Research in our laboratory intersects with several multidisciplinary focus areas within the UGA Department of Poultry Science. Our driving focus investigates host-pathogen interactions during enteric challenges with particular emphasis on coccidiosis and clostridial diseases in chickens and turkeys, very impactful diseases of commercial poultry. Additionally, we explore various applications of antibiotic alternatives to mitigate the adverse effects of enteric (e.g. Eimeria, Clostridium, Histomonas) and foodborne (e.g. Salmonella, Campylobacter) pathogens. In this context, we examine the molecular mechanisms of mucosal immunomodulation and physio-immunological responses of the host during such challenges. Further, we interrogate issues of nutritional immunology specifically applications for enhancing the early development and competence of the immune system as well as promoting a healthy microbiome. We employ unique bacterial and parasitic challenge models with commercial broilers and turkeys to assess the efficacy of vaccines and feed/water additives, including an effective lateral transmission model of Histomonas meleagridis in turkey poults.