2007 Annual Report 1a.Objectives (from AD-416) The objective of this project is to explore and identify cellular and molecular biomarkers associated with tibial dyschondroplasia and femoral head necrosis that could serve as selection markers against these diseases. 1b.Approach (from AD-416) We propose to analyze the hematological, clinical chemistry, and protein profiles of blood and serum from birds with clinically identified bone problems along with age matched control birds from production using CellDyn, clinical chemistry analyzer, gel and capillary electrophoresis, and mass spectrometric techniques. We expect to come up with some biomarkers that may provide some link with these diseases. 3.Progress Report This report serves to document research conducted under a trust agreement between Cobb-Vantress, the primary breeding company for Tyson Foods and ARS. Additional details of research can be found in the report for the parent project 6226-32000-010-00D, Development of Alternative Approaches to Antibiotics for Controlling Bacterial Respiratory Pathogens in Poultry. Elevated levels of fat metabolic indicators may prognosticate femoral head necrosis (FHN) problems in young broilers. Using clinical chemistry parameters we compared sera obtained from 6-wk-old broiler chickens with different leg problems, FHN, tibial dyschondroplasia (TD), femoral cartilage disarticulation, and compared with normal sera. We found that triglyceride, cholesterol, and low density lipoprotein levels in FHN-affected birds were statistically higher compared to other groups. These results suggest that fat metabolism disorders may be a risk factor for FHN. We have compared the sera from these birds with respect to protein differences using differential enrichment by the removal of certain abundantly occurring proteins (e.g., albumin) followed by gel electrophoresis but have not found many differences. Identifying specific or groups of specific metabolites under different disease conditions will enable identifying the presence of the disease, thereby providing tools for better genetic selections.