Replacement of fish meal with two fermented soybean meals in diets for rainbow trout (Oncorhynchus mykiss)

The present study investigated the effect of fish meal (FM) replacement with fermented soybean meal (FSM) on growth and feed utilization of rainbow trout. Two FSM products, FSM1 (more fermentation with more small peptide and acid than FSM2) and FSM2 were used to replace 20%, 40% and 60% of FM in control diet (250 g/kg FM), respectively (FSM1‐20, FSM1‐40, FSM1‐60, FSM2‐20, FSM2‐40 and FSM2‐60). Then the seven diets were fed to rainbow trout (18.1 g) for 8 weeks. Weight gain (WG), feed conversion ratio (FCR) and digestibility of crude protein and dry matter showed no significant difference among the groups of FSM1‐20, FSM1‐40, FSM2‐20, FSM2‐40 and the control, but WG significantly decreased and FCR increased when 60% FM was replaced by both FSMs (p < .05). The replacement of 40%, 60% FM resulted in lower villus height than the control (p < .05), and intestinal protease activity was lower in FSM2‐40, FSM2‐60 and FSM1‐60 groups than the control group (p < .05). In addition, the activity of alkaline phosphatase and superoxide dismutase increased with increasing levels of FSM (p < .05). In conclusion, dietary fish meal could be replaced by 40% with both FSMs without adverse effects on growth and feed utilization of rainbow trout based on an eight weeks feeding trial.     

Effects of fish meal replaced by fermented soybean meal on growth performance,intestinal histology and microbiota of largemouth bass (Micropterus salmoides)

This study was conducted to investigate the effects of replacing fish meal (FM) with fermented soybean meal (FSM) and soybean meal (SM) on growth performance, intestinal histology and microbiota of largemouth bass (Micropterus salmoides). The basal diet contained 350 g/kg FM (CON), and then, FM was replaced with SM and FSM at the ratios of 30% and 60% (SM‐30, SM‐60, FSM‐30 and FSM‐60), respectively. The largemouth bass (4.43 ± 0.13 g) were fed for 8 weeks. The results showed that weight gain of fish fed with FSM‐60 and SM‐60 diets was significantly lower, and feed conversion ratio of SM‐30, SM‐60 and FSM‐60 groups was significantly higher than the CON group (p < .05). The intestinal villus height of SM‐60 group and the villus width of SM‐60 and FSM‐60 group were significantly lower than the CON group (p < .05). The 30% FM replacement by SM and FSM significantly increased the abundance of Cetobacterium and Mycoplasma, respectively (p < .05). In conclusion, FSM could replace 30% FM in diet without negative impacts on the growth performance of largemouth bass, while the SM should be controlled below 30%.     

Effect of tributyrin supplementation in high‐soya bean meal diet on growth performance,body composition,intestine morphology and microbiota of juvenile yellow drum (Nibea albiflora)

Six equal‐protein and equal‐lipid diets were formulated: the fish meal (FM) diet, the soya bean meal (SBM) diet with 40% of FM protein replaced by SBM protein and tributyrin (TB) diets with 0.05% (TB0.05), 0.10% (TB0.1), 0.20% (TB0.2) and 0.40% (TB0.4) tributyrin supplemented in the SBM‐based diet. Each kind of diet was randomly fed to triplicate tanks with 20 fish per tank. Fish were fed apparent satiation twice daily for 56 days. No significant difference in weight gain rate (WGR) and feed efficiency rate (FER) was observed between fish fed the FM, TB0.1 and TB0.2 diets (p > .05). Muscle histidine and arginine proportion of fish fed TB0.1 diet was significantly higher than that of fish fed the SBM diet (p < .05). Intestine morphology results indicated that the supplementation of 0.1% tributyrin significantly improved the mucosal fold height, microvilli length and microvilli density when compared with those of fish fed the SBM diet (p < .05). The supplementation of dietary tributyrin suppressed the pro‐inflammatory gene expression, which may be due to the improvement of physical barrier and modification of microbial communities, such as Acinetobacter, Rhodocyclaceae, Brevundimonas, Sphingopyxis, Hydrogenophaga, Methyloversatilis and Devosia. In conclusion, dietary 0.1% tributyrin supplementation in high‐soya bean meal diet improved growth performance, flesh quality and intestinal morphology structure integrity of yellow drum.     

Evaluation of a fish meal analogue as a replacement for fish meal in practical diets for Pacific white shrimp Litopenaeus vannamei

Three six‐week growth trials and a digestibility trial were conducted to evaluate a fish meal analogue (FMA) as a replacement for fish meal (FM) in shrimp feeds. Trials 1 and 2 evaluated and confirmed the potential of FMA supplementation (0, 48.5, 97, 145.5 and 194 g/kg) as a replacement for FM up to 200 g/kg without balancing for phosphorus (P) in practical diets for juvenile Pacific white shrimp L. vannamei. At the end of trial 1, shrimp offered diets containing 48.5 g/kg FMA exhibited significantly higher weight gain (WG) than those fed with the diet containing 145.5 g/kg FMA. At the end of trial 2, dietary FMA inclusion at 48.5 and 97 g/kg significantly improved WG and protein retention (PR), while reducing FCR and protein content of shrimp body compared to the diet containing 194 g/kg FMA. To determine whether P deficiency is the cause of reduced growth, the third trial was conducted utilizing equivalent diet but balanced for P. At the end of trial 3, shrimp fed diet containing 48.5 g/kg FMA+P showed significantly higher WG and PR than those fed diet containing 145.5 g/kg FMA+P. No decreasing trend of growth was detected in the diets containing FMA compared to the FM‐based diet. Apparent digestibility coefficients of dry matter, energy, protein and amino acids of FMA were determined using chromic oxide as an inert maker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility of FMA were significantly lower than those of soybean meal and FM which were run at the same time. Results of this work indicate that FMA can replace up to 200 g/kg FM in shrimp diets with supplemental inorganic P. Given the good growth across the range of inclusion without any indication of a growth depression, the low nutrient digestibility of FMA may be due to an atypical response or the product simply does not work with the testing technique.     

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.     

Growth and economic analysis of freshwater prawn,Macrobrachium rosenbergii (de Man), produced with feeds substituting sunflower cake for fish meal,soya bean meal and mustard oil cake

A feeding trial with Macrobrachium rosenbergii was carried out to test the effectiveness of sunflower cake (SFC) as a replacement for conventional protein sources. Four isonitrogenous (~30% crude protein) and isocaloric (388–402 kcal) diets were formulated. Diet‐1 was a control made with conventional ingredients including fish meal, soya bean meal and mustard oil cake. Diet‐2, Diet‐3 and Diet‐4 were made with 30%, 40% and 50% SFC, respectively, replacing the usual protein sources used in Diet‐1. After 100 days, diets with SFC inclusion showed favourable growth and economic performance trends compared to control diet‐1, but without significant differences (p > .05). Better production (572.89 ± 62.99 kg/ha) was observed with Diet‐4 followed by Diet‐2, Diet‐3 and Diet‐1. Diet‐4 revealed the best feed conversion ratio (2.56 ± 0.24), specific growth rate (1.18 ± 0.05) and protein efficiency ratio (1.14 ± 0.10) among these diets. Whole carcass composition analysis revealed highest crude protein (18.19%) and lipid (4.43%) content in prawns fed Diet‐3 followed by Diet‐4. Highest total income, gross margin and benefit cost ratio (BCR) per hectare from prawns were US$5,759, US$2,623 and 1.84, respectively, found in Diet‐4. This study demonstrates that 30%–50% inclusion of SFC has favourable impacts on productivity and profitability compared with controls, with 50% SFC inclusion as the most cost‐effective diet for prawns without apparent compromise in growth, flesh quality or economics. The performances of the diets suggest that SFC may be a suitable substitute for fishmeal, soya bean meal and mustard oil cake in prawn feed. The effectiveness of higher SFC concentrations should also be investigated.     

Effect of substitution of dietary fishmeal by soya bean meal on different sizes of gibel carp (Carassius auratus gibelio): nutrient digestibility,growth performance,body composition and morphometry

Four 70‐day growth trials were performed to investigate the effects of substitution of dietary fishmeal (FM) by soya bean meal (SBM) in different sizes of gibel carp CASIII (Carassius auratus gibelio). The initial weights of fry, juvenile, 1‐year fish and broodstock of gibel carp were 0.8, 5.0, 62.7 and 135.6 g, respectively. In each trial, eight diets were formulated to be iso‐nitrogenous and iso‐energetic, and different levels of soy bean meal protein were used to replace fishmeal protein at 0%, 20%, 40%, 60%, 80% and 100%. Another diet containing all SBM protein and supplemented with crystalline amino acids was also tested. The results showed that apparent digestibility coefficients (ADCs) of dry matter and energy decreased with SBM substitution while the ADCs of phosphorus increased. The ADCs of protein of high SBM substitution were higher than those of FM groups. Juveniles show lower ADCs than grown‐up fish. Dietary SBM substitution showed negative effects on survival, growth and feed utilization in gibel carp. One‐year fish and broodstock gibel carp have relatively higher tolerance to dietary SBM than fry and juveniles.     

Aurantiochytrium sp. meal can replace fish oil in practical diets for the juvenile Pacific white shrimp

This study evaluated the use of microalgae (Aurantiochytrium sp.) meal as a substitute for fish oil in the diet of juvenile Pacific white shrimp (Litopenaeus vannamei) reared in a clear‐water system. Dietary treatments at five replacement levels (0%, 25%, 50%, 75%, 100%) were performed in triplicate. After 46 days, only a slight difference in shrimp final weight was observed among treatments (0.61 g). An increase in final weight was observed with replacement of up to 50% fish oil for microalgae meal, while the optimal percentage of replacement estimated was 44.7%. Feed conversion rate (FCR) of animals fed a diet of Aurantiochytrium sp.meal to replace up to 50% fish oil decreased, and the optimal percentage of replacement estimated was 49.3%. The fatty acids profile in shrimp muscle tissue demonstrated an increase in docosahexaenoic acid (DHA) from 10.03% to 14.28% with increased replacement of fish oil by microalgae meal in the diet. Therefore, the partial replacement of fish oil by microalgae meal resulted in improved shrimp growth and FCR, and total replacement of dietary fish oil had no negative effects on these parameters. In addition, inclusion of microalgae meal raises the level of DHA in shrimp muscle.     

Use of Porcine Meal in Plant‐based Practical Diets for Pacific White Shrimp,Litopenaeus vannamei

Two growth trials were conducted to evaluate and confirm the efficacy of a porcine meal (PM) with high protein content (>90%) as an alternative feed ingredient in commercial‐type feed formulation for Pacific white shrimp, Litopenaeus vannamei. Six experimental diets were formulated for the two growth trials. The first five diets contained increasing levels (0, 1, 2, 4, and 6%) of PM as a replacement for soybean meal in a plant‐based diet with low inclusion level (6%) of fish meal (FM). The last experimental diet was produced utilizing 4.2% PM to completely replace FM. In Trial 1, shrimp (1.5 g initial mean weight, 20 shrimp/tank, n = 4) were offered test diets for 6 wk in a semirecirculation system. At the end of Trial 1, shrimp fed with the diet containing 6% PM exhibited significantly enhanced weight gain (WG), feed conversion ratio (FCR), and survival compared to those fed with the diet devoid of FM. As survival was poor across all treatments and different densities could mask growth results the trial was repeated. In Trial 2, shrimp (0.85 g, 15 shrimp/tank, n = 4) were offered diets for 6 wk. Dietary supplementation of PM at 6% significantly improved WG, FCR, and apparent net protein retention in contrast with the treatment devoid of FM, confirming the same trends in Trial 1. No significant difference was detected in protein, lipid, moisture, and mineral profiles of whole‐body shrimp as well as survival across all the treatments. Results of this study indicate that PM is a good high protein source in shrimp feeds, which can be included up to 6% in the low FM‐based diet without compromising the growth of shrimp.     

Replacement of soya bean meal with cashew nut meal as an alternative protein source in the diet of tilapia,Oreochromis mossambicus

An experiment was conducted to replace soya bean meal (SBM) with cashew nut meal (CNM) in the diet of tilapia (Oreochromis mossambicus). Five isonitrogenous (30% CP) and isolipidic (6% CL) diets, CNM0 to CNM4, were prepared replacing SBM at 0%, 12.5%, 25%, 37.5% and 50% with CNM. The feeding trial was conducted in FRP digestibility tanks of 150 L capacity for 60 days. Twenty tilapia fry (20.56 ± 0.05 g) were stocked in each tank. The final weight, weight gain and weight gain% of tilapia that received the CNM4 diet were significantly higher (p < .01) among the treatments. The significantly higher nutrient utilization efficiency in terms of FCR, PER, PRE and LRE was obtained in the CNM4 group. Similarly, a significantly lower (p < .01) body moisture content and a significantly higher (p < .05) body protein content were also observed in the CNM4 diet‐fed group. In tilapia fed the CNM4 diet, the activity of both protease and amylase enzymes was significantly higher (p < .05), but the amylase:protease ratio (A:P) was significantly lower (p < .05). Protease, amylase and A:P were positively correlated with the nutrient digestibility coefficient. The serum protein, albumin and globulin of tilapia fed the CNM4 diet were significantly higher (p < .05) and the liver status enzymes did not vary (p > .05) among the treatments. It can be concluded from the study that 50% replacement of SBM with CNM in the diet is suitable for the enhancement of growth, nutrient utilization and health status of tilapia.     

Effect of dietary fermented soybean meal on growth,intestinal morphology and microbiota in juvenile large yellow croaker,Larimichthys crocea

An 8‐week feeding trial was conducted to evaluate the effect of replacement of fish meal (FM) with fermented soybean meal (FSM) on growth performance, intestinal morphology and microbiota of juvenile large yellow croaker (Larimichthys crocea). Replacement ratio of FM with FSM were 0%, 15%, 30%, 45%, 60% and 75%, respectively (marked as FSM0, FSM15, FSM30, FSM45, FSM60 and FSM75). The results indicated that the survival ranged from 84.78% to 99.44%, and no significant differences were observed among all treatments (p > 0.05). Weight gain ratio (WGR) and specific growth rate (SGR) significantly decreased when the replacement level of FM protein exceeded 60%, and fish fed the FSM60 and FSM75 diets had lower WGR and SGR than those fed the other diets. Feed intake (FI) and feed conversion rate (FCR) significantly increased with replacement levels of FM increasing. Illumina high‐throughput sequence analyses showed that the alpha diversity did not differ among the diets of FSM0, FSM15 and FSM75. The whole community of tested samples was not modified by FSM, Firmicutes and Proteobacteria were the dominant flora in the intestines based on the phyla level. The dominant phyla in the water sample were Proteobacteria, Bacteroidetes. Fish fed the diet containing FSM75 significantly reduced the species abundance of Paenibacillus. There was a certain correlation between the intestine microbiota and SGR, antioxidant, and immune. Results indicated that up to 45% of FM can be replaced by FSM without negative effects on growth performance and intestinal integrity of juvenile large yellow croaker.     

Effects of replacing fish meal with soya protein concentrate on growth,feed efficiency and digestibility in diets for snakehead,Channa striata

Soya bean meal‐based formulated feeds have recently become available for snakehead culture in Vietnam. This study was conducted to determine the appropriate replacement of fish meal (FM) protein by another soya product, soya protein concentrate (SPC), in snakehead (Channa striata) diets. Five iso‐nitrogenous (45% crude protein) and iso‐caloric (19 KJ g^?1) practical diets were formulated to replace 0% (control), 40%, 60%, 80% and 100% of protein FM by protein SPC (100% FM, 40% SPC, 60% SPC, 80% SPC and 100% SPC respectively). A digestibility experiment was also conducted with the same formulated diets with addition of 1% chromic oxide. Fish fed 100% FM and 40% SPC diets had significantly better growth and survival compared with other treatments. Feed intake, feed conversion ratio, protein efficiency ratio and net protein utilization, trypsin and chymotrypsin activities of experimental fish fed 100% FM and 40% SPC diets were significantly higher than those fed other diets. The apparent digestibility coefficient (ADC) of the diet and diet components, ADC_diet, ADC_protein and ADC_lipid, of fish fed diet 40% SPC and 100% FM treatment were significantly higher than those of other treatments. The cost/kg fish produced in diets 100% FM and 40% SPC was much lower compared with other treatments. Dietary inclusion levels of SPC in diet above 40% significantly affected fish survival, growth, digestibility and trypsin and chymotrypsin activities, although fish chemical composition was not greatly affected.     

Partial and complete replacement of fish meal by broad bean meal in feeds for Nile tilapia, Oreochromis niloticus, L., fry

A 16‐week feeding experiment was conducted to study the feasibility of using broad bean meal (BBM) as a replacement for fish meal (FM) for Nile tilapia Oreochromis niloticus fry, initial average weight 1.9±0.18 g. FM (50% of the diet) was used as sole sources of animal protein in the control diet 1. The replacement levels of BBM in diets (2–5) were 25%, 50%, 75% and 100% of the FM. Methionine (1%) and lysine (0.5%) were added to each diet except the control diet. Three groups of fish were fed each of five isonitrogenous (31.2% CP) and isocaloric (20.1 kJ g^?1), and performance was compared against a nutritionally balanced control diet at the end of the experiment. Nile tilapia fed the diet containing 50% BBM exhibited comparable growth with those fed the FM‐based control diet. Digestibility of protein, energy and lipid decreased with increasing levels of BBM above 50% of total replacement FM into the diet. Incorporation of BBM in the diets significantly affected the moisture, fat and energy of whole fish body. These results suggest that BBM can replace 50% of the FM in diet for Nile tilapia fry, without adverse effects on fish performance.     

Evaluation of solid‐state fermented protein concentrates as a fish meal replacer in the diets of juvenile rainbow trout,Oncorhynchus mykiss

We evaluated four fermented protein concentrates (FPCs) as a fish meal replacer in juvenile rainbow trout, Oncorhynchus mykiss. Ten diets were formulated to contain low‐temperature fish meal (LT‐FM), Vietnam fish meal (VT‐FM) and four types of FPCs as fish meal replacers (FPC‐A, B, C & D) at 30% and 50% FM replacement levels. FPC‐A was a mixture of solid‐state fermented soybean meal (SBM) and corn gluten meal (CGM) with Bacillus subtilis; FPC‐B was pretreated acid‐hydrolysed FPC‐A; FPC‐C and FPC‐D were FPC‐A + 2% shrimp soluble extract (SSE) and FPC‐B + 2% SSE, respectively. Triplicate groups of fish (average 15.4 g) were fed one of the experimental diets for 8 weeks. At the end of the feeding trial, fish fed the LT‐FM, FPC‐B, FPC‐C and FPC‐D diets showed significantly higher growth performance at 30% FM replacement than those of fish fed the FPC diets at 50% FM replacement. Fish fed 30FPC‐B, 30FPC‐C and 30FPC‐D diets showed higher weight gain (WG) than fish fed 30FPC‐A diet. Haematological parameters showed no clear trends among the experimental groups. Superoxide dismutase, lysozyme and myeloperoxidase activities were found to be higher in fish fed the LT‐FM, FPC‐A, FPC‐B, FPC‐C and FPC‐D diets at 30% FM replacement than in fish fed the FPC diets at 50% FM replacement. Antinutritional factors such as α‐ and β‐conglycinin, glycinin, trypsin inhibitors or zein were absent in FPC compared with SBM and CGM. Intestinal villi length and muscular thickness were significantly reduced in fish fed the VT‐FM and FPC diets at 50% FM replacement compared to fish fed the LT‐FM and FPC diets at 30% FM replacement. The results show that FPC‐B, FPC‐C, FPC‐D could replace up to 30% of LT‐FM in juvenile rainbow trout.     

Fish meal replacement with rice protein concentrate in a practical diet for the Pacific white shrimp, Litopenaeus vannamei Boone, 1931

Replacement of fish meal (FM) with rice protein concentrate (RPC) as a practical diet for the Pacific white shrimp, Litopenaeus vannamei, was evaluated. Five isonitrogenous (36.6% protein) diets, formulated by replacing 0, 25, 50, 75, and 100% of FM by RPC, were fed to shrimp (initial weight of 6.99 ± 0.08 g) five times daily to satiation for 60 days. Relatively high final weight (FW 17.64–18.25 g) and weight gain (WG 10.81–11.39 g) were obtained in treatments up to 50% of the plant protein inclusion. Above this inclusion level, FW (14.93–14.35 g) and WG (7.68–7.23 g) were reduced. Survival was high (≥95%) and similar for all diets. There were no significant differences (P > 0.05) in tail-muscle composition (moisture, protein, lipid, and ash) among different dietary treatments. Dispensable and indispensable amino acids of the tail muscle of shrimp fed with 25, 50, and 75% RPC were significantly higher than the FM (0%) and 100% RPC diets. A decreasing trend in apparent digestibility coefficient (excluding dry matter) for crude protein (90.52–52.41), ether extract (94.11–80.03), organic matter (87.25–50.16), and gross energy (89.41–55.24) was observed at higher RPC inclusion rates. The results suggest that RPC meal can be a potential candidate for FM replacement up to 50% of the protein in shrimp diets.     

发酵豆粕替代鱼粉对凡纳滨对虾生长、免疫相关酶及免疫相关基因表达的影响

从免疫相关酶活及基因转录水平角度探讨发酵豆粕替代鱼粉对凡纳滨对虾健康生长及免疫机能机制的影响。实验设置5种实用饲料,以30%鱼粉组(FM)为对照组,分别用4%(FSM4)、8%(FSM8)、12%(FSM12)和16%(FSM16)的发酵豆粕,替代9.7%、19.4%、29.1%和38.8%鱼粉,分为4个处理组,饲养体质量为(7.62±0.23)g的凡纳滨对虾60 d后,统计生长性能,检测肌肉营养成分、血清及肝胰腺免疫相关酶活性,肝胰腺HSP70和鳃Toll受体、IMD、溶菌酶(LZM)免疫相关基因m RNA的表达水平。结果显示:(1)与对照组相比,发酵豆粕替代鱼粉对凡纳滨对虾成活率无显著影响;过低或过高水平的发酵豆粕替代鱼粉皆会影响凡纳滨对虾的特定生长率。(2)除FSM12组外,肌肉粗蛋白含量发酵豆粕替代组均低于对照组;粗脂肪含量随着发酵豆粕替代量的升高而降低,FSM16组最低。(3)血清谷丙转氨酶活FSM4和FSM16组显著高于对照组;谷草转氨酶活FSM4组最高,而FSM8组最低;除FSM12组外;碱性磷酸酶活性发酵豆粕替代组显著高于对照组;除FSM16组外,血清总蛋白与肝胰腺丙二醛含量发酵豆粕替代组与对照组无显著性差异。(4)随着发酵豆粕替代量增加,鳃Toll受体m RNA表达呈上升趋势,鳃IMD m RNA表达则呈先升后降趋势,发酵豆粕替代比例过高会降低鳃LZM m RNA表达水平,而肝胰腺HSP70 m RNA表达量则随着发酵豆粕替代比例增加呈上升趋势。综上所述,发酵豆粕适量替代鱼粉对凡纳滨对虾生长性能无显著影响,并可提高免疫相关酶活,改变免疫相关基因的表达。本实验条件下适宜发酵豆粕用量为8%~12%;替代量过高,会引起机体的过度应激。     

Replacing Fish Meal with Rendered Animal Protein Ingredients in Diets for Malabar Grouper,Epinephelus malabaricus,Reared in Net Pens

The potential of using rendered animal protein ingredients, poultry by‐products meal (PBM), meat and bone meal (MBM), and feather meal (FM), to replace fish meal in diets for malabar grouper, Epinephelus malabaricus, was evaluated in a 10‐week net pen experiment. Triplicate groups of fish (initial body weight 50.2 g) were fed eight isonitrogenous and isocaloric diets formulated to contain 52% crude protein and 9% crude lipid. The control diet contained 50% herring meal, whereas in the remaining seven diets, PBM was incorporated at 11.9 (PM1), 23.8 (PM2), and 35.7% (PM3) to replace 25, 50, and 75% of the fish meal; MBM was incorporated at 14.5 (MM1) and 29.0% (MM2) to replace 25 and 50% of the fish meal; and FM was incorporated at 9.4 (FM1) and 18.8% (FM2) to replace 25 and 50% of the fish meal. A raw fish (RF) diet was used as comparison to assess growth performance of fish fed the formulated diets. Feed intake was lower in fish fed the diets PM3 and FM2 than fish fed the control diet. There were no significant differences in weight gain (WG), final body weight (FBW), nitrogen retention efficiency (NRE), energy retention efficiency (ERE), and total nitrogen waste output (TNW) between fish fed the control diet and the diets PM1, PM2, PM3, MM1, MM2, and FM1. Fish fed the diet FM2 had lower WG, FBW, NRE, and ERE but higher TNW than that of fish fed the control diet. Feed conversion ratio (FCR) was higher in fish fed the diets MM2, FM1, and FM2 than fish fed the control diet. At the end of the experiment, there were no significant differences in whole‐body content of moisture, crude protein, and crude lipid among fish fed the formulated diets. WG, FBW, and TNW of fish fed the diet RF were higher, while FCR and NRE were lower than that of fish fed the control diet. No significant differences were found in feed intake, ERE, and whole‐body composition between fish fed the diet RF and the control diet. Results of the present study suggest that dietary fish meal level for malabar grouper can be lowered from 50 to 38% by incorporating PBM, MBM, or FM.     

Evaluation of a novel bacterial biomass as a substitution for soybean meal in plant‐based practical diets for Pacific white shrimp Litopenaeus vannamei

Three growth trials and a digestibility trial were designed to evaluate the efficacy of a novel bacterial biomass (BB) in commercial‐type feed formulation for Pacific white shrimp, Litopenaeus vannamei. In trial 1, the basal diet was supplemented with 0, 60 and 120 g/kg BB to replace soybean meal (SBM). Significant improvement was observed in the survival when BB was incorporated in the diets. However, shrimp fed diets containing 120 g/kg BB exhibited significantly lower weight gain (WG) and higher feed conversion ratio (FCR). To confirm the results from trial 1 and explore the effects of BB supplementation at low levels, the basal diet was incorporated with 0, 10, 20, 40, 60 and 120 g/kg BB to replace SBM in trial 2. Significant reductions in WG, FCR, lipid content of whole body, protein retention efficiency and most amino acids retention efficiency were detected in shrimp fed with diet containing 120 g/kg BB. Trial 3 was designed to elucidate whether the digestible protein is the cause of reduced growth. No improvements in terms of growth performance and FCR were detected in the treatments balanced for digestible protein. Apparent digestibility coefficients of energy, protein and amino acid (AA) for BB were determined using chromic oxide as an inert marker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility coefficients of BB were significantly lower than those of fish meal (FM) and SBM that were given at the same time. Results of this study indicated that BB can be utilized up to 40 g/kg in shrimp feed without causing a decrease in growth. However, supplementations (≥60 g/kg) of BB can result in negative effects on growth response, FCR and protein as well as amino acids retention efficiency. At the lower levels of inclusion, shrimp performance was improved when BB was supplemented on a digestibility basis; however, at the higher level of inclusion, there was no improvement, indicating there may be other nutrients limiting. Based on enhanced survival in the treatment with BB supplementation in trial 1, further research regarding the immune effects of BB in practical shrimp feed will be necessary.     

Response of juvenile tench (Tinca tinca L.) fed practical diets with different protein contents and substitution levels of fish meal by soybean meal

A basal practical diet for juvenile tench (Tinca tinca) was formulated and elaborated to test several protein contents and substitution possibilities of fish meal (FM) by soybean meal (SBM) in a 90‐day trial with 5‐month‐old juveniles (30.54 mm TL, 0.30 g W). A factorial design included nine feeding treatments: three protein contents (50%, 40% or 30%) and three levels of replacement (0%, 25% or 45%) of FM protein by SBM protein. In addition, a commercial carp feed was used as reference. Final survival ranged from 98.2% to 99.4%. The 50% dietary protein with 0% or 25% replacement and 40% dietary protein with 25% replacement diets enabled higher growth (P < 0.05) and lower FCR (P < 0.05) than the rest of practical diets. Fish fed 50% dietary protein had similar growth than those fed carp feed (63.8% protein). Deformed fish averaged 1% for the practical diets and 87.6% for the carp feed. The basal practical diet has showed to be feasible and levels of 40–50% dietary protein with 25% replacement of FM protein by SBM protein can be recommended for juvenile tench aged 5–8 months.     

Evaluation of dried fermented biomass as a feed ingredient in plant‐based practical diets for juvenile Pacific white shrimp Litopenaeus vannamei

Two growth trials were designed to evaluate the utilization of dried fermented biomass (DFB) in commercial type feed formulation for Pacific white shrimp, Litopenaeus vannamei. In trial 1, four experimental diets were formulated to utilize increasing levels (0, 25, 50 and 100 g/kg) of spray‐dried fermented biomass (SDFB) as a replacement of fish meal (FM). Results indicated that SDFB can be utilized up to 50 g/kg as a substitution for FM without causing growth depression in shrimp. However, dietary SDFB supplementation at 100 g/kg significantly reduced the weight gain (WG) of shrimp and increased feed conversion ratio (FCR). This reduction in performance is likely due to palatability or nutrient imbalances of the feed. In trial 2, nine experimental diets were formulated with increasing levels (0, 20, 40, 60 and 120 g/kg) of spray‐dried (S) or granular (G) DFB to replace soy protein concentrate (SPC) or SPC + corn protein concentrate (CPC). This allowed the comparison between spray‐dried and ring‐dried products. Ring drying produced a granular product, reducing dust and increasing product particle size. Shrimp fed with diet containing 20 g/kg GDFB performed the best in terms of final mean weight, WG and FCR. Significantly reduced growth and increased FCR were observed in shrimp fed diets containing 60 and 120 g/kg SDFB. Lipid content of whole body was significantly reduced when GDFB was incorporated at 120 g/kg. No significant differences were detected in survival, protein retention efficiency as well as protein and ash contents of the whole shrimp. Results from analysis of covariance indicated that the processing method (covariant) had a significant effect on final mean weight, WG and FCR. In general, shrimp fed with diet containing granular product performed better as compared to those fed with diets utilizing spray‐dried product. GDFB can be utilized in the diets up to 120 g/kg in practical shrimp feeds as a substitute for SPC and CPC without compromising the growth of shrimp. However, a significant reduction in WG was observed in the diets containing 60 and 120 g/kg SDFB. The results in the current study demonstrate that processing changes to produce a granular product produced an improved feed ingredient for shrimp.