Complete replacement of fish meal by plant protein ingredients with dietary essential amino acids supplementation for juvenile blunt snout bream (Megalobrama amblycephala)

Six extruded diets were formulated with a graded level of fish meal (FM); diet 1 and diet 2 were formulated with 80 g/kg FM; diet 3 and diet 4 were formulated with 40 g/kg FM; and diet 5 and diet 6 were devoid of FM. Hence, diet 2, diet 4 and diet 6 were supplemented with essential amino acids (EAAs). The diets were fed throughout an eight‐week feeding trial. The results revealed that specific growth rate (SGR), feed conversion ratio (FCR), body weight gain (BWG) and protein efficiency ratio (PER) were influenced by FM reduction and improved by the addition of EAA (p < 0.05). A survival rate (SR), whole body content of protein, lipid, moisture and ash, and plasma total protein (TP), albumin (ALB), triglyceride (TG) and urea (UN) did not influence by dietary treatments (p > 0.05). Additionally, target of rapamycin (TOR) pathway did not influence by dietary treatments (p > 0.05). Expression levels of hepatic peptide transporter 1 (Pept1) and peptide transporter 2 (Pept2) decreased against FM reduction and improved significantly in the groups fed diet 4 and diet 6. In summary, the findings revealed that diet containing plant proteins mixture supplemented with EAA could totally replace FM in the practical diet of blunt snout bream.     

Partial replacement of fishmeal with corn gluten meal,pea protein isolate and their mixture in diet of black sea bream (Acanthopagrus schlegelii) juveniles: Effects on growth performance,feed utilization and haematological parameters

Corn gluten meal (CGM), pea protein isolate (PPI) and their mixture (CPP, 1:1 ratio) were evaluated as fishmeal (FM) alternatives in black sea bream (Acanthopagrus schlegelii) juveniles (9.02 ± 0.12 g). A FM diet was designed as control, and other six diets had 20% and 40% FM protein replaced by CGM, PPI and CPP, respectively, with the supplementation of crystalline methionine, arginine and lysine. After the 8‐week feeding trial, significantly lower weight gain was found in fish fed the 40% CGM diet (p < .05), whereas other treatments had no statistical difference (p > .05). The values of feed efficiency ratio and feed intake, as well as proximate compositions of muscle and whole body, were not significantly influenced in all treatments. Apparent digestibility coefficients (ADCs) of dry matter, crude protein, threonine, valine, methionine, isoleucine, leucine, phenylalanine and lysine were significantly influenced by protein source. Fish fed the 40% CGM diet had significantly higher content of essential amino acid in muscle than that of the 20% PPI diet. Fish fed the 40% CGM diet had significantly lower content of serum cholesterol than other treatments (p < .05). Elevated serum superoxide dismutase activity was found in fish fed the 40% plant protein diets. In conclusion, between 20% and 40% FM protein could be replaced by CGM, while about 40% FM protein derived from PPI and CPP could be applied in black sea bream.     

Replacement of fish meal with processed carinata (Brassica carinata) seed meal in low animal protein diets of rainbow trout (Oncorhynchus mykiss)

A 56‐day growth trial was conducted to determine the amount of fish meal (FM) in rainbow trout (Oncorhynchus mykiss) diets containing 200 g/kg FM as the sole animal protein source; that could be replaced with carinata (Brassica carinata) meal (CM) processed by aerobic conversion (AC, by fungi ssp.) followed by a single wash (ACCM). ACCM replaced 50, 100 and 150 g of FM. Replacement of ≥100 g of FM with ACCM, resulted in reduced (p < 0.01) growth, due to reduced dietary lysine and diet consumption (p < 0.01). Fulton's condition factor K decreased (p < 0.01) with increased FM replacement. FCR (p < 0.01) had an inverse relationship with diet consumption. The trend in FCR was similar to the trend in PER (p < 0.01). Apparent net protein utilization was lower (p < 0.01) for the highest FM replacement diet. There was no effect of FM replacement by ACCM on whole‐body composition or viscera, spleen and liver weights. However, visceral fat increased (p < 0.01) with increased feed consumption. There was no apparent effect of ACCM on hematocrit, haemoglobin or mean corpuscular haemoglobin contents. Results of this study indicate that replacement of ≥100 g of FM by ACCM in low FM/animal (200 g/kg) RBT diets may have been achieved if feed consumption and dietary lysine were similar.     

Effects of feeding a fish meal‐free soy protein concentrate‐based diet on the growth performance and nutrient utilization of red sea bream (Pagrus major)

Two groups of red sea bream (average body weight 85 g) were fed to satiation fish meal (FM) or FM‐free soy protein concentrate (SPC)‐based diet (FM‐sat and SPC groups respectively). A third group (FM‐pair) was fed the same amount of FM as of SPC fed to SPC‐sat group for 6 weeks. Growth rate of SPC group was significantly slower than of FM‐sat and FM‐pair groups (p < 0.05). Feed conversion ratios of FM‐sat and FM‐pair groups were similar and were better than that of SPC group (p < 0.05). Visceral fat somatic index of SPC group was significantly lower than of the other groups (p < 0.05), while that of the latter two groups were similar. Plasma triglyceride of FM‐sat and FM‐pair groups was similar and lower than the level of SPC group (p < 0.05). Trypsin activity in hepatopancreas of SPC group was significantly lower than that of other groups (p < 0.05). We suggest a low growth of SPC group was not simply related to low‐feed intake. Feeding of a FM‐free SPC‐based diet may reduce lipid accumulation and consequently lead to low‐growth performance, in red sea bream.     

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

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

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.     

Availability of potato protein concentrate as an alternative protein source to fish meal in greater amberjack (Seriola dumerili) diets

Potato protein concentrate (PPC) is a promising candidate as a fish meal (FM) substitute because it has high protein and essential amino acid content. In the present study, we replaced FM in greater amberjack diets with PPC to investigate the effect on growth and feed utilization. Four isonitrogenous, isolipidic and isocaloric experimental diets were prepared by substituting 0, 20, 40 and 60% of FM protein with PPC (Control, P20, P40 and P60 respectively). The in vitro protein digestibility of protein in PPC was 88.8%, relative to 100% protein in the FM. The in vitro protein digestibility of protein in the experimental diets also decreased with increasing PPC and was lowest at 84.2% in P60. After the 7‐week feeding trial, final body weight, weight gain and thermal growth coefficient tended to decrease with increasing PPC and were significantly lower in P60 than in the control (p < .05). Further, fish fed with diets P40 and P60 showed significantly lower feed conversion and protein efficiency ratios than the control group (p < .05). In conclusion, the results suggest that PPC can replace up to 20% of FM in the diet of greater amberjack without compromising the growth performance or feed efficiency.     

Effects of replacing fish meal with soybean meal and peanut meal on growth,feed utilization and haemolymph indexes for juvenile white shrimp Litopenaeus vannamei,Boone

An 8‐week feeding trial was conducted to evaluate the effects of replacing fish meal (FM) with soybean meal (SBM) and peanut meal (PM) on growth, feed utilization, body composition and haemolymph indexes of juvenile white shrimp Litopenaeus vannamei, Boone. Five diets were formulated: a control diet (FM30) containing 30% fish meal and four other diets (FM20, FM15, FM10 and FM5) in which protein from fish meal was substituted by protein from SBM and PM. The dietary amino acids of diets FM20, FM15, FM10 and FM5 were equal to those of the diet FM30 by adding crystalline amino acids (lysine and methionine). Each diet was randomly assigned to triplicate groups of 30 shrimps (initial weight = 0.48 g), each three times daily. The results indicated that shrimp fed the diets FM15, FM10 and FM5 had poor growth performance and feed utilization compared with shrimp fed the control diet. No difference was observed in feed intake, survival and body composition among dietary treatments. The plasma total cholesterol level of shrimp and the digestibility of dry matter, protein and energy contained in the diets decreased significantly with increasing PM and SBM inclusion levels. Results of this study suggested that fish meal can be reduced from 300 to 200 g kg^?1 when replaced by a mixture of SBM and PM.     

Effects of dietary taurine levels on epidermal thickness and scale loss in red sea bream,Pagrus major

Taurine is often added to artificial fish diets to compensate for a reduction in fish meal (FM). However, the taurine content of FM‐based diets is typically lower than in diets consisting of raw fish, even in diets where FM is the only protein source. We evaluated the effects of dietary taurine in FM‐based diets on epidermal thickness and scale detachability in red sea bream Pagrus major. We compared the effect of diets containing 0% (control), 0.3% (Tau‐0.3%), 0.6% (Tau‐0.6%) and 1.0% (Tau‐1.0%) taurine. Red sea bream (average body weight, 39 g) were fed these diets for 7 weeks. Taurine supplementation had no effect on growth, feed intake, feeding efficiency, or survival. However, the epidermal thickness was higher in fish in the Tau‐0.6% and Tau‐1.0% groups than in the control and Tau‐0.3% groups. Similarly, scale loss was significantly higher in the control group than in the Tau‐0.6% and Tau‐1.0% groups. Our results suggest that supplementation with >0.6% taurine (1.0% in diet) improves skin condition.     

Partial replacement of fish meal by a mixture of soybean meal and rapeseed meal in practical diets for juvenile Chinese mitten crab Eriocheir sinensis: effects on growth performance and in vivo digestibility

An 8‐week experiment was conducted to examine the effect of partial replacement of fish meal (FM) by a mixture of soybean meal (SBM) and rapeseed meal (RM) in practical diets of juvenile Chinese mitten crab Eriocheir sinensis of initial body weight of 1.54±0.12 g (means±SD, n=90). Five isonitrogenous diets were formulated to contain 35% protein and 5% lipid. Soybean meal and RM mix (1:1 ratio) were included at five levels of 0 (control), 15%, 30%, 45% and 60%, replacing 0, 20%, 40%, 60% and 80% FM respectively. When FM was replaced by 15% of SBM and RM, crab showed the highest growth, feed utilization and moulting frequency (MF). Fish meal replaced by SBM and RM did not significantly influence crude protein, lipid and moisture contents of whole body crab, but ash content was the lowest for crab fed the diet with FM replaced by 15% of SBM and RM. Apparent digestibility coefficients (ADCs) of dry matter, crude protein and energy tended to decline with increasing inclusion levels of dietary SBM and RM. In general, ADCs of lipid were high (over 90%) and showed no significant differences among the treatments (P>0.05). Based on these observations above, these results indicated that about 40% of FM can be replaced with a mixture of SBM and RM (1:1 ratio) in the diet of E. sinensis without adverse growth performance, compared with the FM‐based diet. However, 20% of FM replaced by SBM and RM produced the best growth performance and feed utilization.     

Validation of processed animal proteins (mono‐PAPS) in experimental diets for juvenile gilthead sea bream (Sparus aurata L.) as primary fish meal replacers within a European perspective

Experimental diets were formulated to evaluate a “pure” poultry meat meal (PMM) source in diets formulated for juvenile gilthead sea bream (Sparus aurata L.). The digestible protein contribution of fish meal in a control diet was substituted by 25%, 50% and 75% of a processed poultry meat meal (PMM) on a digestible crude protein (DCP) basis and by 5% and 10% for an enzyme‐treated feather meal (EFM) and also a spray‐dried haemaglobin meal (SDHM), respectively. In a consecutive trial, diets were designed to assess the value of a “pure” (defatted) poultry protein substituting the fish meal (FM) protein content. Experimental diets included: a control diet, two test diets where 75% of FM was replaced by a full‐fat PMM (PMM75) or a defatted grade of PMM (dPMM75) and two test diets where 50% of FM was substituted for defatted PMM (dPMM50) or a 50:50 blend of soya bean meal and defatted PMM (SBM/dPMM) to produce a composite product. This soya bean/dPMM blend was tested to enhance the nutritional value of this key plant ingredient commonly employed in sea bream diets that can be deficient in specific amino acids and minerals. In the first trial, gilthead sea bream grew effectively on diets containing up to the 75% replacement of FM attaining a mean weight of 63.6 g compared to 67.8 g for the FM control fed group. For the consecutive trial, the fishmeal‐based control diet yielded the highest SGR followed by dPMM50 and SBM/dPMM blend inclusion but was not significant. Carcass FA profiles of gilthead sea bream conformed to the expected changes in relation to the dietary FA patterns, with the 18:1n‐9 representative of the poultry lipid signature becoming more apparent with PMM inclusion. The ratio of n‐3/n‐6 fatty acids was greatly affected in sea bream fed the full‐fat PMM at 75% inclusion due to fish oil exclusion. Defatted dPMM, however, allowed more of the fish oil to be used in the diet and reducing this latter effect in sea bream carcass, hence restoring the higher total omega‐3 HUFA fatty acids namely EPA and DHA and n‐3/n‐6 ratio. It is concluded that poultry meat meal can be modestly incorporated into formulated diets for sea bream and can be used in conjunction with soya bean meal without any fundamental changes in performance and feed efficiency.     

Evaluation of corn gluten meal as a protein source in diets for gilthead sea bream (Sparus aurata L.) juveniles

A 12‐week growth trial was conducted to evaluate corn gluten meal as an alternative protein source to fish meal in diets for gilthead sea bream juveniles. The experimental diets were formulated to be isonitrogenous and isoenergetic and to have 20%, 40%, 60% and 80% of fish meal protein, the only protein source in the control diet, replaced by corn gluten meal. At the end of the growth trial only the group fed the diet with 80% corn gluten protein exhibited significantly reduced growth and feed efficiency compared with the fish meal‐based diet. This was most likely due to a dietary amino acid deficiency in that diet. A trend was noticed for feed efficiency to improve with the replacement of fish meal protein in the diets up to 60%. There were no significant differences among groups in protein and energy retention (as percentage of intake). At the end of the trial whole body water content of the experimental groups was significantly lower and the lipid content of groups including 60% and 80% corn gluten protein was significantly higher than that in the control. No other differences were observed in whole body composition among groups. Apparent digestibility coefficients (ADC) of the diets were evaluated in a separate trial. The ADC of dry matter of the experimental diets was significantly higher than in the control diet; there were no significant differences among diets in the ADC of energy and protein, except for the ADC of protein of diet with 80% corn gluten protein, which was significantly lower than the control. The results of this study indicate that corn gluten meal can replace up to 60% fish meal protein in diets for gilthead sea bream juveniles with no negative effects on fish performance.     

Effect of partial replacement of dietary fish meal by soybean meal with betaine attractant supplementation on growth performance and fatty acid profiles of juvenile rainbow trout (Oncorhynchus mykiss)

This study was conducted to investigate the effects of dietary incorporation of soybean meal for fish meal replacement and supplementation of betaine as an attractant on growth performance and fatty acid profiles of rainbow trout (Oncorhynchus mykiss). Juvenile trout were fed practical diets, with increasing soybean levels and betaine supplementations. The experimental diets consisted of a control diet with fish meal as the sole protein source (control) and no attractant, 25% soybean‐1% betaine diet (SBM25‐B1), 50% soybean‐2% betaine diet (SBM50‐B2), and 50% soybean‐0% betaine diet (SBM50‐B0). Average body weight was 12.69 ± 0.16 g at the beginning of experiments. Following 54 days feeding programme with experimental diets, average body weights reached 47.45 ± 1.22 g, 58.11 ± 1.77 g, 56.34 ± 1.87 g and 53.76 ± 1.74 g in the control, SBM25‐B1, SBM50‐B2 and SBM50‐B0 groups respectively. As compared with control treatment, significant differences were observed in weight gain, specific growth rate and feed intake of 1% betaine treatment at 25% soybean‐meal‐incorporated diet (p < .05), but no differences were observed in feed conversation ratio and survival rates (p > .05). Compared with the control treatment, betaine‐supplemented groups had significantly higher total saturated fatty acid contents (p < .05). On the other hand, the control treatment showed a significantly higher level of monounsaturated fatty acid than the betaine‐supplemented groups (p < .05). Significant differences were observed in fatty acid profile of 1% betaine‐supplemented group (p < .05) compared with the control. Present findings revealed that 1% betaine supplementation with dietary incorporation of soybean meal at 25% level positively influenced growth performance, feed utilization and fatty acid profiles of rainbow trout juveniles.     

Effect of replacing fish meal with meat and bone meal on growth,feed utilization and nitrogen and phosphorus excretion for juvenile Pseudobagrus ussuriensis

The effect of replacing fish meal (FM) with meat and bone meal (MBM) in diets for juvenile Pseudobagrus ussuriensis was evaluated in a 90‐day feeding trial. Six isonitrogenous (crude protein, 430 g/kg) and isolipidic (crude lipid, 74 g/kg) diets were formulated to contain MBM to replace FM at 0 (S0), 200 (S20), 400 (S40), 600 (S60), 800 (S80) and 1000 g/kg (S100), respectively. The results showed that there was no significant difference in weight gain (WG) among fish fed S0, S20 and S40 diets. However, a significant reduction in WG occurred when 600, 800 and 1000 g/kg FM protein was replaced by MBM (p < .05). Similar trends were observed in specific growth rate and protein efficiency ratio. Apparent digestibility coefficients (ADC) of protein and dry matter of the diets S80 and S100 were significantly lower than those of the other diets. The ADC of phosphorus significantly reduced with the increase in dietary MBM level. Nitrogen and phosphorus excretion increased with the increasing dietary MBM level. Protease, lipase and amylase activities of the diets S80 and S100 were significantly lower than those of the other diets (p < .05). The results of this study showed that the optimum dietary MBM replacement level was 34.3% according to broken‐line model based on WG against dietary MBM replacement level.     

Dietary medicinal herbs and enzyme treated fish meal improve stress resistances and growth performance at early juvenile stage of red sea bream Pagrus major

Red sea bream Pagrus major (RSB) weighing 0.09 g were fed on test diets, composed of 65% fish meal supplemented with 0.49% Crataegi fructus (Cf) and a mixture of Massa medicata, Cf, Artemisia capillaries and Cnidium officinale (HM) or a control diet without herbs, in trial 1. After air exposure and anaesthesia treatment, higher stress tolerances were obtained in herbal groups than control group. Moreover, after challenge test with Vibrio anguillarum, mortalities of the herbal groups were lower than the control group. There was no significant difference in growth performance among the treatments. Feed efficiency (FE) of the test groups was 124–141%. In trial 2, RSB weighing 0.11 g were fed on diets composed of 35% fish meal and 30% enzyme treated fish meal (EFM) with the same herbal treatments as trial 1. The herbal groups revealed higher final body weight and specific growth rate (SGR) and lower daily feed intake than those of the control group. The FE of test groups was 172–203%. These results indicate that the dietary herbs supplementation acts not only as recovery enhancer for some rearing stresses but also as growth enhancer, which is accelerated with dietary EFM in the early juvenile stage of red sea bream.     

Evaluation of rendered animal protein ingredients for replacement of fish meal in practical diets for gibel carp,Carassius auratus gibelio (Bloch)

A 12‐week feeding trial was carried out in fibreglass tanks to examine partial replacement of fish meal (FM) with poultry by‐product meal (PBM), meat and bone meal (MBM) and blood meal (BM) in practical diets for gibel carp Carassius auratus gibelio (Bloch). Triplicate groups of fish (initial body weight 15.3 g fish^?1) were fed eight isonitrogenous (crude protein: 37.5%) and isolipidic diets (crude lipid: 7%). The control diet is the commercial diet of gibel carp, which used 18% of FM as the sole animal protein source. In the other seven diets (Diet 2–Diet 8), 17–83% of FM protein was substituted by a blend of PBM and BM or a blend of PBM, MBM and BM. The final body weight and thermal‐unit growth coefficient of fish fed the feeds in Diet 8 in which 83% of FM protein was replaced by the blend of 3% BM, 10% PBM and 5% MBM is significantly lower than Diet 1 (the control). The feed efficiency ratio in Diet 8 group is significantly lower than Diet 1, 2, 4 and 7 groups. The results of the present study indicated that a combination of PBM, BM and MBM can replace most of the FM protein and the FM level can be reduced to about 6% with satisfactory growth and feed utilization in practical diets for gibel carp.     

Replacing fish meal with a blend of poultry by‐product meal and feather meal in diets for giant croaker (Nibea japonica)

An 8‐week feeding trial was conducted to evaluate the potential of replacing fish meal with poultry by‐product meal (PBM) and feather meal (FEM) in giant croaker (Nibea japonica) diet. The control diet (C) contained 400 g/kg fish meal, and 20%, 40%, 60% and 80% of the fish meal in diet C was replaced by a blend of PBM and FEM (PBM: FEM = 7:3) in diets B20, B40, B60 and B80, respectively. The weight gain and feed intake of fish fed diet C did not differ from those of fish fed diets B20 and B40 (p > .05), but were higher than those of fish fed diets B60 and B80 (p < .05). Phosphorus retention efficiency was lower in fish fed diets C, B20 and B40 than in fish fed diets R60 and R80 (p < .05). No significant differences were found in feed conversion ratio, nitrogen retention efficiency, condition factor, hepatosomatic index, body composition and nitrogen waste among the treatments (p > .05). Ratio of fish meal consumption to fish production linearly declined with the decrease in dietary fish meal level. This study indicates that dietary fish meal for giant croaker could be reduced to 240 g/kg by inclusion of the blend of PBM and FEM.     

Effects of partial substitution of dietary fish meal by fermented soybean meal on growth performance,amino acid and biochemical parameters of juvenile black sea bream Acanthopagrus schlegeli

A feeding trial was conducted to evaluate the effect of replacing fish meal protein with fermented soybean meal (FSM) on the growth performance, feed utilization, amino acid profile, body composition, morphological parameters, activity of antioxidant and digestive enzymes of black sea bream (Acanthopagrus schlegeli) juvenile. Five isonitrogenic and isolipidic diets were prepared with levels of 0 (control), 80, 160, 240 and 320 g kg^?1 FSM. Triplicate groups (40 fish per tank) of juvenile black sea bream with initial weight of 1.17 ± 0.04 g were hand‐fed to visual satiation at three meals per day for 8 weeks. The fish fed diets containing different levels of FSM had no significant differences regarding survival and specific growth rate compared with control group. Feed and protein efficiency ratios of fish fed diet containing 320 g kg^?1 FSM were significantly lower than those of control group. Daily feed intake and daily protein intake of fish fed diet containing 240–320 g kg^?1 were significantly higher than those of control group. Hepatosomatic index and condition factor of fish were not affected by different dietary FSM level. Fish fed diets containing 240–320 g kg^?1 FSM had significantly higher visceral somatic index than control group. Whole body proximate and amino acid compositions of fish were not affected by dietary FSM level. The activity of digestive enzymes in the intestine was not affected by dietary FSM level. The activity of glutathione peroxidase in liver was significantly higher for fish fed the diet containing 160 g kg^?1 FSM compared with control group. This study showed that up to 40% fish meal in the diets of juvenile black sea bream could be replaced by fermented soybean meal with supplementation of methionine, lysine and taurine.     

Effect of dietary replacement of fish meal by soybean protein concentrate on growth performance and phosphorus discharging of juvenile black sea bream,Acanthopagrus schlegelii

The 8‐week experiment was conducted to evaluate the effects of partial replacement of fish meal (FM) with soybean protein concentrate (SPC) on juvenile black sea bream, Acanthopagrus schlegelii (10.70 ± 0.04 g). Diets were formulated to replace FM protein by SPC at 0, 8, 16, 24, 32 or 40% (designated as T1, T2, T3, T4, T5 and T6, respectively). Diets except T1 were supplemented with phytase at 2000 phytase activity U kg^?1. The results showed that survival rate, growth performance and feed utilization were not significantly affected by increasing dietary SPC. Fish fed diet T3 had higher feed intake compared to those fed T1, T2 and T5 diets. Whole body compositions of black sea bream were significantly influenced by SPC replacing FM except for protein, ash and phosphorus content. Condition factor of fish was significantly lower in T2 than that of fish in T3 group. Apparent digestibility coefficients (ADCs) of dry matter was higher in fish fed T6 diet than those of fish fed T1 and T2 diets, ADCs of phosphorus increased with dietary SPC level up to T3 and then decreased. The results obtained in this study indicate that FM protein could be effectively replaced by SPC protein with phytase in diet of black sea bream.     

Effects of soybean meal and high‐protein sunflower meal on growth performance,feed utilization,gut health and gene expression in Arctic charr (Salvelinus alpinus) at the grow‐out stage

The effects of two plant ingredients (solvent‐extracted soybean meal [SBM] and high‐protein sunflower meal [HPSFM]) and three inclusion levels (0 percent, practical diet containing 25 percent fish meal; 12.5 percent; and 25 percent) of these ingredients were investigated on the growth, feed utilization, gut histology and gene expression in the distal intestine of Arctic charr Salvelinus alpinus (average initial weight, 330.1 ± 8.9 g per fish). Feeding experimental diets for 12 weeks resulted in no difference between HPSFM diets in body weight gain (BWG), thermal‐unit growth coefficient (TGC), feed efficiency (FE), feed intake (FI) or pro‐inflammatory mRNA expression (PIE) with increasing dietary inclusion and between SBM FE, FI and PIE. Differences in quadratic contrasts were observed for nitrogen deposition rate (NDR) and nitrogen retention efficiency (NRE) (p < .05), whereby HPSFM diets elicited the strongest positive response. SBM resulted in linear reduction in BWG, TGC and distal intestine simple fold length and width measurements (p < .05) with stepwise increases in dietary inclusion, whereas dietary HPSFM had no effect. Histological observations of individual villi indicated several symptoms of non‐infectious subacute gastrointestinal enteritis in tanks fed SBM, many of which were not present in tanks fed HPSFM. The dietary HPSFM seems to be more adequate to replace fishmeal in Arctic charr diet than SBM, when fed at a level of up to 25 percent at the grow‐out stage.