Replacement Of Fish Meal Protein Research Articles

Use of tunicate meal (pleated sea squirt Styela plicata) protein as a partial replacement of menhaden fish meal protein in the diet of juvenile Black Sea Bass

AbstractObjectiveThe pleated sea squirt Styela plicata (subphylum Tunicata), an invasive marine invertebrate in coastal waters of southeastern North Carolina, was investigated as an alternative protein source to fish meal (FM) in the diet of juvenile Black Sea Bass Centropristis striata.MethodsSix different isoproteic and isolipidic diets were formulated to replace 0.0, 8.3, 16.7, 25.0, 33.3, and 41.6% of FM protein with tunicate meal (TM) protein by supplementing 0, 5, 10, 15, 20, and 25% TM in the diets. The experimental system consisted of eighteen 75‐L tanks supported by a recirculating seawater system in an indoor, climate‐controlled laboratory. Juveniles (average weight = 7.1 g) were stocked at a density of 15 fish/tank (N = 3 tanks/treatment) and were fed the test diets daily to apparent satiation for 55 days.ResultReplacement of FM protein with TM protein caused slight declines in dietary amino acid concentrations (notably arginine, methionine, and tryptophan) at higher replacement levels. At terminal sampling, no significant differences in survival (87–96%), percent body weight gain (157–228%), feed conversion ratio (1.50–1.71), or proximate composition were observed among dietary treatment groups. However, significant positive linear trends were found between incremental levels of TM and final fish weight, body weight gain, and specific growth rate. Whole‐body fatty acid composition reflected dietary levels.ConclusionResults indicate that TM protein can be used to replace at least 41.6% of the FM protein in the diet for juvenile Black Sea Bass without adverse effects on survival, growth, feed utilization, or whole‐body proximate composition.

Growth performance, health status, gut microbiome, and expression of immune and growth-related genes of rainbow trout (Oncorhynchus mykiss) fed diets with pea protein replacement of fish meal

The need for fish meal constrains fish farming and significantly impacts sustainability of the aquaculture industry. Hence, it is important to investigate the use of plant-based protein sources in fish diets. The present study was conducted to determine the effects of different levels of fish meal (FM) replacement by pea protein (PP) in a 60-day feeding experiment in rainbow trout, Oncorhynchus mykiss. Effects on growth performance, body composition, hematology, serum biochemistry and immunology, and immune (TNF-α, IL1-ß and Il-8) and growth-related (GH and IGFI) gene expression were investigated. Five experimental diets (45% protein and 20% lipid) differed in replacement level of FM by PP at rates of 0% (control (PP0)), 25% (PP25), 50%(PP50), 75%(PP75) and 100%(PP100). Fish were fed with experimental diets in triplicate twice daily. The best growth performance was obtained in PP0 and PP25 groups. While fat ratios of fish fillets significantly differed (p < 0.05), there was no significant effects on protein ratios (p < 0.05). There was no significant change in the hematological values of fish, except those fed the PP100 diets, which displayed a reduction in eyrthocyte counts, hemoglobin content and hematocrit. As PP supplementation increased fish showed elevated serum glucose, total protein, cholesterol and myeloperoxidase activity and decreased glutamic pyruvic transaminase and alkaline phosphatase activity. Fish fed diets with between 25 and 75% replacement showed a decline in lactic acid bacteria in the gut. Significant increases in expression were observed in the liver of the PP25 fish relative to the 0% control for all immune and growth-related genes except for IL1-ß. These data suggest that up to 25% of FM can be replaced by PP without any adverse effects on rainbow trout.

Toward sustainable food systems: can spirulina (Arthrospira platensis) become a sustainable source of protein to enhance the nutritional benefits of cultured Nile tilapia (Oreochromis niloticus)?

Hunger affected 278 million people in Africa in 2021, and in Kenya, the proportion of the population unable to afford a healthy diet is 81%. To combat hunger and increase resilience throughout the food system, spirulina (Arthrospira platensis) has been shown to have remarkable properties. The main aim of this study is to investigate whether protein from spirulina is a suitable alternative to protein sourced from fish meal in fish feed for juvenile Nile tilapia (Oreochromis niloticus). In a trial investigating the use of spirulina biomass for fish feed on juvenile Nile tilapia, it has been proven that tilapia fingerlings fed diets with spirulina, replacing up to 30% of fish meal protein, were not affected in terms of growth performance compared to the fish fed the commercial diet. This shows that, nutritionally, protein from spirulina can replace fish meal protein fed to juvenile Nile tilapia. This offers promising opportunities for enhanced food and nutrition security. If produced affordably, spirulina can have a significant impact on the income level of low-income fish farmers in Kenya, who often spend more than 50% of their income on commercial fish feed. Affordability can be made possible if small-scale farmers can produce spirulina using animal manure that is available on the farm instead of using highly priced commercial fertilizer. The additional environmental benefits of spirulina include carbon dioxide sequestration and the removal of nitrogenous and phosphorous waste from the wastewater. Spirulina can therefore increase the sustainability of a whole food system.

Utilization of Black Soldier Fly (Hermetia illucens) Larvae as a Potential Substitute for Fish Meal in the Production of Nile Tilapia (Oreochromis niloticus L.)

Utilization of quality aqua-feed relies heavily on fish meal sources of protein because of its nutritional balance. However, due to its limited supply, high cost, and decline of wild fish populations, aquaculture production has shifted focus to cheaper and more readily available alternatives to guarantee sustainable aquaculture productivity. Black soldier fly (Hermetia illucens) larvae are a promising replacement for fish meal in fish diets due to their relatively high crude protein, lipid and mineral contents, and the bioactive potential with anti-microbial, and other probiotic properties. This study determined the effect of partially replacing fish meal with black soldier fly meal (BSFLM) on the growth performance of Nile tilapia (Oreochromis niloticus). Four isonitrogenous (30% crude protein) diets in which fish meal protein was gradually substituted with BSFLM were prepared as follows: No BSFLM (control)-T0; 25% (BSFLM25)-T25, 50% (BSFLM50)-T50 and 75% (BSFLM75)-T75. The feeds were fed to the Nile tilapia fingerlings (mean weight 25 &amp;plusmn;5 g) which were randomly stocked in 12 cages at a stocking density of 30 fish per cage. The experimental fish were manually fed at 3% of the body weight for 28 days, and 4% of the body weight for 154 days twice a day. The study found that 25% and 50% replacement of fish meal protein with BSFLM resulted in the best growth performance of Nile tilapia, as measured by final mean body weight gain (BWG), specific growth rate (SGR), feed conversion ratio (FCR) and condition factor (K). This suggests that BSFLM is a promising alternative to fish meal in aqua-feeds in the production of Nile tilapia.

The Effects of Replacing Fish Meal Protein with Black Soldier Fly Meal and Sodium Butyrate Supplementation on the Growth Performance, Lipid Peroxidation, and Intestinal Villi Status of Jade Perch, Scortum barcoo Fingerlings

This study investigated the effects of different protein sources and butyric acid contents in aquafeed on the growth, survival rate, lipid peroxidation enzymes, and intestinal villi of 7.3 g jade perch, Scortum barcoo. The experimental treatment groups were the whole fish meal protein (FM) group, the FM + butyric acid (FMB) group, the 50% fish meal protein and 50% black soldier fly meal protein (FBM) group, the FBM + butyric acid (FBMB) group, the whole black soldier fly meal protein (BM) group, and the BM + butyric acid (BMB) group. The experimental results showed that the jade perch fed with the FMB feed had a significantly higher weight gain rate and antioxidant enzyme activity than the other treatment groups. The red blood cell count, hemoglobin concentration, and hematocrit contents in the blood of jade perch were not affected by the protein source, but they increased with the addition of butyric acid. The intestinal villi length of the jade perch that were fed diets containing butyric acid were significantly higher than that of the jade perch that were fed diets without butyric acid supplementation. The results of this study show that the addition of butyric acid to a balanced feed composed of protein can contribute to the growth of jade perch.

Effects of fermented soybean meal substitution for fish meal on intestinal flora and intestinal health in pearl gentian grouper.

This study explored the role of replacing fish meal protein with fermented soybean meal (FSBM) protein on the growth performance and intestinal morphology, immunity, and microbiota of the pearl gentian grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂). Three isonitrogenous and isolipidic diets with increasing levels of FSBM (0%, 20% and 40%; referred to as FM, FSBM20 and FSBM40 diets, respectively) as a replacement for fish meal were selected for this study. The pearl gentian grouper were fed these diets for 10 weeks. The findings revealed that the growth of fish fed the FSBM diets (FSBM20 and FSBM40) were remarkably lower than the fish fed the FM diet. Pathological manifestations of intestinal inflammation, such as shortened intestinal mucosal folds and thickened lamina propria, were observed in the fish fed the FSBM diets. Moreover, the gene expression levels of IL1β, IL12, IL17, and TNFα were remarkably upregulated in fish fed the FSBM40 diet, in contrast to the gene expression levels of IL4, IL5, IL10, and TGFβ1, which were remarkably downregulated (p < 0.05). The FSBM diets significantly affected the stability of the fish gut microbiota. Photobacterium was the dominant phylum in all experimental groups, and the proportion of these bacteria gradually decreased with increasing FSBM substitution. The composition of intestinal flora at the genus level was not the same in the three experimental groups, with a richer composition of intestinal bacteria detected in the FSBM20 and FSBM40 groups (p < 0.05). The correlation between intestinal flora balance and immune gene expression revealed that only Photobacterium was negatively correlated with the above upregulated genes, while other bacteria were positively correlated with these pro-inflammatory factors (p < 0.05). Photobacterium was positively correlated with the above downregulated genes, while other bacteria were negatively correlated with these anti-inflammatory factors (p < 0.05). In conclusion, high levels of substitution of FSBM for fish meal causes intestinal inflammation in pearl gentian grouper. This is likely associated with changes to the intestinal flora. More attention should be paid to the negative role of dietary FSBM on intestinal flora.

Valorization of the insect waste as a source of dietary protein in replacing the fishmeal protein for the cage reared Pangasianodon hypophthalmus: An approach to search the alternate non-conventional feed resource of animal origin

A ninety days experiment was carried-out to evaluate the effect of dietary replacement of fishmeal (FM) (locally available dried non-defatted Coilia dussumieri V.) by graded inclusion levels of non-defatted non-mulberry Indian tropical tasar silkworm spent pupae (Antheraea mylitta D.) on growth performance, feed consumption, digestive enzyme response, body chemical composition, and intestinal cellular micro-morphological status of the reared striped catfish (Pangasianodon hypophthalmus S.). Five iso-nitrogenous (280 g protein kg-1) and iso-energic (19 MJ kg-1) extruded floating feeds were formulated by gradually replacing the FM with NDSWP (non-defatted silkworm pupae) at 0%, 25%, 50%, 75%, and 100% (on protein to protein basis) levels and the diets are designated as NDSWP0, NDSWP25, NDSWP50, NDSWP75, and NDSWP100, respectively. The contribution of calculated pupae crude protein was 0%, 4.75%, 9.50%, 14.25%, and 19% out of the total protein (28%) content in the respective diets. The experiment was executed in the floating net-cage located at the Maithon reservoir, India which is a field research station of ICAR-CIFRI, Barrackpore, Kolkata, India. The designated diets were randomly allocated to 10 numbers of experimental cages (each 5 ×5 ×3 m), in triplicates stocked with 2475 numbers (stocking density at 33 numbers per m3) of striped catfish in each replication and fed daily twice at 08.00 h and 16.00 h. The initial stocking size of the striped catfish fingerling was 16.56 ± 0.08 g. At the termination of the feeding experiment, the final body weight (g), individual weight gain (g), weight gained (%), feed conversion ratio (FCR), specific growth rate (SGR), and protein efficiency ratio (PER) found to be non-significantly different (p < 0.05) up to 50% protein replacement level (NDSWP50) in comparison to the control (NDSWP0). Among the biological indices, hepatosomatic index (HSI) exhibited a non-significant difference stretching to NDSWP50 treatment group with a distinct significant difference between NDSWP25 and NDSWP100 (p < 0.05), when, an inverse trend was recorded in relation to increasing pupae meal in the diets. Among the digestive enzymes, relatively higher protease enzyme activity was observed in the diet fed at NDSWP50 compared to the rest of the treatment groups, although, it was statistically non-significant (p > 0.05). Amylase and lipase enzyme activities recorded a significant difference among the treatment groups (p < 0.05). A higher amount of fish muscle crude protein was noticed in the NDSWP50 treated group than in the rest of the treatment groups. The lipid content of fish muscle indicated its higher content over the initial and exhibited an inverse relationship with moisture and ash content at the end of the experiment. Histo-morphology of gut tissue confirms the suitability of feeding pupae protein incorporated diet with the gradual replacement of fishmeal protein. The findings of the current feeding trial suggests that the inclusion of non-defatted non-mulberry silkworm pupae protein at 50% level of fishmeal protein substitution without compromising the growth performance, nutrient utilization, conversion of feed, and other biological indices, and economics of diet.

Effect of black soldier fly (Hermetia illucens) larvae meal as a fishmeal protein replacement on the growth, feed utilization, survival and whole-body composition of Black molly (Poecilia sphenops)

Effect of black soldier fly (Hermetia illucens) larvae meal as a fishmeal protein replacement on the growth, feed utilization, survival and whole-body composition of Black molly (Poecilia sphenops)

From waste to feed: Microbial fermented abalone waste improves the digestibility, gut health, and immunity in marron, Cherax cainii

New aquafeed ingredients produced by a circular economy approach are the opportunity for sustainable and resilient aquaculture. In the light of this approach, the mixture of abalone waste and Sargassum spp (9:1) fermented by Saccharomyces cereviceae and Lactobacillus casei (Yakult®) (FMAS) were used to replace 0% (FMAS0), 25% (FMAS-25), 50% (FMAS-50), 75% (FMAS-75), and 100% (FMAS-100) of fishmeal (FM) protein in marron, Cherax cainii diet. The marron was fed these diets in triplicate for 90 days. Growth, feed utilization and protein efficiency ratio were unchanged in marron-fed all test diets. Improvement in apparent protein digestibility was aligned with an increase in the size and number of B-cells in the hepatopancreas. Most of the immune responses, except for haemocyte clotting time, hyaline cells and neutral red retention time (NRR time) were unchanged by 42- and 90-days feeding trials compared to those of the control group. 90 days post-feeding marron with FMAS25 showed a lower haemocyte clotting time than the post 42 days feeding marron with the same diet. Hyaline cells increased in marron fed FMAS75 for 90 days compared to marron fed the same diet for 42 days. The challenge test involved injecting marron with Vibrio mimicus resulted in a 100% survival rate after 96 h of exposure. During the challenge test, phagocytosis activity in 24 and 48-h post-challenged marron fed FMAS75 decreased which recovered after 96 h post-challenge. Marron fed FMAS50 also recorded a significantly higher proportion of granular cells after 24 h and NRR time at 96 h compared with that of other treatments. Given the above indicators of bio-growth, feed efficiency and immune responses, total replacement of FM protein of marron practical feed with FMAS are considered feasible and optimum to maintain health status and resistance to disease.

Neem seed protein hydrolysate as a fishmeal substitute in Nile tilapia: Effects on antioxidant/immune pathway, growth, amino acid transporters-related gene expression, and Aeromonas veronii resistance

Whereas fishmeal (FM) is a significant protein supply, its expensive cost has limited its diet use. Therefore, it is necessary to find affordable and accessible FM replacers. The potential of neem seed protein hydrolysate (NSPH) to replace FM protein in the Oreochromis niloticus, Nile tilapia diet was studied after two-month feeding trial. Fish (N = 200) of 27.17 ± 0.09 body weight were haphazardly distributed into five groups and fed on experimental diets having five substitution percentages with NSPH: 0% (control), 10%, 20%, 30%, and 40% (NSPH0, NSPH10, NSPH20, NSPH30, and NSPH40, respectively). Following the feeding experiment, the fish were challenged with Aeromonas veronii (1 × 107 CFU/mL) as a pathogenic bacterium. The results revealed that the growth parameters, growth hormone, digestive enzymes, and immune parameters (nitric oxide, complement 3, lysozyme, and phagocytic activity %) values were linearly (p < 0.01) augmented with all NSPH replacement groups as compared with NSPH0 group. Moreover, the NSPH40 group showed the highest expression of muscular insulin-like growth factor 1 and intestinal amino acids and peptide transporters genes, followed by the NSPH30 group, then the NSPH10 and NSPH20 groups. The splenic immune-related genes (phosphoinositide-3-kinase regulatory subunit 3b, toll-like receptors (TLR-2 and TLR-7), transforming growth factor-beta, interleukins (IL-10 and IL-1β), and tumor necrosis factor-alpha) and antioxidant-related genes (glutathione peroxidase and glutathione synthetase) more up-regulated in the NSPH groups with a concentration-dependent manner than the control one. Among A. veronii-infected fish, mortality rate was decreased with increasing NSPH replacement, where the NSPH40 group had the highest significant (p < 0.05) survival rate (83.33%). From overall results, NSPH can substitute 40% of the dietary FM protein in O. niloticus with promoting the fish's immune competence, growth rate, digestive, and absorptive capability, and disease resistance.

Fishmeal Protein Replacement by Defatted and Full-Fat Black Soldier Fly Larvae Meal in Juvenile Turbot Diet: Effects on the Growth Performance and Intestinal Microbiota.

A 12-week feeding trial was conducted to investigate the effect of the same fishmeal protein level replaced by black soldier fly larvae (Hermetia illucens) meal (BSFL) with different lipid contents on the growth performance and intestinal health of juvenile turbot (Scophthalmus maximus L.) (initial body weight 12.64 g). Three isonitrogenous and isolipidic diets were formulated: fish meal-based diet (FM), diets DF and FF, in which 14% fish meal protein of the FM diet was replaced by defatted and full-fat BSFL, respectively. There were no significant differences in growth performance, intestinal morphology, and mucosal barrier function between the DF and the FM group. However, diet FF markedly reduced the growth performance, intestinal perimeter ratio, and the gene expression of anti-inflammatory cytokine TGF-β (P < 0.05). Compared to group FF, the communities of intestinal microbiota in group DF were more similar to group FM. Moreover, diet DF decreased the abundance of some potential pathogenic bacteria and enriched the potential probiotics, such as Bacillus. Diet FF obviously altered the composition of intestinal microbiota and increased the abundance of some potential pathogenic bacteria. These results suggested that the application of defatted BSFL showed more positive effects on fish growth and intestinal health than the full-fat BSFL, and the intestinal microbiota was closely involved in these effects.

Efficacy of using sunflower meal as an ingredient, and partial fishmeal‐replacer, in practical feed formulated for stinging catfish (Heteropneustes fossilis)

AbstractThis study was conducted to determine the growth performance, body composition, and haematological profile of Heteropneustes fossilis in response to the replacement of fish meal (FM) by sunflower meal (SFM). The experiment was conducted in a completely randomized design (CRD) with five treatments and three replications. The fish (initial average body weight of 2.42 ± 0.01 g) were reared in 15 glass aquaria (40 fish/aquarium) with a 150‐L water capacity. Five isoproteic (35%) diets were prepared by replacing FM protein with SFM protein at a rate of 0% (T0), 10% (T10), 20% (T20), 30% (T30), and 40% (T40). Fish were fed with experimental diet twice a day (9.00 and 16.00), 7 days a week for 8 weeks. Fish were sampled at the end of the experimental period of 8 weeks. At the end of the rearing period, the highest weight gain (6.25 ± 0.11g), % weight gain (163.32%), and specific growth rate (1.61 ± 0.03%/day) were observed in the control (T0) treatment, but the difference was not significant (p &gt; 0.05) with T10 and T20 treatments. However, all the growth factors were decreased with the further inclusion level of SFM in replacement of FM, and the lowest growth performance was observed in T40 treatment. The protein efficiency ratio (PER) and feed conversion ratio (FCR) followed the same pattern as the growth parameters. It was found that the whole‐body proximate composition of fish was also affected significantly (p &lt; 0.05). Haematological parameters significantly (P &lt; 0.05) altered at 30% and 40% levels of replacement of FM with SFM. Based on these results, it can be concluded that 20% FM protein can be substituted with SFM protein in the diet of H. fossilis without compromising growth performance, feed utilization, chemical composition, and haematological status. However, according to polynomial regression analysis, the optimum level of replacement of FM protein with SFM protein was determined to be 14.3% in the diet of H. fossilis.

Effects of dietary replacement of fish meal by soybean meal on growth, feed utilization, and health condition of stinging catfish, Heteropneustes fossilis

Soybean meal (SBM) is a cost-effective alternative protein source to replace costly fish meal in aquaculture. This present study determined to measure the effects of replacing fish meal (FM) protein with SBM on growth, feed utilization, and health condition of stinging catfish,Heteropneustes fossilis. Four isonitrogenous (35 %) diets were applied in four treatment groups designed as SBM0, SBM25, SBM50, and SBM75, where 0 %, 25 %, 50 %, and 75 % of FM protein were substituted by SBM, respectively. Significantly higher mean final weight (g), weight gain (g), percent weight gain (%), specific growth rate (% day−1), and protein efficiency ratio (PER) were recorded in SBM0, SBM25, and SBM50 groups than SBM75 group. Consequently, significantly lower feed conversion ratio (FCR) was found in SBM0, SBM25, and SBM50 groups than SBM75 group. Moreover, protein content of whole-body carcass was significantly higher in SBM25 and lower in SBM0 group however, lipid content was significantly higher in SBM0 and SBM75 than in other groups. Hemoglobin, red blood cells, and white blood cells were significantly higher in SBM0, SBM25, and SBM50 groups compared to SBM75. However, the higher the substitution of FM protein by SBM in diets higher the values of glucose. Morphological analysis of the intestine including villi length (μm), width (μm), and area (mm2); crypt depth (μm); wall thickness (μm); abundance of goblet cell (GB); and muscle thickness (μm) showed an increasing trend in fish fed diet containing upto 50 % replacement of FM protein by SBM. Therefore, the results suggest that SBM could replace upto 50 % FM protein in diets ofH. fossiliswithout compromising growth, feed efficiency, and health status.

Dietary Protein Replacement of Fish Meal with Black Soldier Fly Larvae Meal: Effects on Growth, Whole-Body Composition, Digestive Enzyme Activity, Muscle-Growth-Related Gene Expression and Haemato-Biochemical Responses of Juvenile Goldfish, Carassius auratus

A 60-day indoor growth trial was carried out to investigate the effects of dietary replacement of fish meal (FM) protein with black soldier fly (Hermetia illucens) larvae meal (BSFLM) at graded concentrations on bio-growth parameters, whole-body chemical composition, digestive enzyme activity, muscle-growth-related gene expression and haemato-biochemical responses of goldfish (Carassius auratus) juveniles. Six isonitrogenous and isoenergetic diets were formulated with BSFLM to substitute FM protein at 0 (T0), 20 (T20), 40 (T40), 60 (T60), and 80 (T80), and 100 % (T100). Each diet was randomly assigned to triplicate groups of 20 fish (Mean weight: 2.8±0.3 g) per aquaria were fed twice a day. Goldfish juveniles fed the T60 diet exhibited maximum growth and feed utilization. However, escalating the percentage of fishmeal substitution with BSFLM above 60 percent led to a significant reduction in growth and feed utilization. The protease activity and the haemoglobin (Hb) value were high in fishes fed with the T60 diet. The MyoD was upregulated in fish fed T40 and T60 diets, while the myostatin was downregulated in fish-fed T40 and T60 diets. Thus, the fishmeal protein substituted at 60% with BSFLM with an inclusion level of 201 g/kg of diet will be suitable for the goldfish juveniles.

Replacement of Dietary Fishmeal Protein with Degossypolized Cottonseed Protein on Growth Performance, Nonspecific Immune Response, Antioxidant Capacity, and Target of Rapamycin Pathway of Juvenile Large Yellow Croaker (Larimichthys crocea).

A 70-day feeding experiment was carried out to assess the replacement of dietary fishmeal (FM) protein with degossypolized cottonseed protein (DCP) on large yellow croaker (Larimichthys crocea) with initial body weight (13.09 ± 0.50 g). Five isonitrogenous and isolipidic diets replaced fishmeal protein with 0%, 20%, 40%, 60%, and 80% DCP were formulated and named as FM (the control group), DCP20, DCP40, DCP60, and DCP80, respectively. Results displayed that weight gain rate (WGR) and specific growth rate (SGR) in the DCP20 group (263.91% and 1.85% d-1) were significantly increased compared with the control group (194.79% and 1.54% d-1) (P < 0.05). Furthermore, fish fed the diet with 20% DCP significantly increased the activity of hepatic superoxide dismutase (SOD) compared with the control group (P < 0.05). Meanwhile, the content of hepatic malondialdehyde (MDA) in the DCP20, DCP40, and DCP80 groups was significantly lower than that in the control group (P < 0.05). The activity of intestinal trypsin in the DCP20 group was significantly degraded compared with that in the control group (P < 0.05). The transcription of hepatic proinflammatory cytokine genes (interleukin-6 (il-6); tumor necrosis factor-α (tnf-α); and interferon-γ (ifn-γ)) in the DCP20 and DCP40 groups was significantly upregulated compared with that in the control group (P < 0.05). As to the target of rapamycin (TOR) pathway, the transcription of hepatic target of rapamycin (tor) and ribosomal protein (s6) was significantly up-regulated, while the transcription of hepatic eukaryotic translation initiation factor 4E binding protein 1 (4e-bp1) gene was significantly downregulated in the DCP group compared with the control group (P < 0.05). In summary, based on the broken line regression model analysis of WGR and SGR against dietary DCP replacement levels, the optimal replacement level was recommended to be 8.12% and 9.37% for large yellow croaker, respectively. These results revealed that FM protein replaced with 20% DCP could promote digestive enzyme activities and antioxidant capacity and further activate immune response and the TOR pathway so that growth performance of juvenile large yellow croaker was improved.

Replacing fishmeal protein with blended alternatives alters growth, feed utilization, protein deposition and gut micromorphology of humpback grouper, Cromileptes altivelis

This research aims to investigate the effects of different dietary fishmeal (FM) protein replacements by blended alternative proteins on growth, feed utilization, protein deposition and gut micromorphology of humpback grouper, Cromileptes altivelis. Five isoenergetic (14.23 kJ/g, dry matter), isoproteic (48.91 %, dry matter) and isolipidic (10 %, dry matter) experimental diets were formulated, with 0 % (R0), 21 % (R21), 42 % (R42), 63 % (R63) and 84 % (R84) FM protein being replaced by blended alternative proteins which consisted of soybean protein isolate (SPI), poultry by-product meal (PBM), hemoglobin powder (HP). Triplicate groups of fish (mean initial body weight: 6.50 ± 0.17 g, 12 fish/group) were manually fed each diet to apparent satiety twice daily for 8 weeks. Results showed that different FM protein replacements by the blended proteins significantly influenced percentage weight gain (WG %), daily feed intake (DFI), feed conversion ratio (FCR), protein efficiency ratio (PER) and protein productive value (PPV) of fish. Fish fed R84 had the lowest WG %, PER and PPV among all experimental groups. The quadratic broken-line regression analysis of WG % indicated that the maximum FM protein replacement level by the blended proteins was 67.0 % of dry matter. Fish fed R84 had lower expression of growth hormone (GH), growth hormone receptor (GHR), insulin like growth factor-I (IGF-1), target of rapamycin (TOR) and S6 kinase 1 (S6K1) than fish fed other diets. General control nonderepressible 2 (GCN2) and CCAAT enhancer binding protein β (C/EBPβ) showed higher expression in the R84 group compared to those in other groups. The villous height (hV), villous width (wV) as well as enterocyte height (hE) of gut were also affected by different experimental treatments, with the R84 group having lower values compared to other groups. Generally, 67.0 % of dietary FM protein could be replaced by a blend of SPI, PBM and HP proteins without negatively influencing the WG % of humpback grouper.

Selenium-Enriched Spirulina (SeE-SP) Enhance Antioxidant Response, Immunity, and Disease Resistance in Juvenile Asian Seabass, Lates calcarifer.

The present study examined the efficacy of dietary selenium-enriched spirulina (SeE-SP) on growth performance, antioxidant response, liver and intestinal health, immunity and disease resistance of Asian seabass, Lates calcarifer. A total of 480 seabass juveniles with an initial weight of 9.22 ± 0.09 g/fish were randomly assigned to four dietary groups. The fish were fed a fishmeal protein replacement diets with SeE-SP at 5%, 10%, and 20%, namely SeE-SP5, SeE-SP10, and SeE-SP20, and a fishmeal-based diet as control for 8 weeks. The results indicated that seabass juveniles fed SeE-SP5 and SeE-SP10 diets grew at the same rate as the fish fed a fishmeal-based control diet after 8 weeks of feeding, while SeE-SP20 grew at a significantly lower rate than the control (p < 0.05). Although most of the measured biochemical parameters were not influenced by the Se-SP diets, serum antioxidant-enzyme glutathione peroxidase (GPx) and immunological indices, such as lysozyme activity and immunoglobulin-M, were found significantly higher in the SeE-SP5 and SeE-SP10 diets compared to control. In addition, the fish fed the SeE-SP5 diet showed significantly lower mortalities after the 14-day of bacterial challenge with V. harveyi. These outcomes indicated that up to 10% inclusion of SeE-SP in the diet of juvenile Asian seabass does not compromise growth, while SeE-SP5 enhanced disease resistance in juvenile seabass.

The effects of replacing fishmeal by Chlorella vulgaris and fish oil by Schizochytrium sp. and Microchloropsis gaditana blend on growth performance, feed efficiency, muscle fatty acid composition and liver histology of gilthead seabream (Sparus aurata)

The present study evaluated the effects of replacing fishmeal protein by Chlorella vulgaris meal and fish oil by a blend of Schizochytrium sp. and Microchloropsis gaditana on growth, feed utilization, muscle fatty acid composition and liver histology of Sparus aurata. Fish were fed twice a day for 12 weeks, six isonitrogenous (52% CP) and isoenergetic (21 MJ/Kg) diets at which fishmeal protein of the Control diet was replaced by C. vulgaris meal at 10% (CM10), 20% (CM20) and 30% (CM30) and fish oil of the control diet was replaced by a blend of Schizochytrium sp. and Microchloropsis sp. at 50% (SM50) and 100% (SM100). It was found that the partial replacement of fishmeal protein by C. vulgaris meal up to 30% and the total fish oil replacement by Schizochytrium sp. and M. gaditana blend did not exert any adverse effects on the feed intake, SGR, FCR and PER of fish. Graded levels of C. vulgaris led to an increased lipid retention and deposition mainly in the liver, but no other diet-dependent changes were observed in the whole body and muscle proximate compositions of fish. Microalgae-based diets displayed no major hepatic histomorphological effects, but the very few incidences of hydropic degeneration and haemorrhage that were observed call for further investigation to reveal any potential histopathological impacts of such dietary strategy. Fishmeal replacement by C. vulgaris increased the levels of 18:2n-6 and 18:3n-3 in fish muscle, while EPA and DHA levels were not significantly reduced since dietary fish oil maintained their deposition. Fish oil replacement by the blend of Schizochytrium sp. and Microchloropsis sp. increased the n-6 PUFA and particularly 20:4n-6 and 22:5n-6 in the muscle, while maintained similar EPA and DHA levels compared to the Control group. The present study suggests that the blend of dried biomasses of Schizochytrium sp. and M. gaditana could totally replace dietary fish oil in fishmeal-based diets formulated with soybean oil, without negatively affecting the growth performance, feed efficiency, proximate composition and muscle EPA and DHA levels of S. aurata, even if this resulted in a few histomorphological alterations. Moreover, replacing fishmeal protein by C. vulgaris meal up to 30% that was the maximum level tested did not adversely affect growth performance and feed utilization, even if it resulted in increased lipid retention and deposition in the liver.

Effects of Fly Maggot Protein Replacement of Fish Meal on Growth Performance, Immune Level, Antioxidant Level, and Fecal Flora of Blue Foxes at Weaning Stage.

Simple SummaryGiven the shortage of fish meal, other animal protein replacements are actively being researched. One such alternative is fly maggot protein—a highly nutritious insect protein containing chitin, lysozyme, and other biologically active substances. The purpose of this study was to examine how the replacement of fish meal with fly maggot protein affects growth, immune indexes, antioxidant levels, and fecal microflora in blue foxes (Alopex lagopus) during weaning. The results showed that fly maggot protein replacement had no adverse effects on the growth, immune indexes, and antioxidant levels of blue foxes at weaning. Further, it could modulate the fecal microflora. This indicates that fly maggot protein can serve as a novel animal protein alternative to fish meal for feeding blue foxes.Dietary protein is a key nutritional parameter and warrants special attention in animal husbandry. This study aimed to evaluate the effect of replacing fish meal (F) with fly maggot protein (M) on the growth performance, antioxidant levels, immune indexes, and fecal microflora in weaned blue foxes (Alopex lagopus). Twenty weaned blue foxes were randomly assigned to the control (F diet; 6% of F) or experimental (M diet; F substituted by M) group (10 blue foxes per group). The duration of the trial was 28 days. The results showed that there was no significant difference in average daily gain between group M and group F during the experiment (p = 0.473). Moreover, the diarrhea index was similar between group M and group F during the entire experimental period (p = 0.112). At the end of the experiment, the levels of IL-6 and IgG in group M at 28 d were significantly higher than that in group F (p = 0.004, p = 0.025, respectively), but not IL-1β, IL-2, SIgA, IgM, and TNF-α. The levels of SOD in group M at 28 d were significantly higher than those in group F (p = 0.001), and no difference of MDA and T-AOC was found between group F and M (p = 0.073, p = 0.196, respectively). In both groups, the diversity of fecal microbes first increased and then decreased with the progress of the experimental period. Initially, there were differences in the composition of microbial communities between the two groups. However, this difference was attenuated at later stages of the experimental period. In conclusion, fly maggot protein can replace fish meal as a source of animal protein in feed material for blue foxes during the weaning period.

Partial defatted black solider larvae meal as a promising strategy to replace fish meal protein in diet for Nile tilapia (Oreochromis niloticus): Performance, expression of protein and fat transporters, and cytokines related genes and economic efficiency

Insect meal can be a promising nutrients source in aquafeed, replacing expensive, scarce or unsustainable foods however; molecular mechanisms behind its role on fish growth remain unknown. From this point, the impact of partial or total replacement of fish meal protein with defatted black soldier larvae meal (PD-BSLM) on Nile tilapia's performance, body composition, expression of genes related protein and fatty acids transporters and immunity and economic efficiency was evaluated. A total of 500 Nile tilapia (17.9 ± 0.3 g) was distributed into 4 groups: control fed basal diet with 10% fish meal; the other 3 groups were fed basal in which fish meal was replaced by 25, 50 and 100% of PD-BSLM for 12-weeks. The results described that dietary inclusion of PD-BSLM had no negative impact on Nile tilapia's growth rate, feed conversion ratio, protein utilization and nutrient digestibility even after 100% replacement. Body fat content was significantly decreased with increasing PD-BSLM levels. Amino acids analysis of fish body showed that replacement of fish meal with 100% PD-BSLM has a slight change on its lysine content. Interestingly, lysozymes, IgM and nitric oxide levels were significantly enhanced in group fed PD-BSLM at 100% replacement level. Transcriptomics profile of genes encoding amino acids (SLC3A1-SLC6A19) and peptides transporters (SLC15a1a-SLC15a1b-SLC15a2) revealed no negative effect in response to PD-BSLM. Moreover, mRNA expression of genes controlling fat transportation and metabolism (FABP-2, PPAR-α and PPAR-β) was up-regulated in groups fed higher PD-BSLM levels. Remarkably, mRNA expression of proinflammatory cytokines (IL-1β gene TNF-α) was down-regulated and anti-inflammatory cytokines (IL-10) was up-regulated at higher PD-BSLM levels. Therefore, our study reported that replacement of fish meal with PD-BSLM up to 100% had a positive modulating effect on the expression of protein and fat transporters that can explain a non adversely affected growth performance of Nile tilapia. Besides, the higher inclusion levels of PD-BSLM can boost immunity of Nile tilapia as well as increased the economic efficiency.