IN CATTLE. 2003. JOURNAL OF ANIMAL SCIENCE. 81:2976-2983. Interpretive Summary: The objective of the present study was to identify the location of genes affecting growth and carcass traits in cattle. Locations of genes affecting these traits were detected on nineteen different chromosomes. Eight of these locations influenced more than one trait. Evidence supports the presence of genes affecting growth and carcass traits in five of these regions, while there is evidence only suggesting the presence of genes affecting these traits in the remaining regions. Further studies are necessary to assess if other locations harbor genes associated with growth and carcass traits in these families. However, locations of genes reported here are suitable to be investigated in other populations.
Technical Abstract: The objective of the present study was to detect quantitative trait loci for economically important traits in a family from a Bos indicus x Bos taurus sire. A Brahman x Hereford sire was used to develop a half-sib family (n = 547). The sire was mated to Bos taurus cows. Traits analyzed were birth (kg) and weaning weights (kg), hot carcass weight (kg), marbling score, longissimus area (cm2), USDA yield grade, estimated kidney, pelvic and heart fat (%), fat thickness (cm), fat yield (%), and retail product yield (%). Meat tenderness was measured as Warner-Bratzler shear force at 3 and 14 d postmortem (kg). A total of 312 markers were used in the analysis. Significant quantitative trait loci (Expected number of false-positives per genome scan < 0.05) were observed for birth weight and longissimus area on chromosome 5, for longissimus area on chromosome 6, for retail product yield on chromosome 9, for birth weight on chromosome 21, and for marbling score on chromosome 23. Evidence suggesting (Expected number of false-positives per genome scan < 1) the presence of quantitative trait loci were detected for birth weight on chromosome 1, for USDA yield grade, fat thickness, and birth weight on chromosome 2, for marbling score, fat thickness, and birth weight on chromosome 3, for fat thickness on chromosome 7, for marbling score and hot carcass weight on chromosome 10, for USDA yield grade on chromosome 11, for retail product yield on chromosome 13, for fat thickness, USDA yield grade, and marbling score on chromosome 14, for estimated kidney, pelvic and heart fat on chromosome 16, for hot carcass weight and retail product yield on chromosome 18, for retail product yield and USDA yield grade on chromosome 19, for meat tenderness at 3 d and at 14 d postmortem on chromosome 20, for marbling score on chromosome 27, and for weaning weight, retail product yield, hot carcass weight, and meat tenderness at 14 d postmortem on chromosome 29.