Phytosterol additive boosts adrenal response to ACTH in male Japanese quail (Coturnix coturnix japonica)

To investigate the adrenal effect of a phytosterol (PS) additive, 80 male Japanese quail were divided into four sub-groups and fed 0, 40, 400, and 4,000 ppm of PS, respectively, for 21 days. Subsequently, 50% of the birds from each dosage group were subjected to a 6-day adrenal function test, whereby they were injected with long-lasting adrenocorticotropin (ACTH). The remaining quail in each PS dosage group were raised under normal conditions. The groups receiving 400 and 4000 ppm PS exhibited decreased serum levels of LDL-cholesterol with and without ACTH stimulation (P < 0.01). No amount of dose of PS changed serum corticosterone (CORT) under normal conditions (P > 0.05). Enhancement of CORT was observed on the 2nd and the 6th days of the ACTH challenge in birds receiving 400 ppm (P < 0.05). Average ACTH-induced CORT levels in the 400 ppm group were higher than in the 0 ppm group (P < 0.01). Our results demonstrated that PS can boost ACTH-induced CORT levels in male Japanese quail.