投饲蚕豆对草鱼生长和肌肉品质的影响

分别以配合饲料、浸泡蚕豆、发芽蚕豆喂养体质量为(530±20)g的草鱼(Ctenopharyngodon idellus)77 d,以考察投饲蚕豆对草鱼生长和肌肉品质的影响.结果表明,配合饲料组、浸泡蚕豆组和发芽蚕豆组草鱼的增重率分别为83.08%、55.01%和62.82%,饵料系数分别为2.03、2.96和2.70,投饲浸泡蚕豆或发芽蚕豆显著降低了草鱼增重率(P<0.05),增加了饲料系数(P<0.05):与配合饲料组相比,浸泡蚕豆组和发芽蚕豆组草鱼肌肉粗脂肪含量和肌肉失水率显著降低(P<0.05),胶原蛋白含量和肌纤维直径显著增加(P<0.05);肌肉游离氨基酸中呈味氨基酸的含量显著下降(P<0.05),而必需氨基酸含量显著增加(P<0.05);肌肉的硬度和黏性也有了显著提高(P<0.05).上述结果表明,饲喂蚕豆可显著改善草鱼肌肉品质,但同时降低了草鱼生长性能.[中国水产科学,2008,15(6):1 042-1 049]     

不同饲料原料对草鱼生长和肌肉品质的影响

分别以专用配合饲料、浸泡蚕豆、浸泡豌豆喂养体质量为(1540.9±57.5)g的草鱼(Cteno-pharyngodon idellus)90d,以考察不同原料对草鱼生长和肌肉品质的影响。结果表明,配合饲料组、浸泡蚕豆组和浸泡豌豆组草鱼的增重率分别为17.3%、13.7%和12.2%,饵料系数分别为5.00、4.09和5.08,三种原料对草鱼的脏体比、肝体比没有显著影响;与普通草鱼相比,三种原料组草鱼肌肉粗脂肪含量和肌肉失水率显著降低(P0.05),胶原蛋白含量和肌原纤维长度显著增加(P0.05)。上述结果表明,三种原料均可显著改善草鱼肌肉品质;与浸泡蚕豆组相比,专用配合饲料组显著提高了草鱼的生长性能。     

投喂蚕豆对草鱼生长及肌肉营养特性分析

分别用配合饲料、浸泡蚕豆和发芽蚕豆喂养平均体重(1000±20)g草鱼70d,分析投喂蚕豆对草鱼生长及肌肉营养的影响。结果表明,配合饲料组、浸泡蚕豆组和发芽蚕豆组的草鱼增重率分别为79.5%、40.32%和50.10%,饵料系数分别为2.11、4.78和4.31,投喂蚕豆降低了草鱼增重率(P<0.05),显著增加了饵料系数(P<0.05)。与配合饲料组相比,浸泡蚕豆组和发芽蚕豆组肌肉中粗脂肪和粗蛋白含量显著降低(P<0.05)。浸泡蚕豆组和发芽蚕豆组的必需氨基酸含量、鲜味氨基酸含量、氨基酸总量比配合饲料组显著提高(P<0.05)。投喂蚕豆降低了草鱼的生长性能,但是显著提高了草鱼肌肉品质。投喂发芽蚕豆的效果要优于投喂浸泡蚕豆。     

饲料中添加氯化胆碱对草鱼成鱼生长、脂肪沉积和脂肪代谢酶活性的影响

选用初始体质量为(314.7±9.9)g的草鱼(Ctenophary ngodon idella)240尾,随机分成4组,每组3个重复,每重复20尾鱼,分别饲喂氯化胆碱添加量为0%(对照组)、0.2%、0.4%和0.6%(占饲料的质量分数)的4组饲料(粗蛋白、粗脂肪含量分别为28.01%和4.54%),胆碱实测含量分别为1010mg/kg、2516mg/kg、4184mg/kg、5852mg/kg,养殖77d后,考察氯化胆碱对草鱼成鱼生长性能、脂肪沉积及脂肪代谢酶活性的影响。结果表明,与对照组相比较,添加0.4%和0.6%氯化胆碱可显著提高鱼体增重率(P0.05)、特定生长率(P0.05),降低饲料系数(P0.05);添加0.2%～0.6%氯化胆碱可显著降低肝胰脏和全鱼脂肪含量(P0.05);添加0.4%和0.6%氯化胆碱,肌肉脂肪含量显著下降(P0.05);添加0.2%～0.6%氯化胆碱可显著提高血清甘油三酯和总胆固醇含量(P0.05),添加0.4%和0.6%氯化胆碱可显著降低肝胰脏甘油三酯和总胆固醇含量(P0.05);在脂肪代谢酶方面,添加0.2%～0.6%氯化胆碱可显著提高前肠脂肪酶活性(P0.05),添加0.6%氯化胆碱显著提高脂蛋白脂酶活性(P0.05),添加0.4%～0.6%氯化胆碱可显著升高肝脂酶和总脂酶活性(P0.05)。综上所述,适量添加胆碱能改善草鱼成鱼生长性能,提高饲料利用率,降低肝胰脏、全鱼和肌肉的脂肪含量,提高脂肪代谢酶活性。建议草鱼实用饲料中氯化胆碱添加量为0.4%～0.6%。     

投饲蚕豆对草鱼生长和肉质影响的初步研究

分别以配合饲料(对照组)、蚕豆(蚕豆组)饲喂平均体重为496.5 g的草鱼(Ctenopharyngodon idella)66d,考察蚕豆对草鱼生长和肉质的影响。结果表明:配合饲料组和蚕豆组增重率为82.76%,36.96%;饵料系数为2.17,4.45;肥满度为13.09,7.72;粗脂肪含量为0.89%,1.43%;肌肉失水率为27.14%,15.87%;肌原纤维长度为28.32μm,33.31μm;羟脯氨酸0.12mg/g,0.16mg/g。在生长方面,与配合饲料组相比,蚕豆组草鱼的增重率、肥满度极显著降低,饲料系数极显著增加(P<0.01);在肌肉品质方面,失水率极显著降低;粗脂肪含量、肌原纤维长度、羟脯氨酸含量极显著提高(P<0.01)。结果表明,投喂蚕豆对草鱼肌肉具有特殊的改变作用。     

肉碱对草鱼生长性能、体成分和脂肪代谢酶活性的影响

在基础饲料中分别添加100、200、300和400mg/kg DL-肉碱，饲喂平均体重134.3±12.1g的草鱼(Ctenopharyngodon idella)8W，以增重率、饲料系数(FCR)，肌肉和肝胰脏中蛋白脂肪含量，肠道脂肪消化酶，肝胰脏脂蛋白脂酶(LPL)、肝脂酶(HL)和脂肪酸合成酶(FAS)等指标为判据，研究肉碱对草鱼生长性能、体成分和脂肪代谢酶活性的影响。结果表明，添加200mg/kg肉碱提高鱼体增重率5.70%(P < 0.05)，降低FCR5.26%(P < 0.05)；添加200～400mg/kg肉碱显著降低了肌肉和肝胰脏中的脂肪含量(P < 0.05)；当肉碱添加量为300mg/kg时，肌肉蛋白含量最高；肉碱对肌肉水分和灰分、肝胰脏的蛋白含量无影响(P > 0.05)；添加200、400mg/kg肉碱显著降低了血清胆固醇含量(P < 0.05)；在脂肪代谢酶活性方面，200mg/kg肉碱组肠道脂肪消化酶和HL活性较对照组提高28.0%、38.6%(P < 0.05)；添加400mg/kg肉碱提高肠道脂肪消化酶、HL及总脂酶活性41.41%、36.26%、10.66%(P < 0.05)，降低FAS活性47.3%(P < 0.05)。综上所述，适量肉碱能改善草鱼生长性能、降低肌肉和肝胰脏脂肪含量及促进脂肪降解。建议草鱼饲料中肉碱添加量为200mg/kg。     

蚯蚓粉替代鱼粉对大鳞副泥鳅生长、肌肉成分、血清生化指标及免疫性能的影响

以初始体重为(3.86±0.23)g的大鳞副泥鳅(Paramisgurnus dabryanus)为试验对象,研究蚯蚓(Eisenia foetida)粉替代鱼粉对其生长、肌肉成分、血清生化指标及免疫性能的影响。以0代替鱼粉为对照组,用蚯蚓粉替代25%、50%、75%、100%的鱼粉配制成5组等氮等能饲料,在网箱中进行10周的养殖试验。结果显示,饲料中的蚯蚓粉替代鱼粉对大鳞副泥鳅的存活率无显著影响;随着替代水平的升高,饲料系数、增重率升高(P0.05),肥满度、肝体比降低(P0.05)。各组间脾体比、特定生长率均无显著性差异;75%和100%替代组肌肉粗脂肪含量显著高于对照组(P0.05),100%替代组粗蛋白和水分含量显著低于对照组(P0.05)。随着饲料中蚯蚓粉水平的上升,鱼体肌肉蛋白质的精氨酸、胱氨酸、天门冬氨酸含量升高(P0.05),脯氨酸、组氨酸、蛋氨酸、苏氨酸、苯丙氨酸含量显著降低(P0.05);各组间血清谷丙转氨酶活力、高密度脂蛋白胆固醇含量、脂肪酶和淀粉酶活性均无显著性差异(P0.05)。随着代替水平的上升,血清甘油三酯和总胆固醇含量显著升高(P0.05),谷草转氨酶显著降低(P0.05);随着替代水平的继续上升,肝胰脏过氧化氢酶、谷胱甘肽过氧化物酶、溶菌酶活力下降,肝胰脏丙二醛含量、碱性磷酸酶活力、攻毒后的发病率和死亡率上升。各组间的肝胰脏总超氧化物歧化酶活力和总抗氧化能力均无显著性差异(P0.05)。研究表明,本实验条件下,蚯蚓粉可部分替代(22%)饲料鱼粉而不影响大鳞副泥鳅的生长和存活,且能提高鱼体肌肉成分,有效预防肝胰脏损伤和过氧化,但显著降低了鱼类免疫性能(P0.05)。     

高铜饲料对凡纳滨对虾生长、肌肉和肝胰脏铜积累的影响

采用在实用饲料(含铜11.68 mg/kg)中分别添加铜(以分析纯CuSO4.5H2O为铜源)了0 mg/kg(对照组),25 mg/kg(适量组),50、100、200、400 mg/kg(高铜组)(编号为C0、C25、C50、、C100、C200、C400)的6组饲料,喂养凡纳滨对虾(Litopenaeus vannamei)(0.49±0.03 g)8周,研究了高铜饲料对凡纳滨对虾生长、肌肉和肝胰脏铜积累的影响。结果显示:饲料铜含量过高具有毒性,C100~C4003组存活率显著低于其它组(P<0.05),分别为51.11%、37.78%、14.81%;随饲料铜水平的增加,增重率、饲料效率、特定增长率先升高后降低,C50组的增重率和特定生长率显著高于其他组(P<0.05),C25、C50组的饲料效率显著高于其他组(P<0.05);随饲养时间的延长,肌肉、肝胰脏铜积累增加,试验末期各组肌肉、肝胰脏铜积累显著升高(P<0.05),试验期间肌肉铜积累在3.10~11.08 mg/kg之间,而肝胰脏铜积累则在10.89~449.48 mg/kg之间,同组对虾肝胰脏铜积累量远高于肌肉;饲养8周肌肉铜积累小于50 mg/kg,符合食品安全,而肝胰脏除C0组外均大于50 mg/kg。     

橡胶籽油替代豆油对草鱼(Ctenopharyngodon idellus)生长性能、消化酶活性及部分生化指标的影响

为研究橡胶籽油替代豆油对草鱼(Ctenopharyngodon idellus)生长性能、消化酶活性、血脂水平、蛋白质代谢及抗氧化功能的影响,分别以橡胶籽油替代0(对照组)、25%、50%、75%和100%豆油配制5种等氮等能饲料,进行10周饲养实验。实验显示,0~50%替代组草鱼增重率、日增重系数显著高于100%替代组(P0.05)。随着橡胶籽油替代豆油比例的升高,饲料系数呈先下降后上升的趋势,其中,25%替代组饲料系数最低,显著低于50%~100%替代组(P0.05);25%替代组蛋白质效率最高,显著高于其他处理组(P0.05)。随着橡胶籽油替代比例的升高,肠道胰蛋白酶、脂肪酶活性呈先上升后下降的趋势,其中,25%替代组脂肪酶活性最高,显著高于其他处理组(P0.05),50%替代组胰蛋白酶活性最高,显著高于对照组、75%和100%替代组(P0.05)。0~50%替代组肝胰脏胰蛋白酶活性显著高于75%和100%替代组(P0.05)。25%~100%替代组血清总胆固醇(TC)含量显著低于对照组(P0.05)。随着橡胶籽油替代比例的升高,肝胰脏天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)活性呈先下降后上升的趋势,其中,25%替代组AST、ALT活性最低,显著低于对照组和100%替代组(P0.05)。0~25%替代组血浆总抗氧化力(TAC)显著低于75%和100%替代组(P0.05)。对照组血浆、肝胰脏丙二醛(MDA)含量显著高于100%替代组(P0.05)。由此可知,橡胶籽油替代25%~50%豆油对草鱼生长性能、饲料利用率、血脂水平、抗氧化功能指标均无不良影响;但替代超过50%时显著降低草鱼生长性能和消化酶活性。     

壳聚糖投喂方式对草鱼抗饥饿胁迫能力的影响

在基础饲料中添加0.5%的壳聚糖,采用3种不同的投喂方式(方式A:连续投喂基础饲料,对照组;方式B:连续投喂添加0.5%壳聚糖的饲料,连续组;方式C:先投喂0.5%壳聚糖饲料再投喂基础饲料且每15天间隔投喂,不连续组)饲喂初始体重(19.46±0.04)g的草鱼60d后,对草鱼进行饥饿胁迫处理[各投喂方式分为投喂组(feeding,F)和饥饿组(starvation,S)],以生长、一氧化氮(nitrogenoxide,NO)含量和溶菌酶(lysozyme,LSZ)活性为指标考察壳聚糖不同投喂方式对草鱼抗饥饿胁迫处理的能力。结果显示,(1)连续组和不连续组60d时草鱼增长率和增重率显著高于对照组(P<0.05),15d饥饿处理后也呈现投喂组和饥饿组的增长率和增重率高于对照组的趋势(P>0.05);(2)对照组头肾、肝胰脏NO含量和血清、头肾溶菌酶活性饥饿组显著高于投喂组(P<0.05),连续组除头肾外NO含量和各组织溶菌酶活性饥饿组显著低于投喂组(P<0.05)或与投喂组无显著差异(P>0.05),不连续组除脾脏外NO含量和除肝胰脏外的溶菌酶活性饥饿组显著低于投喂组(P<0.05)或与投喂组无显著差异(P>0...     

The supplementation of nutrient additives in broad bean-based diet improved the growth of “crisped” grass carp,Ctenopharyngodon idellus

To investigate the effects of supplemental nutrient additives in broad bean-based diets on growth, flesh quality, and collagen gene expression of grass carp, five diets were prepared, including complete formula diet (control), soaked broad bean (SBB), and three broad bean-based diets containing 80% broad bean without (BBD1) or with the supplementation of methionine (BBD2), and methionine+vitamins+minerals (BBD3), and were fed to grass carp (171.9 ± 1.1 g), Ctenopharyngodon idellus, for 84 days. The results showed that broad bean-based diets significantly increased weight gain (WG) and reduced the feed conversion ratio (FCR) of grass carp when compared to the SBB (p < .05). The BBD3 group reached levels similar to the WG and FCR of the control group (p > .05). Grass carp fed the BBD3 diet had lower steaming loss of flesh, higher muscle fiber density, and higher collagen content in muscle and skin than the control (p < .05). The relative expressions of COL1A1 and COL1A2 mRNA in muscle and skin were significantly higher in the BBD3 and SBB groups than in other groups (p < .05). In conclusion, the combination of methionine, vitamins, and minerals in broad bean-based diets promoted the growth of “crisped” grass carp and improved flesh quality and collagen gene expression when compared to the control formula diet.     

橡胶籽油替代豆油对草鱼(Ctenopharyngodon idellus)生长性能、消化酶活性及部分生化指标的影响

为研究橡胶籽油替代豆油对草鱼(Ctenopharyngodon idellus)生长性能、消化酶活性、血脂水平、蛋白质代谢及抗氧化功能的影响,分别以橡胶籽油替代0(对照组)、25%、50%、75%和100%豆油配制5种等氮等能饲料,进行10周饲养实验。实验显示,0~50%替代组草鱼增重率、日增重系数显著高于100%替代组(P<0.05)。随着橡胶籽油替代豆油比例的升高,饲料系数呈先下降后上升的趋势,其中,25%替代组饲料系数最低,显著低于50%~100%替代组(P<0.05);25%替代组蛋白质效率最高,显著高于其他处理组(P<0.05)。随着橡胶籽油替代比例的升高,肠道胰蛋白酶、脂肪酶活性呈先上升后下降的趋势,其中,25%替代组脂肪酶活性最高,显著高于其他处理组(P<0.05),50%替代组胰蛋白酶活性最高,显著高于对照组、75%和100%替代组(P<0.05)。0~50%替代组肝胰脏胰蛋白酶活性显著高于75%和100%替代组(P<0.05)。25%~100%替代组血清总胆固醇(TC)含量显著低于对照组(P<0.05)。随着橡胶籽油替代比例的升高,肝胰脏天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)活性呈先下降后上升的趋势,其中,25%替代组AST、ALT活性最低,显著低于对照组和100%替代组(P<0.05)。0~25%替代组血浆总抗氧化力(TAC)显著低于75%和100%替代组(P<0.05)。对照组血浆、肝胰脏丙二醛(MDA)含量显著高于100%替代组(P<0.05)。由此可知,橡胶籽油替代25%~50%豆油对草鱼生长性能、饲料利用率、血脂水平、抗氧化功能指标均无不良影响;但替代超过50%时显著降低草鱼生长性能和消化酶活性。     

Assessing the feasibility of using pomegranate (Punica granatum) seed oil,rich in conjugated linolenic acid,as a lipid source in the diet of common carp,Cyprinus carpio,juveniles

In this study, the feasibility of using pomegranate seed oil, rich in conjugated linolenic acid and its partial replacement for fish oil in fish diet were investigated. Common carp, Cyprinus carpio, juveniles (1.8 ± 0.1 g) were fed four isonitrogenous and isolipidic diets with similar basal composition but different oil mixture containing 100% fish oil (A), 50% fish oil +50% sunflower oil (B), 50% fish oil +25% sunflower oil +25% pomegranate seed oil (C) and 50% fish oil +50% pomegranate seed oil (D) for 8 weeks. The highest weight gain was observed in fish fed diet D (p < 0.05). Test diets had no significant effect (p > 0.05) on saturated and monounsaturated fatty acid contents of fish muscle. Docosahexaenoic acid (22:6n‐3; DHA) was significantly lower in the muscle of fish fed diet B (p < 0.05) compared to those fed diet A. However, there was no significant difference in the muscle DHA content of fish fed diets A, C, or D. No specific hepatocyte damage associated to dietary pomegranate seed oil was found in this study. This study showed a 50‐50 combination of fish oil and pomegranate seed oil could be used as dietary lipid source for common carp without any adverse effect on growth performance or muscle n‐3 content while accumulated punicic acid in the muscle could be considered as added value for the final human consumer.     

Comparative nutritional evaluation of differentially processed mucuna seeds [Mucuna pruriens (L.) DC. var. utilis (Wall ex Wight) Baker ex Burck] on growth performance, feed utilization and body composition in Nile tilapia (Oreochromis niloticus L.)

A fish feeding trial was conducted in a warm‐water recirculating system for 8 weeks to assess the nutritive value of processed mucuna seeds as a dietary protein replacement for fish meal in practical diets of tilapia. Diets 2–6 contained mucuna seeds processed as follows: raw, soaked in water, soaked in sodium bicarbonate solution (0.07%), soaked in ascorbic acid solution (0.1%) or soaked in water containing 3% of freeze‐dried moringa leaf powder, followed by autoclaving. The mucuna seed meals were then used to replace 25% of the total dietary protein in each diet. The performance of fish fed these diets was compared with fish fed a fish meal‐based control diet (diet 1), which contained 35% protein. All diets were prepared to be isonitrogenous and isoenergetic. Each treatment had three replicates, using seven fish per aquarium, with a mean initial body weight of 3.9 ± 0.06 g. Fish were fed five times about their maintenance level (3.0 g feed × body weight (kg)^?0.8 day^?1), and no mortality was observed during the experiment. The growth rate, feed conversion ratio and protein productive value of fish fed diets 1, 3, 4, 5 and 6 were similar. However, with regard to energy retention and apparent net lipid utilization, the values observed in fish fed diet 1 were similar to those of fish fed diets 5 and 6, and diet 6, and significantly higher than other dietary groups. Fish fed diet 2 showed a significantly (P < 0.05) reduced growth performance, higher carcass moisture and ash contents, and lower levels of lipid and energy compared with all other dietary groups. Fish fed diet 2 had a significantly lower plasma cholesterol level compared with other diets. However, no significant variation of muscle cholesterol was found between the dietary groups. Even though the hepato‐somatic index of the fish fed diets 3, 4, 5 and 6 was significantly lower than diet 1, these values appeared to be significantly higher compared with fish fed diet 2. The present study indicates that the inclusion of mucuna seed meal (replacement of 25% of total dietary protein of feed) after soaking in any one of the tested solutions followed by autoclaving significantly improved the growth performance and feed utilization of tilapia compared with that of the raw seeds. Moreover, these values were similar to the performance obtained with the fish meal‐based control diet 1. This might be due to the relative reduction of anti‐nutrients, particularly the non‐protein amino acid 3, 4‐dihydroxyphenylalanine, and increased palatability and nutrient availability of processed beans.     

Evaluation of raw and hydrothermically processed Prosopis juliflora seed meal as supplementary feed for the growth of Labeo rohita fingerlings

Hydrothermically processed Prosopis juliflora (PJ) seed meal as a supplementary diet for Labeo rohita is found to be rich in protein (330 g kg^?1) having antinutritional factors in permissible limits and containing essential amino acids adequately except lysine, methionine and cysteine. Ten iso‐nitrogenous and iso‐energetic diets with crude, soaked and autoclaved seed meal at 20%, 35% and 50% replacement of fish meal were tested (D1–D9, respectively). The growth of fish (weight gain, specific growth rate, feed conversion ratio and protein efficiency ratio) fed diet D4 (soaked seed meal at 20% replacement) was higher among the test diets, but lower than reference diet (RD). Diets with 50% seed meal resulted in lowering of growth, carcass composition, digestive enzyme activity and digestibility compared to test diets at 20% and 35% inclusion levels in the respective groups. Hydrothermically processed seed meal improved the growth compared to unprocessed one, though not up to RD level. This could be because of amino acid imbalance and presence of non‐starch polysaccharides in seed meal. Looking to the easy availability and its nutritional quality, processed PJ seed meal can be incorporated in carp diet at lower inclusion level.     

Effect of diets containing laurel seed oil on growth and fatty acid composition of rainbow trout,Oncorhynchus mykiss

The aim of this study was to determine the effects of replacing fish oil (FO) with laurel seed oil (LSO), as an alternative plant lipid source in diets on the growth and fatty acid composition of rainbow trout (Oncorhynchus mykiss; 111.47 ± 0.2 g mean individual weight). At the end of the feeding trial, survival was 100% in all treatments. No significant differences were seen in growth between the dietary groups (P > 0.05). The protein, lipid and ash contents were not significantly different among the groups (P > 0.05); however, there was a significant difference in protein and ash content between the treatment groups and the initial, and between the 50LSO group and the initial group, respectively (P < 0.05). The viscerosomatic index (VSI) and hepatosomatic index (HSI) values were not affected by increasing LSO percentages in the diets. The n‐6 polyunsaturated fatty acid (PUFA) concentration increased with increasing LSO levels in the diets. In contrast, the n‐3 PUFA levels decreased with increasing LSO levels in the diets. The liver and muscle were used for the analysis of fatty acids. The highest level of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations was recorded in fillet of fish fed the FO diet and the lowest in those fed the 50LSO diet. However, EPA and DHA ratios in the liver of fish fed the 75LSO diet were higher than those in fillet of fish fed the FO and 50LSO diets. No significant differences were seen in fatty acid composition between the dietary groups (P > 0.05). Based on the results of growth performance and fatty acid composition of the experimental fish in this study, it can be concluded that the 75% concentration of laurel seed oil performed best among the diets tested in the experiment.     

Evaluation of micronized lupin seed meal as an alternative protein source in diets for gilthead sea bream Sparus aurata L. juveniles

A 12‐week growth trial was performed to evaluate the effect of lupin seed meal as a protein source in diets for gilthead sea bream (Sparus aurata) juveniles. Six experimental diets were formulated to be isonitrogenous and isoenergetic and to contain 10%, 20% and 30% of raw lupin (Lupinus angustifolius) seed meal protein or 20% and 30% lupin (L. angustifolius) seed meal processed by infrared radiation (micronized) in place of fish meal protein, the only protein source of the control diet. Fish accepted all diets well and no significant differences in feed utilization among groups were noticed during the trial. Final weight of fish fed the experimental diets was identical or higher than the control group. Final weight of fish fed diets including 20% micronized lupin protein was even significantly higher than that of fish fed the fish meal‐based control diet. Moreover, at the same dietary lupin seed meal protein inclusion levels, final weight of fish fed diets including micronized lupin was significantly higher than with raw lupin. A trend was also noticed for a decrease of final weight with the increase in lupin seed meal in the diets. At the end of the trial no significant differences in proximate whole‐body composition, hepatosomatic and visceral indices were observed among groups. It is concluded that lupin seed meal can replace up to 30% fish meal protein in diets for gilthead sea bream juveniles with no negative effects on growth performance. Furthermore, micronization of lupin seeds improves its dietary value for gilthead sea bream juveniles. At the same dietary lupin inclusion levels, diets including micronized lupin seeds promote significantly higher growth rates than raw lupin seeds.     

Tributyrin‐supplemented high‐soya bean meal diets of juvenile black sea bream,Acanthopagrus schlegelii: Study on growth performance and intestinal morphology and structure

An 8‐week growth trial was conducted to evaluate the effects of different levels of tributyrin supplementation in a high‐soya bean meal diet on juvenile black sea bream (11.30 ± 0.16 g). The positive control (PC) diet contained 45% fishmeal and 20% soya bean meal, while the negative control (NC) contained 12% fishmeal and 45% soya bean meal. Graded levels of tributyrin were added to the NC diet at 0.05% (TB 0.05), 0.1% (TB 0.1), 0.2% (TB 0.2), 0.4% (TB 0.4) and 0.8% (TB 0.8). Ultimately, the fish fed the PC diet had a higher weight gain and specific growth rate than the fish fed other diets. The fish fed the NC diet had the lowest growth, and TB 0.05–TB 0.2 diets increased growth performance while TB 0.4–TB 0.8 diets caused reduction in growth. Dietary tributyrin supplementation improved protease activity and enhanced antioxidant capacity. Compared with the fish fed the NC diet, the fish fed the tributyrin‐supplemented diets had improved gut morphology and structure, and the results were similar to those of the fish fed the PC diet. Furthermore, the analysis of the dose response with second‐order polynomial regression indicated that the optimum tributyrin supplementation for juvenile black sea bream is 2.24 g/kg in the 45% soya bean meal diet.     

Use of full-fat winged bean Psophocarpus tetragonolobus seed meal as a protein feedstuff in fish-meal free diets for African catfish Clarias gariepinus

Mature winged bean Psophocarpus tetragonolobus seeds were quick-cooked and the full-fat meal derived was used to completely replace menhaden fish meal as a dietary protein source for the African catfish Clarias gariepinus . Five dry practical diets (400 g crude protein kg⁻¹ and 17.5 kJ gross energy g⁻¹ dry diet) containing menhaden fish meal (diet 1) or winged bean meal with or without graded levels of supplemental L -methionine (diets 2, 3, 4 and 5; 0, 5, 10 and 15 g kg⁻¹, respectively) were fed to catfish fingerlings (5.8  +  1.2 g) for 70 days. Weight gain, growth rate, feed conversion and protein utilization by catfish fed a winged bean meal diet without L -methionine supplementation (diet 2) was inferior ( P  > 0.05) to that in catfish fed the other diets, where performance differed nonsignificantly. Carcass protein of catfish was lower ( P  < 0.05) while liver protein was higher ( P  < 0.05) in catfish fed the winged bean meal diet without methionine supplementation. Results suggest that winged bean meal cannot replace fish meal as a protein source in catfish diets except with a minimum supplementation with 5 g L -methionine kg⁻¹ diet.     

Dietary folic acid requirement determined for grass shrimp, Penaeus monodon

A feeding trial was conducted to determine the dietary folic acid requirement of juvenile grass shrimp, Penaeus monodon. Purified basal diets were formulated using vitamin-free casein as the protein source. Graded levels (0, 1, 2, 5, 10, 15, 30, and 60 mg folic acid/kg diet) of folic acid were added to the basal diet, resulting in eight dietary treatments in the experiment. Each diet was fed to three replicate groups of shrimp initially averaging 0.79±0.01 g for 8 weeks. Shrimp fed diets supplemented with 2 mg folic acid/kg diet had greater (P<0.05) weight gain and hepatopancreatic folic acid concentrations than shrimp fed the unsupplemented control diet. Feed efficiency (FE) was highest in shrimp fed the diets supplemented with 2 mg folic acid/kg diet, followed by the groups fed 1 mg/kg, then the control group. Hepatosomatic index (HSI) was highest in shrimp fed the control diet, followed by 1 mg folic acid/kg and lowest in shrimp fed diets supplemented with 2 mg folic acid/kg. Weight gain percentage, hepatopancreatic folic acid concentration and hepatosomatic index of the shrimp analyzed by broken-line regression indicated that the adequate dietary folic acid concentration in growing P. monodon is 1.9–2.1 mg/kg diet.