Effects of high fat diets or prednisolone treatment on femoral head separation in chickens.

1. The effects of high fat diets and prednisolone treatment were studied to understand the etiology of femoral head separation (FHS) in fast growing broiler chickens. Dietary effects on production parameters such as growth, feed conversion ratio (FCR) and blood chemistry were also measured. 2. Three groups of chickens, consisting of 30 birds each, in two replicate pens, were fed isonitrogenous diets containing 40 (control), 60, or 80 g poultry fat supplements per kg feed. The birds were fed a starter diet containing the fat supplements for the first three weeks, then switched to a grower diet containing the same supplements for the rest of the experimental period. Two groups of birds were also raised with the control diets, but were administered either cholesterol or prednisolone intramuscularly at 30 and 32 days of age to evaluate their effects on FHS incidences. 3. The chickens were euthanised and necropsied at 37 d of age. The presence of femoral head weakness was determined by applying mild pressure o...