title: Gender, caponization and exogenous estrogen effects on lipids, bone and blood characteristics in Taiwan country chickens.
abstract: This study investigated gender, caponization and exogenous estrogen effects on lipids, bone and blood characteristics in Taiwan country chickens. Thirty male chickens were caponized at 8 weeks (capons); 15 capons were injected with estrogen (5 mg/bird estradiol 3-benzoate) every 2 weeks from 8 to 28 weeks, and 15 sham-operated male (shams) chickens and 15 females were selected for this trial. The results showed that the shams had lower relative abdominal and chest subcutaneous fat than females (P < 0.05). The estrogen-treated capons had greater relative abdominal and chest subcutaneous fat than shams and capons (P < 0.05), which might result from higher blood very low-density lipoproteins and triacylglycerol concentrations (P < 0.05). Caponization could dramatically increase relative abdominal fat (506%; P < 0.05). The shams had higher tibia weight and biomechanical properties, such as maximum bone strength and bending moment values than the capons (P < 0.05). Tibia biomechanical properties were reduced by estrogen treatment (P < 0.05). The females obtained the lowest biomechanical value in all treatments (P < 0.05). Histological examination revealed cavity formation in the cortical bone of estrogen-treated capons and female chickens, which suggested that estrogen reduced bone biomechanical properties by destroying its structural integrity.
authors.affiliation: Department of Animal Science, National Chiayi University, Chiayi, Taiwan.
authors.forename: Shih Yi
authors.initials: SY
authors.lastname: Chen
authors.forename: Tsung Yu
authors.initials: TY
authors.lastname: Li
authors.forename: Chih Heng
authors.initials: CH
authors.lastname: Tsai
authors.forename: Dan Yuan
authors.initials: DY
authors.lastname: Lo
authors.forename: Kuo Lung
authors.initials: KL
authors.lastname: Chen
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology*; D002369:Castration; D002645:Chickens / Q000502:physiology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D008055:Lipids / Q000097:blood*; D008297:Male; D012737:Sex Factors; D013624:Taiwan
chemical_list: D004967:Estrogens; D008055:Lipids
keywords: Taiwan country chicken; bone; caponization; estrogen; lipid