Technical Abstract: The effects of high fat diets or transient treatment with cholesterol or a synthetic glucocorticoid, prednisolone, on femoral head fragility of broiler chickens was examined along with other production parameters such as growth, feed conversion, and blood chemistry. Three groups of broiler chicks consisting of 30 birds per group in two replicate pens were fed isonitrogenous diets containing 4 (control), 6 or 8% poultry fat. Two groups receiving control diets consisting of 4% fat were injected with either cholesterol or prednisolone by intramuscular route on days 30 and 32. All birds were killed and necropsied on day 37. They were examined for femoral head fragility by applying mild pressure on the pelvic joint that results in the separation of the femoral growth plate from its articular cartilage in case of arthropathy. High fat diets did not cause any discernible change in final body weights (BW) or other parameters including femoral head separation (FHS) index. Injection of cholesterol, a precursor compound of glucocorticoids, caused no significant change in the above parameters compared with prednisolone which caused decreased BW, decreased feed efficiency, increased FHS index, and elevated blood lipids. These results suggest that prednisolone induced FHS may serve as a good experimental model for studying femoral head separation and necrosis problems in poultry.