饲料中添加肉毒碱降低养鱼成本

饲料中添加肉毒碱对陆生动物有促长作用,且可使动物耐受不良环境,提高饲料转换率。为验证L一肉毒碱对鲤生长的影响,在饲料中添加3种含量（200,400,600mg／kg）进行试验,并在内毒碱添加量400mg／kg的饲料中添加蛋氨酸或赖氨酸。试验用鲤体重30～125g,试验60天。结果表明：投喂添加L-肉毒碱400mg／kg和600mg／kg饲料的鱼,饲料转换率、特定生长率、蛋白质效率比值均高于不添加肉毒碱的对照鱼,而且与对照组相比,耗饵量降低10％,鱼体耗氧量和氨排泄量降低15％。可见饲料中添加肉毒碱因释放氮和磷可降低精养鲤的成本。饲料中添加肉毒…     

不同脂肪条件下添加牛磺酸对鲤生长性能、体成分、肝胰脏生化指标及抗氧化能力的影响

为探索不同脂肪条件下添加牛磺酸对幼鲤生长性能、体成分、肝胰脏生化指标及抗氧化能力的影响,实验在脂肪水平为4.65%和10.22%（高脂水平）的饲料中分别添加0、400、800和1 600 mg/kg的牛磺酸,配制成8种等氮等能实验饲料。以720尾初始体质量为（1.17±0.01）g的健康幼鲤为实验对象,随机分为8组,每组3个重复,每个重复30尾实验鱼,分别投喂8种实验饲料,养殖时间为56 d。结果发现,未添加牛磺酸时,4.65%脂肪组幼鲤增重率（WGR）、特定生长率（SGR）和蛋白质效率（PER）显著高于10.22%脂肪组,而FCR显著低于10.22%脂肪组。添加牛磺酸后,4.65%和10.22%脂肪组中幼鲤的WGR、SGR和PER均显著提高,FCR显著降低;且随着牛磺酸添加量的提高,幼鲤WGR、SGR和PER均呈先升高后趋于稳定的变化趋势,且均在牛磺酸添加量为800 mg/kg时最大;FCR则均呈先降低后趋于稳定的变化趋势,均在牛磺酸添加量为800 mg/kg时最小;牛磺酸添加量大于800 mg/kg时,10.22%脂肪组幼鲤WGR、SGR和PER显著高4.65%脂肪组,而FCR则显著低于4.65%脂肪组。幼鲤肝胰脏中总胆固醇及甘油三酯均随牛磺酸添加量的升高而呈逐渐降低的变化趋势,但在4.65%脂肪组中差异不明显,而10.22%脂肪组中差异显著,随着牛磺酸添加量的提高,幼鲤的肥满度均呈先增大后趋于稳定的变化趋势,HSI、VSI则均呈先降低后趋于稳定的变化趋势;幼鲤体组织中粗蛋白质含量呈先升高后趋于稳定的变化趋势,粗脂肪含量呈先降低后趋于稳定的变化趋势;幼鲤肝胰脏中SOD、CAT活性均呈先升高后降低的变化趋势,且SOD、CAT活性均在牛磺酸添加量为800 mg/kg时最强;而MDA含量则呈降低的变化趋势,且MDA均在牛磺酸添加量为1 600 mg/kg时最低。研究表明,添加800~1 600 mg/kg牛磺酸可显著提高幼鲤对饲料脂肪的利用率,促进其生长,减少体内的脂肪沉积,改善肌肉品质,提高机体的抗氧化能力。     

喹烯酮对建鲤和斑点叉尾鮰生长性能和抗缺氧能力的影响

在池塘养殖条件下,饲料中添加3个不同含量(50、75和100 mg/kg)的喹烯酮来饲养建鲤(Cyprinus carpio var.Jian)和斑点叉尾鮰(Ietalurus Punetaus),养殖周期为60 d,研究喹烯酮对建鲤和斑点叉尾鮰生长性能和抗缺氧能力的影响。结果表明:与不添加喹烯酮的对照组相比,添加喹烯酮的实验组中建鲤和斑点叉尾鮰生长速度加快,死亡率降低,饲料系数下降。当饲料中添加喹烯酮的剂量为75 mg/kg时,其对建鲤和斑点叉尾鮰的生长效率提高最佳(P0.05),饲料系数最低,成活率最高。在75 mg/kg的喹烯酮添加量下,建鲤和斑点叉尾鮰的抗缺氧能力、血细胞和血红蛋白量均有提高,但与对照组相比,差异均不显著(P0.05)。饲料中添加喹烯酮对建鲤和斑点叉尾鮰生长性能的作用呈现非剂量依赖性,而且添加75 mg/kg喹烯酮对其抗缺氧能力影响不显著(P0.05)。研究表明,建鲤和斑点叉尾鮰养殖中喹烯酮的最适用量为75 mg/kg。     

实用饲料添加肌醇对草鱼生长、脂质代谢及抗氧化机能的影响

为探讨肌醇对草鱼生长、脂质代谢及抗氧化机能的影响,以实用饲料配方为基础,分别添加0(对照)、50、100、150、200、300和400 mg/kg肌醇,配制成7组等氮等脂的饲料,每组饲料设4个重复,每个重复饲喂初始体质量为(15.00±0.15)g的草鱼25尾,养殖56 d。结果显示,饲料中添加100~150 mg/kg肌醇能显著提高草鱼终末均重(FBW)、增重率(WGR)、特定生长率(SGR)及饲料效率(FE);随饲料肌醇添加水平的上升,全鱼脂肪、肝脏脂肪和脂肪沉积率先升后降,在50~300 mg/kg均与对照组存在显著差异,且均在100 mg/kg达到最大值。肌肉脂肪则逐渐下降并趋于稳定,在100 mg/kg达到最小值,100~400 mg/kg差异不显著;肠脂肪酶、血浆总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)含量及高密度/低密度脂蛋白胆固醇(HDL-C/LDL-C)均呈先升后降的趋势,除LDL-C在各组间差异不显著外,其余指标均在100~150 mg/kg达到最大值;添加肌醇能显著增强肝脏和肌肉中肉碱脂酰转移酶(CPT-I)和乙酰辅酶A羧化酶(ACC)的活性。与对照组相比,100 mg/kg肝脏CPT-I的增幅比例低于ACC的增幅比例,肌肉则相反;当肌醇添加水平为100~150 mg/kg时,肝脏和肌肉中超氧化物歧化酶(SOD)的活性显著升高,丙二醛(MDA)含量及血浆中谷丙转氨酶(ALT)、谷草转氨酶(AST)均显著降低。研究表明,实用饲料添加适宜的肌醇能改善草鱼的生长、饲料转化和肝脏功能,促进脂肪消化,加快脂肪酸的合成与分解代谢,使全鱼和肝脏增脂、肌肉降脂,且能够提高肝脏和肌肉的抗氧化机能。以FE和SGR为效应指标,草鱼实用饲料肌醇适宜添加量为90.3~96.4 mg/kg。     

牛至油对慢性氨氮胁迫下幼鲤组织结构的影响

本试验旨在研究饲料中添加牛至油对慢性氨氮胁迫下幼鲤（Cyprinus carpio）鳃、肝、肾、肠道组织结构的影响。挑选450尾初始体重为（17.02 ± 0.40）g的幼鲤,随机分为6组：L（对照组,养于正常水体中并饲喂基础饲料）;L0、L300、L600、L900、L1200（试验组,养于4.87 ± 0.21 mg/L氨氮水体中并分别饲喂添加0、300、600、900、1200 mg/kg牛至油的试验饲料）,每组设3个重复,每个重复25尾鱼,养殖试验为期56 d。结果表明：添加量为900 mg/kg时,牛至油对鳃、肝、肾组织发挥的缓解作用最大;当牛至油添加量达到1200 mg/kg 时,其缓解氨氮胁迫的作用降低。日粮中牛至油添加量为300、600、900 mg/kg可以显著增加肠绒毛高度,促进幼鲤肠道的生长发育;当牛至油添加量达到1200 mg/kg时,牛至油对于肠绒毛的促生长作用有所减弱。结论：日粮中添加900mg/kg的牛至油有助于缓解由氨氮胁迫造成的幼鲤鳃、肝、肾、肠道组织的损伤,并且对于幼鲤肠绒毛的生长,肠道消化吸收能力具有促进作用。     

猪饲料中添加高剂量铜、锌对粗脂肪及粗蛋白质消化率的影响

分铜、锌进行了2个消化试验,分别选择20kg左右的健康长×荣去势猪只24头,随机分为4组,每组6个重复,每个重复1头,消化代谢笼单圈饲养。测定了猪饲料中添加高剂量铜(100mg/kg、200mg/kg、300mg/kg、400mg/kg)、锌(100mg/kg、250mg/kg、500mg/kg、3000mg/kg)对粗脂肪及粗蛋白质消化率的影响。结果表明,饲料中添加高剂量铜、锌能提高猪对粗脂肪及粗蛋白质的消化率。含铜200mg/kg组粗脂肪消化率最高,极显著地高于100mg/kg组(P<0.01),300mg/kg组及400mg/kg组显著地高于100mg/kg组(P<0.05),铜对粗蛋白质消化率的影响也表现出含铜200mg/kg组最高,显著地高于100mg/kg组(P<0.05);含锌250mg/kg组及3000mg/kg组粗脂肪的消化率均极显著地高于100mg/kg组(P<0.01),500mg/kg组显著地高于100mg/kg组(P<0.05),而3个高锌组之间差异不显著(P>0.05),饲料中添加高剂量锌对粗蛋白质消化率也有不同程度提高,但均未达显著性水准(P>0.05)。     

L-肉碱对鲫鱼生长和肌肉营养成分的影响

200尾均重25.1g的高背鲫按L-肉碱在饲料中添加量的不同(0,50,100,150,200mg/kg)随机分成5组,用于研究L-肉碱对鲫鱼生长及肌肉营养成分的影响。结果表明:鲫鱼饲料中添加50～100mg/kg的L-肉碱能显著提高鲫鱼的相对生长率、饲料效率,其中添加100mg/kg的L-肉碱效果最好,其相对生长率和饲料效率与对照组相比分别提高了122.4%和91.3%(P<0.05);在鲫鱼饲料中添加50～150mg/kg的L-肉碱时均能显著提高肌肉中蛋白质的含量,同时显著降低肌肉中脂肪的含量,其中添加150mg/kg的L-肉碱时肌肉中蛋白质含量比对照组提高4.04%,而脂肪含量降低了45.1%(P<0.05),但添加L-肉碱对鲫鱼的空壳率没有明显影响,各组差异均不显著。     

蛋氨酸铬对鲤血清生化指标和非特异性免疫活性的影响

为研究蛋氨酸铬对鲤血清生化指标和非特异性免疫指标的影响,配制蛋氨酸铬添加水平分别为0、0.1、0.2、0.4、0.8、1.6、3.2 mg/kg的7种饲料,选取初始体质量为(40.95±4.80)g的鲤1 260尾,进行了为期8周的饲养试验。结果表明:(1)添加0.4 mg/kg蛋氨酸铬的试验组,其胆固醇(TC)、甘油三脂(TG)含量最低,与其它组差异显著(P0.05);添加1.6 mg/kg的组,其高密度脂蛋白(HDL)含量最高;添加0.8mg/kg的组,其低密度脂蛋白(LDL)显著高于对照组(P0.05)。添加0.4~3.2 mg/kg蛋氨酸铬的试验组,鲤血清中的谷草转氨酶(GOT)活性高于对照组(P0.05)。(2)添加蛋氨酸铬的试验组,鲤肝胰脏中超氧化物歧化酶(SOD)的活性均高于对照组;0.8 mg/kg添加组的总抗氧化能力(T-AOC)和过氧化氢酶(CAT)活性均显著高于对照组(P0.05);0.4 mg/kg添加组的丙二酮(MDA)含量低于其它各组。添加0.2~3.2 mg/kg蛋氨酸铬的试验组,其AKP活性显著低于对照组(P0.05);鲤肝胰脏中谷草转氨酶(GOT)的活性随着蛋氨酸铬添加量的增加呈现上升趋势,且均显著高于对照组(P0.05);除3.2 mg/kg添加组外,其它各组的谷丙转氨酶(GPT)活性均显著下降。综上所述,在饲料中添加0.4~0.8 mg/kg的蛋氨酸铬能够增强鲤肝胰脏的非特异性免疫力。     

饲料中添加肉毒碱对黄颡鱼生长的影响

以鱼粉和豆粕为蛋白源、大豆油为脂质源配制成1个蛋白质水平（35％）X5个脂肪水平（4％,10％,16％,22％,26％）X2个肉毒碱水平（0mg／Kg,150mg／Kg）的10种配方饲料,投喂平均体重为（10．0±0．6）g的黄颡鱼,进行肉毒碱对黄颡鱼生长影响的研究。经100d饲养表明：饲养中添加150mg/Kg肉毒碱对黄颡鱼生长没有影响。在黄颡鱼低蛋白配合饲料中,体重增长率最大,饵料系数、蛋白质效率较好的是最低的脂肪含量组（4％）。高脂肪含量对黄颡鱼的生长不利。     

饲料中添加稀土氨基酸配合物养殖鲤鱼虹鳟鱼的应用试验报告

本文报告了饲料中添加300mg/kg和400mg/kg稀土氨基酸配合物（由稀土蛋氨酸和稀土赖氨酸各50％混合而成），在网箱养鲤应用试验中，实验鲤鱼比对照鲤鱼增重率分别提高6．3％和16％。在虹鳟鱼养殖应用保，实验虹鳟鱼比对照虹鳟鱼分别提高11．2％和29．6％。试验结果初步表明：饲料中添加400mg/kg稀土氨基酸配合物有促进鲤鱼和虹鳟鱼快速生长的作用。     

Separate and combined effects of cyclic fasting and l‐carnitine supplementation in red porgy (Pagrus pagrus,L. 1758)

We examined the effects of cyclic fasting in red porgy (Pagrus pagrus) fed different dietary carnitine levels. Juvenile fish (23.58 ± 3.49 g) were divided into eight groups – four groups were fed every day to apparent satiation, while the other four were fasted for 7 days every 2 weeks. In each feeding regime, two replicates were fed an l ‐carnitine non‐supplemented diet (46 mg kg^?1) and the other two groups were fed an l ‐carnitine supplemented diet (630 mg kg^?1). Fish fed 630 mg l ‐carnitine accumulated two times more l ‐carnitine in muscle than fish fed 46 mg l ‐carnitine. Cyclic fasting reduced the growth performance and lipid content in the liver. Carnitine supplementation did not affect performance and body composition, but decreased the n‐6 PUFA content. Moreover, the combined effects of fasting and carnitine supplementation were observed on reducing the n‐3 fatty acid content. Areas of steatosis were found in the livers of red porgy, but the results revealed that supplementation of l ‐carnitine in cyclic fasted fish contributed towards a lower degree of vacuolization than in fish fed to apparent satiation. Regardless of the feeding regime applied, the spleen of fish fed the l ‐carnitine‐supplemented diet was haemorrhagic and hyper activation of melanomacrophage cells was observed.     

Effects of dietary carnitine and lipid on growth and body composition of hybrid striped bass (Morone chrysops ♀× M. saxatilis ♂)

A study was undertaken to investigate the effects of graded dietary levels and different types of carnitine on hybrid striped bass (Morone chrysops × M. saxatilis %) fed different levels of lipid. An incomplete factorial design was utilized in which diets containing lipid at either 5 or 10% were supplemented with l-carnitine at 0, 500, or 1000 mg kg^–1 diet, dl-carnitine at 1000 mg kg^–1 diet, or carnitine chloride to provide 1000 mg carnitine kg^–1 diet. Juvenile hybrid striped bass (3.3 g fish^–1) were stocked into individual 38-l aquaria connected as a brackish water (6), recirculating system and fed each diet in triplicate for 9 weeks.Supplementation of the diet with 1000 mg carnitine kg^–1 increased muscle carnitine from 35.5 to 47.7 g g^–1 tissue. Carnitine supplementation did not result in increased weight gain regardless of carnitine level or type; however, weight gain showed a significant (p<0.05) response to dietary lipid with fish fed diets containing 10% lipid growing 34% more than fish fed diets with 5% lipid. The hepatosomatic index also was unaffected by diet, but the intraperitoneal fat (IPF) ratio was significantly elevated (5.1 vs 3.2%) in fish fed diets with 10% lipid compared to those fed diets with 5% lipid. Fish fed diets containing 1000 mg carnitine kg^–1 had increased IPF ratio values at 4.7% compared to 3.9% for fish fed the basal diet. Liver lipid also was responsive to dietary treatment, increasing from 6.7 to 8.8% of wet weight as dietary lipid increased from 5 to 10%. The relative quantities of triglycerides, free fatty acids and phospholipids in muscle and liver were not influenced by carnitine level, carnitine type or dietary lipid level. Supplementation of carnitine does not appear to be beneficial to hybrid striped bass based on either growth performance or body composition.     

Comparative effects of dietary l‐carnitine supplementation on diploid and triploid rainbow trout (Oncorhynchus mykiss)

This study compared the effects of dietary l ‐carnitine and ploidy on growth performances and fatty acid content in rainbow trout (Oncorhynchus mykiss). Fish [initial body weight (BW) = 30 g] reared under high density (50 kg biomass m^?3) were hand‐fed in triplicate (3 tanks treatment^?1, 34 fish tank^?1) twice a day, with three nutritionally identical diets containing 15, 200 or 530 mg l ‐carnitine kg^?1 of diet. No significant growth differences were observed over a 56‐day grow‐out period, during which BWs increased threefold. Growth performances and survival were not significantly affected by either ploidy or dietary l ‐carnitine content, although daily growth index showed an increasing trend (2.52–2.65% day^?1) with increasing dietary l ‐carnitine. Body l ‐carnitine content increased significantly with dietary l ‐carnitine content. Diploid fish had higher plasma ammonia (716–725 μmol L^?1) and osmolality (297–303 mOsm) levels than triploid trout (523–649 μmol L^?1 and 285–291 mOsm, respectively). l ‐carnitine, ploidy and their interaction showed to affect significantly the concentration of several fatty acids. Palmitoleic (16:1), oleic (18:1) and erucic (22:1) acids showed lower concentrations, while the eicosadienoic (20:2n‐6) and arachidonic (20:4n‐6) acids were elevated in liver of triploid fish. Eicosapentaenoic acid (22:5n‐3) was significantly higher in fish fed 200 mg than in fish fed 15 mg l ‐carnitine.     

饲料中添加L-肉碱对大菱鲆生长及肝脏脂肪酸的影响

在以鱼粉和大豆浓缩蛋白为蛋白源的基础饲料中分别添加0、200、400、600、800、1 000和2 000 mg/kg的L-肉碱配置7种等氮等能的试验饲料.经8周的摄食生长试验,结果表明:600 mg/kg添加组大菱鲆表现出最好的特定生长率,800mg/kg添加组大菱鲆表现出最好的饲料效率.各实验组间特定生长率及饲料效率均未表现出显著差异(P＞0.05).添加不同梯度L-肉碱对大菱鲆的肥满度、脏体比及肝体比未造成显著影响(P＞ 0.05).同时,各实验组大菱鲆体组成及肝脏脂肪酸含量无显著差异(P＞ 0.05).综合考虑L-肉碱对大菱鲆生长性能及经济效益,建议在以鱼粉为主要蛋白源的大菱鲆饲料不需添加L-肉碱.     

Lysine limitation alters the storage pattern of protein,lipid and glycogen in on‐growing Atlantic salmon

This experiment aimed to test the interaction of lysine limitation with nutrient accretion and muscle carnitine depot in Atlantic salmon. Fish were fed adequate or low‐lysine diets for 3 months. Lysine intake was significantly less (48%) in fish fed the low‐lysine diet as compared with that fed the adequate one. There was no difference in dietary amino acids between treatments, with the exception of lysine. The lower lysine intake was reflected in plasma free lysine being 52% less while the free lysine concentration in the liver and muscle were unaffected. Although there was no significant difference between voluntary feed intakes among treatments, fish fed the low‐lysine diet had reduced growth, protein and energy deposition as compared with fish fed the adequate lysine diet. White trunk muscle contained more glycogen and less protein in fish fed the low‐lysine diet while no difference in lipid was observed. The livers from fish fed the low‐lysine diet contained less glycogen and slightly more fat and protein than the livers from fish fed the adequate lysine diet. Lysine limitation reduced carnitine in the liver without affecting muscle carnitine depot. Thus, low‐lysine diets did not likely affect the fatty acid oxidation capacity. This fact was supported by unaffected fatty acid profiles and lipid classes between treatments during the 3‐month study. In conclusion, lysine limitation does not deplete the muscle carnitine depot during the on‐growing seawater phase of Atlantic salmon, but affects the deposition pattern of nutrients.     

Accumulation of zinc from diet and its release in common carp

High zinc diet of 2000 mg kg^–1 was fed to common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idellus) and tilapia (Oreochromis aureus) for 8 weeks to compare the accumulation of Zn in fish. It was found that accumulation of zinc from diet by grass carp and tilapia was low when compared to common carp. The largest difference occurred in digestive tract tissue. The digestive tract tissue of common carp had a large pool of stored zinc, the mean storable capacity is about 1500 g Zn g^–1 fresh tissue, and the time needed to saturate the tissue when feeding 2000 mg Zn kg^–1 diet is about 8 weeks. The accumulated Zn in the digestive tract tissue of common carp was released when the dietary Zn was reduced to normal level (50 mg kg^–1) or deficient level (4 mg kg^–1) for 4 weeks.Subcellular fractionation results indicate that Zn accumulated in digestive tract tissue of common carp was accumulated mainly in the nuclei/cell debris fraction. Exposure to a high Zn diet induced some metallothionein-like substance in the digestive tract tissue and the hepatopancreas of common carp, but the amount was very low when compared with the amount of Zn accumulated in the nuclei/cell debris fraction.     

Dietary effects of poly‐β‐hydroxybutyrate on the growth performance,digestive enzyme activity,body composition,mineral uptake and bacterial challenge of rainbow trout fry (Oncorhynchus mykiss)

This study investigated the effects of diet supplementation with poly‐β‐hydroxybutyrate (PHB) on growth performance, digestive enzyme activity, lipid metabolism, mineral uptake and bacterial challenge of the rainbow trout fry (initial weight: 111.3 ± 13.7 mg) during a 6‐week experimental period. In the experimental set‐up, the commercial diet of rainbow trout fry was replaced with 0.5%, 1% and 2% PHB. The results of our work showed that the replacing of diets with PHB in experimental treatments decreases the weight of rainbow trout fry during the first 2 weeks before significantly increasing final weight at the end of the 6‐week period. PHB also improved digestive enzyme activity in experimental treatments. The highest total protease, pepsin activity and pancreatic enzyme secretion were observed with the 0.5% PHB treatment. A higher concentration of Na and K was observed in the whole body of the fry fed on 1% and 2% PHB‐supplemented diets. Enhanced survival rates occurred in all groups of fry after bath exposure to Yersinia ruckeri compared to rates in those fed the control diet. Our results suggest that the diet supplemented with PHB may improve growth performance, digestive enzyme activity and the functioning of the immune system. These positive effects could be considered for new applications in aquaculture.     

绿原酸对建鲤生长、非特异性免疫功能和抗氧化能力的影响

为探究饲料中添加不同浓度绿原酸 (Chlorogenic acid)对泥鳅生长性能、消化酶活性、免疫功能及抗氧化能力的影响,选用无病无伤初始体重为 (3.50±0.01) g的泥鳅,随机分为5组,在基础饲料投喂中分别添加0、200、400、600和800 mg/kg的绿原酸实验饲料,每组3个重复,饲养56 d。饲养实验结束后,测定泥鳅生长性能、消化酶活性、生化指标、免疫功能及抗氧化能力。结果发现,与对照组相比较饲料中加入绿原酸可以显著增高泥鳅的终末体重 (FBW)、增重率 (WGR)和特定生长率 (SGR) (P < 0.05);且显著提高肝脏和肠道中蛋白酶、脂肪酶和淀粉酶的活性以及肝脏与肠道中总抗氧化能力 (T-AOC)、过氧化氢酶 (CAT)、超氧化物歧化酶 (SOD)、谷胱甘肽 (GSH)和谷胱甘肽过氧化物酶 (GSH-Px)的活性,丙二醛 (MDA)的生成被降低,肝脏中谷草转氨酶 (AST)、谷丙转氨酶 (ALT)活性随绿原酸浓度增加而提高,分别在400和600 mg/kg时达到最大值。随着绿原酸浓度的升高,血清中AST、ALT活性均显著下降。随着绿原酸浓度的增加,血清中乳酸脱氢酶 (LDH)逐渐下降,在浓度400 mg/kg时达到最低值;血清补体3 (C3)和补体4 (C4)含量先升高后下降,分别在绿原酸浓度为400和600 mg/kg时达到峰值含量;血清中免疫球蛋白M (IgM)水平显著升高,在浓度为600 mg/kg时达到最大;血清中溶菌酶 (LYS)含量先上升后下降,在浓度为400时含量为最大值。研究表明,在饲料当中添加400~600 mg/kg绿原酸可显著提高泥鳅生长性能和消化酶活性,增强泥鳅的免疫功能和抗氧化能力。

     

Effect of dietary ascorbate on lipogenesis and lipolysis activities in black sea bream, <Emphasis Type="Italic">Acanthopagrus schlegelii</Emphasis>

To assess the effect of dietary ascorbate on lipid metabolism, 1-year black sea bream (Acanthopagrus schlegelii) were reared on a casein-based purified diet and an ascorbate fortified diet (1,100 mg of l-ascorbyl-2- monophosphate-Mg/kg diet). The fortified ascorbate was effectively incorporated into the fish body and elevated muscle carnitine content. Fortifications of dietary ascorbate depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancreas and intraperitoneal fat body. Starvation after feeding experiment activated carnitine palmitoyltransferase as a lipolysis enzyme in the hepatopancreas in both control and vitamin C(VC) groups, while the lipolysis activity was significantly higher in VC group. These results confirmed that dietary ascorbate depressed lipogenesis and activated lipolysis, i.e., influenced the lipid metabolism of black sea bream.     

Effects of Varying Concentrations of l-carnitine-incorporated Diets on Growth and Body Composition of Fry of Cirrhinus mrigala (Hamilton, 1822)

Experiment was conducted to ascertain the effect of l ‐carnitine on growth and body composition of Cirrhinus mrigala fry (0.342 ± 0.03 g) using five different concentrations (0.25, 0.50, 0.75, 1, and 0%) of l ‐carnitine‐incorporated diets for 120 d. At the end of trial, weight gain, feed conversion efficiency, and protein efficiency of fishes fed with 0.25% l ‐carnitine diet were observed to be significantly higher. Poor growth was recorded in the fry fed diet with no carnitine, while intermediate growth was observed when fed with 0.50, 0.75, and 1% l ‐carnitine‐incorporated diets. The analysis of body composition of C. mrigala fry indicated that there is no significant difference (P > 0.05) in moisture, protein, and ash contents, but significant difference (P < 0.05) was found in body lipid content of fry, fed with different concentrations of l ‐carnitine. Decrease in viscerosomatic and hepatosomatic indices were observed in fishes fed with l ‐carnitine‐incorporated diets. Results of this study indicated that diet containing 0.25% l ‐carnitine can promote higher growth in C. mrigala fry.