Author
VAN EENENNAAM, A. - UNIV. OF CALIF., DAVIS | |
LI, J. - CORNELL UNIV., ITHACA | |
Thallman, Richard - Mark | |
QUAAS, R. - CORNELL UNIV., ITHACA | |
DIKEMAN, M. - KANSAS STATE, MANHATTAN | |
GILL, C. - TEXAS A&M UNIVERSITY | |
FRANKE, D. - LOUISIANA STATE UNIV. | |
THOMAS, M. - NEW MEXICO STATE UNIV. |
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/31/2006 Publication Date: 4/2/2007 Citation: Van Eenennaam, A.L., Li, J., Thallman, R.M., Quaas, R.L., Dikeman, M.E., Gill, C., Franke, D.E., Thomas, M.G. 2007. Validation of commercial DNA tests for quantitative beef quality traits. Journal of Animal Science. 85:891-900. Interpretive Summary: Effects of three commercially-available genetic marker panels on beef quality were validated by the National Beef Cattle Evaluation Consortium (NBCEC). Validation was interpreted to be the independent verification of associations between genetic tests and traits as claimed by the commercial genotyping company. This was done through the analysis of DNA test results and beef quality data derived from reference cattle populations. One marker panel is comprised of two DNA markers and is being marketed as a test associated with marbling and quality grade. In this validation study, the DNA test results were not associated with marbling score, however the association with increased quality grade (percentage of cattle grading choice or prime) approached significance, mainly due to the effect of one of the two markers in the test. Two marker panels are being marketed as tests associated with meat tenderness. In both panels, there were highly significant associations with tenderness. The genotype effects of the two tenderness panels were very similar to each other, with a 1 kg difference in Warner-Bratzler shear force being observed between the most and least tender genotypes. Independent third-party validation of commercial DNA tests provides producers with some assurance that DNA-based tests perform in accordance with the claims of the companies marketing them. Such studies also provide some of the information necessary to estimate the genetic gain that can be achieved through the use of marker-assisted selection and may ultimately facilitate the integration of marker data into the national cattle evaluation framework. Technical Abstract: Associations between three commercially-available genetic marker panels (GeneSTAR(TM) Quality Grade, GeneSTAR(TM) Tenderness, and Igenity TenderGENE(TM)) and quantitative beef traits were validated by the National Beef Cattle Evaluation Consortium (NBCEC). Validation was interpreted to be the independent verification of associations between genetic tests and phenotypes as claimed by the commercial genotyping company. This was done through the analysis of phenotypes and genotypes derived from reference cattle populations. The GeneSTAR(TM) Quality Grade marker panel is comprised of two markers and is being marketed as a test associated with marbling and quality grade. In this validation study, the genotype results from this test were not associated with marbling score, however the association of substituting favorable alleles of the two markers with increased quality grade (percentage of cattle grading choice or prime) approached significance (P = 0.06), mainly due to the effect of one of the two markers. The GeneSTAR(TM) Tenderness and Igenity TenderGENE(TM) marker panels are being marketed as tests associated with meat tenderness. These marker panels share two common micro-calpain SNPs and each has a different calpastatin SNP. In both panels, there were highly significant (P < 0.001) associations of both the calpastatin marker and the micro-calpain haplotype with tenderness (Warner-Bratzler shear force). The genotype effects of the two tenderness panels were very similar to each other, with a 1 kg difference in Warner-Bratzler shear force being observed between the most and least tender genotypes. Validation studies represent a potential source of some of the data required to enable the integration of maker data into genetic evaluations. As DNA tests associated with an increasing number of beef production traits enter the marketplace, it will become increasingly important, and likely more difficult, to find independent populations with suitable phenotypes for validation studies. |