Thermodynamic Cooking Methods

Genetic evaluations for traditional carcass characteristics have been published for limited numbers of sires by various beef breed associations. Collection of carcass information is difficult, which limits the amount of information generated for these traits. The routine carcass field data collected do not include observations for measures of tenderness or any information on sensory panel assessment of meat quality, prohibitive due to costs and logistics. An objective of the National Cattlemens Beef Association’s Carcass Merit Project (CMP) was to collect data on tenderness and sensory panel assessments along with the traditional carcass characteristics from a set of legacy bulls from all breeds participating in the project. These data are being used to provide information for the calculation of expected progeny differences (EPD’s) and to validate the segregation of quantitative trait loci (QTL’s), discovered in the Texas A&M Angleton Project, in these breeds. Eleven QTL’s are being validated, six for Warner-Bratzler shear force, three for marbling, and one each for sensory panel tenderness scores and rib eye area. Estimates of heritability for shear force measures on Simmental and Angus cattle in the project were 0.22 and 0.25, respectively. Genetic evaluations, ignoring QTL information, for Simmental bulls in the CMP result in a spread of sire EPD’s of 0.45 kg of shear force. To date, nine bulls representing four breeds have completed the progeny test required and the DNA analysis in the CMP. Five of the six tested shear force QTL’s have been found to be heterozygous (p≤0.05) in at least one bull. One of the nine bulls has been found to be heterozygous for the QTL for the sensory panel score of tenderness. The difference in progeny group performance, groups defined by which marker allele was inherited for the tenderness QTL, in one Simmental bull was almost as large as the spread in sire EPD’s for that breed. A pleiotropic effect of one QTL (tested as a shear force QTL) with marbling has been found. Evidence for segregation of the three marbling QTL and the rib eye area QTL has not been found in the nine tested bulls.