饲料中添加雨生红球藻对七彩神仙鱼生长、体色及抗氧化力的影响

为探讨雨生红球藻(Haematococcus pluvialis)对七彩神仙鱼(Symphysodon haraldi)增色效果以及对机体抗氧化力的影响,分别用添加0(对照组)、3.33、6.66、9.99、13.32和16.65 g/kg雨生红球藻(折算成虾青素添加量分别为0、100、200、300、400和500 mg/kg饲料)的饲料饲喂七彩神仙鱼6周,测定七彩神仙鱼皮肤、鳍条、肌肉和肝脏中的虾青素含量、体表的三刺激值和肝脏总抗氧化能力(T-AOC)和谷胱甘肽(GSH)含量。结果显示:饲料中添加雨生红球藻可以显著提高七彩神仙鱼的增重率,当添加量为9.99 g/kg其增重率最大。七彩神仙鱼皮肤、鳍条、肌肉和肝脏虾青素含量随着雨生红球藻添加量的增加而升高,当雨生红球藻添加量超过6.66 g/kg,各组织中虾青素的含量趋于稳定。随着雨生红球藻添加量增加,皮肤L*值(亮度)下降、而a*值(红度)和b*值(黄度)升高,皮肤中虾青素含量与三刺激值间的相关性均达到高度相关,并与a*值的相关性最高。随着雨生红球藻添加量的增加,七彩神仙鱼肝脏的T-AOC和GSH的含量也逐渐升高。结果表明,在饲料中添加雨生红球藻可提高七彩神仙鱼的增重率,提高七彩神仙鱼皮肤虾青素含量,改善七彩神仙鱼体色,增强机体的抗氧化能力;雨生红球藻的添加量建议为6.66~9.99 g/kg(虾青素含量为200~300 mg/kg)。     

慢性氨氮暴露诱发黄颡鱼幼鱼谷氨酰胺积累、氧化损伤及免疫抑制的研究

为了研究慢性氨氮胁迫对黄颡鱼幼鱼生长性能、大脑谷氨酰胺积累、肝脏抗氧化酶活性、非特异性免疫应答及抗嗜水气单胞菌感染能力的影响,实验挑选初始体质量为(1.94±0.05)g的健康黄颡鱼幼鱼180尾,开展为期56 d的慢性氨氮胁迫实验.结果表明,实验鱼的终末体质量、增重及饲料效率,氨氮组与对照组无显著性差异,但肝体比氨氮组显著高于对照组;氨氮组实验鱼大脑中氨氮和谷氨酰胺含量显著高于对照组,但谷氨酸含量各组间无显著性差异;氨氮组实验鱼肝脏中超氧化物歧化酶、过氧化物酶及谷胱甘肽过氧化物酶活性显著低于对照组,但硫代巴比妥酸反应物含量氨氮组显著高于对照组;氨氮组实验鱼肝脏中溶菌酶活性、头肾巨噬细胞吞噬指数和呼吸爆发显著低于对照组;感染嗜水气单胞菌14d后,氨氮组和对照组实验鱼累计死亡率无显著性差异.研究表明,黄颡鱼幼鱼遭受亚致死浓度的慢性氨氮胁迫,能够导致大脑中谷氨酰胺含量升高;氨氮组黄颡鱼肝脏中硫代巴比妥酸反应物的过度积累表明,应激产生的大量自由基并不能被机体自身的抗氧化酶体系完全清除;亚致死浓度的慢性氨氮胁迫会对黄颡鱼幼鱼的免疫应答体系造成抑制.     

两种免疫增强剂对黄颡鱼生长、消化及免疫性能的影响

将180尾黄颡鱼随机分成3组,即Ⅰ、Ⅱ、Ⅲ组,每组3重复,Ⅰ组为对照组,投喂基础日粮,Ⅱ、Ⅲ为试验组,分别在投喂基础日粮中添加0.01%的芽孢杆菌与0.01%低聚糖复合制剂(Ⅱ)和1%中草药免疫增强剂(Ⅲ),连续投喂60天,测定了黄颡鱼增重率,成活率及胃肠消化酶,肝胰,血清免疫酶活性。结果显示:与对照组相比,Ⅱ,Ⅲ组均显著提高了黄颡鱼的增重率,成活率(P<0.05)。Ⅱ组胃消化酶,肠蛋白酶和和Ⅲ组胃消化酶活性与对照相比提高显著(P<0.05),但Ⅱ组和Ⅲ组肠淀粉酶活性有所下降。与对照组相比,试验组肝胰ACP,肝胰AKP,肝胰SOD,血清ACP,血清AKP活性均不同程度提高。结果表明:在饲料中添加免疫增强剂,能够提高黄颡鱼的生产性能及消化免疫能力。     

复方中草药制剂对黄颡鱼长和非特异性免疫功能的影响

在基础饲料中添加0.5%、1.0%、2.0%的复方中草药制剂,连续投喂60d后,通过测定供试黄颡鱼的生长性能、血细胞的吞噬活性、血清溶菌酶活性,比较了复合中草药制剂对黄颡鱼促生长及非特异性免疫功能的影响。结果显示:饲料中添加0.5%的复方中草药制剂对黄颡鱼的生长影响显著(P0.05),添加1.0%和2.0%的中草药制剂对黄颡鱼的血细胞的吞噬活性、溶菌酶活力影响极显著(P0.01)。试验组可显著提高黄颡鱼生长、血细胞的吞噬活性、溶菌酶活力。     

饲料色素对黄颡鱼皮肤类胡萝卜素、叶黄素含量和酪氨酸酶活力的影响

以平均体重45.25 g的1冬龄黄颡鱼为试验对象,在饲料中分别添加0.4%的加丽素红、0.5%的金黄素、0.5%的金菊黄、6%的玉米蛋白粉作为色素源,以不含色素源的饲料为对照,在室内循环养殖系统中养殖56 d,观察各试验组黄颡鱼的体色,分别测定其背部和腹部皮肤、血清中的酪氨酸酶活力、总类胡萝卜素和叶黄素含量。结果为金菊黄组黄颡鱼血清酪氨酸酶活力显著提高,而其他各试验组之间无显著性的差异;对照组黄颡鱼总类胡萝卜素含量在背部皮肤下降11.2%、腹部皮肤下降57.5%,叶黄素含量变化与此类似;玉米蛋白粉组类胡萝卜素含量在腹部皮肤降低了38.5%、背部皮肤无显著性变化,背部和腹部皮肤中叶黄素含量有一定程度的增加;加丽素红组黄颡鱼总类胡萝卜素含量在腹部皮肤中降低了45%、背部皮肤无显著性变化,背部和腹部皮肤中叶黄素含量显著降低;金黄素组鱼体背部、腹部皮肤中总类胡萝卜素的含量分别升高了1.8倍和1.5倍,金菊黄组鱼体背部和腹部皮肤中总类胡萝卜素的含量分别升高了1倍和0.49倍;叶黄素含量也显著增加。试验结果表明,黄颡鱼能够选择性地沉积来源于饲料色素物质,饲料色素对黄颡鱼体色具有较大的影响。     

小球藻对草鱼生长、免疫、消化酶活性和肌肉的影响

为探明饲料中添加不同水平的小球藻对草鱼生长性能、非特异性免疫机能、消化酶活性及肌肉品质的影响,选用平均体质量(105.92±2.79) g的草鱼随机分为5个组,每组30尾,分别投喂添加小球藻为0(对照组)、0.25%、0.50%、0.75%和1.00%的试验饲料,饲养周期为28 d。试验结果显示,0.50%、0.75%和1.00%添加组的终末平均体质量、质量增加率和特定生长率均显著高于对照组(P<0.05),饲料系数均显著低于对照组(P<0.05)。当添加量达0.75%时,能显著提高草鱼血清的溶菌酶和碱性磷酸酶的活性,增强草鱼的非特异性免疫机能(P<0.05)。各添加组血清中超氧化物歧化酶活性和抗氧化能力(除0.25%添加组)显著提高。各添加组草鱼脂肪酶和胰蛋白酶活性明显升高,淀粉酶(除0.25%添加组)活性显著减弱(P<0.05)。添加组草鱼肌肉的氨基酸组成与对照组无显著差异(P>0.05)。1.00%添加组的草鱼肌肉中亚麻酸和二十碳五烯酸含量显著高于对照组(P<0.05),0.25%、0.75%和1.00%添加组的花生四烯酸和二十二碳六烯酸含量显...     

饲料中小球藻添加量对杂交黄颡鱼“黄优1号”生长性能的影响

开展了饲料中小球藻添加量对杂交黄颡鱼“黄优1号”生长性能和抗氧化能力影响试验。共设置5组,分别为1个对照组(G0)和4个处理组(G1—G4)。其小球藻的添加量分别为0.00%(G0),2.50%(G1),5.00%(G2),7.50%(G3)和10.00%(G4)。于养殖的第28和56天,测定杂交黄颡鱼“黄优1号”鱼体生长指标和抗氧化能力指标。结果表明,随着饲料中小球藻含量的增加,杂交黄颡鱼“黄优1号”的体质量增加率和特定体质量增加率呈上升趋势,并显著高于对照组(P<0.05),饵料系数呈下降趋势,肝体指数较对照组无显著差异(P>0.05)。抗氧化能力方面,饲料中添加小球藻可以显著提高杂交黄颡鱼“黄优1号”肝脏和血清中超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性,能降低鱼体内丙二醛含量。指出,饲料中添加小球藻不仅可以促进杂交黄颡鱼“黄优1号”的生长,并提高其抗氧化能力。     

饲料中不同维生素E添加量对黄颡鱼幼鱼生长性能及免疫功能的影响

本研究探讨了饲料中不同维生素E添加量对黄颡鱼(Pelteobagrus fulvidraco)幼鱼生长和免疫的影响。在以鱼粉、豆粕为蛋白源的基础饲料中分别添加0mg/kg(对照组)、25mg/kg、75mg/kg、125mg/kg和175mg/kg的维生素E配成5种实验饲料。在水温(24.0±3.0)℃下,用上述实验饲料分别饲喂平均体质量约为5.1g的黄颡鱼幼鱼50d。实验结果表明,饲料中维生素E的添加量对黄颡鱼的特定生长率和饲料效率的影响不显著(P0.05);而添加量为175mg/kg时,黄颡鱼摄食率显著降低(P0.05);随着饲料中维生素E添加量的增高,黄颡鱼血浆超氧化物歧化酶(SOD)的活性未产生显著变化(P0.05);添加量为125mg/kg和175mg/kg时,血浆中丙二醛(MDA)的含量显著降低(P0.05);白细胞吞噬指数随添加量升高显著上升(P0.05),而吞噬百分率没有显著变化(P0.05)。综合以上结果,饲料中添加适量的维生素E可适当改善黄颡鱼的摄食,增强黄颡鱼的非特异性免疫力和抗氧化能力,从而提高动物的健康状况。推荐在黄颡鱼幼鱼饲料中添加125mg/kg的维生素E。     

香菇多糖对黄颡鱼抗氧化及非特异性免疫指标的影响

为探讨香菇多糖(Lentinan,LNT)对黄颡鱼(Pelteobagrus fulvidraco)抗氧化及非特异性免疫指标的影响,用添加不同水平香菇多糖的饲料进行投喂试验.将540尾鱼随机分成6组,每组3个平行,每个平行30尾鱼,分别投喂添加0、300、600、900、1200、1500 mg· kg-1香菇多糖的饲料,饲养期为8周.试验结束后测定黄颡鱼体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、溶菌酶(LSZ)活力,检测丙二醛(MDA)、一氧化氮(N0)的含量、吞噬细胞的吞噬百分比、吞噬指数以及攻毒后的死亡率与免疫保护率等指标.结果表明:与对照组相比,各试验组黄颡鱼体内SOD、CAT的活力提高,MDA的含量降低(P＜0.05);各试验组鱼体各组织的NO含量均有提高,但与多糖浓度成负相关;添加香菇多糖能显著提高鱼体内溶菌酶的活性、鱼体吞噬细胞的吞噬百分比和吞噬指数(P＜0.01),并可降低攻毒后鱼体的死亡率和提高免疫保护率.由此可见,在饲料中添加香菇多糖对提高黄颡鱼体内抗氧化及特异性免疫能力具有良好的效果.     

组胺对黄颡鱼生长及体色变异的影响

试验在基础饲料中分别添加0、10、100、1 000 mg/kg的组胺,制成4种等氮饲料(分别记为C、H10、H100和H1000),以黄颡鱼(Pelteobagrus fulvidraco)(102.13±0.52)g为试验对象,进行56 d的养殖试验,研究不同添加水平组胺对黄颡鱼生长、皮肤显微结构、皮肤黑色素含量、酪氨酸酶活力和脑中黑素皮质素受体-1(MC1R)mRNA表达量的影响。试验采用微流水室内养殖系统,结果表明:饲料中添加不同量组胺对黄颡鱼生长(增重率和特定生长率)无显著影响(P0.05),而高组胺添加量组(H1000组,组胺含量1 390 mg/kg)黄颡鱼皮肤中黑色素含量及脑组织中MC1R mRNA表达量显著低于对照组(P0.05),低添加量组(H10和H100)黄颡鱼皮肤黑色素含量和脑中MC1R mRNA表达量与对照组无差异(P0.05)。随着饲料中组胺添加量的增加,皮肤酪氨酸酶活力呈下降趋势,但各组间差异不显著(P0.05)。结果表明:组胺对黄颡鱼生长表现无影响,但会引起黄颡鱼体色白化,且白化程度与饲料中组胺含量密切相关。     

Long-term effects and interactions of dietary vitamins C and E on growth and reproduction of yellow perch, Perca flavescens

This study was conducted to examine the effects of dietary vitamin C and/or E and their interaction on growth and reproductive performance in yellow perch. Yellow perch juveniles were divided into four treatments with triplicate groups and fed with one of four semi-purified diets for 32 weeks. The experimental diets were formulated to contain no or high vitamin E levels (160 mg/kg) without or with vitamin C supplementation (250 mg/kg) designated as diets −C−E, −C+E, +C−E, or +C+E, respectively. The growth rates and survival of yellow perch fed with +C−E and +C+E diets were significantly higher than the fish fed with −C−E diet. Total- and dehydro-ascorbate concentrations in liver and testis increased in response to its dietary supplementation. The -tocopherol concentration in sperm was significantly affected by dietary supplementation of vitamin C. Gonadosomatic index of males was lower in the fish fed with −C−E diet compared to that of fish fed with other diets. Hatching rates of embryos obtained from testing sperm viability was significantly improved in fish fed with the diets sufficient in vitamin C (82±7%) compared to the fish fed with the −C−E diet (59±7). This study indicates that supplementation of dietary vitamin C and E increase growth rate, and semen quality can be improved by dietary vitamin C supplementation within one maturation cycle, and vitamin C may spare sperm vitamin E depending on vitamin E stores in tissues.     

豆粕型饲料中添加蛋氨酸对江黄颡鱼生长的影响

研究了在豆粕型饲料中添加不同浓度的蛋氨酸对江黄颡鱼生长的影响。试验鱼分为3个组,蛋氨酸的添加量分别为0、0.2%、0.4%,分别对应Ⅰ、Ⅱ、Ⅲ组,Ⅰ组设为对照组,饲养周期为8周。试验结果表明,Ⅱ组、Ⅲ组的质量增长率显著高于对照组(P<0.05),其中Ⅱ组质量增长率最高(176.22±3.56)%;Ⅱ组的成活率显著高于对照组(P<0.05);各组的饲料系数与对照组比较无显著性差异(P>0.05),Ⅲ组饲料系数最小(2.60±0.13);各试验组之间的摄食量差异不显著(P>0.05),Ⅱ组的摄食量较对照组高12.50%。在本研究条件下,建议蛋氨酸的添加量为0.2%~0.4%。     

Comparison of Channel Catfish,Ictalurus punctatus,and Blue Catfish,Ictalurus furcatus,Fed Diets Containing Various Levels of Protein in Production Ponds

A comparative study was conducted on growth and protein requirements of channel catfish, Ictalurus punctatus, and blue catfish, Ictalurus furcatus. Four diets containing 24, 28, 32, or 36% protein were fed to both channel (initial weight 6.9 g/fish) and blue (6.6 g/fish) catfish for two growing seasons. There were significant interactions between dietary protein and fish species for weight gain and feed conversion ratio (FCR). No significant differences were observed in weight gain of channel catfish fed various protein diets, whereas higher protein diets (32 and 36%) resulted in better weight gain in blue catfish than lower protein diets (24 and 28%). No consistent differences were observed in the FCR of channel catfish fed various levels of dietary protein, whereas significantly higher FCRs were noted in blue catfish fed the 24 and 28% protein diets compared with fish fed 32 and 36% protein diets. Regardless of dietary protein levels, blue catfish had higher carcass, nugget, and total meat yield, and higher fillet moisture and protein, but lower fillet yield and fillet fat. Regardless of fish species, fish fed the 36% protein diet had higher carcass, fillet, and total meat yield than fish fed the 28 and 32% protein diets, which in turn had higher yields than fish fed the 24% protein diet. It appears that blue catfish can be successfully cultured by feeding a 32% protein diet.     

Response of Pond‐raised Fingerling Hybrid Catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus,to Dietary Protein Concentrations and Sources

This study examined four experimental diets with different protein concentrations and sources for pond‐raised fingerling hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus. A 35% protein diet with fishmeal was used as the control diet. Test diets were 32 and 28% all‐plant‐protein diets and a 28% protein diet with porcine meat, bone, and blood meal. Small fingerlings with a mean initial weight of 2.9 g/fish were stocked into 20 earthen ponds (0.04 ha) at a density of 172,970 fish/ha. They were fed once daily to apparent satiation for 107 d. No significant differences were observed for total diet fed, gross yield, final weight, survival, or condition factor among dietary treatments. However, fish fed the 28 and 32% all‐plant‐protein diets had a significantly higher feed conversion ratio than fish fed the 35% protein diet with fishmeal. There were no significant differences in chlorophyll a and nitrite concentrations in the pond water, but ponds receiving the 35% protein diet had significantly higher ammonia than those receiving 28% protein diets. Economic analysis suggested potential cost savings by using low‐protein and all‐plant‐protein diets for hybrid catfish fingerling production.     

不同小麦淀粉和脂肪水平对大黄鱼的生长性能、饲料利用及糖代谢关键酶活力的影响

为探讨饲料中添加不同小麦淀粉和脂肪水平对大黄鱼幼鱼生长、饲料利用以及糖代谢关键酶活力的影响,进行了为期8周的生长实验。设计了3个小麦淀粉水平(5%、10%和30%)和2个脂肪水平(5%和10%)的3×2的两因子实验,配制了6种等氮的饲料,分别喂养平均体质量为(6.75±0.12)g的大黄鱼幼鱼。结果显示,饲料中小麦淀粉和脂肪水平对大黄鱼增重率(WG)、特定生长率(SGR)、饲料效率(FE)、成活率(SR)、肝体比(HSI)和肥满度(CF)无显著交互作用,对脏体比(VSI)有显著交互作用。在同一脂肪水平下,淀粉水平为30%组WG和SGR显著高于10%淀粉组。不同小麦淀粉和脂肪水平对肝糖原含量无显著交互作用,而对肌糖原含量有显著交互作用,在饲料脂肪水平为5%时,30%小麦淀粉水平下的肝糖原含量显著高于10%和20%淀粉水平,10%淀粉水平下的肌糖原含量显著高于20%和30%淀粉水平;在脂肪水平为10%时,10%淀粉水平下的肝糖原含量显著高于20%和30%淀粉水平,而30%小麦淀粉水平下的肌糖原含量显著高于10%和20%淀粉水平。小麦淀粉和脂肪水平对血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆固醇(TC)和葡萄糖(GLU)含量无显著交互作用,对总蛋白(TP)和甘油三酯(TG)交互作用显著。不同小麦淀粉和脂肪水平对肝脏脂肪酶活性有显著的交互作用,对淀粉酶活性无显著交互作用;同一脂肪水平下,脂肪酶的活性随着淀粉水平的升高而升高,同一饲料淀粉水平下,饲料脂肪水平为10%组的脂肪酶活性显著高于5%组。不同小麦淀粉和脂肪水平对肝脏丙酮酸激酶(PK)的活性有显著的交互作用,而对葡萄糖激酶(GK)、磷酸果糖激酶(PFK)、磷酸烯醇式丙酮酸羧激酶(PEPCK)、1,6-二磷酸果糖酶(FBPase)和6-磷酸葡萄糖酶(G6Pase)的活性均无显著交互作用。研究表明,当饲料脂肪水平为5%时,大黄鱼能够通过调节糖酵解关键酶活性及肝糖原含量来维持血糖平衡,改善对小麦淀粉的利用能力;而当脂肪水平为10%时,大黄鱼对小麦淀粉的利用能力降低。     

Preliminary evaluation of purified lignin and hemicellulose as prebiotics candidates for Atlantic Salmon,Salmo salar L.

A study was conducted to investigate the potential of purified lignin and hemicellulose as prebiotics in diets for Atlantic salmon, Salmo salar L., postsmolt in seawater (30 ppt) at 14.9 ± 1.2°C. Triplicate groups of fish (initial individual body mass of 101.6 ± 1.2 g) were fed either the fishmeal-dense (32% of fishmeal) control diet (A) or one of the nine diets (15% fishmeal) supplemented with lignin:hemicellulose ratios (% diet:% diet) of 0.05:0 (B), 0.25:0 (C), 0.50:0 (D), 1.00:0 (E), 0:0.05 (F), 0:0.25 (G), 0:0.50 (H), 0.05:0.25 (I), and 0.25:0.50 (J) for 12 weeks in a complete randomized experimental design. At the end of the experiment, the thermal-unit growth coefficient (TGC) was significantly lower in salmon fed diets with 0.50% and 1.00% purified lignin than those fed the control diet, while there was no significant difference between the other treatments and the control diet (P < 0.05). The feed efficiency (FE) was significantly lower in salmon fed diets with 0.50% and 1.00% purified lignin and 0.05% hemicellulose than those fed the control diet, while there was no significant difference between the other treatments and the control diet (P < 0.05). The hepatosomatic index (HSI), intestinal villus length, and apparent digestibility coefficient (ADC) of nutrients in diets were similar (P > 0.05) among all the diets. This study demonstrated that inclusions of up to 0.25% of dietary purified lignin alone, and 0.25%–0.50% of dietary hemicellulose alone or in combination with dietary lignin can be considered as candidate prebiotics in Atlantic salmon nutrition.     

Growth,immune response and resistance to Aeromonas hydrophila of darkbarbel catfish,Pelteobagrus vachelli (Richardson), fed diets with different linolenic acid levels

Experimental diets were formulated containing six levels of linolenic acid (0%, 0.5%, 1.0%, 1.5%, 2.0% and 2.5%) and each diet was fed to darkbarbel catfish Pelteobagrus vachelli in triplicate for 84 days. Weight gain, specific growth rate and feed efficiency increased with the increasing levels of dietary linolenic acid, but were not significantly different among diets containing 1.0%, 1.5%, 2.0% and 2.5% linolenic acid. Red blood cell count and haemoglobin were significantly higher in fish fed the 1.0% linolenic acid than other diets. Lysozyme activity and immunoglobulin M content in fish fed 1.0% of linolenic acid were significantly higher compared with the other diets. Antibody titre in fish fed 1.0–2.5% linolenic acids was significantly higher than in fish fed 0 or 0.5% linolenic acid 14 days after Aeromonas hydrophila challenge. This study indicates that linolenic acid is essential to darkbarbel catfish. Two‐straight broken‐line analysis with SGR showed that a dietary level of 1.29% linolenic acid is the minimum required for adequate growth of darkbarbel catfish. Considering other measured indicators of fish performance, a level of 1.0–1.5% linolenic acid in the diet is recommended for the darkbarbel catfish.     

The Effects of Soybean Lecithin Supplementation to a Practical Diet Formulation on Juvenile Channel Catfish,Ictalurus punctatus: Growth,Survival, Hematology,Innate Immune Activity,and Lipid Biochemistry

A feeding trial was conducted to determine the effects of soy lecithin supplementation on production performance of juvenile channel catfish, Ictalurus punctatus (mean ± SE; 5.8 ± 0 g). The basal diet consisted of a practical dietary formulation for channel catfish, containing 4.3% endogenous phospholipids (PL) from dietary ingredients, to which supplemental PL from soybean lecithin were added. The study diets were 1 control and 2 experimental diets to which 0, 2, or 4% supplemental lecithin was added, respectively. Soy lecithin inclusion did not affect survival, growth, feed consumption, whole‐body total lipid, innate immune response, plasma cholesterol or triglyceride concentrations, or hepatosomatic index. Feed conversion (gain/intake) improved in fish fed 4% supplemental lecithin compared with 0% lecithin. Whole‐body crude protein was greater in fish fed 2% supplemental lecithin compared with 0% lecithin, while 4% supplemental lecithin was intermediate. Phosphatidylcholine (PC) content was greater in fish fed 2 or 4% lecithin than 0% lecithin. Plasma concentrations of PC were inversely proportional to dietary concentrations. Liver glycogen was greater in fish fed 0% lecithin compared with 2 or 4% lecithin. Liver lipid and phospholipid were lower in fish fed 0% lecithin than 2 or 4% lecithin. The dietary phospholipid requirement, if any, of juvenile channel catfish for growth and survival is less than or equal to 4.3% (1.5% PC) of the diet. Feed conversion is improved in channel catfish fed diets supplemented with 4% soy lecithin (7.2% phospholipid; 5.1% PC), which might offset additional costs due to phospholipid supplementation. Dietary soy lecithin inclusion altered plasma and liver lipid composition, but it is unknown whether these effects can alter the ability of juvenile catfish to survive and grow under various conditions.     

日粮中鱼蛋白水解物对黄颡鱼生长、体成分和血清生理指标的影响

为了探讨鱼蛋白水解物对黄颡鱼生产性能的影响,以日本鳀粉为对照,以实用型黄颡鱼饲料配方模式为基础开展实验:1以30.5%鱼粉为对照(FM),在相同配方模式下,以6%鱼蛋白水解物(MPH6)替代20%的鱼粉;2以30.5%鱼粉为对照(FM),在无鱼粉日粮中分别添加3%(FPH3)、6%(FPH6)、12%(FPH12)鱼蛋白水解物;共设计5组等氮等能实验日粮,在池塘网箱中养殖黄颡鱼[初始体质量(30.08±0.35)g]60 d。结果显示:与FM相比,FPH12在SGR、FCR、PRR和FRR方面均无显著差异,而MPH6、FPH3、FPH6组SGR降低了15.45%~24.39%,FCR升高了32.14%~42.86%,MPH6、FPH6差异显著,在PRR和FRR方面,MPH6、FPH3、FPH6组PRR降低了21.11%~27.78%,MPH6组FRR降低了41.51%;全鱼水分、粗蛋白、粗脂肪和灰分各组间差异不显著,FPH3、FPH6、FPH12肌肉多种游离氨基酸水平显著高于FM,其中Thr、Val、His与其在日粮中的水平显著相关;FPH6组HSI显著低于FM,鱼蛋白水解物对CP、VSI、肠体比的影响不显著;血清AST、ALT、HDL、LDL、TP、CHOL、TG无显著差异,FPH3组ALB显著低于FM。研究表明:黄颡鱼日粮中,12%鱼蛋白水解物(干物质)与30.5%鱼粉在生长速度、饲料效率、血清生理指标等方面具有一定的等效性;过高的植物蛋白日粮影响了黄颡鱼的生产性能;饲喂鱼蛋白水解物日粮使黄颡鱼肌肉游离氨基酸的含量升高,特别是呈味氨基酸的含量增加。