QTL MAPPING IN CHICKEN USING A 3 GENERATION FULL SIB FAMILY-STRUCTUREOF AN EXTREME BROILER X BROILER CROSS

A three generation population has been created for mapping both produc tion and health traits in chicken. The F1 and F2 population were genot yped while phenotypes were collected on the F3 animals. The population consisted of 10 full-sib families with a total of 476 individuals (F1 and F2), and an F3 generation consisting of over 18,000 animals. In t otal, 264 microsatellites were analyzed on all F1 and F2 animals, and an additional 120 microsatellites were analyzed on only 4 of the 10 fa milies (196 animals). A linkage map of the chicken genome containing 3 84 microsatellite markers has been constructed by analyzing the segreg ation of these markers in this population. Preliminary analysis indica te a QTL for body weight at 48 days on chromosome 1. Body weight was m easured on 2100 F3 animals housed in cages, and the data was analyzed by a regression interval mapping approach. Higher F-values were obtain ed by using a bivariate approach showing that differences in mean and variance of a trait measured on both sexes should be taken into accoun t in the analysis.