Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2008
Publication Date: 3/1/2009
Citation: Durairaj, V., Okimoto, R., Rasaputra, K.S., Clark, F.D., Rath, N.C. 2009. Histopathology and serum clinical chemistry evaluation of broilers with femoral head separation disorder. Avian Diseases. 53(1):21-25. Interpretive Summary: Commercial poultry are bred for rapid growth which also causes metabolic bone problems leading to lameness. One such problem is where the upper leg bone disarticulates from the cartilage that attaches to the pelvis. To find what causes this problem and whether there are changes in the blood chemistry that can be used to prognosticate we compared groups of chickens with or without leg problems. The blood chemistry of birds with femoral problems showed an elevation in the blood lipids. We believe that high blood lipid levels may be a risk factor for femoral disarticulation problems in chickens.
Technical Abstract: Femoral head disarticulation (FHD) and necrosis is a sporadic leg problem of unknown etiology in broiler breeders. To determine the underlying physiology of FHD, the blood chemistry and the histopathology of the femoral heads of the affected chickens were compared with their age matched controls. Chickens were categorized on the basis of their leg problems determined at necropsy as, (1) femoral heads separated from articular cartilage without growth plate laceration (FHD), (2) FHD with lacerations and lesions in the growth plate (FHDL), and (3) tibial dyschondroplasia (TD), identified by a widened growth plate and unresorbed cartilage at the proximal tibia. Control birds were without any femoral or tibial problems. The histopathology of FHDL growth plates revealed occasional chondrocyte death, hypocellularity, dysplasia in the prehypertrophic zones, and the absence of inflammatory infiltrate in the lesion areas. Hematoxylin/ eosin staining showed brown chromogenic deposits in the metaphyseal bone marrow areas. Blood chemistry of chickens with FHDL showed modest but a significant elevation of cholesterol, triglycerides, and low density lipoproteins (LDL). Only cholesterol and LDL were moderately elevated in FHD groups. Other blood parameters such as protein, blood urea nitrogen (BUN), magnesium, and iron levels showed differential changes in birds with leg problems but without any specific trends. Neither blood ovotransferrin (OVT), a marker of chronic inflammation, nor corticosterone, a marker of stress, showed significant differences from the controls. These results suggest that FHD is a metabolic problem in poultry which may be related to fat metabolism disorders.