花鲈对七种蛋白质原料的表观消化率

为了解花鲈(Lateolabrax maculatus)对水解羽毛粉、喷雾干燥血球蛋白粉、鸡肉粉、黄粉虫粉、大豆分离蛋白、大豆浓缩蛋白和脱酚棉籽蛋白等七种蛋白质原料的干物质、钙、磷、粗蛋白和氨基酸的表观消化率,实验选取平均体重为(54.3±1.5)g的花鲈240尾,随机分成8组,每组3个平行,对照组投喂基础饲料,试验组分别投喂试验饲料,试验饲料由70%基础饲料和30%实验原料组成,以0.1%的三氧化二钇(Y2O3)为外源指示剂。结果显示:花鲈对七种蛋白质原料的干物质和粗蛋白表观消化率以血球蛋白粉、鸡肉粉、大豆分离蛋白和大豆浓缩蛋白较高,脱酚棉籽蛋白和黄粉虫粉次之,水解羽毛粉最低。其中,花鲈对血球蛋白粉的粗蛋白消化率最高,为95.64%,显著高于其他六种原料;鸡肉粉次之,为90.61%,与大豆分离蛋白和大豆浓缩蛋白之间差异不显著;水解羽毛粉最低,为71.18%,与黄粉虫粉和脱酚棉籽蛋白之间差异不显著,与其他蛋白原料之间差异显著。花鲈对鸡肉粉和黄粉虫粉的总钙的表观消化率分别为30.39%和42.65%。花鲈对总磷的表观消化率从高到低依次为大豆分离蛋白(76.04%)、脱酚棉籽蛋白(67.49%)、大豆浓缩蛋白(51.24%)、鸡肉粉(42.88%)、黄粉虫粉(38.40%)。花鲈对各蛋白质原料中氨基酸的表观消化率与粗蛋白质的表观消化率变化趋势基本一致。结果表明,喷雾干燥血球蛋白粉、鸡肉粉、大豆分离蛋白和大豆浓缩蛋白可作为花鲈优质的蛋白源,脱酚棉籽蛋白、黄粉虫粉和水解羽毛粉在花鲈饲料中添加量不宜过高。     

晶体氨基酸提高混合动物蛋白替代花鲈饲料中鱼粉的潜力

实验以鸡肉粉∶牛肉骨粉∶喷雾血球干燥粉∶水解羽毛粉=40∶35∶20∶5的比例组成的混合动物蛋白(animal protein blend,APB)分别直接替代或在补充赖氨酸、蛋氨酸、苏氨酸后替代花鲈饲料中50%、75%、100%的低温干燥鱼粉,研究其对花鲈生长及生理功能的影响。经过8周的饲养后发现,花鲈的生长性能随替代比例的提高而降低;摄食含APB饲料的花鲈,其成活率,摄食率和生长性能均显著低于对照组(P<0.05)。与APB直接替代鱼粉的处理组相比,添加3种必需晶体氨基酸极显著提高了花鲈的生长性能及全鱼蛋白、脂肪、能量含量(P<0.01),显著降低了花鲈的全鱼水分、灰分,肝指数及脏体比(P<0.05)。晶体氨基酸与APB的替代水平对花鲈的生长性能、形体指标及体组成成分存在显著的交互作用(P<0.05)。实验结果表明,(1)混合动物蛋白替代初始体重为13.2 g的花鲈饲料中白鱼粉的比例应小于50%;(2)添加必需晶体氨基酸能显著提高APB在花鲈饲料中的应用潜力;(3)花鲈具备一定的利用晶体氨基酸的能力。     

花鱼骨 鱼种对11种蛋白质饲料原料的消化率

为获得花(鱼骨)对常用蛋白源的可消化性数据,按照"70%基础饲料+30%被测原料"的饲料配制方法,用三氧化二铬指标物,测定了花(鱼骨)鱼种对白鱼粉、褐鱼粉、四海豆粕、加佳豆粕、血粉、蚕蛹粉、啤酒酵母、菜籽粕、棉籽粕、花生粕、玉米蛋白粉等11种蛋白原料干物质和粗蛋白的表观消化率.结果表明:花(鱼骨)对11种原料的干物质和蛋白质表观消化率分别为54.84%～86.96%和69.17%～96.77%.其中自鱼粉、褐鱼粉、血粉以及豆粕、啤酒酵母等的干物质消化率较高,白鱼粉、褐鱼粉及豆粕、花生粕等的蛋白质消化率较高.     

复合蛋白替代鱼粉对花鲈生长、消化能力和肠道健康的影响

以初均重为(5.80±0.07) g的花鲈(Lateolabrax maculatus)幼鱼为实验对象,研究复合蛋白替代鱼粉对花鲈生长、消化和肠道健康的影响。用复合蛋白分别替代对照组饲料中0、20%、40%、60%和80%的鱼粉,配制成5种等氮等脂的实验饲料,分别用这5种饲料投喂花鲈70 d;养殖实验期间水温为(29.5±1.5)℃,盐度为29±1,溶解氧≥6.5 mg/L。养殖实验结束后采集样品进行分析,结果显示,20%替代组花鲈生长性能与对照组无显著差异(P>0.05),但随鱼粉替代比例的升高,花鲈增重率(WGR)、存活率(SR)、饲料效率(FE)以及蛋白质效率(PER)显著下降(P<0.05),花鲈肠道蛋白酶活性以及饲料干物质、粗蛋白与粗脂肪表观消化率皆显著降低(P<0.05),且花鲈后肠黏膜组织结构出现损伤,肠道促炎因子TNF-α、IL-1β基因表达量升高,抗炎因子基因IL-4、IL-10表达量相应降低。研究表明,复合蛋白替代花鲈饲料中鱼粉比例不宜超过20%。     

脱脂黄粉虫粉替代鱼粉对花鲈生长性能和肠道健康的影响

为研究脱脂黄粉虫(Tenebrio molitor)粉替代鱼粉对花鲈(Lateolabrax maculatus)生长性能和肠道健康的影响,以花鲈幼鱼[初始体重为(2.83±0.02) g]为实验对象,配制鱼粉水平为30%的饲料作为对照组(FM)饲料,用脱脂黄粉虫粉(TM)分别替代对照组饲料中5% (5% TM)、10% (10% TM)、15% (15%TM)和20% (20% TM)的鱼粉,配制成5种等氮等脂的实验饲料,对实验花鲈进行为期 9周的摄食生长实验。结果显示,随着脱脂黄粉虫粉添加水平的增加,花鲈增重率、特定生长率和蛋白质沉积率均呈先升高后降低的趋势,5% TM组最高,显著高于20% TM组,但与FM、10% TM和15% TM组差异不显著。各组饲料效率、摄食率、存活率、肝体比、腹脂率以及全鱼体组成均无显著差异。脏体比随着替代水平的增加先升高后降低,20% TM组显著高于FM组和5% TM组。花鲈血清溶菌酶活性随脱脂黄粉虫粉替代比例的增加呈先升高后降低的趋势,5% TM组显著高于其他脱脂黄粉虫粉添加组。肠道组织观察发现,花鲈肠道的绒毛高度、绒毛宽度和肌层厚度随着脱脂黄粉虫粉替代水平的升高呈先升高后降低的趋势,5% TM组花鲈肠道的绒毛高度、绒毛宽度和肌层厚度达到最高,而20% TM组最低。随着替代水平的升高,花鲈肠道促炎因子IL-1β的相对表达量随脱脂黄粉虫粉替代水平的增加呈先降低后升高的趋势,5%~15% TM组显著低于FM组和20% TM组;抑炎因子IL-4的相对表达量呈先下降后上升的趋势,10% TM组具有最低值,而20% TM组具有最高值;肠道屏障相关基因(ZO-1和Ocln)的表达量呈先升高后降低的趋势,5% TM组的ZO-1和10% TM组的Ocln的表达量最高。各组微生物多样性指数无显著差异,但脱脂黄粉虫粉替代鱼粉改变了肠道有益菌和有害菌的相对丰度。与FM组相比,10% TM和15% TM组芽孢杆菌属(Bacillus)的相对丰度均显著增加,而5% TM和10% TM组邻单胞菌属(Plesiomonas)的相对丰度有下降趋势。综上所述,脱脂黄粉虫粉替代饲料中5%的鱼粉有利于花鲈肠道健康和生长;替代15%时不会对花鲈生长以及肠道健康产生负面影响;当脱脂黄粉虫粉替代比例超过20%时,不利于花鲈肠道健康,降低了其免疫能力,使其生长性能下降。根据二次回归模型计算结果,建议在淡水养殖时花鲈饲料中脱脂黄粉虫粉替代鱼粉水平不高于7.31%。     

不同蛎壳粉添加比例对花刺参生长的影响

研究了不同饲料组成对花刺参生长的影响。实验采用50%自配饲料+50%蛎壳粉(A)、50%自配饲料+40%蛎壳粉+10%海泥(B)、50%自配饲料+30%蛎壳粉+20%海泥(C)、50%自配饲料+20%蛎壳粉+30%海泥(D)、50%自配饲料+10%蛎壳粉+40%海泥(E)、50%自配饲料+50%海泥(F)和自制配合饲料(G)7种饲料投喂花刺参,进行了为期90天的养殖实验。实验结果显示,B组的特定生长率最高,饲料系数最低;A组和C组次之;D组、E组、F组和G组的投喂效果不理想。研究表明降低饲料中海泥的比例,适当提高蛎壳粉的比例,有利于提高花刺参饲料的适口性,促进花刺参生长。     

饲料中n-3长链多不饱和脂肪酸水平对花鲈幼鱼血清生化指标的影响

为研究饲料中n-3长链多不饱和脂肪酸(n-3LC-PUFA)水平对花鲈幼鱼血清生化指标的影响,以初始体重(29.2±1.34)g的花鲈幼鱼为研究对象,分别投喂n-3LC-PUFA含量分别为0.13、0.30、0.56、1.03、1.45、2.41(%饲料干物质)的饲料,实验周期63d。结果表明,饲料中n-3LC-PUFA水平对花鲈幼鱼血清碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)活性、总甘油三酯(TG)、总胆固醇(TC)含量无显著性影响(P0.05),而血清中肌酐(CREA)水平在饲料中n-3含量为1.45%时显著高于其余各组(P0.05)。结果表明,以血清CREA含量为标准,花鲈幼鱼饲料中n-3LC-PUFA含量应低于1.45%。     

饲料中不同维生素A含量对花鲈生长和血清生化指标的影响

以酪蛋白和明胶为蛋白源,鱼油和豆油为脂肪源,糊精为糖源并添加氨基酸混合物配制精制基础饲料,通过向基础饲料中添加维生素A醋酸酯使饲料中的维生素A含量达到0、1 000、2 000、4 000、8 000和16 000 IU/kg(实测含量为245、1 005、1 835、3 781、7 583和15 273 IU/kg),配制出6种等氮等能的实验饲料(饲料1～6).以花鲈为实验对象,在室内流水系统中进行为期9周的生长实验,探讨精制饲料中不同维生素A含量对花鲈生长和血清学生化指标的影响.结果表明:摄食不添加维生素A组(饲料1)饲料的花鲈在养殖后期表现出较高的死亡率,并出现眼球浮肿、膨胀、鳍基充血以及鳃盖扭曲等维生素A缺乏症,而在其他维生素A添加组(饲料2～6)并未出现类似症状.体成分分析表明:饲料中不同维生素A含量会显著增加花鲈体脂肪含量,但对蛋白质和水分的含量没有显著影响.对花鲈血清指标分析表明:饲料添加维生素A含量会显著增加花鲈血清碱性磷酸酶(AKP)、甘油三酯(TG)和胆固醇(TC)含量,但显著降低丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)活力.采用折线模型,当以增重率为评价指标时,花鲈对饲料中维生素A的需求量为1 934.8 IU/kg;当以肝脏维生素A含量为评价指标时,花鲈对饲料中维生素A的需求量为3 546.6 IU/kg.     

不同饲料蛋白水平下点带石斑鱼对鸡肉粉、羽毛粉和血粉混合物的利用能力

通过10周网箱养殖实验,评价了不同饲料蛋白水平下点带石斑鱼对1种鸡肉粉、羽毛粉和血粉混合物的利用能力。采用2×4实验设计,设2个饲料蛋白水平(490 g/kg和530 g/kg粗蛋白),每个饲料蛋白水平下设4个鱼粉水平,其中1组饲料中加入500 g/kg鱼粉(对照),另外3组饲料中分别加入139、278、416 g/kg的鸡肉粉、羽毛粉和血粉混合物(鸡肉粉∶羽毛粉∶血粉=65∶20∶15)替代对照饲料中30%、60%、90%的鱼粉。实验鱼初始体重为(33.4±0.1) g。实验期间,除恶劣天气外,每天分两次按饱食量投喂实验鱼。实验结果表明,饲料蛋白水平对摄食量、增重,饲料系数、氮储积效率、能量储积效率和鱼体组成无显著影响;饲料鱼粉含量显著影响增重,饲料系数、氮储积效率和能量储积效率,但对摄食量和鱼体组成无显著影响。在相同饲料蛋白水平下,特定生长率(SGR)随鱼粉含量降低而下降;当鱼粉含量相同时,摄食高蛋白饲料的鱼SGR略高于摄食低蛋白饲料的鱼。本实验结果显示,通过添加鸡肉粉、羽毛粉和血粉混合物可将点带石斑鱼饲料鱼粉含量降低到200 g/kg,在490~530 g/kg范围内提高饲料蛋白水平无助于降低点带石斑鱼饲料鱼粉含量。     

蚕粉替代鱼粉对加州鲈幼鱼生长、饲料利用及体成分的影响

本研究评价了蚕粉对加州鲈(Micropterus salmonides)幼鱼生长、饲料利用率和体成分的影响。选用初始均体重为(3.13±0.04) g的加州鲈540尾,随机分成6个实验组,每组3个重复,每个重复30尾实验鱼,分别以蚕粉替代0(对照组)、10%、20%、30%、40%和50%的鱼粉设计出6种等氮、等能的饲料配方,按照配方配制实验饲料。由于后期养殖气温下降,不适合继续进行实验,本养殖时间为45 d。结果显示,加州鲈的增重率(WGR)、特定生长率(SGR)及蛋白质效率(PER)均随蚕粉替代水平的升高呈先上升后下降的变化趋势,且其WGR、SGR和PER均在蚕粉替代水平为30%时达到最大(分别为227.87%、1.98%/d和164.55%)(P0.05);饲料系数(FCR)则随蚕粉替代水平的升高呈先降后升的变化趋势,且在蚕粉替代水平为30%时达到最低(为1.43)(P0.05);肥满度(CF)、肝体比(HSI)、脏体比(VSI)则随蚕粉替代水平的升高而呈先上升后下降并趋于稳定的趋势(P0.05);实验期间各组实验鱼的成活率(SR)差异不显著(P0.05)。通过二次回归分析可知,加州鲈幼鱼WGR、SGR、FCR及PER最优时饲料的蚕粉替代比例分别为19.90%、22.00%、18.11%和17.90%;加州鲈全鱼粗脂肪含量随蚕粉替代水平的升高呈先降低后升高的变化趋势(P0.05),粗蛋白含量随蚕粉替代水平的升高无明显变化(P0.05),水分除蚕粉替代水平为10%和40%组差异显著外(P0.05),其余各实验组差异不显著(P0.05),蚕粉替代水平大于20%时,全鱼灰分显著降低(P0.05)。在本实验条件下,综合考虑实验鱼的生长指标、饲料利用和体成分,饲料中蚕粉适宜的替代水平为17.90%～22.00%。     

High dietary incorporation levels of rendered animal protein ingredients on performance of rainbow trout Oncorhynchus mykiss (Walbaum, 1972)

Two growth trials were conducted using spray-dried blood meal (BM), feather meal (FEM), meat and bone meal (MBM) and poultry by-product meal (PBM) as major protein sources in the diet of rainbow trout. In the first trial, five diets were formulated to examine the nutritive value of spray-dried BM and PBM. Increasing levels of BM (6, 12%) or PBM (10, 20, and 30%) replaced fish meal and corn gluten meal in the diet. For the second trial, eight diets were formulated to contain the following combinations: FEM + MBM, FEM + PBM or MBM + PBM. The diets containing FEM + MBM and FEM + PBM were supplemented with either L-lysine or DL-methionine, the amino acids predicted to be the two most limiting in these diets. Each experimental diet was allocated to three tanks of fish and fed for 20 weeks in the first trial or 16 weeks in the second trial. All the experimental diets were readily consumed by the fish and high growth and good feed efficiency ratio (FER) were achieved for all diets. In the first trial, there were no significant differences (P > 0.05) in weight gain or FER of fish fed the five experimental diets, suggesting that BM and PBM had high nutritive values for rainbow trout. In the second trial, growth of the fish fed the diet containing the FEM + PBM combination was not statistically different from growth of fish fed the control diet. Growth of fish fed diets with FEM + MBM or PBM + MBM combinations were slightly lower than that of fish fed the control diet. Supplementation of diets with either L-lysine or DL-methionine had no effect on the performance of the fish. The results from this study show that feather meal, poultry by-product meal, blood meal and meat and bone meal have good potential for use in rainbow trout diets at high levels of incorporation.     

Apparent digestibilities of common feedstuffs for bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides using individual test ingredients

Apparent digestibility of dry matter and energy, and availability of amino acids from blood meal (BM), fish meal (FM), meat and bone meal (MBM), poultry by-product meal (PBM), soybean meal (SBM), corn, wheat and yellow grease (YG) were determined for bluegill Lepomis macrochirus (mean weight, 57 g), and likewise, but not for BM or wheat, for largemouth bass Micropterus salmoides (mean weight, 30 g). To avoid nutrient interaction from a reference diet, diets containing 98.5% (985 g kg⁻¹) of test ingredients were used, except for semi-solid, YG which was mixed with corn to permit pelletization. Faeces were collected by a siphoning method. Apparent dry matter digestibility values ranged from 50% (corn) to 87% (BM) for bluegill and from 53% (MBM) to 76% (PBM) for largemouth bass. Apparent energy digestibility values ranged from 53% (corn) to 92% (BM) for bluegill and from 63% (MBM) to 93% (YG) for largemouth bass. Apparent digestibility of most amino acids exceeded 90% for evaluated protein sources, except for MBM which showed slightly lower values (80–90%) for both fishes. Isoleucine digestibility from BM was relatively low (82%) for bluegill. High digestibility values for SBM, PBM and BM, indicate good potential for replacing FM in diets for both fishes.     

Apparent Digestibility Coefficients of Nutrients and Nutritional Value of Poultry By-product Meals for Rainbow Trout Oncorhynchus mykiss Measured in vivo Using Settlement

Fish meal production is not growing worldwide, therefore, it is important to search for alternative protein sources. Three types of poultry by-product meals (feed grade, prime, and refined) and two fish meals (herring and menhaden) were mixed into a casein-gelatin purified reference diet at 30% to measure apparent digestibility coefficients (ADCs) for rainbow trout Oncorhynchus mykiss . A total of 90 fish (initial mean body weight 294.6 ± 10.7 g) were stocked into six 140-L fiberglass digestibility tanks at 15 fish per tank. Individual tanks were assigned randomly to each of the five experimental diets and the reference diet. Fecal collection by settlement lasted for 2 wk. Feces collected in each week represented a replicate, and they were analyzed separately. The ADCs of nutrients for herring meal, menhaden meal, feed grade poultry by-product meal, prime poultry by-product meal, and refined poultry by-product meal were: dry matter, 81.3, 70.9, 70.9, 71.5, and 74.5%, respectively ( P = 0.0168); crude protein, 89.8, 85.8, 83.1, 84.8, and 87.1%, respectively ( P = 0.0032); crude fat, 91.5, 90.7, 79.7, 82.7, and 79.9%, respectively ( P = 0.0004); ash, 76.6, 66.2, 74.1, 77.4, and 79.6%, respectively ( P = 0.2880); phosphorus, 58.2, 46.9, 49.4, 45.8, and 56.0%, respectively ( P = 0.0143); gross energy, 88.2, 84.0, 81.9, 83.4, and 79.8%, respectively ( P = 0.2466). Significant differences in ADCs of essential amino acid existed only for arginine, leucine, and tryptophan when comparing refined poultry by-product meal with herring meal. Results showed that refined poultry by-product meal had similar ADC values to herring meal, thus, it has a similar nutritional value and can replace portions of herring meal in rainbow trout feeds. Furthermore, differences exist in ADC values among grades of poultry by-product meals that should dictate appropriate use levels in rainbow trout feeds.     

Inclusion of rendered animal ingredients as fishmeal substitutes in practical diets for cuneate drum, Nibea miichthioides (Chu, Lo et Wu)

Potential of using rendered animal ingredients, poultry by‐product meal (PM), meat and bone meal (MBM), feather meal (FM) and blood meal (BM) to replace fishmeal in practical diets for cuneate drum Nibea miichthioides (Chu, Lo et Wu) was examined in a net pen experiment. A total of 10 dietary treatments were compared. Nine diets were formulated to contain 363 g kg⁻¹ digestible protein and 14.8 MJ kg⁻¹ digestible energy, and a dietary treatment consisting of raw fish (RF) served as reference. In the formulated diets, the control diet contained 350 g kg⁻¹ herring meal, whereas in the other eight diets, the fishmeal were replaced by MBM (30% fishmeal replacement), PM (50% fishmeal replacement), a blend of PM, MBM, FM and BM (30%, 50% and 80% fishmeal replacement), or a blend of PM, MBM and BM (30%, 50% and 80% fishmeal replacement), respectively. Cuneate drum fingerling (initial body weight 28 g) were fed the test diets for 8 weeks. Specific growth rate (SGR), final body weight (FBW), nitrogen retention efficiency (NRE), condition factor and contents of moisture, crude protein and crude lipid in carcass were not significantly different between fish fed the formulated diets. Fish fed the formulated control diet exhibited lower SGR and FBW, but higher FCR, NRE, hepatosomatic index and crude lipid content in carcass and liver than those of the fish fed the RF. Results of the present study indicate that combination of rendered animal protein ingredients can replace most of the fishmeal in practical diets for cuneate drum.     

Red Drum,Sciaenops ocellatus,Production Diets

Abstract

The replacement of fish meal with soybean meal in fish diets has met with varying degrees of success. Quite often, poor responses to high soybean meal diets are due to a reduced palatability of the diet when fish meal is removed. Recent work has demonstrated that poultry by-product meal can be used as a substitute for fish meal in practical diets for juvenile red drum (Sciaenops ocellatus), indicating it may have favorable palatability characteristics for this species. The present research was designed to evaluate the replacement of menhaden fish meal with solvent-extracted soybean meal in practical diets containing 20% poultry by-product meal and formulated to contain 44% protein and 10% lipid. Test diets were adjusted for phosphorus and methionine content to ensure that minimal dietary requirements were maintained. The response of red drum (mean initial weight 179 g) to diets containing fish meal ranging from 40 to 5% of the diet, as well as the response to a low fish meal diet supplemented with krill hydrolysate, were evaluated over a 14-week growth period. Final weights (percent gain) ranged from 588 g (237.8%) to 651 g (258.5%), with feed conversion efficiencies ranging from 62.1% to 69.9% and protein conversion efficiencies ranging from 27.8% to 30%. No significant differences (P > 0.05) were observed for diet intake, feed conversion efficiency, protein conversion efficiency, intraperitoneal fat ratio, or weight gain. Significant differences in protein intake and the hepatosomatic index were observed. The present findings suggest that fish meal can be reduced to 5% of the diet by replacing it with solvent-extracted soybean meal as well as methionine and phosphorus supplements. Although diets without poultry by-product meal were not tested, it is presumed that the poultry meal enhanced the palatability of the diets, allowing the replacement of fish meal with soybean meal.     

Total replacement of fish meal with animal protein sources in Nile tilapia,Oreochromis niloticus (L.), feeds

The effects of total replacement of dietary fish meal (FM) with animal protein sources on the growth, feed efficiency and profit indices of Nile tilapia, Oreochromis niloticus (L.), were investigated. Shrimp meal (SM), blood meal (BM), meat and bone meal (MBM), BM + MBM mix and poultry by-product meal (PBM) replaced FM in six isonitrogenous (30% crude protein), isocaloric (400 kcal GE 100 g^–1) diets. The diets were fed to O. niloticus fingerlings (12.5 g) to satiation twice a day for 150 days. The growth of fish fed SM, PBM and MBM was not significantly different from those fed the FM-based diet, while feed conversion and protein efficiency ratios were significantly retarded. Further reduction in fish performance was noticed when BM or BM + MBM replaced FM in the control diet. Cost–benefit analyses of the test diets indicated that these sources were economically superior to FM. The PBM-based diet produced higher carcass lipid than other diets. Fish fed SM, MBM and PBM diets had significantly higher ash contents (P < 0.05).     

Replacement of Fish Meal with Soybean Meal in the Production Diets of Juvenile Red Snapper, Lutjanus campechanus

The replacement of fish meal with soybean meal in fish diets has met with varying degrees of success. Quite often, poor responses to high soybean meal diets are either due to shifts in the nutrient profile or a reduced palatability of the diet when fish meal is removed. The present research was designed to evaluate the replacement of menhaden fish meal with solvent-extracted soybean meal in practical diets containing 10% poultry by-product meal and formulated to contain 40% protein, 8% lipid, and a total sulfur amino acid content of > 3.0% of the protein. The response of red snapper (mean initial weight 10.9 g) to diets containing graded levels of fish meal (30,20, 10, 0%) as well as the response to a low fish meal diet (10%) without poultry by-product meal were evaluated over a 6-wk growth period. Significant ( P ± 0.05) differences in final mean weight, percent weight gain, and feed conversion were observed. Final weights (percent gain) ranged from 30.9 g (185.5%) for fish offered diets with 30% fish meal to 12.6 g (16.3%) for fish offered diets with 0% fish meal. Corresponding feed conversion efficiencies ranged from 60.1% to 7.7%. No significant differences were observed for survival between treatment means. Although there was a clear reduction in performance as the fish meal was replaced with soybean meal, the use of 10% poultry by-product meal or 10% fish meal resulted in similar performance of the fish. This is a good indication that poultry by-product meal does not have palatability problems and could be used as a substitute. The present findings suggest that replacing fish meal with high levels of soybean meal appears to reduce the palatability of the diet. While the cost reducing benefit, with respect to the replacement of fish meal, has been shown with other species, before high levels of inclusion can be efficiently utilized further research is needed to address the palatability problems observed with red snapper.     

Apparent protein and energy digestibility of common and alternative feed ingredients by Atlantic cod, Gadus morhua (Linnaeus, 1758)

Studies were conducted with Atlantic cod, Gadus morhua (L.), to determine the apparent digestibility coefficients (ADCs) of protein and energy and the digestible energy (DE) content in feed ingredients widely available in Canada. We also tested the assumption of “independency” used in digestibility studies. The feed ingredients included two fish meals (herring, anchovy), three crustacean by-product meals (whole krill, crab, shrimp), two animal by-product meals (poultry by-product, hydrolyzed feather), six oilseed meals (soybean, soy protein concentrate, soy protein isolate, canola, canola protein concentrate, flaxseed), two pulse meals (white lupin, pea protein concentrate) and two cereal grain meals (corn gluten, wheat gluten). Protein ADCs were high for wheat gluten meal (99.9%), soy protein concentrate (98.6%), soy protein isolate (97.4%), whole krill meal (96.3%), herring meal (93.3%), soybean meal (92.3%), anchovy meal (92.2%), pea protein concentrate (89.8%), white lupin meal (89.7%), crab meal (89.4%), canola protein concentrate (88.8%) and corn gluten meal (86.3%); mid-range for poultry by-product meal (80.2%) and canola meal (76.0%); and low for shrimp meal (66.7%), hydrolyzed feather meal (62.4%) and flaxseed meal (50.2-55.0%). Energy ADC was high for whole krill meal (96.3%), wheat gluten meal (95.4%), soy protein concentrate (94.9%), herring meal (92.8%), soy protein isolate (92.1%), soybean meal (88.1%) and anchovy meal (86.4%); mid-range for canola protein concentrate (83.3%), corn gluten meal (82.7%), crab meal (82.4%), pea protein concentrate (76.7%) and white lupin meal (75.3%); and low for poultry by-product meal (71.0%), canola meal (60.6%), hydrolyzed feather meal (58.9%), shrimp meal (41.4%) and flaxseed meal (21.2-37.4%). From the protein ADC data, results clearly showed that the basal diet and test feed ingredients were digested independently of one another in nearly all cases, the only exceptions being for those diets containing test ingredients of very high (> 99%, wheat gluten) or very low (< 67%, hydrolyzed feather and flaxseed) protein ADCs. In the case of DE, the basal diet and test feed ingredients were digested independently in all test diets without exception.     

Replacement of fish meal with blend of rendered animal protein in diets for Siberian sturgeon (Acipenser baerii Brandt), results in performance equal to fish meal fed fish

An 8w growth trial was conducted to determine the effect of partial replacement of fish meal (FM) by a blend of rendered animal protein (BAP, comprised of 40% meat and bone meal, 40% poultry by‐product meal, 20% hydrolyzed feather meal in diets for juvenile Siberia sturgeon (Acipenser baerii Brandt). Five experimental diets were formulated. The control diet (C) contained 48% FM, whereas in the remaining four diets, FM were replaced by BAP at 25% or 50% level balanced by crystallized amino acid (AA) or spray‐dried blood meal (BM), which named as BAP25‐AA, BAP25‐BM, BAP50‐AA and BAP50‐BM, respectively. Weight gain rate of BAP50‐AA group was significantly higher than that of C group, while other BAP diets did not show negative effect on growth performance. The BAP25‐BM group exhibited the lowest feed conversion rate (FCR) (P < 0.05). FM replacement by BAP did not affect chemical composition of the whole body and crude fat level of the liver, but significantly affect the fillet lipid content. Hepatic aspartate aminotransferase and serum total protein, total cholesterol and triglyceride were reduced in fish fed diet BAP50B. Siberian sturgeon showed high efficiency on utilization of crystalline amino acid as good as those from BM.