Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/25489
標題: 去勢對畜試土雞台畜肉十三號公雞之生長、血液、屠體與骨骼性狀之影響
Effects of Caponization on Growth, Blood, Carcass and Bone Characteristics in TLRI Native Chicken Cockerels Taishi Meat No. 13
作者: 林正鏞
Lin, Cheng-Yung
關鍵字: Caponization;去勢;Slip;Growth performance;Carcass characteristics;Bone characteristics;復陽雞;生長性能;屠體性狀;骨骼性狀
出版社: 畜產學系
摘要: 
本研究旨在比較閹雞、復陽雞及公雞之生長性能、血液性狀、屠體部位與內臟比例、皮膚與肌肉色澤、肌肉組成、ATP-關連化合物含量、肌肉物理性質、官能品評、骨骼機械性狀及礦物質組成等之差異及探討去勢與屠宰週齡及飼糧鈣含量對閹雞之影響,以建立畜試土雞台畜肉十三號之適當去勢與屠宰週齡、經濟飼養期及提供改善閹雞腳弱問題之方向。本試驗雞隻於6至14週齡間去勢。結果顯示,閹雞之直腸溫度、體重、飼料採食量、腳脛長度、羽毛完整性、腹脂比例、腸道、背部、翅膀及胸部比例、肌肉脂肪、肌核苷含量、皮膚與肌肉亮度、黃色度、胸肉K值與內聚性、血漿離子鈣、鉀離子、無機磷、三酸甘油酯、總膽固醇、高密度脂蛋白、低密度脂蛋白、白蛋白、球蛋白、總蛋白質、肌酸激酶及抑鈣素等顯著(P < 0.05)較公雞高;而屠宰率、心臟、頭頸及腿部比例、肌肉水分、蛋白質、胸肉IMP與ATP+ADP+AMP+IMP及腿肉次黃嘌呤含量、肌肉紅色度、韌度、蒸煮失重與主胸肌肌纖維直徑、血球比容積、血漿pH值、尿酸、肌酸酐、總羥脯胺酸與睪固酮濃度、骨骼比例、相對脛骨長度、脛骨皮層厚度、破裂強度、灰分、鈣、磷及鎂含量等,閹雞顯著(P < 0.05)較公雞低;飼料轉換率、雞群整齊性、胸寬、肝、砂囊與脾臟比例、肌肉彈性、咀嚼性、及腿肉內聚性與腓腸肌肌纖維直徑、血漿總鈣、副甲狀腺素、鎂、鹼性磷酸酶、鈉離子、氯離子、及甲狀腺素濃度與脛骨長度等,在二者間則無顯著(P > 0.05)差異;但腿肉肌纖維直徑及血漿甲狀腺素濃度,閹雞有較公雞低之趨勢(P < 0.10);閹雞腿肉之風味與多汁性及胸肉之風味與嫩度官能品評顯著(P < 0.05)較公雞佳,腿肉嫩度及胸肉多汁性之感官品評等,在二者間雖無顯著差異,但仍以閹雞之評分優於公雞(P < 0.10)。復陽雞方面,其體重、腳脛長度、直腸溫度、羽毛完整性及皮膚亮度等顯著(P < 0.05)較公雞重、長或高;雞冠面積、脾臟比例、骨骼錳含量顯著(P < 0.05)較閹雞為高;血漿氯離子濃度顯著(P < 0.05)較閹雞及公雞高外,其餘之性狀大多介於閹雞與公雞間,但多數性狀較趨近閹雞。體增重、飼料利用效率,血漿總鈣/無機磷與肌酸酐、尿酸、三酸甘油酯、總膽固醇、離子鈣、無機磷及鹼性磷酸酶濃度、屠宰率、頭頸、腿部、背部、翅膀及胸部比例、肌肉脂肪、水分、蛋白質、IMP、肌核苷及次黃嘌呤含量及K值、肌肉亮度、紅色度與黃色度、蒸煮失重、剪切值、官能品評之風味、嫩度與多汁性、骨骼比例、脛骨長度、骨骼破裂強度、脛骨皮層厚度、骨骼灰分、鈣、磷與鎂含量均顯著(P < 0.05)受年齡與去勢之影響;閹雞與公雞之腳部比例及血漿鎂濃度顯著(P < 0.05)受年齡之影響。去勢後死亡率、血漿鹼性磷酸酶與白蛋白濃度、肝臟比例、皮膚b* 值與肌肉L*值、肌肉脂肪含量、肌纖維直徑與面積及肌肉蒸煮失重,隨去勢週齡增加而降低,去勢死亡率、血漿肌酸酐濃度、心臟比例、肌肉水分與蛋白質含量,則隨去勢週齡增加而增加。去勢對雞隻之影響依序為血液組成(去勢後4週),屠體部位比例、肌肉色澤、組成、蒸煮失重、剪切值及骨骼性狀(去勢後6週)、屠宰率及肌肉官能品評(去勢後10週)。畜試土雞台畜肉十三號於8週齡以前去勢較適當,經濟飼養期以不超過24週齡為宜,22週齡以後屠宰者,屠體性狀及肌肉嗜口性較18週齡以前屠宰者佳,單獨提高飼糧中鈣含量至1.1﹪並無法改善閹雞骨骼強度變差之缺點。
由試驗結果發現睪固酮對雞隻第二性徵之刺激作用(雄性化作用),較同化作用敏感(肌肉與骨骼之生長與蓄積),睪固酮濃度過高會抑制雞隻生長,且有一閾值存在,睪固酮對骨骼同化作用之閾值較第二性徵及肌肉生長之閾值高,缺乏睪固酮(去勢),會造成骨骼組成分流失,睪固酮具有增加骨骼成分蓄積及抑制骨骼溶解之功用,睪固酮(去勢)會顯著影響生長、體溫、羽毛完整性、屠體性狀、肌肉組成、皮膚與肌肉色澤、肌纖維直徑、肌肉嗜口性、血液組成。

The objectives of this study were (1) to compare differences in growth, blood, organ and carcass part ratios, skin and muscle color, mucle compositions, ATP-related compounds, physical properties and sensory panel scores, and bone mechanical traits and mineral contents, between male and caponized TLRI native chicken Taishi Meat No.13; (2) to establish caponization and slaughter age, and dietary calcium level effects on the growth, blood, carcass and bone characteristics in caponized TLRI Native Chicken Taishi Meat No. 13. These data can be used to improve foot weakness and determine the optimal caponization and marketing age in caponized TLRI Native Chicken Taishi Meat No. 13. Caponized birds were surgically altered at 6 to 14 weeks old. The results indicated that the capons had significantly (P < 0.05) higher rectal temperature, live body weight, feed intake, shank length, feather integrity, abdominal fat and intestine ratios, back, wing and breast part ratios, muscle fat and inosine contents, skin and muscle L* and b* values, breast muscle K value and cohesiveness. Capons also had higher (P < 0.05) plasma Ca2+, K+, inorganic phosphorus, triglyceride, total cholesterol, HDL, LDL, albumin, globulin, total protein, creatine kinase and calcitonin concentrations than male had. Capons had lower(P < 0.05) dressing percentage, heart, head and neck and thigh part ratios, muscle moisture, protein, breast muscle IMP and ATP+ADP+AMP+IMP and thigh muscle hypoxanthine contents, muscle a* value, cooking loss and toughness , Pectoralis major fiber diameter, PCV and plasma pH than male had. Capon also had lower (P < 0.05) plasma uric acid, creatinine, testosterone and total hydroxyproline concentrations, relative tibiae length, bone percentage, breaking strength, cortical thickness, bone ash, Ca, P and Mg contents than male had. No significant difference (P > 0.05) was observed in feed conversion, flock uniformity, breast width, gizzard, liver and spleen ratios, muscle elasticity and chewiness, thigh muscle cohesiveness, Gastrocnemius pars extrna fiber diameter, and total calcium, parathyroid hormone, magnesium, alkaline phosphatase, Na+, Cl- and thyroxine plasma concentrations, and tibial length between the capons and intact birds. However, the Gastrocnemius pars extrna fiber diameter and plasma thyroxine concentration trended to be lower (P < 0.10) in the capons. The sensory panel scores for thigh muscle flavor and juiciness and for breast muscle flavor and tenderness for the capons were significantly (P < 0.05) higher than that for males. Sensory panels scores for thigh muscle tenderness and breast muscle juiciness showed no significant difference. However, the capons tended to have higher scores (P < 0.10). The slips had significantly (P < 0.05) higher comb area, spleen ratio, and bone Mn content than capons. Significantly (P < 0.05) higher live body weight, shank length, rectal temperature, feather integrity and skin L* value in slips than those in intact birds. The slips also had significantly (P < 0.05) higher plasma Cl- concentration than capons or intact birds. Other characteristic values measured in slips, such as dressing and carcass part percentages, skin and muscle color value, muscle compositions, toughness and fiber diameter, PCV, plasma pH and compositions, relative bone percentage, breaking strength, cortical thickness and bone ash and mineral contents were between those for capons and intact birds. Most of these values in slips were closer to capons than intact birds. Live body weight, feed conversion, plasma creatinine, uric acid, triglyceride, total cholesterol, Ca2+, inorganic phosphorus, total calcium/inorganic phosphorus and alkaline phosphatase concentrations, dressing percentage, thigh, wing, breast, back, head and neck part ratios, muscle fat, moisture, protein, IMP, hypoxanthine, inosine contents and K, L*, a* and b* values, cooking loss, shear value, muscle sensory panel scores for flavor, juiciness and flavor, relative bone percentage, breaking strength, cortical thickness, bone ash, Ca, P and Mg contents were significantly (P < 0.05) influenced by caponization and the slaughter age. However, the foot part ratio and plasma magnesium concentration were significantly(P < 0.05)influenced by slaughter age only. Mortality of caponized after 24 hours, plasma alkaline phosphatase and albumin concentrations, liver ratio, skin b* value, muscle L* value, muscle fat content and cooking loss, Gastrocnemius pars extrna fiber diameter and area increased with increasing age at caponization, whereas the mortality of caponized within 24 hours, plasma creatinine concentrations, heart ratio, muscle moisture and protein contents decreased with increasing age at caponization. Caponized effects were first observed in plasma compositions (caponized treatment after 4 wks) followed by of carcass part ratios, muscle color, composition, cooking loss, shear value and bone characteristics(caponized treatment after 6 wks), and dress percentage and sensory panel scores(caponized treatment after 10 wks). The optimal caponization age was before 8 weeks of age for mortality, slip ratios and meat quality, and the optimal marketing age was 24 wks of age for B.W. gain and feed conservation. After 22 weeks of age, birds had better carcass traits and eating quality than birds before 18 weeks of age. Raising calcium content to 1.1% did not affect growth performance, carcass characteristics and meat quality, or improves bone characteristics of the capons from 9 to 26 wks of age.
The results of this study indicated that androgenic effects on secondary sexual characteristics are stronger than those promoting anabolic growth responsein testosterole. High testosterone tended to inhibit the growth performance of chickens and that appeared to have a concentration threshold. Testosterone can directly influence bone composition fluxes in male chickens. Caponization resulted in increasing cancellous and cortical tibiae bone skeletal loss in young chickens. Testosterone can increase bone deposition and suppress bone resorption. Live weight, shank length, rectal temperature, feather integrity, skin and muscle color values, carcass characteristics, muscle compositions, toughness, fiber diameter, packed cell volume, plasma pH value and compositions, and eating quality were significantly (P < 0.05) influenced by caponization.
URI: http://hdl.handle.net/11455/25489
Appears in Collections:動物科學系

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