Background Testosterone deficiency is associated with increased serum cholesterol levels.However,how testosterone deficiency precisely affects cholesterol metabolism remains unclear.Therefore,in the current study,we examined the effect of testosterone deficiency on cholesterol metabolism and liver gene expression in pigs fed a high-fat and high-cholesterol (HFC) diet.Methods Sexually mature male miniature pigs (6-7 months old) were randomly divided into 3 groups as follows: intact male pigs fed an HFC diet (IM + HFC),castrated male pigs fed an HFC diet (CM + HFC),and castrated pigs with testosterone replacement fed an HFC diet (CM + HFC + T).Serum testosterone levels and lipid profiles were measured,and gene expression levels associated with hepatic cholesterol metabolism were determined.