POULTRY IS THE THIRD LARGEST AGRICULTURAL COMMODITY AND THE PRIMARY MEAT CONSUMED IN THE U.S. THE U.S. INDUSTRY ALSO IS THE LARGEST PRODUCER AND EXPORTER OF POULTRY MEAT IN THE WORLD. PRIMARILY DUE TO GENETICS AND ADVANCED POULTRY BREEDING PROGRAMS, TREMENDOUS PROGRESS IN PRODUCTION TRAITS HAS BEEN MADE TO MEET THE RAPIDLY GROWING DEMANDS OF CONSUMERS FOR POULTRY MEAT AND EGGS.SEVERAL MAJOR ISSUES CONFRONT THE POULTRY INDUSTRY TODAY. WITH HIGH-DENSITY CHICKEN REARING, REDUCED GENETIC DIVERSITY FROM INDUSTRY CONSOLIDATION, AND CONSUMER DEMANDS TO LIMIT ANTIBIOTIC USAGE, CONTROLLING INFECTIOUS DISEASES AND PREVENTING DISEASE OUTBREAKS ARE CRITICAL FOR SUSTAINING ECONOMIC VIABILITY, MAINTAINING PUBLIC CONFIDENCE IN POULTRY PRODUCTS, AND ENHANCING ANIMAL WELFARE.AMONG POULTRY DISEASES, MAREK'S DISEASE (MD), A T-CELL CANCER CAUSED BY THE HIGHLY ONCOGENIC VIRUS MAREK'S DISEASE VIRUS (MDV), CONTINUES TO BE AT OR NEAR THE TOP OF THE LIST OF CONCERNS. CONCERN REGARDING MD IS HEIGHTENEDDUE TO THE UNPREDICTABLE YET RECURRENT VACCINE BREAKS THAT RESULT IN DEVASTATING LOSSES TO POULTRY FARMS. ESTIMATED WORLDWIDE ANNUAL LOSSES FROM MD DUE TO MEAT CONDEMNATION AND REDUCED EGG PRODUCTION EXCEED $2 BILLION. CONSEQUENTLY, ALTERNATIVE CONTROL METHODS, ESPECIALLY IMPROVING GENETIC RESISTANCE, ARE NEEDED AND HIGHLY DESIRED.IN THIS PROJECT, UTILIZING AND INTEGRATING THE LATEST GENOMIC METHODS, WE IDENTIFY DNA SEQUENCES THAT VARY BETWEEN BIRDS THAT ACCOUNT FOR DIFFERENCES IN GENETIC RESISTANCE TO MD. THE RESULTING INFORMATION CAN THEN BE USED TO DIRECTLY SELECTION FOR BIRDS WITH ENHANCED MD GENETIC RESISTANCE WHEN APPLIED TO COMMERCIAL FLOCKS, THEREBY, IMPROVING ANIMAL PRODUCTION AND WELFARE, AND ULTIMATELY BENEFITING US CONSUMERS FOR MORE AFFORDABLE AND SAFE POULTRY PRODUCTS.?