【作者】 聂月美；

【导师】 邵庆均；

【作者基本信息】 浙江大学 ， 动物营养与饲料科学， 2006， 硕士

【摘要】 维生素C是水产动物所必需的微量营养成分。本课题以中华鳖为试验对象，研究维生素C对中华鳖血浆补体、免疫球蛋白含量和免疫相关酶活力的影响；对中华鳖肌肉和裙边常规营养成分、肌肉氨基酸和脂肪酸组成和含量、肌肉肉质相关指标的影响；对中华鳖不同部位胶原蛋白含量的影响。选取同一放养批次、体质健康的中华鳖，随机分为5组，每组4个重复，每个重复3只，平均体重为150g，进行为期60d的养殖试验。其中的一组作为对照组，对其投喂基础饲料，另外的四组为试验组，分别对其投喂以多聚磷酸酯维生素C形式添加100、200、400和2000mg／kg维生素C的试验饲料1-4。养殖试验结束后，宰杀所有试验鳖，制备血浆后，解剖取脾脏称重；同时取腿肌、裙边和背甲样品，分析中华鳖的体组成并对肌肉样品进行肉质分析，同时测定血浆免疫相关指标和应激指标。饲料添加维生素C能够提高中华鳖血浆补体和免疫球蛋白的含量。添加维生素C的各试验组补体C₃含量都显著高于对照组（P＜0.05），饲料添加2000mg／kg维生素C组的补体C₃含量最高，比对照组提高了286.67％。血浆C₄含量随着维生素添加量的增加也呈增加趋势，维生素C添加量为200mg／kg的试验组C₄含量最高，比对照组提高了33.33％（P＜0.05）。血浆免疫球蛋白含量随着饲料维生素C添加量的增加呈升高趋势，维生素C添加量等于或高于200mg／kg时IgM含量显著高于对照组（P＜0.05），维生素C添加量等于或高于400mg／kg时IgA含量显著高于对照组（P＜0.05），而添加维生素C对血浆中IgG含量的没有显著影响（P＞0.05）。饲料添加维生素C还能增强中华鳖血浆免疫相关酶的活力。血浆溶菌酶（LSZ）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）和谷胱甘肽还原酶（GR）活力随着饲料维生素C含量的增加而升高，当维生素C添加量最大即2000mg／kg时酶活力均达到最高并显著高于对照组（P＜0.05），分别比对照组提高了68.75％、7.97％、94.45％、43.23％和222.41％。饲料添加维生素C也能够增强酸性磷酸酶（ACP）、碱性磷酸酶（ALP）和髓过氧化物酶（MPO）的活力，血浆ACP和ALP活力均在饲料维生素C为400mg／kg时最高并与对照组差异显著（P＜0.05），且分别比对照组提高了29.74％和66.76％；而血浆MPO活力在饲料中维生素C为200mg／kg时最高并与对照组差异显著（P＜0.05），比对照组提高了76.98％。饲料添加维生素C能够增强中华鳖抗应激能力。随着饲料中维生素C水平的提高，中华鳖血浆皮质醇和葡萄糖含量也呈下降趋势，并且各试验组血浆葡萄糖和皮质醇含量都显著低于对照组（P＜0.05）。其中试验组-1、试验组-2、试验组-3和试验组-4的血浆皮质醇含量分别比对照组下降了35.17％、31.98％、34.59％和37.89％。饲料添加维生素C能改善中华鳖体组成和肉品质。随着饲料维生素C添加量的增加，肌肉和裙边必需氨基酸（EAA）、非必需氨基酸（NEAA）、鲜味氨基酸（FAA）和总氨基酸（TAA）的含量也逐渐升高。肌肉饱和脂肪酸（SFA）、单不饱和脂肪酸（MUFA）随着饲料维生素C添加量的升高而逐渐降低，但是多不饱和脂肪酸（PUFA）却逐渐升高。肌肉乳酸脱氢酶（LDH）活力、肌酸激酶（CK）活力、丙二醛（MDA）、肌酐（CRE）和胆固醇（CHO）含量随着饲料维生素C水平的增加而呈下降趋势，并且当维生素C添加量最高即为2000mg／kg时均达到最低并与对照组差异显著（P＜0.05）。而饲料添加维生素C对肌肉和裙边的常规营养成分没有显著影响（P＞0.05）。另外，饲料添加维生素C能够促进中华鳖机体的胶原蛋白合成能力，随着维生素C添加量的增加胶原蛋白含量也呈升高趋势，肌肉、裙边、肝脏和背甲的胶原蛋白含量均以维生素C添加量为400mg／kg时最高。更多还原

【Abstract】 Vitamin C is an essential micronutrient for aquatic animals. Chinese soft-shelled turtle was used as target animal in this research. Effects of vitamin C on immune indices, serum complement, immunoglobulins levels and enzyme activity, antistress and meat quality parameters such as body proximate compositions and contents of collagen in muscle, liver, carapace and calipash were studied.Sixty Chinese soft-shelled turtles （average weight 150g） were randomly divided into five groups, each included four replicates of 3 soft-shelled turtles. Experimental diets supplemented with five levels of 0, 100, 200, 400, 2000mg per kg diet vitamin C in the form of L-ascorbyl-2-polyphoshate were respectively fed to turtles twice a day. After 60 days of feeding, all turtles were decollated to collect spleen, muscle, carapace, calipash and blood samples for analysis.The results showed that supplementation of dietary vitamin C in soft-shelled turtle could elevate levels of complements （C₃ and C₄） and immunoglobulins in plasma. In contrast to the control, addition of 2000mg/kg vitamin C could raise the content of complement C₃ by 286.67% （P<0.05） and excelled the other treatment groups （P<0.05）; supplementation of 200mg/kg vitamin C could increase the content of complement C₄ by 33.33% （P<0.05）. A concentration of 200mg/kg, 400mg/kg and 2000mg/kg could improve the levels of IgM by 40.62% （P<0.05）, 43.30% （P<0.05） and 90.48% （P<0.05） compared with the control. While dierary supplied with 400mg/kg and 2000mg/kg could elevate the content of IgA by 9.39%（P<0.05） and 12.73% （P<0.05） compared with the control. No significant changes were found in the content of IgG （P>0.05）.The activity of lysozyme （LSZ）, superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-Px）, glutathione reductase （GR） increased with increasing dietary vitamin C levels, and dietary supplied with 2000mg/kg showed enhanced enzyme activity by 68.75% （P<0.05）, 7.93% （P<0.05）, 43.23% （P<0.05）, 94.45% （P<0.05） and 222.41% （P<0.05） respectively compared with the control. Also, vitamin C supplementation exerted significant effects on the activity of acids phosphates （ACP）, alkaline phosphatase （ALP） and myeloperoxidase （MPO）, they respectively peaked in the groups fed at 400mg/kg vitamin C, 400mg/kg vitamin C and 200mg/kg vitamin C by 29.74%, 66.76% and 76.89% respectively compared with control.Dietary vitamin C could improve the antistress ability of Chinese soft-shelled turtle. Serum glucose （Glu） and cortisol in turtle decreased with dietary vitamin C addtion. In contrast to the control, the treatment groups with 100mg/kg, 200mg/kg, 400mg/kg and 2000mg/kg respectively decreased by 35.17% （P<0.05）, 31.98% （P<0.05）, 34.59% （P<0.05） and37.89% （P<0.05）.Essential amino acids （EAA）, non-essential amino acids （NEAA）, total amino acids （TAA） and fresh flavor amino acids （FAA） levels of muscle and calipash increased with increasing dietary vitamin C levels. Also polyunsaturated fatty acids （PUFA） increased with increasing of dietary vitamin C levels, while saturated fatty acids （SFA） and monounsaturated fatty acids （MUFA） decreased. And a concentration of 2000mg/kg vitamin C could improved the contents of TAA, EAA, NEAA, FAA in muscle by 4.61% （P<0.05）, 4.49% （P<0.05）、4.42% （P<0.05） and 3.75% （P<0.05） compared with the control. At the same time, research showed that 2000mg/kg vitamin C could elevate the contents of TAA, EAA, NEAA, FAA in calipash by 3.75% （P<0.05）, 1.66% （P<0.05）, 2.63% （P<0.05） and 1.31% （P<0.05） compared with the control. In contrast to control, dietary supplement of 2000mg/kg vitamin C could enhance the levels of C18:2, C18:3, C20:4, C22:6, C20:5, C22:5 by 17.33%、33.33%、16.54%、17.29%、13.07% and 25.16% respectively. Lactate dehydrogenase （LDH） and creatine kinase （CK） activity in muscle of Chinese soft-shelled turtle decreased with increasing dietary vitamin C, the dietary with 2000mg/kg vitamin C significantly decreased by 36.28% and 37.29% compared with control （P<0.05）. At the same vitamin C concentration, the levels of malefic dialdehyde （MDA）, cholesterol （CHO）and creatinine （CRE） of muscle were notably less than those of control （P<0.05）. However, supplementation of vitamin C showed no significant differences on proximate compositions in muscle and calipesh.Dietary vitamin C supplementation also influenced contents of collagen in muscle, liver, carapace and calipash of Chinese soft-shelled turtle. The levels of collagen of muscle, liver, carapace and calipash raised with increasing dietary vitamin C levels and peaked in the same group fed at 400mg/kg diet.更多还原