脱脂黑水虻虫粉替代鱼粉对大黄鱼幼鱼生长、体成分、血清生化指标及抗氧化能力的影响

本实验旨在探讨脱脂黑水虻(Hermetia illucens)虫粉(DBSFLM)替代鱼粉(FM)对大黄鱼(Larimichthys crocea)幼鱼生长、体成分、血清生化指标及抗氧化能力的影响。实验设计6组等氮(粗蛋白45%)等脂(粗脂肪10%)饲料,用黑水虻脱脂虫粉分别替代饲料中0%、20%、40%、60%、80%和100%的鱼粉蛋白,分别记为G0、G20、G40、G60、G80和G100。选用2160尾平均体重为(50.08±3.31)g的大黄鱼幼鱼随机分为6组,每组3个重复,每个重复120尾,在室内水泥池(2 m×1 m×1 m)进行为期7周的投喂实验。结果表明:(1) G100组大黄鱼幼鱼存活率显著低于其他实验组, G40组大黄鱼增重率(WGR)、蛋白质效率(PER)均显著高于其他组(P0.05);(2)大黄鱼肌肉粗蛋白含量随着DBSFLM替代FM水平的增加而下降,替代40%及以上鱼体粗蛋白含量显著降低(P0.05);肌肉的粗脂肪和粗灰分含量则随DBSFLM替代FM水平的增加而升高,其中替代60%及以上鱼体粗脂肪和粗灰分含量显著升高(P0.05);(3)随着替代水平的升高(40%),大黄鱼血清谷丙转氨酶(ALT)和谷草转氨酶(AST)活性显著上升(P0.05),甘油三酯(TG)和胆固醇(CHOL)水平显著下降(P0.05);(4)G20组大黄鱼肝脏总抗氧化能力(T-AOC)及G40组实验鱼肝脏超氧化物歧化酶(SOD)活性均为最高,G40组大黄鱼肝脏丙二醛(MDA)含量最低。过氧化氢酶(CAT)活性随着DBSFLM替代FM水平升高呈现下降趋势,替代40%及以上CAT活性显著下降(P0.05)。综上所述,在本实验条件下,脱脂黑水虻虫粉替代饲料中40%鱼粉蛋白对大黄鱼幼鱼的生长性能、体成分及健康状况无负面影响。     

酶解豆粕替代鱼粉对珍珠龙胆石斑鱼幼鱼生长和主要代谢酶活力的影响

用酶解豆粕替代基础饲料中0、20%、40%、60%和80%的鱼粉,配制5种等氮等能的饲料(HSM0、HSM20、HSM40、HSM60、HSM80,其中HSM0为对照组)。研究了酶解豆粕替代鱼粉对珍珠龙胆石斑鱼(Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂)幼鱼生长、体组成、消化和代谢的影响。结果显示:1)HSM40组幼鱼的增重率和特定生长率显著提高(P0.05),HSM80组增重率、特定生长率和蛋白质效率显著降低(P0.05),酶解豆粕替代40%以上时显著提高了幼鱼的摄食率。2)HSM40组肌肉粗蛋白含量显著升高(P0.05),HSM40~HSM80组全鱼和肌肉粗脂肪含量显著低于其余组(P0.05),HSM40和HSM60组全鱼粗灰分含量显著高于其余组(P0.05),各试验组肌肉氨基酸含量差异不显著(P0.05)。3)HSM80组胃蛋白酶和胰蛋白酶活力显著降低(P0.05);脂肪酶活力在替代量大于60%时显著降低(P0.05),各组淀粉酶活力无显著差异(P0.05)。4)各试验组谷草转氨酶活力与对照组无显著差异(P0.05),HSM80组谷丙转氨酶、脂肪酸合成酶活力显著降低(P0.05),HSM20和HSM40组葡萄糖-6-磷酸酶活力显著升高(P0.05)。综合考虑,酶解豆粕可替代60%的鱼粉而不降低珍珠龙胆石斑鱼幼鱼的生长,在替代量为40%时促进生长。     

饲料中豆粕蛋白替代鱼粉蛋白对花(鱼骨)生长的影响

配制豆粕蛋白对鱼粉蛋白的替代量分别为:0、12.5%、25%、37.5%、50%、62.5%和75%的7种等氮等能的半精制饲料,饲养初始体重为(2.25±0.01)g的7组(三重复)花(鱼骨)6周,以评估花(鱼骨)饲料中豆粕的适宜用量.试验结果表明:豆粕蛋白对鱼粉蛋白替代量为75%饲料组的鱼体末体重和增重率均显著低于其它6组饲料组(P＜0.05),而其它6组饲料组间的鱼体末体重和增重率无显著差异(P＞0.05),各饲料组间花(鱼骨)的存活率、饲料系数、肥满度、脏体比、肝体比及蛋白质积累没有显著差异(P＞0.05),花(鱼骨)全鱼粗脂肪含量随着饲料中豆粕蛋白含量的增加而降低,而豆粕蛋白对鱼粉的替代对全鱼水分、粗蛋白、灰分无显著影响(P＞0.05),本实验花(鱼骨)配合饲料中豆粕蛋白对鱼粉蛋白的最大替代量为625%.     

肉骨粉替代鱼粉对吉富罗非鱼生长、体组成、消化和非特异性免疫能力的影响

为研究肉骨粉替代鱼粉对罗非鱼(Oreochromis niloticus)生长性能、体组成、消化酶活性和免疫能力的影响,设计通过调节油脂以及补充包膜赖氨酸、蛋氨酸,分别形成等氮、等脂、等赖氨酸、等蛋氨酸的日粮,进行饲养比较试验。试验分4组,对照组(D1)饲料鱼粉含量为12%,试验组(D2~D4)饲料肉骨粉分别替代鱼粉33.33%(D2)、66.67%(D3)、100%(D4)。试验选取体重(24.91±0.06)g的罗非鱼360尾,随机分为4组,每组3个重复,每个重复30尾,试验期为56 d。结果显示:试验组(D2~D4)增重率、特定生长率和饲料系数、内脏比、肥满度、全鱼水分、粗蛋白质与对照组差异不显著,全鱼粗脂肪含量逐渐下降。肉骨粉替代鱼粉33.33%、66.67%和100%后,胃蛋白酶活性显著高于对照组,肠蛋白酶活性与对照组差异不显著;替代组肠淀粉酶活性显著低于对照组,替代组之间差异不显著;肠脂肪酶活性差异不显著。罗非鱼对肉骨粉的干物质、蛋白及脂肪的表观消化率都显著低于鱼粉。血清超氧化物歧化酶(SOD)和溶菌酶(LYZ)在66.67%替代组最高,显著高于对照组和33.33%、100%替代组;丙二醛(MDA)含量66.67%替代组最低。肉骨粉替代鱼粉66.67%可以显著提高罗非鱼抗氧化能力和免疫能力。结果表明:罗非鱼日粮中肉骨粉替代鱼粉不影响罗非鱼的生长性能、体组成,不会降低胃、肠蛋白酶活性及机体免疫能力,可以全部替代鱼粉。     

发酵啤酒糟替代配合饲料中豆粕对奥尼罗非鱼生长与生化指标的影响

以发酵啤酒糟分别替代饲料中0、20%、40%、60%、80%和100%的豆粕,配制成6种等氮等能的试验饲料,研究发酵啤酒糟对奥尼罗非鱼(Oreochromis niloticus×O.aureu)生长性能、体组成和血清生化指标的影响,以探明发酵啤酒糟在鱼类配合饲料中的适宜用量。将540尾初始体重为(3.00±0.08)g的奥尼罗非鱼随机分为6个试验组,每组3个重复,每个重复30尾鱼,在室内循环水养殖系统中进行为期60 d的生长试验。结果表明:当发酵啤酒糟替代豆粕的比例在0~60%时,各试验组间增重率、特定生长率、饲料效率和蛋白质效率均无显著差异;超过60%时,生长性能显著下降(P0.05)。以增重率和饲料效率为判据,通过折线模型分析得到,奥尼罗非鱼幼鱼饲料中发酵啤酒糟替代豆粕的最适比例分别为54.1%和55.4%。随着发酵啤酒糟替代豆粕比例的升高,试验鱼肌肉和全鱼组织脂肪含量及脏体比、肝体比均呈下降趋势,而水分和灰分呈上升趋势(P0.05)。血清谷草转氨酶(AST)和谷丙转氨酶(ALT)的活性及血糖含量随着发酵啤酒糟替代比例的增加而升高,当替代比例超过40%时,血清AST和ALT活性及血糖含量显著高于对照组(P0.05)。血清甘油三酯和胆固醇含量则随替代比例的增加而呈下降趋势,替代比例超过40%时,甘油三酯含量显著低于对照组(P0.05);当替代比例超过60%时,胆固醇含量显著低于对照组(P0.05)。在本试验条件下,综合考虑生长和血清生化指标,奥尼罗非鱼饲料中发酵啤酒糟替代豆粕的最适比例为54.1%~55.4%。     

干啤酒糟替代饲料中豆粕对奥尼罗非鱼生长与生化指标的影响

以干啤酒糟分别替代饲料中0、20%、40%、60%、80%和100%的豆粕,配制成6种等氮等能的试验饲料,研究干啤酒糟对奥尼罗非鱼(Oreochromis niloticus×O.aureus)生长性能、体组成、血清生化指标和抗氧化能力的影响。将540尾初始体重为(3.00±0.08)g的奥尼罗非鱼随机分为6个试验组,每组3个重复,每个重复30尾鱼,在室内循环水养殖系统中进行为期60 d的生长试验。结果表明:当干啤酒糟替代豆粕的比例在0~40%时,各试验组间增重率、特定生长率、饲料效率和蛋白质效率均无显著差异(P0.05),且显著高于60%、80%和100%替代组(P0.05)。以增重率和饲料效率为依据,通过折线模型分析得到,奥尼罗非鱼幼鱼饲料中干啤酒糟替代豆粕的最适比例分别为27.0%和28.9%。试验鱼全鱼和肌肉组织蛋白和脂肪含量随着饲料干啤酒糟替代比例的增加而逐渐下降,当替代比例为100%时,试验鱼体蛋白和体脂肪含量显著低于对照组(P0.05)。试验鱼脏体比随着替代比例的增加而升高,而肥满度则显著降低(P0.05)。随着干啤酒糟替代豆粕比例的增加,试验鱼血清谷丙转氨酶的活性逐渐升高,当替代比例超过60%时,显著高于对照组(P0.05);血清谷草转氨酶则随替代比例的增加而显著升高(P0.05),而血糖含量则呈相反的趋势,当替代比例超过40%时,显著低于对照组(P0.05)。试验鱼血清总抗氧化能力随着替代比例的增加而逐渐降低,当替代比例超过20%时,显著低于对照组(P0.05);血清超氧化物歧化酶则随替代比例的增加而显著降低(P0.05)。综合分析,奥尼罗非鱼饲料中干啤酒糟替代豆粕的最适比例为27.0%~28.9%。     

饲料牛磺酸对尼罗罗非鱼生长、体成分及组织游离氨基酸含量的影响

本文探讨了饲料牛磺酸水平对尼罗罗非鱼幼鱼生长性能、体成分及游离氨基酸含量的影响。选用体重为5.89±0.03g的罗非鱼300尾,随机分为5个处理组,每个处理3个重复,每个重复20尾。在基础饲料中分别添加0、0.4%、0.8%、1.2%、1.6%的牛磺酸,配制成5种试验料,分别饲喂不同处理组的罗非鱼,饲养周期为56d。结果表明： 0.8%牛磺酸组罗非鱼增重率最高,且显著高于0%和1.6%组(P<0.05);饲料牛磺酸水平(0.4%-1.2%)显著提高了罗非鱼摄食率、肝脏指数和内脏指数,显著降低了饲料系数(P<0.05)。随着饲料牛磺酸水平的提高,鱼体粗蛋白质和粗脂肪含量随之升高,鱼体水分和粗灰分含量随之降低(P<0.05);以增重率为指标,通过二次曲线回归分析得出罗非鱼饲料牛磺酸最适需要量为0.75%。罗非鱼血清、肝脏、肌肉和全鱼中牛磺酸含量与饲料牛磺酸含量存在正相关关系,且牛磺酸添加组血清、肝脏、肌肉和全鱼牛磺酸含量显著高于对照组相(P<0.05)。罗非鱼肝脏和肌肉中游离氨基酸含量随饲料牛磺酸含量的增加均呈逐渐下降的趋势,且牛磺酸添加组肝脏和肌肉中游离氨基酸含量显著低于对照组(P<0.05)。     

吉富罗非鱼对饲料中苯丙氨酸的需要量

分别用含6种水平(质量比分别为0.78%、0.95%、1.09%、1.34%、1.51%和1.72%)苯丙氨酸(phenylalanine,Phe)的等氮等能(粗蛋白30.10%,总能17.73 MJ/kg)饲料,在池塘网箱中(实验期间水温为24~32℃)饲喂初始体重为(52.70±1.80)g的吉富罗非鱼60 d,考察饲料Phe对吉富罗非鱼(GIFT,Oreochromis niloticus)生长性能、饲料系数、体成分、部分血清生化指标及前肠消化酶活性的影响,以期获得吉富罗非鱼对饲料苯丙氨酸的需要量。结果表明,随着饲料中Phe水平的升高,吉富罗非鱼的增重率、特定生长率、蛋白质效率、蛋白质沉积率、肥满度、肝体比和脏体比均呈现先上升后下降的趋势,饲料系数呈现先下降后上升的趋势;全鱼粗脂肪和全鱼灰分含量显著上升(P0.05),肌肉灰分含量显著下降(P0.05)。饲料中Phe对全鱼水分和粗蛋白质、肌肉水分、肌肉粗蛋白质和肌肉粗脂肪含量无显著性影响(P0.05);各实验组的肌肉氨基酸含量差异不显著(P0.05)。饲料中Phe显著影响血清中谷丙转氨酶活性,甘油三酯、总胆固醇和葡萄糖的含量(P0.05),对谷草转氨酶活性无显著性影响(P0.05);Phe显著影响肠蛋白酶、肠脂肪酶和肠Na~+-K~+-ATP酶活性(P0.05),而对肠淀粉酶活性影响不显著(P0.05)。以增重率、饲料系数和蛋白质效率为评价指标,通过二次回归分析可知,吉富罗非鱼对饲料中Phe需要量为1.17%~1.21%,占饲料蛋白质的3.89%~4.02%。本研究结果为合理配制吉富罗非鱼配合饲料提供了理论依据。     

柠檬酸对罗非鱼生长、体成分和消化酶活性的影响

研究了饲料中添加不同水平柠檬酸 (0 .1%、0 .2 %、0 .3%、0 .4 % )对奥尼罗非鱼 (Oreochromisniloticus×O .aureus)幼鱼 (初始平均体重约 2 .0g)生长、饲料利用、体成分和消化酶活性的影响。共设 5组试验饲料 ,每一饲料组设 3个重复水族箱 ,每箱随机放鱼 15尾 ,投喂率为 6 % ,自然光周期 ,循环过滤水系统饲养 9周 ,每周称重 1次并相应调节投喂量。结果表明 :随着柠檬酸添加量的增大 ,饲料pH值呈下降趋势 ;添加 0 .2 %柠檬酸的试验组罗非鱼的特定生长率显著高于对照组 (P <0 .0 5 ,LSD多重比较 ,下同 ) ;饲料效率在 0 .3%柠檬酸组显著高于对照组 (P <0 .0 5 ) ;罗非鱼血清葡萄糖含量在0 .4 %组显著低于对照组、0 .1%组和 0 .3%组 (P <0 .0 5 ) ;0 .2 %组和 0 .3%组血清甘油三酯含量最高 ,但组间差异不显著(P >0 .0 5 ) ;全鱼水分、粗蛋白、粗脂肪和灰分含量在组间差异不显著 (P >0 .0 5 ) ;胃蛋白酶、胰蛋白酶和肠蛋白酶活性随柠檬酸添加量增加呈先上升后下降的趋势 ,0 .2 %组的最高 ,但组间差异不显著 (P >0 .0 5 ) ;肝胰脏和肠淀粉酶活性分别在 0 .2 %和 0 .3%组最高 ,组间差异亦不显著 (P >0 .0 5 )。结果提示 ,饲料中适量添加柠檬酸 ,能提高罗非鱼幼鱼消化酶活性 ,提高饲料利用率 ,促进罗非鱼生长     

饲料级鸡肉粉对黄鳝生长、消化酶及血清生化指标的影响

将初始体质量(26.67±0.05) g的健康黄鳝饲养在1.5 m×2.0 m×1.5 m的网箱中,网箱内水花生覆盖水面90%以上,投喂用饲料级鸡肉粉替代鱼粉的5组等氮等脂饲料:鱼粉组(对照组)、15%替代组、30%替代组、45%替代组和60%替代组,研究以饲料级鸡肉粉替代鱼粉对黄鳝生长、肠道消化酶活力以及血清生化指标的影响。8周的养殖试验结果表明,随着替代水平的增加,黄鳝质量增加率呈下降趋势( P <0.05),当鸡肉粉替代比例超过30%时,血清补体3与补体4含量显著升高( P <0.05)。高比例替代组的饲料系数、全鱼粗脂肪和甘油三酯含量显著高于鱼粉组( P <0.05) ,30%替代组和45%替代组的低密度脂蛋白显著升高( P <0.05)。除45%替代组外,各替代组肠道脂肪酶活力均显著下降( P <0.05)。各替代组白蛋白含量均低于鱼粉组但差异不显著( P >0.05)。15%替代组、30%替代组的谷丙转氨酶活性和60%替代组的谷草转氨酶活性均显著高于鱼粉组( P <0.05)。综上所述,本试验条件下,饲料级鸡肉粉可替代饲料中30%的鱼粉而不影响黄鳝的生长和生理功能。     

Fly Prepupae as a Feedstuff for Rainbow Trout, Oncorhynchus mykiss

Fly larvae may provide an effective method to mitigate two large and growing global concerns: the use of fish meal derived from capture fisheries in aquaculture diets and manure management in livestock and poultry facilities. A 9‐wk feed trial was conducted to determine whether fly larvae could be used as a partial fish meal and fish oil replacement in rainbow trout, Oncorhynchus mykiss, diets. A trout diet was formulated to contain 40% crude protein and 15% fat. Sixty‐seven percent of the protein in the control diet was derived from fish meal, and all the fat was derived from fish oil. Two of the test diets included using the black soldier fly, Hermetia illucens, prepupae, which are 40% protein and 30% fat, as 25 and 50% replacement for the fish meal component of the control diet. The total protein derived from black soldier fly prepupae in these two test diets was 15 and 34%, respectively. A third test diet included using housefly, Musca domestica, pupae, which is 70% protein and 16% fat, as 25% replacement for the fish meal component of the control diet. Data suggest that a rainbow trout diet where black soldier fly prepupae or housefly pupae constitute 15% of the total protein has no adverse effect on the feed conversion ratio of fish over a 9‐wk feeding period. In addition, the diet with black soldier fly prepupae permitted a 38% reduction in fish oil (i.e., from 13 to 8%); however, fish fed black soldier fly diets low in fish oil had reduced levels of omega‐3 fatty acids in their muscle fillets. The findings from this study suggest that either the black soldier fly or the housefly may be a suitable feedstuff for rainbow trout diets.     

Bio‐Ag reutilization of distiller's dried grains with solubles (DDGS) as a substrate for black soldier fly larvae,Hermetia illucens,along with poultry by‐product meal and soybean meal,as total replacement of fish meal in diets for Nile tilapia,Oreochromis niloticus

A feeding trial was conducted in a closed system with Nile tilapia, Oreochromis niloticus, juveniles (mean initial weight, 2.66 g) to examine total replacement of menhaden fish meal (FM) with distiller's dried grains with solubles (DDGS), which had been used as substrate for the production of black soldier fly larvae, Hermetia illucens, in combination with soybean meal (SBM) and poultry by‐product meal (PBM), with or without supplementation of the amino acids (AA) DL‐methionine (Met), L‐lysine (Lys) and a commercial non‐amylaceous polysaccharide enzyme (Enz) product. Fish were fed seven isoenergetic [available energy (AE) = 4.0 kcal g^?1 of diet] and isonitrogenous (350 g kg^?1 protein as‐fed basis) practical diets formulated with equivalent digestible protein levels. Diet 1 was formulated to be similar to a commercial, high‐quality, tilapia diet containing 200 g kg^?1 FM. Diets 2–5 were formulated as a 2 × 2 factorial to replace FM with similar contributions from DDGS (45%), PBM (25%) and SBM (2.1–2.9%), but to differ in supplementation of AA and/or Enz preparation. Diets 6 and 7 were formulated to investigate the effects of a 2/3 and 1/3 reduction, respectively, in DDGS contribution to the replacement protein mix, with concomitant increases in SBM, with respect to diet 3, and were balanced with Lys and Met. After 6 weeks, growth responses were slightly attenuated (P ≤ 0.05) and average daily intake (ADI) and feed conversion ratio (FCR) were slightly higher in tilapia fed DDGS diets 2–5 compared to those of fish fed the FM control diet 1. Growth responses were not significantly affected by the presence or absence of AA or Enz (diets 2–5), or the level of DDGS (diets 3, 7 and 6). Whole‐body proximate composition was not different among treatments. Amino acid profiles of fish fed DDGS diets were not significantly different from those of fish fed the FM control. Evidence of interaction between AA and Enz supplementation was detected in whole‐body amino acid concentrations such that AA content was higher with AA or Enz addition alone, but lower when both were added to the diet. Results suggest that DDGS replacement of FM in tilapia diets can be substantial when diets are formulated on a digestible protein basis and DDGS is combined with highly digestible animal (PBM) and plant proteins (SBM).     

Replacement of soybean (Glycine max (L.) Merrill) meal by lupin (Lupinus angustifolius) seed meal in diet for juvenile tilapia (Oreochromis niloticus×O. aureus) reared indoors

An 8‐week trial was conducted to assess the feasibility of replacing soybean meal (SBM) by lupin seed meal (LSM) in simulated commercial diets for juvenile tilapia starting at 0.3 g. Of the dietary protein (26% crude protein), 3.45% was from fishmeal and the rest came from the vegetable protein sources. The protein source of the control (C) diet came mainly from SBM and none (0%) from LSM. For the other diets, 33%, 67%, or 100% of the SBM protein was replaced by protein from either whole or dehulled LSM. One further diet was used: AW100, where alkaloid of the whole lupin seed was reduced. Survival, growth, and feed performance were compared among seven orthogonal contrasts to determine the effects of replacing SBM with whole LSM or dehulled LSM, and of reducing the alkaloid content. No differences in survival were found among all contrasts. No differences in fish growth and feed performance were found between feeding diet C and the other six diets ((whole, dehulled) × (33, 67, and 100)). Dehulled LSM diets resulted in better growth and feed performance than the whole LSM diets. Partial replacement of SBM by either dehulled LSM or whole LSM in diets obtained better growth and feed performance than total replacement. The AW100 diet resulted in equal fish growth but better feed performance than the W100 diet. This study concluded that partial, but not total, replacement of soybean protein with lupin seed protein in juvenile tilapia diets resulted in better, or at least equal, growth and feed performance. Dehulling further enhanced the growth and performance of LSM. Alkaloid removal improved feed performance but not the growth.     

饲料中豆粕蛋白替代鱼粉蛋白对齐口裂腹鱼幼鱼生长性能、体成分及血液生化指标的影响

试验分别以豆粕替代0(对照组)、20%、40%、60%、80%、100%的鱼粉蛋白设计出6种等氮等能的饲料配方, 按照配方配制试验饲料(A1、A2、A3、A4、A5和A6)。将540尾体质量为(14.67±0.51) g的齐口裂腹鱼随机分为6个试验组, 每组3个重复, 每个重复30尾试验鱼, 分别投喂6种不同的试验饲料, 养殖时间为45 d。结果表明, 豆粕蛋白替代水平对齐口裂腹鱼的生长有显著影响。豆粕替代鱼粉蛋白的比例为60%时, 试验鱼的增重率(WGR)、特定生长率(SGR)、饲料蛋白效率(PER)均达到最高(分别为118.08%、1.95%/d和207.22%), 饵料系数(FCR)最小(1.27)(P<0.05)。与其余各试验组相比, 替代比例为100%的试验组的WGR、SGR、PER显著降低, FCR显著升高(P<0.05)。通过二次多项式回归分析可知, 齐口裂腹鱼生长性能最佳时豆粕蛋白替代比例为34.25%~45.46%; 随着豆粕替代鱼粉蛋白比例的增大, 鱼体水分、粗灰分、肥满度差异不显著(P>0.05), 粗蛋白在豆粕蛋白替代水平为60%时达到最高(15.53%), 但在豆粕蛋白替代比例小于80%时试验鱼体粗蛋白、粗脂肪含量无显著差异(P>0.05), 肝体指数则随豆粕蛋白替代水平增加而增大, 但在0~80%之间均无显著差异(P>0.05)。随着豆粕蛋白替代比例的增加, 超氧化歧化酶(SOD)的活性有一定的波动, 在豆粕蛋白替代比例为40%达到最高, 豆粕蛋白替代比例在20%~60%时, 溶菌酶(LSZ)的活性逐渐升高, 但各组间及与对照组间的差异不显著(P>0.05), 谷草转氨酶(AST)和谷丙转氨酶(ALT)随着豆粕替代比例增加而逐渐升高, 但豆粕蛋白替代比例小于80%时差异不显著(P>0.05)。豆粕蛋白替代比例为100%时AST、ALT活性显著高于其余各试验组(P<0.05)。说明饲料中豆粕替代一定比例的鱼粉蛋白可促进齐口裂腹鱼的生长, 提高对饲料蛋白的代谢和免疫能力, 但豆粕替代鱼粉蛋白比例超过80%则可引起肝损伤或组织病变。在本试验条件下, 综合考虑其生长指标、体成分及免疫指标, 齐口裂腹鱼的饲料中豆粕对鱼粉蛋白的最大替代比例为80%, 当其替代比例为34.25%~45.46%时可获得最佳生长效果。     

Soldier fly, Hermetia illucens L., larvae as feed for channel catfish, Ictalurus punctatus (Rafinesque), and blue tilapia, Oreochromis aureus (Steindachner)

Abstract. Three feeding trials, involving pre-pupal larvae of soldier fly, Hermetia illucens L., grown on poultry manure, were conducted to assess: (1) channel catfish, Ictalurus punctatus (Rafinesque), response to substitution of dried meal larvae for the fish meal component of the catfish diet and (2) if feeding 100% whole or chopped larvae to channel catfish or blue tilapia, Oreochromis aureus (Steindachner), will support normal growth comparable to those fed a commercial diet. Effects on fish quality were also evaluated. Replacement of 10% fish meal with 10% soldier fly larvae resulted in slower growth over a 15-week period for subadult channel catfish grown in cages (trial 1). However, the replacement did not reduce growth rate significantly when channel catfish were grown in culture tanks at a slower growth rate (trial 2). Feeding 100% larvae did not provide sufficient dry matter or protein intake for good growth for either species grown in tanks (trials 2 and 3). Chopping of the larvae improved weight gain and efficiency of the utilization.     

Fish Offal Recycling by the Black Soldier Fly Produces a Foodstuff High in Omega-3 Fatty Acids

Abstract.— The black soldier fly, Hermetia illucens , has the potential to reduce animal waste on livestock facilities and produce an animal-grade feedstuff high in protein and fat. The lipid content of insects is largely dependent on their diet. Data from this study suggest that black soldier fly prepupae incorporate α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) when fish offal is included in their diet. Fly larvae were fed three different proportions of fish offal and cow manure diets over a 21-d trial. An additional group of larvae were fed 22% fish offal diet within 24 h of their pupation. Larvae fed fish offal were, on average, 30% lipid, which was 43% more than the controls fed cow manure only, and approximately 3% of this lipid was omega-3 fatty acids (EPA, DHA, and ALA). Furthermore, this concentration of omega-3 fatty acids was achieved within 24 h of feeding fish offal. These omega-3 fatty-acid-enhanced prepupae may be a suitable fish meal and fish oil replacement for carnivorous fish and other animal diets. In addition, they may provide a method of reducing and recycling fish offal from processing plants.     

Substituting fish meal with soybean meal in diets of juvenile cobia Rachycentron canadum

An 8-week feeding trial was conducted with cobia to determine the amount of soybean meal that could replace fish meal in formulated diets without reducing growth. Juvenile cobia (initial mean weight, 32 g) were fed 48% crude protein diets in which dietary protein was supplied by brown fish meal or a mixture of hexane extracted soybean meal and the fish meal, resulting in 10%, 20%, 30%, 40%, 50% and 60% of fish meal protein being replaced by soybean protein. The fish readily accepted all seven experimental diets and no fish died during the trial. Detrimental effects on growth performance were obvious when half of the fish meal protein was replaced by soybean protein. There existed a significant difference in fish weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER) and net protein utilization (NPU) when the replacement level for fish meal protein was increased from 40% to 50%, indicating that up to 40% of fish meal protein can be replaced by soybean meal protein without causing reduction in growth and protein utilization. On the other hand, quadratic regression analysis shows a growth optimum at 16.9% replacement of fish meal protein by soybean meal protein. Lipid concentrations in the cobia muscle increased significantly as dietary soybean meal increased. Muscle concentrations of free threonine and histidine decreased as use of the soybean meal increased in the diets. Since methionine concentration in the test diets decreased from 2.52 to 1.36 g 16 g⁻¹ N as the soybean meal protein replacement level was increased from 0% to 60% while all other essential amino acids remained relatively constant, dietary requirement of methionine was calculated assuming it was equally available between the two proteins. The broken-line model analysis based on fish weight gain shows a breakpoint when dietary methionine+cystine concentration was 2.66 g 16 g⁻¹ N or 1.28 g 100 g⁻¹ diet.     

Effect of soybean meal diets on the growth performance,ammonia excretion rates,gut histology and feed cost of Nile tilapia (Oreochromis niloticus) fry

Aquaculture development in Ghana is currently limited by inadequate supply of fingerlings and prohibitive cost of commercial feeds among other challenges. This study tested the feasibility of using low‐cost feeds containing soybean meal instead of fishmeal for nursing Nile tilapia (Oreochromis niloticus) fry. Three isonitrogenous (~48% crude protein) and isoenergetic (~17 kJ/g) diets with increasing inclusions of soybean meal as partial replacements for fishmeal were formulated. A commercial fishmeal‐based fry feed served as the control diet. Triplicate groups of 225 fish per tank (average initial weight: 2.09 ± 0.14 g) were stocked in a recirculating aquaculture system and fed the experimental diets for 21 days. Afterwards, we investigated the postprandial metabolism, nutrient digestibility, growth and gut histology in Nile tilapia fry. Simple economic analyses were also conducted to assess the cost‐effectiveness of the diets used in the feed trial. The dietary inclusions of the soybean meal significantly reduced feed cost by ~43% relative to the control diet. The growth performance and feed utilization parameters did not vary significantly among the different treatments. The soybean diets elicited significant reductions in villi heights and goblet cell numbers, which corresponded with increasing dietary levels of soybean meal. This study confirms the potential of soybean meal as a partial replacement for fishmeal in Nile tilapia fry diets in terms of lower feed costs, fish growth performance, nutrient digestibility and postprandial nitrogenous excretions. The inclusion of soybean, however, affected negatively the gut integrity of the fry.     

Potential of the use of peanut (Arachis hypogaea) leaf meal as a partial replacement for fish meal in diets for Nile tilapia (Oreochromis niloticus L.)

The rapid growth of tilapia culture has stimulated the expansion of tilapia feed production and a search for novel protein sources to replace fish meal. Vegetable or plant sources are promising alternatives and legumes are both naturally abundant and high in protein content. A study was carried out to evaluate the effects of replacing the protein from fish meal with peanut ( Arachis hypogaea ) leaf meal (PLM) in diets for male tilapia ( Oreochromis niloticus , initial body weight 75.3 g). Four isonitrogenous (35% CP) and isocaloric (18.834 kJ g⁻¹) diets were prepared to include 0% (CON), 10% (PLM10), 20% (PLM20) and 30% (PLM30) of PLM protein. Average fish weights at the end of the 126-day experiment were not statistically different among the fish fed CON, PLM10 and PLM20 diets. The PLM30 diet produced the poorest growth performance. Organic matter and protein contents of fish were similar in the CON, PLM10 and PLM20 diets. Carcass chemical composition showed a decrease in body fat content as PLM replacement levels increased. The high survival ratio in all dietary groups (>97%) suggests that PLM can be used in O. niloticus feeds for long periods without affecting fish growth performance or health.