- 學位論文
膽鹼改善龍膽石斑油脂代謝及抗緊迫能力
Improvement in lipid metabolism and stress tolerance of juvenile giant grouper, Epinephelus lanceolatus (Bloch), fed supplemental choline
摘要
石斑魚是亞太地區重要的海水養殖物種。其中龍膽石斑具有高經濟價值、體型大及成長快速等優點，成為主推的養殖物種。但長期餵食商業飼料之龍膽石斑易出現脂肪肝及抗緊迫能力下降之問題，導致產量及經濟上損失。本研究擬探討不同濃度膽鹼飼料對龍膽石斑成長、油脂代謝及氨-氮耐受性之影響。 本研究共配製六種飼料分別為基礎魚粉飼料添加每公斤0 g (Control)、0.25 g (0.25CD)、0.5 g (0.5CD)、1 g (1CD)、2.5 g (2.5CD)及5 g (5CD)之氯化膽鹼，測得飼料膽鹼實際濃度分別為每公斤2.57 ±0.03 g、2.67 ±0.11 g、2.94 ±0.44 g、3.48 ±0.11 g、4.99 ±0.08 g及7.71 ±0.35 g膽鹼。以不同濃度膽鹼之飼料餵飼龍膽石斑56天與30天，各別觀察成長及油脂代謝與緊迫能力。在第一部分實驗，以不同濃度膽鹼飼料餵食龍膽石斑56天後，發現增重率、存活率及飼料效益沒有明顯的差異。然而，隨著膽鹼濃度增加，肝體比、肝臟中油脂、三酸甘油酯和膽固醇含量及血清中三酸甘油酯和膽固醇含量都出現下降的趨勢。此外，當龍膽石斑攝食膽鹼含量大於2.94 g/kg可增加背部肌肉油脂含量，亦可改善龍膽石斑在氨氮緊迫下能力，包括存活率及行為表現。由本研究證實，膽鹼對龍膽石斑之脂質代謝及緊迫的耐受性有很重要的改善作用。
並列摘要
Six fish meal basal diets supplied with 0 (control), 0.25, 0.5, 1, 2.5 and 5 g/kg of choline chloride, resulting in choline levels of 2.57, 2.67, 2.94, 3.84, 4.99 and 7.71 g/kg, respectively, were fed to giant grouper, Epinephelus lanceolatus, for 56 and 30 days to evaluate the growth and lipid metabolism, and stress tolerance respectively. In the first trial, fish fed different levels of choline containing diets for 56 days had no significant difference in weight gain, survival and feeding efficiency. Fish fed increased levels of dietary choline, however, tended to have decreases in the hepatic somatic index; lipids, triglycerides, and cholesterol in liver; and triglycerides and cholesterol in serum. A increase of lipid content in dorsal muscle was recorded in fish fed the diets containing choline >2.94 g/kg. Additionally, dietary choline improved the reactions of fish to ammonia stress, including survival and behavioural responses, in fish fed diets containing choline levels >2.94 g/kg. These findings indicate that choline plays important roles in lipid metabolism and stress tolerance in giant grouper.