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This study investigated the effects of the dietary replacing fishmeal (FM) with fermented cottonseed meal (FCSM) on growth performance, body coloration, serum biochemistry, muscle quality, and liver antioxidant capacity of juvenile golden pompano (Trachinotus ovatus). Fish were fed with five experimental diets (0 (FM), 12.5% (CSM12.5), 25% (CSM25), 50% (CSM50), and 100% (CSM100) replacement levels) for 8 weeks. The weight gain rate (WGR), specific growth rate (SGR), and condition factor (CF) in fish fed with CSM25 were significantly higher than those of the FM (P < 0.05). ALT, GLU, TG, TC, and LDL of fish fed with CSM100 diet were significantly higher than those in FM (P < 0.05). No significant difference was observed in SOD, CAT, and MDA among all treatments (P > 0.05). The relative gene expression of Nrf2 of fish fed with CSM25 diet was higher than that of the other groups (P < 0.05). The relative gene expression of Keap-1 of fish fed with CSM25 diet was lower than those in FM (P < 0.05). In addition, the replacement of a high proportion of FM with FCSM negatively affect the liver antioxidant capacity of fish. With dietary replacement of FM with FCSM increasing 0%–25%, the relative expressions of GH, myf5, and MSTN were significantly upregulated (P > 0.05). Based on these results, we recommend that of FCSM in the diet of golden pompano, whereas the optimal level of FCSM should be carefully evaluated. In conclusion, the optimum level of dietary replacing FM with FCSM in T. ovatus diet was 24.74%−29.38% based on SGR and WGR. [ABSTRACT FROM AUTHOR]

The persistent challenges posed by pollution and climate change are significant factors disrupting ecosystems, particularly aquatic environments. Numerous contaminants found in aquatic systems, such as ammonia and metal toxicity, play a crucial role in adversely affecting aquaculture production. Against this backdrop, fish feed was developed using quinoa husk (the byproduct of quinoa) as a substitute for fish meal. Six isonitrogenous diets (30%) and isocaloric diets were formulated by replacing fish meal with quinoa husk at varying percentages: 0% quinoa (control), 15, 20, 25, 30 and 35%. An experiment was conducted to explore the potential of quinoa husk in replacing fish meal and assess its ability to mitigate ammonia and arsenic toxicity as well as high-temperature stress in Pangasianodon hypophthalmus. The formulated feed was also examined for gene regulation related to antioxidative status, immunity, stress proteins, growth regulation, and stress markers. The gene regulation of sod, cat, and gpx in the liver was notably upregulated under concurrent exposure to ammonia, arsenic, and high-temperature (NH3 + As + T) stress. However, quinoa husk at 25% downregulated sod, cat, and gpx expression compared to the control group. Furthermore, genes associated with stress proteins HSP70 and DNA damage-inducible protein (DDIP) were significantly upregulated in response to stressors (NH3 + As + T), but quinoa husk at 25% considerably downregulated HSP70 and DDIP to mitigate the impact of stressors. Growth-responsive genes such as myostatin (MYST) and somatostatin (SMT) were remarkably downregulated, whereas growth hormone receptor (GHR1 and GHRβ), insulin-like growth factors (IGF1X, IGF2X), and growth hormone gene were significantly upregulated with quinoa husk at 25%. The gene expression of apoptosis (Caspase 3a and Caspase 3b) and nitric oxide synthase (iNOS) were also noticeably downregulated with quinoa husk (25%) reared under stressful conditions. Immune-related gene expression, including immunoglobulin (Ig), toll-like receptor (TLR), tumor necrosis factor (TNFα), and interleukin (IL), strengthened fish immunity with quinoa husk feed. The results revealed that replacing 25% of fish meal with quinoa husk could improve the gene regulation of P. hypophthalmus involved in mitigating ammonia, arsenic, and high-temperature stress in fish. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to determine the effects of thermal treatment (autoclaving) of several dietary feed ingredients, including fishmeal, soybean meal, wheat bran, yellow corn, and barley, on the apparent digestibility coefficients ADCs, as well as the growth and feed efficiency of common carp, Cyprinus carpio fingerlings. The feed ingredients were autoclaved for 10 min at 121ºC and 15 psi in a laboratory autoclave. Two experiments were conducted, the first consisted of 11 diets, reference, and 10 experimental diets (reference was mixed with each raw or autoclaved test ingredient in a ratio of 70:30) to determine the digestibility of feed ingredients. The second experiment consisted of 8 diets, a control diet of raw ingredients and seven experimental diets were formulated, five of them in which one of the raw feed ingredients was replaced with the autoclaved one, the sixth in which three raw ingredients (wheat bran, yellow corn, and barley) were replaced together with the autoclaved ones, and the seventh in which all the raw ingredients were replaced with the autoclaved ones. The results of the first experiment presented that autoclaving significantly enhanced ADCs of dry matter, protein, and energy, of all feed ingredients except fishmeal. The results of the second experiment similarly presented that the thermal treatment significantly enhanced ADCs in the diets containing autoclaved soybean meal or wheat bran, yellow corn, and barley or all ingredients compared control diet. The growth and feed efficiency were better significantly in autoclaved soybean meal or all ingredients diets compared control diet. It is advised that plant-based ingredients, especially soybean meal, be thermally-processed to improve their nutritional value and lessen their environmental impact. [ABSTRACT FROM AUTHOR]

Fishmeal (FM) is considered a preferred source of protein for aquatic feed due to its good palatability and digestibility, a balanced amino acid profile, and a low level of anti-nutritional factors (ANFs). Shortage of FM supply and increases in price, however, are major challenges faced by feed producers and aquaculture farmers. Fermented soybean meal (FSBM) has been proposed to partially replace FM because of its high nutritional value and low cost. The optimal FSBM concentration for substituting FM and effects of FSBM substitution on growth performance, energy metabolism, and immune response nevertheless remain unclear. We evaluated the effects of shrimp diets containing FSBM at 0% (FM), 25% (FSBM25), 50% (FSBM50), 75% (FSBM75), and 100% (FSBM100) on the shrimp Penaeus vannamei Boone, 1931. FSBM50 led to a significantly higher weight gain (postlarvae 1927.36 ± 46.64%, young juveniles 237.00 ± 8.25%, and juveniles 153.96 ± 2.18%) than the other experimental and control diets in different stages of the shrimp. The FM group consumed less oxygen than the experimental diet groups. FSBM75 and FSBM100 led to a significantly higher ammonia-N excretion than FM, FSBM25, and FBSM50. All experimental diet groups exhibited a significantly higher O:N ratio (8.3 ± 0.8–9.4 ± 1.7) than the FM group (7.1 ± 0.2). Shrimp fed with FSBM25- and FSBM50-containing diets exhibited an increased total hemocyte count, and FSBM25, FBSM50, and FSBM100 led to a significantly higher superoxide anion production than FSBM75 and FM. FSBM substitution in shrimp diets resulted in a significantly higher phagocytic activity than the FM diet, suggesting that FSBM substitution improves the cell-mediated immune response in shrimps. In challenge trials with white spot syndrome virus (WSSV), all experimental diets led to a higher survival rate than the FM diet, and in Vibrio parahaemolyticus challenge trials, FSBM50 led to a higher survival rate than the other experimental and control diets, indicating that FSBM substitution in shrimp diets could improve the defense capacity of shrimps against WSSV and V. parahaemolyticus. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the effects of fermented soybean meal (FSBM) or/and unfermented SBM replacing a portion of fish meal (FM) on the growth performance, antioxidant capacity, immunity, and mechanistic target of rapamycin (mTOR) signaling pathway of juvenile coho salmon (Oncorhynchus kisutch). Four groups of juvenile coho salmon (initial weight 152.23 ± 3.21 g) in triplicate were fed for 12 weeks on four different iso-nitrogen and iso-lipid experimental diets: G0 diet (28% FM protein, control group), G1 diet (18% FM protein and 10% SBM protein), G2 diet (18% FM protein, 5% SBM protein, and 5% FSBM protein), and G3 diet (18% FM protein and 10% FSBM protein). The main results were compared with the G0 diet; the weight gain rate, specific growth rate, and condition factor of juveniles in G3 were increased significantly (p < 0.05). The content of muscle crude protein, the total protein, glucose, albumin, total cholesterol in serum, and the total antioxidant capacity in the liver of juveniles in G3 was increased significantly (p < 0.05). The activities of pepsin, trypsin, α-amylase, and lipase in the intestine, the superoxide dismutase, catalase, and alkaline phosphatase in the liver of juveniles in G3 were increased significantly (p < 0.05). The expression levels of phosphatidylinositide 3-kinases, serine/threonine kinase, mTOR, and ribosomal protein S6 kinase 1 genes in the liver of juveniles in G3 were upregulated significantly (p < 0.05). The feed coefficient ratio, viscerosomatic index, the contents of muscle moisture, and malondialdehyde in the liver of juveniles in G3 were decreased significantly (p < 0.05). The expression levels of tumor necrosis factor α, interleukin 1β, and interleukin 6 genes in the liver of juveniles in G3 were downregulated significantly (p < 0.05). However, there was no significant effect (p > 0.05) on the survival rate, food intake, and muscle crude lipid and ash of juveniles among the experimental groups. In conclusion, FSBM to replace a portion FM had a positive effect on the growth performance, protein deposition, antioxidant enzyme activity, digestive enzyme activity, protein synthesis, and immune-related genes of juvenile coho salmon. [ABSTRACT FROM AUTHOR]

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The potentiality of using two novel aqua-derived meals from fish waste biomass in either nonfermented (FW) or fermented (FFW) form as dietary partial fishmeal (FM) substitutes for juvenile European seabass, Dicentrarchus labrax, (IBW, 29 g) was investigated. FW meal (40% crude protein, 20% lipids, and 7.5% ash) was fermented using the marine fungus, Beauveria bassiana. The influence of partial substitution of dietary FM using either FW or FFW meal at, 15%, 30% and 45% levels, on fish immunity and liver and intestinal histomorphology was examined to determine the appropriate form and optimal inclusion level of each. Fish were fed a basal control diet and six test diets containing either FW or FFW, each at three FM substitution levels, for 90 days. Results showed that the total serum protein, albumin, globulin, phagocytic activity of leucocyte, respiratory burst, lysozyme activities, and immunoglobulin IgM were all significantly improved in fish consumed the FW diet, at all incorporation levels, relative to the other diets. Intestinal and liver histology were also examined for any morphological alteration. Normal fish liver architecture was recorded in all experimental fish groups, with no signs of inflammation. Inspection of the proximal, mid, and distal intestine via the light and electron microscopy illustrated that seabass fed the FW30 diet had normal gut structure. Meanwhile, administration of the highest dietary FW/FFW level (45%) induced some inflammatory signs in the proximal intestinal mucosa of seabass. These findings suggest that FW meal is a feasible alternative for replacing 30% of FM in the seabass diet without compromising fish immunity and liver / intestinal integrity. [ABSTRACT FROM AUTHOR]

A growth trial was carried out to evaluate differences in feed utilisation and growth performance in response to substitution of fishmeal (FM) by either partly defatted insect meal or microalgae powder in different strains of rainbow trout. Three iso-nitrogenous and iso-energetic diets were fed to 495 juvenile rainbow trout with initial weight of 150 ± 37 g. Whereas, the control diet included 20% FM, the two experimental diets were free of FM. Instead of that, an equal amount of spray-dried Spirulina powder (SP) or partly defatted Hermetia meal (HM) was applied as alternative protein source. Feed utilisation and growth response were investigated in a commercial breed (TL) and three local strains (HK3, HK7, and HK8) over a period of 56 days using three replicates per diet. Diets were fed relative to fish body weight throughout at a constant rate of 1.0%. Although growth was comparable among diets, growth and feed utilisation differed between breeds. The strain TL tended to express the highest specific growth rate, however, associated with lower feed conversion. Protein utilisation was superior in local strains irrespective of diet, most pronounced between strains HK7 and TL. Due to large differences in initial body weights, compensatory growth might have affected the study's outcome. Both alternative protein sources showed to be adequate to fully replace FM in diets for rainbow trout. Improved adaption to diets including high levels of HM or SP might be achieved by selective breeding. [ABSTRACT FROM AUTHOR]

The study investigated the effects of dietary sodium butyrate (SB) on the growth performance, nutrient utilization, intestinal histology, and microbiota of rainbow trout (Oncorhynchus mykiss). A high fishmeal diet and a low fishmeal diet were formulated to contain 200 g/kg or 100 g/kg fishmeal, respectively. Coated SB (50%) was supplemented to each of the diets at levels of 0, 1.0, and 2.0 g/kg to create 6 diets. The diets were fed to rainbow trout with initial body weight of 29.9 ± 0.2 g for 8 weeks. Compared to the high fishmeal group, the low fishmeal group showed significantly lower weight gain (WG), intestine muscle thickness, and significantly higher feed conversion ratio (FCR) and amylase activity (P < 0.05). The supplementation of SB in high or low fishmeal diet did not significantly affect the WG, FCR, protein retention, and the digestibility of dry matter and crude protein (P > 0.05). The supplementation of 2.0 g/kg SB in low fishmeal diet significantly increased the villus height, villus width, and muscular thickness, while the supplementation of 2.0 g/kg SB in high fishmeal diet also significantly increased the intestinal villus height (P < 0.05). In intestinal microbiota, the supplementation of 2.0 g/kg SB significantly increased the abundance of Proteobacteria and Aeromonas, and decreased the abundance of Firmicutes and Mycoplasma (P < 0.05), but the flora at genus and phylum level were not affected by SB supplementation in low fishmeal diet (P > 0.05). In conclusion, the addition of SB in diets containing 100 or 200 g/kg fishmeal did not enhance the growth performance and nutrient utilization of rainbow trout, but improved intestinal morphology and changed intestinal microbial flora. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effects of replacing fishmeal with fermented soybean meal on some hematological and immunological indices of Beluga, Huso huso. For this purpose, 240 Beluga (394.6 ± 4.3 g) were distributed in eight treatments (with three replications). The experimental treatments included T1: fish meal (FM), T2: (FM + methionine and lysine), T3: Fermented soybean 40% (FSBM40), T4: (FSBM60), T5: (FSBM80), T6: (FSBM40 + methionine and lysine), T7: (FSBM60 + methionine and lysine) and T8: (FSBM80 + methionine and lysine). During the 56-day feeding period, the fish were fed to apparent satiation three times daily. The results showed that there was no significant difference in hemoglobin, hematocrit, MCHC, neutrophil, monocyte and eosinophil values (p>0.05). However, the highest number of white and red blood cells was observed in the diets containing FM and FM + methionine and lysine, respectively (p<0.05). Furthermore, higher amounts of MCV and lymphocytes in T6 and higher amounts of MCH in T5, T6 and T8 were observed than in the other treatments (p<0.05). Also, the highest amounts of lysozyme were observed in T4. In addition, T4 and T7 exhibited higher amounts of IgM and total immunoglobulin than the other treatments (p<0.05). Based on the results, the best performance of hematological and immunological indices was observed in replacing 40-60% fishmeal with fermented soybean meal. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to investigate the effects of replacing fishmeal with defatted black soldier fly larvae meal (DBSFLM) in the diets of Japanese eel on their growth performance, fillet texture, serum biochemical parameters, and intestinal histomorphology. Six isoproteic (520 g kg−1), isolipidic (80 g kg−1), and isoenergetic (15 MJ kg−1) diets were formulated with fishmeal replacement levels of 0% (R0), 15% (R15), 30% (R30), 45% (R45), 60% (R60), and 75% (R75). The growth performance, feed utilization efficiency, survival rate, serum liver function enzymes, antioxidant ability, and lysozyme activity of fish were not affected (P > 0.05) by DBSFLM. However, the crude protein and cohesiveness of the fillet in groups R60 and R75 significantly decreased, and the fillet hardness significantly increased (P < 0.05). Additionally, the intestinal villus length significantly decreased in the R75 group, and the goblet cell densities were significantly lower in the R45, R60, and R75 groups (P < 0.05). Overall, high levels of DBSFLM did not affect growth performance and serum biochemical parameters but significantly altered fillet proximate composition and texture and intestinal histomorphology (P < 0.05). The optimal fishmeal replacement level is 30% with 184 g kg−1 DBSFLM. [ABSTRACT FROM AUTHOR]

Increasing dietary replacement levels of fish meal by alternative plant proteins are of value for aquaculture. Here, a 10-week feeding experiment was undertaken to explore the effects of fish meal replacement by mixed plant protein (at a 2 : 3 ratio of cottonseed meal to rapeseed meal) on growth performance, oxidative and inflammatory responses, and mTOR pathway of yellow catfish Pelteobagrus fulvidraco. Yellow catfish (2.38 ± 0.1 g , mean ± SEM) were randomly divided into 15 indoors fiberglass tanks, 30 fish each tank, and fed five isonitrogenous (44% crude protein) and isolipidic (9% crude fat) diets with fish meal replaced by mixed plant protein at 0% (the control), 10% (RM10), 20% (RM20), 30% (RM30), and 40% (RM40), respectively. Among five groups, fish fed the control, and RM10 diets tended to have higher growth performance, higher protein content, and lower lipid content in livers. Dietary mixed plant protein substitute increased hepatic free gossypol content and damaged liver histology and reduced the serum total essential amino acids, total nonessential amino acids, and total amino acid contents. Yellow catfish fed the control, and RM10 diets tended to have higher antioxidant capacity. Dietary mixed plant protein replacement tended to promote proinflammatory responses and inhibited mTOR pathway. Based on the second regression analysis of SGR against mixed plant protein substitutes, the optimal replacement level of fish meal by mixed plant protein was 8.7%. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the potential of enhancing the dietary substitution of fishmeal (FM) with corn protein concentrate (CPC) in the diets of red hybrid tilapia, Oreochromis sp., by blending CPC with soy protein concentrate (SPC) and adding betaine‐HCl and dried basil leaves (DBL; feeding attractants). Seven isonitrogenous diets [FM100‐CPC0‐SPC0 (control); FM25‐CPC75‐SPC0 (75% of FM replaced by CPC); FM25‐CPC50‐SPC25 (50% and 25% of FM replaced by CPC and SPC, respectively); FM25‐CPC50‐SPC25B (with 0.5% betaine and 2% DBL); FM0‐CPC100‐SPC0 (100% diet protein from CPC); FM0‐CPC75‐SPC25 (75% and 25% of FM replaced by CPC and SPC, respectively) and FM0‐CPC75‐SPC25B (with 0.5% betaine and 2% DBL)] were formulated. Triplicate groups of tilapia fingerlings (average initial weight, 7.31 ± 0.03 g) were fed one of the diets for 56 days. The effects of high dietary levels of plant protein concentrate (PPC) on growth, nutrient utilization, body composition, body colouration and gut histology of tilapia were investigated. High levels of dietary CPC significantly (p < 0.05) reduced fish growth and feed intake. Blending CPC with SPC restored the growth performance of tilapia at the 75% PPC inclusion level. The addition of palatability enhancers further improved the growth of tilapia fed high PPC‐based diets. [ABSTRACT FROM AUTHOR]

This study investigated the potential use of acid-fermented chicken silage on growth performance, digestive enzymes, liver and intestinal histology in Oreochromis mossambicus (Mozambique tilapia) (Peters 1852). Five silage-based diets were formulated by replacing fishmeal at 0% (control), 25%, 50%, 75% and 100%, thereafter denoted as D1, D2, D3, D4 and D5, respectively. The control diet (0%) contained 40% of fishmeal while D5 contained no fishmeal. The diets contained the same protein (30.06%), fat (15%) and energy levels (18 MJ kg−1). Silage (29.31% protein and 10.97% fat) fed alone and a commercial feed (35% protein and 2.97% fat) were designated as D6 and D7, respectively. Each diet was randomly assigned to triplicate groups of O. mossambicus (6.06 ± 0.27 g) stocked in 400-L fiberglass tanks (50 fish/tank). Fish were fed with the diets to apparent satiation twice daily for 45 days. Among the silage-based diets, weight gained was significantly higher (P < 0.05) in D4 (18.34 ± 1.51 g) and D5 (20.86 ± 1.95 g) than in D1 (14.28 ± 1.21 g), D2 (14.19 ± 1.51 g) and D3 (14.43 ± 1.34 g). The highest specific growth rates were found in D4 (1.10 ± 0.19%) and D5 (1.23 ± 0.04%) than in D1 (0.96 ± 0.22%), D2 (0.74 ± 0.06%) and D3 (0.92 ± 0.04%). The best feed conversion ratio was found in D4 (2.55 ± 0.27) and D5 (2.41 ± 0.32) compared to D1 (3.13 ± 0.38), D2 (3.50 ± 0.34) and D3 (3.26 ± 0.42). Apparent digestibility coefficient for protein values was higher in D4 (93.50 ± 2.96%) and D5 (92.55 ± 3.90%) than in the control (86.68 ± 2.80%). However, the best growth rates were recorded in the D6 and D7 diets. The highest protease, amylase and lipase activities were recorded in D6 and D7 followed by D5 and D4. No pathological alterations were observed in the liver and intestines of fish among dietary treatments. This study confirmed that acid-fermented chicken silage could serve as an alternative and cheaper protein source, as well as complete diet for O. mossambicus. [ABSTRACT FROM AUTHOR]

Single‐cell protein (SCP) derived from methanotrophic bacteria has significant potential as a fishmeal alternative in aquafeeds. However, SCP has known palatability issues, to overcome these issues tuna hydrolysate and garlic powder were tested as palatability enhancers against basal diets without these additives. This study tested the inclusion of SCP at four dietary levels of 0%, 10%, 20% and 30%, representing 0%, 25%, 50% and 75% fishmeal replacement in juvenile yellowtail kingfish (Seriola lalandi) (YTK) diets. YTK were fed these diets in triplicate over 35 days. Compared with the control diet, fish fed the SCP10% diet ate less feed, but had equal growth and subsequently an improved FCR. Feed intake decreased with increasing SCP inclusion, and the palatability enhancers were ineffective at improving intake. Despite the significant reduction in feed intake, FCR was equal across all SCP inclusion levels, demonstrating that the reduced growth performance at these higher inclusion levels was a function of only the reduced intake. Data showing equal protein retention efficiency and apparent digestibility coefficients across diets support this finding. This study showed that SCP derived from methanotrophic bacteria can replace 25% of fishmeal in a 400 g/kg FM diet and suggests if palatability issues can be overcome then higher inclusion of SCP could be achieved in YTK diets. [ABSTRACT FROM AUTHOR]

Potato protein concentrate (PPC) is a potential fish meal (FM) substitute. We replaced FM in greater amberjack diets with low-temperature air-dried PPC (LT-PPC) and high-temperature rotary-dried PPC (HT-PPC) to investigate their effects on growth and feed utilization. Four experimental and one control diet was prepared. The control diet comprised FM, wherein the experimental diets were prepared by replacing 20 and 40% of FM in the control diet with LT-PPC (LP20 and LP40) or HT-PPC (LP20 and LP40). Following an 8-week growth trial, the final mean body weight, specific growth rate, and feed intake of HP40 diet-fed fish were significantly lower than those of control diet-fed fish (p < 0.05). However, these parameters in LT-PPC and HP20 diet-fed fish did not differ significantly from those of the control diet-fed fish (p > 0.05). In vitro relative protein digestibility did not differ between LT-PPC (91.1%) and HT-PPC (89.5%) (p > 0.05); however, the digestion speed of LT-PPC was higher (63.8%) than that of HT-PPC (46.8%) (p < 0.05). In conclusion, the findings demonstrate that LT-PPC and HT-PPC could be used to replace up to 40 and 20% of FM in greater amberjack diets, respectively, without compromising growth performance. [ABSTRACT FROM AUTHOR]

We replaced fish meal (FM) with porcine blood meal (BM) in red sea bream (Pagrus major) diets to examine the influence on growth performance. Four experimental diets were prepared to be isonitrogenous and isolipidic by replacing 0%, 10%, 20% and 30% FM protein with BM (BM0, BM10, BM20 and BM30, respectively). After the 8‐week feeding trial, the final mean body weight, weight gain, specific growth rate, daily feeding rate, condition factor and survival rate were not significantly different among the treatments (p > 0.05). However, feed efficiency tended to lower linearly as the dietary BM level increased, and no significant difference was observed between the BM20 and BM0 groups (p < 0.05). The protein digestibility in the BM20 and BM30 groups decreased significantly compared with that in the BM0 group (p < 0.05). Fat digestibility decreased significantly in the BM30 group than in other treatment groups (p < 0.05). The total serum protein and total cholesterol concentrations in the BM30 group were the highest among all treatment groups. In conclusion, BM can replace up to 20% of FM in the red sea bream diet without adversely affecting growth performance. [ABSTRACT FROM AUTHOR]

The increased price and limited supply of fish meal (FM) have become constraints for the sustainable development of aquaculture. In the present study, soybean meal (SBM) and meat and bone meal (MBM), as alternative protein sources, were mixed (1:1) to replace 0%, 10%, 30% and 50% of the FM formulating four isonitrogenous and isoenergetic diets (i.e. FM500, FM450, FM350 and FM250). An 84‐day feeding experiment was conducted to assess the nutritional contribution of each protein source to the growth of rainbow trout (Oncorhynchus mykiss) juveniles using stable isotopic analysis. At the end of the experiment, no significant growth difference was observed amongst individuals fed the FM500 and FM450 diets, whereas growth was repressed in the FM350 and FM250 groups. Isotopic fractionation amongst the different groups ranged from 0.38% to 4.61‰ and was negatively correlated with the δ15N values of the diets. More importantly, the nutritional contribution of the SBM and MBM components was significantly higher in the FM450 group than expected. This study demonstrates that a mixture of SBM and MBM replacing 10% dietary FM could be an effective diet formulation strategy for rainbow trout culture. [ABSTRACT FROM AUTHOR]

This study aimed to examine the effects of dietary tuna hydrolysate supplementation on feed intake, growth, feed utilization and health status of Asian sea bass. Experimental diets included a high fish meal‐based diet (HFM diet) containing 45% of fish meal, a low fish meal‐based diet (LFM diet) in which 55% of fish meal protein was replaced with soybean meal and the LFM diet coated with 2.5% tuna hydrolysate (LFM + TH diet). Fish were fed diets for 8 weeks. Growth rate, feed intake, feed efficiency, protein efficiency ratio, nitrogen retention, intraperitoneal fat and serum albumin of fish‐fed LFM + TH diet were significantly higher than those of fish‐fed LFM diet (p < 0.05). No significant differences in carcass chemical compositions, serum cholesterol, triglyceride, aspartate aminotransferase, lysozyme activity, superoxide dismutase and trypsin and lipase activities were found in hepatopancreas and anterior intestine among the dietary treatments. Fish‐fed LFM + TH diet displayed a longer length of distal intestine villi than those of fish‐fed LFM + TH diet. No histopathological changes in the liver were observed in this study. The results suggest that dietary supplementation of 2.5% tuna hydrolysate is sufficient to enhance the diet palatability, which can increase the replacement levels of fish meal protein with soybean meal up to 55% in a low fish meal soybean meal‐based diet without negative impacts on feed intake and growth performance of juvenile Asian sea bass. [ABSTRACT FROM AUTHOR]

To evaluate the growth and health of yellow catfish (5.50 ± 0.61 g) under the conditions of unbalanced and balanced amino acid composition, an 8-week growth experiment was conducted. Three isoenergetic and isonitrogenous diets were formulated with a graded level of fishmeal: control group was formulated with 560.00 g/kg fishmeal, and 25%PP group and 25%PP + AA group were formulated with 420.00 g/kg fishmeal (replace 25% of fishmeal with plant protein), and then 25%PP + AA group was supplemented with threonine, glycine, alanine, methionine, isoleucine, histidine, and lysine. Compared with control group, weight gain (WG), specific growth rate (SGR), and survival (SUR) in 25%PP group were significantly the lowest (p < 0.05), but feed conversion ratio (FCR) was higher than those in control group (p < 0.05). After supplementation of crystalline amino acid, the WG, SGR, SUR, and FCR in 25%PP + AA group were recovered to the level of control group (p > 0.05). Compared with control group, the activities of trypsin and lipase were significantly increased in 25%PP group and 25%PP + AA group (p < 0.05). Liver impairment was exhibited in 25%PP group, mainly manifested as significantly increased contents of aspartate aminotransferase (AST) and alanine transaminase (ALT) (p < 0.05). Supplementation of crystalline amino acids based on a 25%PP diet significantly reduced activities of AST and ALT (p < 0.05). In addition, total antioxidant capacity (T-AOC), superoxide dismutase (SOD), acid phosphatase (ACP), and alkaline phosphatase (AKP) activities in 25%PP group increased significantly (p < 0.05). Data from 25%PP + AA group showed that crystalline amino acid supplementation ameliorated antioxidant (T-AOC and SOD) and immune (ACP and AKP) (p < 0.05). One of the characteristics of intestinal damage is shortening of villi height, which was significantly reduced in 25%PP group (p < 0.05). In short, unbalanced amino acid intake can impact growth, survival, and physiological status of yellow catfish. Diet supplemented with unbalanced amino acid can cause abnormal accumulation of amino acid content in muscle, resulting in unnecessary consumption of nutrients. Dietary supplementation of crystalline amino acid improves growth performance and health of yellow catfish that reduced by plant proteins replacement of fishmeal. [ABSTRACT FROM AUTHOR]

A 60‐day feeding trial was conducted to evaluate the effects of yellow mealworm (YM) (Tenebrio molitor) (9%, 18%, 27% and 36%) and black soldier fly larvae (BSFL) (Hermetia illucens) (7%, 14%, 21% and 28%) meal replacing fish meal (FM) on growth performance and antioxidant capacity of red claw crayfish (Cherax quadricarinatus). Nine diets, including control, were fed with quadruplicate of 20 crayfish (0.20 ± 0.05 g). The highest weight gain (WG) and lowest feed conversion ratio were observed in crayfish fed YM18 and BSFL14. The highest superoxide dismutase activity and the lowest malondialdehyde content were detected in the hepatopancreas of the crayfish fed YM18 and BSFL14. Compared with the control group, crayfish fed BSFL14 had higher levels of glutathione peroxidase, catalase acid and alkaline phosphatase and the lowest malondialdehyde (MDA) content in hemocytes. The mRNA expression of CqBAF, HSP70 and MnSOD in the hepatopancreas of crayfish showed an increasing trend. Based on the second‐order polynomial regression analysis of WG, the optimal dietary replacement level of FM with YM meal and BSFL was determined to be 21.9% and 17.1% for juvenile C. quadricarinatus. [ABSTRACT FROM AUTHOR]

Different raw materials are routinely used in aquaculture feeds to satisfy the dietary nutrients required by aquaculture species. There are several components that should be taken into account in the evaluation of a particular ingredient in feed formulation, such as digestibility, palatability and nutrient utilization and interference. The aim of this review was to produce a global overview about the alternative to fish meal and fish oil for gilthead sea bream diets in aquaculture. Particular attention was given to the effect on gut health. Moreover, the information collected in this review might be used as a tool in fine‐tuning of new diets for gilthead seabream. The parameters reported in works are not often standardized, and in some works, not all parameters are present; therefore, it is difficult to compare different trials. For this reason, we think that the collection of these data may help researchers to standardize in the future of the parameters necessary to evaluate alternative protein and lipid stuffs for gilthead seabream. [ABSTRACT FROM AUTHOR]

The optimum level of fishmeal (FM) protein replacement by bacterial protein meal (BPM) was determined in the diet of juvenile red sea bream, Pagrus major. Six isoproteic and isolipidic diets were formulated to replace 0 (control diet), 190 , 280, 370, 470 and 560 g of the FM protein kg‐1 diet with BPM protein, and referred to as C, BP19, BP28, BP37, BP47 and BP56, respectively. Each diet was fed to triplicate groups of twenty fish (mean weight ~43 g) twice per day to apparent satiation. Fish fed diets C and BP19 did not show significant differences (p >.05) in growth, apparent digestibility or protein and lipid retention efficiency, but the daily feeding rate (DFR) was significantly lower under BP19 than under C. However, almost all growth parameters were significantly reduced when FM protein replacement with BPM was further increased from 280 to 560 g kg‐1 diet (p <.05). The results of polynomial regression analysis (second‐order) revealed significant negative correlations between dietary copper levels and final mean weight (R2 =.913), specific growth rate (R2 =.913) and DFR (R2 =.956). The results indicated that BPM could replace approximately 190 g of FM protein kg‐1 diet in the juvenile red sea bream diet without compromising growth performance or feed efficiency. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of replacing fish meal with dehulled soybean meal (SBM) with and without Bacillus subtilis in red sea bream diets. Five diets with dehulled SBM as a replacer for fish meal protein at 0 (FR0), 500 g kg−1 (FR50), 750 g kg−1 (FR75), 500 g kg−1 + 1 g B. subtilis (FRB50), and 750 g kg−1 + 1 g B. subtilis (FRB75) were formulated. FRB50 showed a marked increase in the growth performance parameters, whereas FR75 showed the lowest values. Interestingly, digestibility parameters were significantly enhanced in FRB50 and FRB75. FR0 and FRB50 groups showed the highest body protein content, whereas FR50 and FRB50 groups showed the highest lipid content. The intestines exhibited increased villi, enterocyte, and microvillus height in FR0, FRB50, and FRB75. FR0, FRB50, and FR50 groups showed high antioxidant potential than control and other groups. Respiratory burst activity showed significant enhancement in FRB50 and FRB75 groups. Also, fish fed on FRB50 displayed a high level of activity in immune‐related enzymes. Low salinity stress resistance increased significantly with FRB50 groups, whereas FR75 showed the lowest value. In this work, dietary B. subtilis increased the inclusion of dehulled SBM without affecting red sea bream growth, digestion capacity, immunity, or health status. [ABSTRACT FROM AUTHOR]

Nine experimental diets were formulated to study the effects of fishmeal replacement on Opsariichthys bidens. Weight gain rate, protein efficiency rate and apparent digestibility coefficient of fish in fishmeal (FM), maggot meal (MM) and soybean meal (SM) groups were significantly the highest. There was no significant difference in intestinal amylase activity between FM and SM groups. Principal component analysis showed that SM group and wild fish (WF) individual had similar essential amino acid compositions in muscle. The lowest value of serum malondialdehyde and the highest value of total antioxidant capacity were found in SM group, but fish in MM group did the opposite. Fish in MM group had the higher whole‐body lipid, serum triglycerides, glucose, complement C3, C4 and immunoglobulin contents and lysozyme activity. After ammonia exposure, cumulative mortality of fish in FM and SM groups was significantly the lowest. Liver carbamyl phosphate synthetase activity of fish in FM group was significantly the highest, but the highest values of glutamine synthetase and glutamate dehydrogenase were found in SM group. This study suggests that fishmeal replacement with soybean meal is acceptable, and muscle amino acid compositions of fish in SM group were more similar to wild individual. [ABSTRACT FROM AUTHOR]

A 7‐week growth trial was conducted to assess the potential of using soybean protein isolate (SPI) to replace poultry by‐product meal (PBM) protein in low fishmeal (FM) diets for juvenile hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂). Seven isoproteic (490 g kg−1) and isolipidic (90 g kg−1) experimental diets were formulated, including six low FM diets and a high FM diet (HFMP). The low FM diets contained 0, 74.8, 149.7, 224.5, 299.4 and 374.2 g kg−1 SPI, replacing approximately 0%, 20%, 40%, 60%, 80% and 100% of the PBM protein (designated as SPIP0, SPIP20, SPIP40, SPIP60, SPIP80 and SPIP100, respectively). Each diet was hand‐fed to triplicate groups of 12 hybrid grouper juveniles (average initial body weight: 14.30 ± 0.1 g per fish). After being fed for 7 weeks, fish fed with HFMP and SPIP60 showed significantly higher (p <.01) weight gain percentage (WG%), protein efficiency ratio and protein productive value than fish fed with other experimental diets. These three parameters were elevated with the increment in PBM protein (PBMP) replacements, reaching the peak value at the 60% replacing level, and then, they were significantly reduced at the 80% or 100% replacing level. Analysis of the two‐slope straight broken‐line model showed that the maximum PBMP replacement level by SPI protein (SPIP) at the intercept value of WG% was estimated to be 60%. Feed conversion ratio showed an opposite tendency of variation to WG%. Fish fed with SPIP80 and SPIP100 displayed lower mRNA levels of hepatic insulin‐like growth factor‐1, hypothalamus neuropeptide Y and head‐kidney nuclear factor erythroid 2‐related factor 2 than fish fed with other experimental diets. Generally, 60% of PBM protein could be replaced with SPI protein in low FM diets for hybrid grouper. [ABSTRACT FROM AUTHOR]

This study was performed to evaluate effects of fish meal replacement by yeast hydrolysate (YH) on crude protein via TOR pathway of Jian carp, Cyprinus carpio var. Jian (initial average weight 19.44 ± 0.06 g). Six hundred fish were assigned into five groups and fed with five isonitrogenous and isocaloric diets replacing fish meal by 0g/kg (G1), 10g/kg (G2), 30g/kg (G3), 50g/kg (G4) and 70g/kg YH (G5). The results showed crude protein of fish in G2 and G3 were significantly higher (p <.05) than in G1. YH significantly increased AST and ALT activities of hepatocytes (p <.05) compared with the control group, but had no effects (p >.05) on AST and ALT contents in conditioned medium of hepatocytes. Furthermore, MyoD, TOR and S6K1 mRNA levels in muscle of G2 and G3 were significantly higher than of G1 (p <.05). Meanwhile, YH significantly increased MyoD, TOR and S6K1 mRNA levels in hepatocytes compared with the control group. In conclusion, 10g/kg and 30g/kg YH increased crude protein content of muscle in fish and increased TOR pathway genes expression levels in muscle and hepatocytes. [ABSTRACT FROM AUTHOR]

The current study evaluated the effects of replacing fish meal (FM) and fish oil (FO) with plant ingredients without or with lecithin supplementation on Nile tilapia growth, blood biochemistry, intestinal morphology, growth- and lipid-metabolism-related gene expression. Fingerlings were assigned to six dietary groups: FM and FO (G1), FM and plant oil (G2), plant protein and plant oil (G3), and the same three treatments but with lecithin supplementation (G4-G6) respectively. Fingerlings in G1 and G2 showed higher body weight than fish in G3 (p > 0.05). Lecithin supplementation improved (p < 0.05) growth, particularly in fish fed plant ingredients (G6). Fish fed different diets showed a significant increase (p < 0.05) in serum total cholesterol and low-density lipoprotein concentrations compared with G1. Albumin concentration was significantly reduced in G3 and G6. Partial or complete replacement of FO and FM with plant ingredients, with or without lecithin, significantly modulated (p < 0.05) expression levels of some regulatory genes related to growth and lipid metabolism, with the highest expression in lecithin-supplemented fish. It could be concluded that the complete replacement of FM and FO with plant ingredients (plant protein and oil) non-significantly reduced fish performance. Nevertheless, with lecithin supplementation, Nile tilapia can effectively utilize this plant-based diet as reflected with enhanced growth. [ABSTRACT FROM AUTHOR]

Spray‐dried haemoglobin meal, a by‐product and derivative of the swine processing industry, is formed when haemoglobin is separated hygienically from pig's blood. A 120‐days feeding trial using snub nose pompano Trachinotus blochii (1.01 ± 0.02 g) tested spray‐dried haemoglobin meal (SHM) as an ingredient in six iso‐nitrogenous (crude protein of 50%) and iso‐lipidic (crude fat of 8%) diets, namely, a diet with 0% SHM (control) and five diets replacing fishmeal with SHM at 4, 8, 12, 16 and 20%. Weight gain percentage (WG%) significantly decreased (p < 0.05) when fish were fed diets with 12, 16 and 20% SHM inclusion levels. Feed conversion ratio and survival significantly decreased (p < 0.05) when fish were fed diets with 16 and 20% SHM inclusion levels. However, visceral somatic index, hepatosomatic index, condition factor and proximate composition were not affected (p > 0.05) by SHM inclusion levels. As an ingredient for pompano feed, SHM has digestibilities for protein, lipid and dry matter at 89, 78 and 45% respectively. No apparent pathological changes were observed in the intestines. However, physiological changes in the liver have been seen in fish fed diets containing 12, 16 and 20% of SHM. Based on the quadratic regression model at the maximum response of weight gain percentage, the optimum inclusion level of SHM was estimated to be 3.08% (5.87% SHM protein in the diet). [ABSTRACT FROM AUTHOR]

The effects of methionine supplementation in diets with different replacement levels of fish meal (FM) by pea protein concentrate (PPC) on survival, growth performance and body composition of juvenile tench (0.39 g of initial weight) were studied in a 90‐day experiment. Six practical diets (50% crude protein) differing in replacement level of FM by PPC were tested: 0% (control diet), 35%,45%, 60%, 75% or 85%, corresponding to 0, 285, 366, 487, 608 and 685.4 g PPC kg−1 diet respectively. To provide the same amount as in control diet, methionine was included from the 45% substitution level. Survival rates were high, between 93.7% and 100%, without differences among treatments. Juveniles fed 75% and 85% of replacement diets showed lower (p < 0.05) weight and specific growth rate, which cannot be attributed to methionine deficiency. In all treatments, percentages of fish with externally visible deformities were low (under 0.1%). The increase in PPC diet content resulted in a significant reduction of lipid content in whole‐body juvenile. Minimum methionine requirements for juvenile tench could be estimated in 10 g kg−1 diet and supplementation over this amount would be not necessary. Juvenile tench exhibited a high tolerance to PPC dietary content, up to 487 g kg−1, without affecting growth performance, which make possible to consider this vegetal source of protein as a suitable substitute to FM. [ABSTRACT FROM AUTHOR]

Six experimental isonitrogenous (380 g kg‐1 crude protein) and isolipidic (80 g kg‐1) diets were formulated for juvenile carp Cyprinus carpio. The fish meal protein component of a basal diet (control treatment) was effectively replaced by yeast protein concentrate unrefined (YPCU), yeast protein concentrate refined (YPCR), yeast protein concentrate potable alcohol (YPCPA) at 300 g kg‐1 of total dietary protein originating from a novel wheat fermentation process. Distillers dried grains with solubles (DDGS) at two levels (150 and 300 g kg‐1) of dietary protein were also tested separately. After an 8‐week feeding trial, carp fed YPCU30 recorded the highest (p ≤.05) growth performance and feed efficiency. The apparent net protein utilization of phosphorus, sodium, magnesium and chromium for all diets tested showed significant differences of retention efficiencies. The control fed carp had (p <.05) significantly lower phosphorus and magnesium efficiency than the carp fed other diets. Histological examinations showed the density of microvilli in the region of fish fed YPCU30, YPCPA30, DDGS15 and DDGS30 was decreased compared with the control fed fish with no significant differences were found among the treatments (p ≥.05). Significant differences in the number of hepatocytes were observed between fish fed YPCR30 or YPCPA30 and DDGS30. Furthermore, no significant (p ≥.05) differences were obtained in the number of hepatocytes in the fish fed YPCU30 and DDGS15 diets with fish fed the control diet. Hepatic structure showed that the liver of the fish fed the control, YPCU and YPCR diets appeared to be healthy with no signs of pathological change. In conclusion, fermented wheat‐derived yeast protein concentrate and distillers dried grains with solubles are promising ingredients in carp diets to reduce feed costs and achieve aquaculture sustainability. [ABSTRACT FROM AUTHOR]

A 63‐day feeding trial was conducted to investigate the effects of enzyme‐treated soybean (ESB) replacing fish meal (FM) on growth performance, muscle composition, biochemical indices, digestive enzymes activities and intestinal morphology of juvenile largemouth bass (Micropterus salmoides). Largemouth bass with initial weight of (18.14 ± 0.11) g were randomly divided into 5 groups with 3 replicates, each group of 30 fish per replicate. Five diets were formulated by replacing 0, 80, 120, 160 and 200 g kg−1 FM with ESB (ESB0, ESB80, ESB120, ESB160 and ESB200, respectively). Results showed that weight gain rate and specific growth rate significantly improved in ESB160 group (p <.05). Crude protein content in muscle significantly increased with FM replacement amount up to 160 g kg−1, while crude lipid content significantly decreased (p <.05). Activities of lysozyme and catalase reached the highest level in ESB120 group (p <.05). The activity of superoxide dismutase was significantly increased in ESB200 group, while malondialdehyde concentration significantly decreased. With increasing dietary ESB level, activities of protease and lipase in stomach had significant increase in ESB160 group (p <.05). The intestinal wall thickness and villi length in ESB160 group were significantly higher than those in other groups (p <.05). To sum up, the present study suggested that the optimal replacement level of dietary FM by ESB was 160 g kg−1, which means the supplemented levels of FM and ESB in diet were 400 and 260 g kg−1, respectively. [ABSTRACT FROM AUTHOR]

There has been an increasing global demand for large bluegill (Lepomis macrochirus) to supply the food‐fish market. Current bluegill diets resemble those for largemouth bass and contain a high percentage of marine fish meal (FM). Research into the use of alternative protein ingredients for bluegill diets need to be conducted to not only conserve finite marine resources, but to reduce cost and expand the supply of bluegill to the global market. We evaluated growth, survival and body composition of bluegill fed diets in which FM was partially or totally replaced by various combinations of soybean meal, poultry by‐product meal, canola meal, soy protein concentrate, wheat gluten or a commercial protein blend (Pro‐Cision™). Seven isonitrogenous (40% protein), isolipidic (11%) and isocaloric (17.1 kJ/g) diets were formulated to meet the known nutrient and energy requirements of largemouth bass and bluegill using centrarchid nutrient availability data for most of the dietary ingredients. One of the test diets consisted exclusively of plant protein sources. Juvenile bluegill (9.1 g initial weight) were reared in a recirculating aquaculture system (3 tanks/diet; 20 fish/tank) and fed the test diets once daily to satiation for 70‐day. The test diets in which various percentages of SBM, PBM and/or a commercial protein‐blended product (Pro‐Cision) which completely replaced FM resulted in similar growth performance, feed efficiency and body composition of juvenile bluegill compared to fish fed diets containing 30% FM. However, as formulated, the all‐plant diet resulted in reduced growth. Mean diet performance rankings based on response measures along with differences in essential nutrient and energy levels (i.e. amino acids, P and starch) provided some insight into subtle differences in performance among diets. It appears that bluegill can be fed fish meal‐free diets without reduced production (growth) if animal‐source protein ingredients (PBM or Pro‐Cision) are added; however, as formulated in this feeding trial, an all‐plant diet resulted in reduced growth. Further study on formulating all‐plant diets for bluegill is warranted. [ABSTRACT FROM AUTHOR]

To characterize the effects of a defatted superworm meal (SWM) on the zootechnical performance and nutrient utilization of fingerling rainbow trout, we provided five practical diets with 0 (control), 10, 20, 30 and 40% SWM to substitute fishmeal. Fingerlings (N = 225; 9.9 ± 0.5 g) were randomly allocated over five treatments in triplicate. After eight weeks, the replacement of fishmeal with SWM up to 110 g/kg did not induce significant variations in the final weight and weight gain rate compared to the control group, while dietary 220 g/kg SWM had negative impacts on the growth and feed utilization attributes. The contents of protein and methionine were significantly reduced in the whole body with incremental dietary SWM. The pepsin and chymotrypsin activities were not influenced in the groups, but the lowest trypsin activity was seen in 40% replacement by SWM (p <.05). Total carotenoid content and redness of the fillet were improved with dietary SWM. No variation was seen in the digestibility of protein and dry matter in diets including 55 g/kg and 110 g/kg SWM compared to the control group (p >.05). Overall, optimum fishmeal replacement by SWM ranged from 162.6 to 184.2 g/kg in rainbow trout diet based on the broken‐line regression model. [ABSTRACT FROM AUTHOR]

This study evaluates the potential to replace fish meal with gamma‐ray (γ) irradiated soybean meal (SM) in the diet of largemouth bass (Micropterus salmoides) and the role of brewer's yeast (Saccharomyces cerevisiae) supplementation in fish meal replacement. The reference diet (490 g kg−1 crude protein, 90 g kg−1 lipid and 400 g kg−1 fish meal) was formulated into six isoproteic and isolipidic experimental diets. In the first three diets (S20, S40 and S60), 20%, 40% and 60% of fish meal in the reference diet was replaced with γ‐irradiated SM, respectively. The brewer's yeast was then supplemented to diets S20, S40 and S60 at 10 g kg−1 to form other three diets (SY20, SY40 and SY60). The feeding trial lasted 8 weeks. Fish weight gain was not affected by the level of fish meal replacement, yeast supplementation and their interactions. Fish meal replacement and yeast supplementation significantly affected feed intake, feed conversion ratio (FCR), retention efficiencies of nitrogen (NRE) and phosphorus (NRE), nitrogen waste, phosphorus waste and the ratio of fish meal consumption to fish production (RCP). The hepatosomatic index and body contents of moisture and lipid were dependent on the level of fish meal replacement. The contents of protein, ash and phosphorus in the whole body depended on fish meal replacement and the interaction between fish meal replacement and yeast supplementation. No significant difference was found in weight gain between fish fed the reference diet and six experimental diets. Feed intake and FCR were lower in fish fed the reference diet than those fed diets S20, S40, S60, SY20 and SY60. However, feed intake, FCR, NRE and nitrogen waste in fish fed diet SY40 did not differ from those fed the reference diet. The RCP declined with the decrease of dietary fish meal. This study indicates that the γ‐irradiated SM is a promising ingredient as a fish meal substitute. Fish meal can be reduced to 160 g kg−1 with γ‐irradiated SM as the substitute in the largemouth bass diet. The supplementation of S. cerevisiae at 10 g kg−1 did not show a positive role for the reduction of fish meal in the largemouth bass diet. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects with and without 1000 mg taurine supplement and five levels (0%, 25%, 50%, 75% and 100%) of fishmeal (FM) replaced by soybean concentrate (SBC) in the diet on white shrimp. After 8‐weeks' feeding, the results showed that the taurine supplement significantly affected final weight (FW), weight gain (WG%), feed intake (FI%), glutamate‐pyruvate transaminase (GPT), triglyceride and cholesterol in plasma and glutathione peroxidase (GPx) in haemocytes of white shrimp. There is no significant effect on growth performance, haemolymph parameters and immune responses up to 50% but significant effect at 75 and 100% FM replacement by SBC. Generally, the taurine concentration in plasma, whole body and muscle decreased with an increase of FM replacement in the diets, but they were not significantly affected by 1000 mg taurine supplement in diets. In conclusion, a dietary supplement of taurine at 1000 mg/kg diets significantly enhanced WG of white shrimp after the SBC replacing FM up to a higher than 50% level. FM can be replaced by SBC up to 50% without a significant negative effect on growth performance, haemolymph parameters and immune responses. [ABSTRACT FROM AUTHOR]

Reducing the usage of fishmeal in shrimp feed has been a demand for the sustainability of aquaculture. An 8‐week feeding trial was performed to evaluate the potential application of fermented soya bean meal (FSBM) with Shewanella sp. MR‐7 in shrimp diet. The diet with 30% fishmeal was set as the control (FM), and four levels of FSBM (15%, 30%, 45% and 60%, referred as F15, F30, F45 and F60) were formulated to replace fishmeal isonitrogenously. The growth performance, biochemical indexes, immune response, intestinal microbiome composition and response to ammonia stress were determined. Results showed that FSBM groups had comparable growth performance with FM group when the replacement level was not more than 45%. Replacement of 60% fishmeal with FSBM significantly depressed the trypsin activity and the expression of immune‐related genes in hepatopancreas. Intestinal microbiome analysis showed the abundance of beneficial bacteria (Romboutsia) in F60 group decreased while potential pathogen (Vibrio and Fusibacter) enriched. Survival rate of F60 group was significantly lower when exposed to ammonia stress for 48 h. Taken together, FSBM with Shewanella sp. MR‐7 could reduce fishmeal level from 30% to 16.5% without inducing inferior performance on shrimp. [ABSTRACT FROM AUTHOR]

Growth performance and apparent digestibility coefficient (ADC) of fatty acids, amino acids and macronutrients for diet containing fish meal, Chlorella vulgaris or Spirulina platensis (=Arthrospira platensis) by African catfish (Clarias gariepinus) were assessed in a 42-day feeding trial using a fishmeal-based control diet (REF) and two other test diets containing Spirulina or Chlorella replacing fishmeal in the control diet. The Spirulina-based diet exhibited higher ADC of crude protein than the Chlorella-based diet. The Spirulina- and Chlorella-based diets exhibited higher ADC for all essential amino acids (EAA) when compared with the control diet. High methionine and lysine ADC of Spirulina and Chlorella diet were also observed. The Chlorella diet was significantly higher in ADC of histidine, arginine, valine, isoleucine and tryptophan. Chlorella diet had the highest ADC values for n_6 and n_3 PUFA, lipid. The Spirulina diet exhibited significantly higher lysine, crude fibre, energy, dry matter carbohydrate and docosahexaenoic acid (DHA)ADCs than the Chlorella diet. EPA of reference diet was however, significantly more digestible than Chlorella but not in Spirulina. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of replacing fish meal with red lentil meal (RLM) as an alternative plant protein source in diets for juvenile rainbow trout (10.14±0.04 g mean initial weight) on growth performance and amino acid composition of fish. Four iso-nitrogenous and iso-lipidic experimental diets were prepared to include 15% (RLM15), 20% (RLM20) and 25% (RLM25) of fish meal. At the end of the 60 day feeding trial, the highest mean individual weight gain (30.55±0.08 g) of fish was found in control group but not significantly different from RLM15. Crude protein level of whole body/fillet gradually decreased with increase in RLM percentages in the diets. Generally, essential amino acid (EAA) profiles of whole body/fillets reflected the dietary EAA profile. EAA profile of fish fed RLM15 diet was close to control group (P>0.05). However, lysine levels of fish decreased with increasing dietary RLM levels. RLM20 fed fish had the highest body contents of phenylalanine (P<0.05). Naturally, EAA levels of fillets were higher than whole body's EAA levels. Histidine levels of fillets were highest in control group and the lowest in RLM20 group. In contrast, isoleucine levels of fillets were highest in RLM20 group whereas the control group had the least level (P<0.05). Leucine and valine values of fish fed the control diet were lower than the other experimental groups. Threonine level was highest in fish fed the RLM25 diet (P<0.05). Results of the present study showed that 15% of dietary fish meal can be replaced by RLM in diets of juvenile rainbow trout without any adverse effects on growth performance and body amino acid composition. [ABSTRACT FROM AUTHOR]

This review has highlighted - without claiming to be exhaustive - the recent trends in fish feed ingredients, started with the problems of fish meal and fish oil. The possible alternatives were presented and evaluated as replacement of FM in finfish diets. Current alternative feed ingredients are complimentary. Feeds that include several ingredients are more balanced and reduced the ANFs of each separate ingredient, what leads to better growth rates and animal health. Currently, vegetable-based sources like soy are dominating issue of the fishmeal replacement. By high level of processing and using novel techniques the digestibility and nutrient availability can be enhanced. There is room, however, for certain novel ingredients, such as algae- and insect-based feeds to gain a larger share of feed ratios in aquaculture. Yeasts and their derivatives are used by choice as alternatives for antibiotics. Processing of wood raw materials into a protein-rich components are also very promising ingredients for fish feeds. Many times, we have to use pre- and probiotic compounds, feed additives to enhance the utilization, palatability of the alternative ingredients. Maintaining good health and welfare of fish is vital to be sustainable and cost effective. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of lysine supplement on the growth performance of blunt snout bream Megalobrama amblycephala fed diets with fish meal (FM) replaced by rice protein concentrate (RPC) with the potential mechanisms characterized. Fish were fed three diets, including the FM diet (containing FM), the RPC diet (FM replaced by RPC), and the MRPC diet (the RPC diet supplemented with lysine) for 8 weeks. Weight gain, protein efficiency ratio, and nitrogen and energy utilization of fish fed the FM diet were all significantly higher than those of the RPC treatment, but they showed no statistical difference with those of the MRPC group. Fish fed the RPC diet showed shorter villi length of the distal intestine than that of the other treatments. No significance was found in whole-body composition and intestinal and hepatic cell proliferation among all the treatments. However, fish fed the RPC diet obtained relatively low transcriptions of growth hormone (GH), GH receptor, insulin-like growth factor-I (IGF-I), target of rapamycin (TOR), ribosomal protein S6 kinase 1, myoblast determination protein, myogenic factor 5, and myostatin a (MSTNa) but high levels of eukaryotic translation initiation factor 4E-binding protein 2 (4E-BP2) than those of the other groups. Furthermore, little difference was found in the transcriptions of 4E-BP2, myogenin, muscle-specific regulatory 4, and MSTNb in muscle. Overall, these results showed that dietary supplement of lysine benefits the growth performance of blunt snout bream fed FM-free diets through the mediation of the GH-IGF-I axis, TOR signaling pathway, myogenic regulatory factors, and MSTN. [ABSTRACT FROM AUTHOR]

In finfish aquaculture, fish meal is heated during the manufacturing process, which affects the digestibility and protein absorption by fish. However, manufactured fishmeal that is not heated does not undergo thermal denaturation. Few studies have investigated the effects of non-heated animal protein sources on the growth performance of fish. We investigated the effects of heated and non-heated squid and krill meal as diets for red sea bream. Five test diets were formulated to contain heated squid meal, non-heated squid meal, heated krill meal, non-heated krill meal, and fish meal as a control. Fifty fish (initial mean weight = 3.5 g) were distributed in ten 100-l experimental tanks. Fish were fed one of the five diets 3 times daily until satiation for 5 weeks. Regarding growth performance, fish fed the krill meal diet exhibited better growth than those fed squid meal during the first week of the rearing period. However, the squid meal diet group showed better performance than the krill meal diet group during the third week. Moreover, differences in body weight among treatments were greater during the fifth week. Better weight gain and thermal growth coefficient were recorded in the non-heated diet groups than in the heated diet groups. Higher feed intake was observed in the non-heated diet groups than in the heated diet groups. These results suggest higher performance of non-heated squid and krill meal as the protein source of the red sea bream diet. Further, the suitability of the diet type (e.g., squid and krill) might depend on the feeding period and/or developmental stage of fish. [ABSTRACT FROM AUTHOR]

The present experiment was conducted to evaluate the efficacy of dietary protein from black soldier fly, Hermetia illucens, larval meal (BSFL) to replace fish meal (FM) protein in juvenile barramundi, Lates calcarifer. Larvae of black soldier fly were fed with the underutilised crop, sesbania, Sesbania grandiflora. Five isonitrogenous (44% crude protein) and isocaloric (16.0 kJ available energy/g) experimental diets were formulated to replace FM using processed BSFL meal at 0 (control), 25% (BSFL25), 50% (BSFL50), 75% (BSFL75) and 100% (BSFL100). Data for proximate and amino acid analysis suggested BSFL meal as an inferior protein ingredient than FM, but parallel to soybean meal. At the end of 8 weeks of fish feeding trial, there were no significant differences in the average weight gain (WG) and specific growth rate among the group of fish-fed control, BSFL25 and BSFL50 diets ( P < 0.05). Although numerical differences were recorded in the fish whole-body proximate composition, crude protein and moisture content were not much affected by the different dietary treatments. Essential amino acids including arginine, histidine, lysine and methionine were found to be higher in the whole body of fish-fed BSFL100 diet. Broken line regression analysis of average WG showed an optimum FM replacement level of 28.4% with BSFL meal. Therefore, the present experiment clearly demonstrates that the maximal dietary inclusion level of BSFL meal as FM protein replacer for the optimum growth of juvenile barramundi reared in freshwater could be greater than 28.4% but less than 50%, without any adverse effects on the fish whole-body proximate and amino acid composition. [ABSTRACT FROM AUTHOR]

The potential of soya protein concentrate ( SPC) as an alternative protein source in diets for Totoaba macdonaldi juveniles was evaluated. Seven isonitrogenous and isolipidic diets were formulated containing 15-100% SPC ( SPC15, SPC30, SPC45, SPC60, SPC75, SPC90 and SPC100) to replace fishmeal ( FM-protein), and a FM-protein-based diet without SPC was used as a reference diet ( RD). Each diet was randomly assigned to triplicate groups of 20 totoaba (50 ± 1.0 g) and was fed twice daily to apparent satiation. After 60 days of experiment, effects on totoaba were evaluated. Growth performance in fish fed RD to SPC45 was similar. The maximum FM-protein replacement for weight gain (g kg ABW−1 day−1) was estimated to be 34.17% using a broken-line model. In vitro digestibility of fish fed RD, SPC15 and SPC30 was similar. Trypsin activity was higher in fish fed the RD (9.38 ± 0.52 mU × 10−3 mg protein−1. Chymotrypsin activity was similar in fish fed RD, SPC15 and SPC30. Activity of alkaline protease and phosphatase was similar in fish fed RD, SPC15 and SPC30. Red blood cells ( RBC) were the highest in fish fed RD to SPC60. Fish fed the RD, SPC15 and SPC30 present the highest haematocrit ( HT) and haemoglobin ( HB) content. Diets SPC90 and SPC100 presented similar MCV and MCHC. Total protein ( TP) profile overall decreased in fish fed SPC90 and SPC100, pointing to nutritional hypoproteinemia due to deficient digestion and absorption. These results indicate that SPC-based diets could be used efficiently by totoaba with FM-protein replacement of less than 45%. [ABSTRACT FROM AUTHOR]

The effects of poultry by-product meal ( PBM) and selenium yeast (Se-yeast) supplementations on fish meal replacement by soybean meal ( SBM) in the diet of golden pompano ( Trachinotus ovatus) were examined. In trial I, a 2 × 3 layout including two PBM levels (100 and 170 g kg−1) and three levels of fish meal replacement (0, 40 or 60%) was used. At 100 g kg−1 PBM, fish fed the basal diet exhibited the highest weight gain ( WG) and nitrogen retention efficiency ( NRE) and the lowest feed conversion ratio ( FCR). At 170 g kg−1 PBM, no significant differences were found in WG and NRE between fish fed the basal diet and diet with 40% of fish meal replaced by SBM. In trial II, the basal diet containing 170 g kg−1 PBM (trial I) served as a reference. A 2 × 2 layout included two levels of fish meal replacement (40 or 60%) and two levels of Se-yeast addition (0 and 1 g kg−1). No significant differences were found in WG, feed intake, FCR and NRE between fish fed the reference diet and diet with 40 or 60% fish meal replacement plus 1 g kg−1 Se-yeast addition. This study indicates that supplementations of PBM and Se-yeast can enhance the level of fish meal replacement by SBM in golden pompano diet. Dietary fish meal level can be reduced to 140 g kg−1 by optimizing inclusion of SBM, PBM and Se-yeast. [ABSTRACT FROM AUTHOR]

Different levels of dietary soybean meal (SBM) as a fish meal (FM) replacer, with and without amino acid supplementation, for whiteleg shrimp, Litopenaeus vannamei reared in the biofloc system was examined in eight weeks of feeding trial. Eight experimental diets consisted of a basal diet with 0% FM replacement by SBM provided in clear sea water without biofloc system (SSW), four diets replacing FM at 0% (S), 33% (S), 67% (S) and 100% (S) by SBM, and three diets replacing FM at 33% (SA), 67% (SA) and 100% (SA) by SBM supplemented with amino acids (methionine and lysine) in the seawater biofloc system. Results of water quality analyses showed significantly lower total suspended solids and nitrate for SSW group than all other treatments. Diets S and SA resulted in higher weight gain and specific growth rate among all groups, with no significant differences with S group. In addition, whole-body protein and amino acid compositions of shrimp fed SSW were lower than most biofloc groups. Haemolymph parameters showed significant differences in total protein, cholesterol and triglyceride between groups S and SSW. Also, superoxide dismutase activity showed a decreasing trend with increasing replacement level. In conclusion, based on these results, SBM could replace up to 33% of FM with or without amino acid supplementation in juvenile whiteleg shrimp diets reared in the biofloc system. [ABSTRACT FROM AUTHOR]

Feeding trials were conducted to determine the dietary level of yeast extract ( YE) for replacing dietary fish meal for evaluating whether yeast extract was superior to intact yeast as an alternative protein source for shrimp Litopenaeus vannamei. The basal diet (control, D0, containing 25% fish meal), was compared with five isonitrogenous and isoenergetic experimental diets [replacing 15% (D15), 30% (D30), 45% (D45), 60% (D60) or 100% (D100) of the fish meal in the basal diet with IYE]. The digestibility, growth and muscle composition of the shrimp were measured. The results showed that all replacement treatments displayed higher apparent digestibility of crude protein than did the control. The trypsinase activity in shrimp hepatopancreas increased significantly, whereas lipase activity decreased as the amount of dietary YE increased. The shrimp treated with D30 diet displayed the highest amylase activity in hepatopancreas. There was no significant difference in the weight gain ( WG) and survival of shrimp between the control and the YE replacement treatments. Feed conversion ratio ( FCR) increased as the dietary YE increased, and the FCRs of the D60 and the D100 treatments were significantly higher than that of the control ( P < 0.05). The growth performance among the treatments was closely related to the similarity of the essential amino acids in the diets. There was no significant difference in muscle composition of the shrimp between control and other treatments. In conclusion, up to approximately 45% of the fish meal in shrimp diet can be replaced by yeast extract in the presence of supplemental fish oil, phosphorus and calcium. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted to determine the dietary threonine requirement of juvenile large yellow croaker ( Larmichthys crocea). Six diets were formulated containing 45% crude protein with six graded levels of threonine (0.71-2.46% in about 0.35% increment). Each diet was randomly assigned to triplicate groups of 60 juvenile fish (initial body weight 6.00 ± 0.10 g). Fish were fed twice daily (05:00 and 16:30) to apparent satiation for 8 weeks. The result indicated that significant difference was observed in the weight gain among all treatments. Specific growth rate ( SGR), feed efficiency ( FE), protein efficiency ratio ( PER) and nitrogen retention ( NR) increased with increasing levels of threonine up to 1.75% diet ( P < 0.05), and thereafter, declined. No significant differences in body dry matter, crude protein, crude lipid or ash content were found among dietary treatments. Theronine contents of fish muscle were significantly affected by dietary threonine levels ( P < 0.05). Fish fed the diet with 0.71% threonine showed the lowest threonine content (2.94%) in fish muscle, while fish fed the diet with 1.75% threonine had the highest value (3.16%). Other essential amino acid contents of muscle were not significantly different among the dietary treatments. On the basis of SGR, FE or NR, the optimum dietary threonine requirements of juvenile L. crocea were estimated to be 1.86% of diet (4.13% of dietary protein), 1.90% of diet (4.22% of dietary protein) and 2.06% of diet (4.58% of dietary protein), respectively, using second-order polynomial regression analysis. [ABSTRACT FROM AUTHOR]

Cottonseed meal (CM) was used at up to 36.95% content in the diet (replacing 60% of dietary fish meal protein) without any negative eff ects on growth performance of pre-adult grass carp (initial body weight, 761 g) under outdoor conditions. A culture trial was conducted in net cages installed in a large concrete pond. Seven isonitrogenous and isoenergetic diets containing a gradient of CM concentrations (0, 12.2%, 24.4%, 36.6%, 48.8%, 54.8%, and 61.0%) as replacement for dietary fish meal protein (0, 20%, 40%, 60%, 80%, 90%, and 100%) were formulated. Dietary non-resistant starch (from maize) was inverse to dietary CM. Growth performance and feed utilization of fish fed the diets containing CM replacing 0-40% fishmeal protein were not aff ected after the 6-week feeding trial. Accumulation of hepatopancreatic total gossypol in the hepatopancreas was significantly correlated with free gossypol content in the diets (HTG=88.6+1.5×DFG, R=0.89, P<0.05). Intestinal α-amylase and γ-glutamyl transpeptidase activities rose along with increasing dietary CM level. The structure of the mid-intestinal tissues and the ultrastructure of the enterocyte microvilli were normal when dietary CM was <36.6% (60% protein replacement). Increasing dietary CM content increased serum alanine aminotransferase levels but decreased serum alkaline phosphatase, cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and albumin ( P<0.05). [ABSTRACT FROM AUTHOR]

With the aim to evaluate different replacement levels of fish meal ( FM) by pea protein concentrate ( PPC) on survival, growth performance and body composition of juvenile tench ( Tinca tinca), a 90-day experiment was conducted with 6-month-old juveniles. Four practical diets (50% crude protein) differing in the level of replacement of FM protein by PPC protein were tested: 0% (control), 25%, 35% or 45%, corresponding to 0, 207.5, 290.4 or 373.3 g PPC kg−1 diet respectively. Survival rates ranged from 96.4% to 98.5%. The 25% and 35% replacement diets resulted in similar growth values ( P > 0.05) to those obtained with the control diet (average of the three feeding treatments: 57.57 mm total length, 2.48 g weight and 1.87% day−1 specific growth rate). The 45% replacement diet had the lowest growth ( P < 0.05). Fish with externally visible deformities ranged from 0% to 1.5%. The relation among amino acid profiles of the diets, body composition, growth performance of juveniles and amino acid requirements of other fish species is discussed. An amount of 290.4 g PPC kg−1 diet (35% replacement of FM protein) can be included in juvenile tench diets without impairing growth performance. [ABSTRACT FROM AUTHOR]