【作者】 肖林栋；

【导师】 麦康森；

【作者基本信息】 中国海洋大学 ， 水产养殖， 2009， 博士

【摘要】 本文以我国新兴海水养殖鱼类军曹鱼(Rachycentron canadum L.)为研究对象,在室内流水养殖系统中(300 L/水族箱)进行为期9-10周的摄食生长实验。探讨饲料中添加不同水平的硫胺素、核黄素、烟酸、维生素C和胆碱对军曹鱼(初始体重:4 g左右)生长和生理状态的影响,并根据不同评价指标确定了军曹鱼对这5种水溶性维生素的需求量。采用梯度营养素法配制半精制饲料,每个实验设置6个处理,每个处理设置3个重复。每天投喂2次(08:00和17:00),每次饱食投喂。实验期间水温变化范围:28.5-32℃;盐度范围:24-26‰;溶氧含量:≥7 mg/L。主要研究结果如下:1.未添加硫胺素饲料组(对照组)军曹鱼出现生长不良、摄食下降和死亡率升高等缺乏症。饲料中添加硫胺素显著提高了军曹鱼的存活率、摄食率(feeding rate, FR)、增重率(weight gain, WG)和饲料转化率(feed efficiency ratio, FER)(P<0.05)。对照组军曹鱼的存活率、FR、WG和FER均显著低于添加硫胺素饲料组(P<0.05)。随着饲料中硫胺素水平的升高,军曹鱼WG和FER逐渐升高,当饲料中硫胺素含量达到或超过6.44 mg/kg饲料时,WG和FER逐渐趋于平稳。饲料中添加硫胺素显著影响了军曹鱼肝脏焦磷酸硫胺素(thiamin pyrophosphate, TPP)含量、红细胞转酮醇酶活性(erythrocyte transketolase activity, ETKA)和焦磷酸硫胺素效应(TPP效应)(P<0.05)。肝脏TPP含量和ETKA随着饲料硫胺素含量升高而显著升高(P<0.05),并逐渐趋于稳定,而TPP效应则随着饲料硫胺素含量的升高而显著降低并逐渐趋于稳定(P<0.05)。上述结果表明,硫胺素是军曹鱼必需维生素,硫胺素缺乏时会抑制军曹鱼生长并导致高死亡率。而饲料中高含量的硫胺素不会对军曹鱼的生长产生负面影响。采用折线模型,分别以军曹鱼WG、肝脏TPP含量、ETKA和TPP效应为评价指标时,军曹鱼对硫胺素的适宜需求量为6.80 mg/kg、8.31 mg/kg、9.00 mg/kg和8.56 mg/kg饲料。2.未添加核黄素饲料组军曹鱼出现生长不良、摄食下降、死亡率升高、体色变黑和体型短小等缺乏症。饲料中添加核黄素显著提高了军曹鱼的存活率、WG、FR、FER、肝脏核黄素含量(liver riboflavin concentration, LRC)和肝脏D-氨基酸氧化酶(D-amino acid oxidase, D-AAO)活力(P<0.05)。未添加核黄素饲料组军曹鱼的FR显著低于核黄素含量大于或等于31.21 mg/kg饲料组(P<0.05)。未添加核黄素饲料组军曹鱼的存活率、WG、FER、LRC和D-AAO活力显著低于添加核黄素的饲料组(P<0.05)。随着饲料中核黄素水平的升高,军曹鱼的WG显著升高(P<0.05),且当饲料核黄素含量达到或超过6.86 mg/kg时逐渐趋于平稳。LRC和D-AAO活力与WG存在相似的变化趋势,当饲料中核黄素含量达到或超过14.25 mg/kg时,军曹鱼的LRC和肝脏D-AAO活力达到最高水平并趋于平稳。上述结果表明,核黄素是军曹鱼必需维生素,核黄素缺乏时不仅抑制军曹鱼生长,导致高死亡率,而且会产生一系列缺乏症。而饲料中高含量的核黄素不会对军曹鱼生长产生负面影响。当分别以WG、LRC或肝脏D-AAO活力为评价指标时,通过折线模型得到军曹鱼对核黄素的最适需要量分别为7.63、9.13或9.40 mg/kg饲料。3.烟酸缺乏的饲料组军曹鱼出现厌食、生长不良、死亡率升高等缺乏症。饲料中添加烟酸显著提高了军曹鱼的存活率、FR、WG和FER(P<0.05)。未添加烟酸饲料组军曹鱼FR显著低于烟酸水平大于或等于18.9 mg/kg饲料组(P<0.05),添加烟酸饲料组军曹鱼FR差异不显著(P>0.05)。未添加烟酸饲料组军曹鱼的存活率、WG和FER均显著低于添加烟酸的饲料组(P<0.05)。随着饲料中烟酸水平的升高,军曹鱼的存活率、WG和FER均显著升高(P<0.05)。当饲料烟酸水平达到或超过18.9 mg/kg时,军曹鱼的存活率、WG和FER逐渐趋于稳定。饲料中添加烟酸显著提高了军曹鱼肝脏烟酸含量(P<0.05),当饲料烟酸水平达到或超过38.6 mg/kg时,军曹鱼肝脏烟酸含量达到最高水平并逐渐趋于稳定。上述结果表明,烟酸是军曹鱼必需的维生素,烟酸缺乏会抑制军曹鱼生长并导致高死亡率。在本研究条件下,高含量的烟酸不会对军曹鱼生长产生负面影响。分别以WG和肝脏烟酸含量为评价指标,军曹鱼对烟酸的最适需求量分别为15.03 mg/kg和23.26 mg/kg饲料。4.维生素C缺乏饲料组军曹鱼表现出生长下降、死亡率增高和厌食等缺乏症。饲料中添加维生素C显著提高了军曹鱼的存活率、WG、FR和FER (P<0.05)。未添加维生素C饲料组军曹鱼的FR显著低于维生素C水平大于或等于80.6 mg/kg饲料组(P<0.05)。未添加维生素C饲料组军曹鱼的存活率、WG和FER均显著低于添加维生素C的饲料组(P<0.05)。随着饲料中维生素C水平的提高,军曹鱼的存活率、WG和FER均显著升高(P<0.05),并逐渐趋于平稳。当饲料中维生素C含量达到或超过80.6 mg/kg时,军曹鱼生长最佳。饲料中添加维生素C显著提高了军曹鱼肝脏和肌肉维生素C含量(P<0.05)。随着饲料维生素C水平的提高,军曹鱼肝脏和肌肉维生素C含量随之显著升高(P<0.05),当饲料维生素C水平达到或者超过80.6 mg/kg饲料时,军曹鱼肝脏维生素C含量逐渐趋于稳定。而当饲料维生素C水平达到或者超过240.8 mg/kg饲料时,军曹鱼肌肉维生素C含量逐渐趋于稳定。上述结果表明,维生素C是军曹鱼必需的维生素,维生素C缺乏会抑制军曹鱼生长并导致高死亡率,而饲料中高含量的维生素C不会对军曹鱼生长产生负面影响。当分别以WG、肝脏中维生素C含量和肌肉中维生素C的含量为评价指标时,军曹鱼对饲料中维生素C的最适需要量分别为44.74、53.94和103.72 mg/kg饲料。5.未添加胆碱饲料组军曹鱼出现生长下降、厌食、饲料转化率降低和肝脏脂肪含量升高等缺乏症。饲料中添加胆碱显著提高了军曹鱼的存活率、WG、FER和FR(P<0.05)。未添加胆碱的饲料组军曹鱼的存活率显著低于添加胆碱的饲料组(P<0.05)。随着饲料中胆碱水平的升高,军曹鱼WG和FER显著升高(P<0.05),并分别在饲料胆碱含量大于或等于939.6 mg/kg和大于或等于547.9 mg/kg时,达到稳定状态。军曹鱼肝指数随着饲料胆碱含量的升高而显著降低(P<0.05)。军曹鱼肝脏脂肪含量总体上呈现逐渐降低的趋势,而肌肉脂肪含量则逐渐升高。未添加胆碱的饲料组军曹鱼肝脏脂肪含量显著低于胆碱含量为350.0 mg/kg饲料组(P<0.05)。此后,随着饲料中胆碱含量的不断升高,军曹鱼肝脏脂肪含量显著降低(P<0.05),并在饲料中胆碱含量达到或超过939.6 mg/kg时逐渐趋于稳定。未添加胆碱饲料组军曹鱼肌肉脂肪含量显著低于饲料胆碱含量大于或等于2016.7 mg/kg饲料组(P<0.05)。未添加胆碱饲料组军曹鱼肝脏和肌肉胆碱含量显著低于添加胆碱饲料组(P<0.05)。随着饲料中胆碱水平的升高,军曹鱼肝脏和肌肉中的胆碱含量显著升高并逐渐趋于稳定。当分别以WG、肝脏和肌肉中胆碱含量为评价指标时,军曹鱼对胆碱的最适需求量为695.89、876.75和949.81 mg/kg饲料。更多还原

【Abstract】 Nine-week or ten-week feeding trials were conducted to investigate the nutritional physiology of major water-soluble vitamins for cobia (Rachycentron canadum L.). The dietary requirements of thiamin, riboflavin, niacin, vitamin C and choline for cobia (average initial weight: about 4 g) were estimated using different indicators. Semi-purified diet was used and the experiments were conducted in indoor flow-through system (300 L/tank). Results of these studies are presented as follows:1. Fish fed the diet without supplemented thiamin appeared poor growth, depressed feed intake and high mortality. Supplementation of dietary thiamin significantly improved the survival, feeding rate (FR), weight gain (WG) and feed efficiency ratio (FER) of cobia. The survival, WG and FER of cobia in the control group were significantly lower than fish fed the diets with supplemented thiamin. With the increasing dietary thiamin, the WG and FER of cobia were improved significantly and then leveled off. When the dietary thiamin was equal to or higher than 6.44 mg/kg diet, the WG and FER of cobia reached the highest level and then leveled off. The supplementation of thiamin significantly infulenced the liver thiamin pyrophosphate (TPP) concentration, erythrocyte transketolase activity (ETKA) and thiamin pyrophosphate effect (TPP-effect) of cobia. With the increase of dietary thiamin, the liver TPP concentration and ETKA increased significantly and then leveled off. However, the TPP-effect reduced significantly and then leveled off. These results indicate that thiamin is the necessary vitamin for cobia, thiamin deficiency restrains growth of cobia and leads to high mortality. There is no negative effect on growth or physiological metabolism of cobia fed diets with excessive deitary thiamin. Based on WG, liver TPP concentration, ETKA and TPP-effect of cobia, the optimal dietary thiamin requirement were estimated to 6.80 mg/kg, 8.31 mg/kg, 9.00 mg/kg and 8.56 mg/kg, respectively.2. After nine weeks feeding trial, fish fed the riboflavin-deficient diet performed poorly in terms of growth parameters and exhibited typical signs of riboflavin deficiency such as anorexia, poor growth, dark skin coloration and short body dwarfism. Supplementation of dietary riboflavin significantly improved the survival, FR, WG and FER of cobia. Fish fed the diet containing 0.83 mg riboflavin/kg dry diet showed significantly lower survival, lower WG and lower FER compared with fish fed the other diets. With the increasing dietary riboflavin, the survival, WG and FER of cobia were improved significantly and then leveled off. Supplementation of dietary riboflavin significantly increased liver riboflavin concentration (LRC) and liver D-amino acid oxidase (D-AAO) activity of cobia. When dietary riboflavin was equal to or higher than 14.25 mg/kg diet, the LRC and D-AAO acitvity reached the highest level and then leveled off. These results indicate that riboflavin is the necessary vitamin for cobia, riboflavin deficiency inhibits growth of cobia and leads to a series of deficiency signs. There is no negative effect on growth or physiological metabolism of cobia fed diets with excessive deitary riboflavin. Based on broken-line analysis, the dietary riboflavin requirements were 7.63, 9.13 and 9.40 mg/kg diet, based on maximum weight gain, liver riboflavin content and D-AAO activity, respectively.3. After nine weeks feeding trial, fish fed diet without supplemented niacin appeared poor growth, higher mortality and lower FR. Supplementation of niacin definitely improved the growth of cobia. Fish fed the control diet had the significantly lower survival, WG, FR, FER and liver niacin concentration. With increasing dietary niacin, the survival, WG, FR, FER and liver niacin concentration increased significantly. When dietary niacin was equal to or higher than 18.9 mg/kg diet, the WG, FER and liver niacin concentration reached the highest leveled and then leveled off. These results indicate that niacin is the necessary vitamin for cobia, niacin deficiency restrains growth of cobia and leads to high mortality. There is no negative effect on growth or physiological metabolism of cobia fed diets with excessive deitary niacin. The dietary niacin requirement of cobia was estimated to 15.03 mg/kg diet based on maximum growth or 23.26 mg/kg diet based on liver niacin concentration, respectively.4. After ten weeks feeding trial, fish fed diet without supplemented AA appeared poor growth, higher mortality and lower FR. Supplementation of dietary AA significantly improved the survival, FR, WG and FER of cobia. Fish fed the control diet had significantly lower survival, lower WG and lower FER. With the increase of dietary AA, the survival, WG, FER, liver and muscle AA concentrations of cobia significantly increased and then leveled off. Fish fed the diets with equal to or higher than 28.3 mg/kg diet had the similar survival and significantly higher than fish fed other diets. The WG and FER of fish fed diets with equal to or higher than 80.6 mg/kg diet were similar and significantly higher than fish fed other diets. Supplementation of dietary AA significantly increased the liver and muscle AA concentration. Fish fed the diets with equal to or higher than 80.6 mg/kg diet had similar liver AA concentrations and significantly higher than fish fed other diets. Fish fed diets with equal to or higher than 240.8 mg/kg diet had similar muscle AA concentrations and signigicantly higher than fish fed other diets. These results indicate that AA is the necessary vitamin for cobia, AA deficiency restrains growth of cobia and leads to high mortality. There is no negative effect on growth or physiological metabolism of cobia fed excessive deitary AA. The dietary AA requirement of cobia was estimated to be 44.74 mg kg-1 based on WG, 53.94 mg kg-1 or 103.72 mg kg-1 based on either liver or muscle AA concentration, respectively.5. After ten weeks feeding trial, fish fed diet without supplemented choline appeared poor growth, high mortality, depressed feed intake and higher liver lipid concentration. Supplementation of choline significantly influenced the survival, FR, WG, FER, hepatosomatic index (HSI), liver lipid concentration and choline concentration in liver and muscle of cobia. The fish in the control group had significantly lower survival than other groups. With increasing dietary choline, WG or FER of cobia increased significantly and then leveled off. HSI of fish in groups containing choline equal to or lower than 350.0 mg/kg were significantly higher than the value of groups with dietary choline equal to 939.6 mg/kg or higher. Generally, liver lipid concentration appeared reduced trend and muscle choline concentration appeared increased trend, correspondingly. Choline concentration in liver and muscle was positively correlated with dietary choline and had the similar pattern as WG. When dietary choline was equal to or higher than 939.6 mg/kg diet, the liver and muscle choline concentration reached the highest level and then leveled off. These results indicate that choline is the necessary vitamin for cobia, choline deficiency restrains growth of cobia and leads to high mortality. There is no negative effect on growth or physiological metabolism of cobia fed diets with excessive deitary choline. Based on WG, liver or muscle choline concentration, the optimal dietary choline requirement for cobia was estimated to be 695.89, 876.75 or 949.81mg/kg diet, respectively.更多还原