1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
Intensive genetic selection for fast-growing high-yield birds has led to remarkable improvements in production efficiency of poultry over the last two decades. Selection pressure for rapid growth has negatively affected the physiology and metabolism of several organs of maintenance that succumb to metabolic disorders and contribute to greater than 30% of all production mortality. In fast-growing meat-type poultry, skeletal, cardio-pulmonary, and gastrointestinal systems exhibit growth and metabolic problems, resulting in the loss of billions of dollars to poultry industry annually. The ultimate objective of this research is to identify mechanisms and the genes and gene products associated with metabolic diseases in poultry with respect to: (a) the pathogenesis of tibial dyschondroplasia, a developmental skeletal defect of the tibial bone growth plate that contributes to lameness, bone breakage, and osteomyelitis; (b) ascites, a cardiopulmonary dysfunction associated with pulmonary hypertension; and (c) gastrointestinal dysfunction. The proposed research is aimed at developing a better understanding of the mechanisms and etiology of these disorders, with the goal of improving the health and production efficiency of poultry. Furthermore, we are exploring possible genetic linkages of these metabolic diseases, conventionally thought to be system-independent, with the goal of elucidating common underlying genetic defects and potential complementary phenotypic improvements. The molecular mechanisms of tibial dyschondroplasia, a common poultry skeletal problem is being studied by employing thiram (a fungicide) that disrupts chondrocyte growth and differentiation leading to tibial dyschondroplasia with the intent to find whether this important skeletal problem can be prevented using nutritional means. Cardio-pulmonary defect, the basis of ascites, is being studied utilizing genetically divergent susceptible and resistant lines of broilers that were developed with collaborators over the last 8 years. Recent work in our laboratory has demonstrated that impairment of intestinal metabolism, function, and even microanatomical structure may be strongly linked to the genotypes associated with genetic selection for susceptibility to ascites syndrome. This newly established linkage of genetically based ascites susceptibility/resistance to metabolic gastrointestinal dysfunction will also be further investigated by employing a prebiotic/probiotic model that influences intestinal development and resistance to disease. The identification of the molecular basis of these disorders will ultimately lead to appropriate interventions to reduce the incidence of these diseases and will tremendously benefit the poultry industry and consumers.

The research falls under National Program 103 - Animal Health, that addresses the Action Plan component 2 and 6 "Genetic and Biological Determinants of Disease Susceptibility" and "counter measures to prevent enteric disease in poultry" with outputs of (a) biological determinants of innate and adaptive immunity, (b) to determine and quantify factors associated with poutry gastrointestinal diseases.