Effect of caponization and different exogenous androgen on hepatic lipid and beta-oxidase of male chickens.

Caponization and different exogenous androgens effects hepatic lipid and beta-oxidation metabolism in male chickens compared with intact male and female. Healthy male chickens were caponized at 12 wk old and selected at 16 wk of age for a 10-wk feeding-trial. Sixteen each male caponized (capon) and female chickens were assigned for trial 1, and 16 sham-operated (sham) and 64 capons were selected in trial 2, in which capons were randomly divided into 4 treatments and implanted (1.62 mm i.d. x 3.16 mm o.d., 10.4 +/- 0.4 mg) with cholesterol (CHOL), testosterone (TES), 5alpha-dihydrotestosterone (5alpha-DHT), or 19-nortestosterone (19-NorT) at 16, 20, and 24 wk of age. In trial 1, caponization increased abdominal fat weight, hepatic total lipid content, and saturated fatty acid percentage more than males (P < 0.05), and the last achieved compatible level to females (P > 0.05). Caponization increased NAD phosphate-malate dehydrogenase (MDH) activity more than males, but was still lower than females (P < 0.05). Capons showed lower enoyl-coenzyme A hydratase (ECH) and 3-ketoacyl-coenzyme A thiolase (KT) activities than males (P < 0.05) and lower acyl-coenzyme A dehydrogenase activity than females (P < 0.05). In trial 2, the CHOL group increased abdominal fat weight and total hepatic lipid content more than the sham (P < 0.05), and different forms of TES groups appeared to have lower abdominal fat weight (P < 0.05), but only the 19-NorT group achieved a compatible level to the sham (P > 0.05). Cholesterol or different forms of TES implantation increased hepatic MDH activity more than the sham (P < 0.05). Cholesterol implantation decreased ECH and KT activities more than the sham, but the 5alpha-DHT or 19-NorT group showed a compatible ECH activity to the sham (P > 0.05). The 19-NorT group also increased KT activity, but was still less than the sham (P > 0.05). Capons increased abdominal fat weight and hepatic lipid biosynthesis more than males, mainly because capons raised MDH activity and reduced ECH and KT activities. Different forms of TES-implanted capons decreased abdominal fat weight, and hepatic lipid biosynthesis order was 19-NorT, 5alpha-DHT, and TES.