|Bauer, Nathan - USDA, FSIS|
|Shultz, Craig - USDA, FSIS|
|Chitko Mckown, Carol|
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 30, 2004
Publication Date: January 1, 2005
Citation: Heaton, M.P., Keen, J.E., Clawson, M.L., Harhay, G.P., Bauer, N., Shultz, C., Green, B.T., Durso, L.M., Chitko Mckown, C.G., Laegreid, W.W. Use of bovine SNP markers to verify sample tracking in beef processing [abstract]. Plant and Animal Genome Conference Proceedings. p. 124. Technical Abstract: Objective: To determine whether a selected set of 20 beef cattle single nucleotide polymorphism (SNP) markers will verify sample tracking in a commercial slaughter facility that processes primarily culled dairy cows. Design: Prospective blinded validation study. Animals: 165 cows and 3 bulls from 18 states (82% Holstein, 8% other dairy breeds, and 10% beef breeds). Procedure: Blood was collected by venipuncture from random animals just prior to slaughter. The purported corresponding liver samples were collected during beef processing and genotype profiles were obtained for each sample. Results: Based on the SNP allele frequencies in these cattle, the average probability that 2 random individuals would possess identical genotypes at all 20 loci was 4 x 10^-8. Thus, the chance of a coincidental genotype match between 2 animals was 1 in 23 million. Genotype profiles confirmed the match of 152 of 168 purported blood-liver pairs (90.5%) and revealed 16 mismatched blood-liver pairs. In these 16 mismatched cases, 33 to 76% of the 20 SNP genotypes did not match (average of 52%). Genotype discordance attributed to genotyping error was estimated to be less than 1% based on results from split samples. Conclusions and Clinical Relevance: This selected set of 20 bovine SNP markers is sufficiently informative to verify accuracy of sample tracking in slaughter plants that process either beef or dairy cattle. These or similar SNP markers may facilitate high-throughput DNA-based traceback programs designed to detect drug residues in tissues, control animal diseases, or enhance food safety.