Effects of castration and testosterone treatment on serum lipid levels. (A) Serum total cholesterol (TC) levels. (B) Serum low-density lipoprotein cholesterol (LDL-C) levels. (C) Serum high-density lipoprotein cholesterol (HDL-C) levels. (D) Serum triglyceride (TG) levels. IM: intact male pigs fed an HFC diet; CM: castrated male pigs fed an HFC diet; CMT: castrated male pigs fed an HFC diet and given testosterone replacement therapy. Data are expressed as means ± SEMs, n = 6 per group. *P < 0.05 and **P < 0.01, IM vs. CM; #P < 0.05 and ##P < 0.01, CMT vs. CM.