Date of Graduation


Document Type


Degree Name

Doctor of Philosophy in Cell & Molecular Biology (PhD)

Degree Level



Biological Sciences


Douglas Rhoads

Committee Member

Mack Ivey

Second Committee Member

Charles Rosenkrans

Third Committee Member

Nicholas Anthony


Biological sciences, Ascites syndrome, Broiler chickens, Genome-wide association studies


Ascites syndrome in broiler chickens has developed into a source of economic loss in the last three decades. Intensive selective pressure, and implementation of flock management practices, has successfully reduced ascites frequency, but has not eliminated its occurrence. For this reason, it is imperative to better understand the genetic cause to ascites in broiler chickens. Previous studies of this magnitude have been attempted, but, thus far, a consensus of genomic associations have not been made. This collection of studies was aimed at identifying and interpreting genomic and genetic associations to ascites phenotype specific to a broiler line representative of a 1990s elite male line. A next generation sequencing technique, termed genome wide association studies, was initially implemented to identify chromosomal regions experiencing correlations with ascetic events in broilers. Individual loci were then evaluated for their impact on resistance and susceptibility, with particular interest in sex effects and parental genotypes. Finally, statistical models were evaluated for their potential use in predicting ascites incidence. Models represent a less time consuming and more cost effective method aimed at conserving genetic accuracy in selected breeding programs. Together, these studies represent gains in the current knowledge of ascites genetics and serve as a possible source for novel selective breeding practices in an industry setting.