Effects of castration and testosterone implantation on growth, energy retention, and energy consumption of tissues in male chickens
| Autor: | Chih-Heng Tsai, 蔡智恆 |
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| Rok vydání: | 2004 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 92 The purpose of this experiment was conducted to study the effects of castration and testosterone implantation on growth, nutrition availability, absorption and storage, and energy consumption of tissues in male chickens. Ninety 8 week-old Single Comb White Leghorn male chickens (SCWL) were castrated and divided equally into sham-operated, castration implanted with cholesterol and castration implanted with testosterone groups, respectively for trial 1 and trial 2. Fifteen male chickens were sham operated, the others were castrated at 8-week-old and allotted into the three treatment groups: sham-operated (Sham + CHOL), cholesterol-implanted capons (Capon + CHOL) and testosterone-implanted capons (Capon + TES). The results showed that castration significantly increased 26wk-old body weight, and significantly improved feed conversion ratio between 17 and 26 weeks in capons, and significantly decreased comb development (P < 0.05), and significantly increased abdominal fat weight, carcass gross energy and crude fat contents (P < 0.05), and significantly decreased carcass moisture content in 26wk-old capons (P < 0.05). However, capons implanted with testosterone significantly decreased abdominal fat weight, carcass gross energy and crude fat contents (P < 0.05), and significantly increased carcass moisture content (P < 0.05). The effect of castration and testosterone implantation significantly increased protein availability in 16wks-old male chickens (P < 0.05). The castration can significantly decreased testosterone content in the serum of male chickens before or after sexual maturity. Capons implanted with testosterone significantly increased testosterone and glucose contents, but decreased creatinine content in the blood. However, cascration did not influence crude fat and gross energy availability of 16wk-old male chickens, but decreased gross energy availability. Testosterone implantation capons significantly decreased crude fat availability. The castration significantly decreased ash, gross energy and dry matter availability in 26wk-old male chickens (P < 0.05). The castration significantly increased blood triacylglycerol in 26wks-old male chickens (P < 0.05), and significantly decreased blood uric acid content. However, capons implanted testosterone significantly decreased blood triacylglycerol and increased blood uric acid content (P < 0.05). The study suggested that castration decreased testosterone level in blood but did not influence tissue energy consumption and nutrient availability; However, it increased carcass fat and energy retentions in male chickens; Testosterone implantation can restrained fat and energy retention in male chickens. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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