Replacement Of Fish Meal Protein Research Articles

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.

Aquaculture wastewater-raised Azolla as partial alternative dietary protein for Pangasius catfish

Azolla is a freshwater floating aquatic fern found in the tropical, subtropical and temperate regions with a high nitrogen-fixing rate from the result of symbiotic relationship with the blue-green cyanobacterium, Anabaena azollae. Azolla can effectively remediate aquaculture wastewater owing to its high production capacity and the ability to absorb nutrients and toxic compounds. The Azolla biomass generated as a by-product is currently underutilized and could potentially benefit the aquafeed industry in replacing the unfeasible and expensive fishmeal protein at a certain level. This study evaluates the incorporation of red tilapia wastewater-raised Azolla as a dietary protein for the growth performance, feed efficiency, survival, body indices, body composition and nutrient utilization of Pangasius catfish Pangasianodon hypophthalmus during a 90-days feeding experiment. Dried Azolla was incorporated into four isonitrogenous (30 g kg−1) and isolipidic (12 g kg−1) practical diets containing 0 g kg−1 (Control), 10 g kg−1 (A10), 20 g kg−1 (A20) and 30 g kg−1 (A30) fishmeal protein replacement. One hundred and twenty juveniles with an initial mean weight of 45 ± 15 g were distributed into 12 tanks representing four dietary treatments in triplicates. Results showed significant (p < 0.05) improvement in weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) in Pangasius catfish fed 10 g kg−1 Azolla protein. Beyond that, WG, SGR, PER and FCR decreased to the lowest value when fed with 30 g kg−1 Azolla protein. No significant (p > 0.05) effects were recorded for feed intake, survival, body indices and nutrient utilization amongst all dietary treatments. In conclusion, Azolla raised from red tilapia aquaculture wastewater can replace fishmeal protein up to 10 g kg−1 in the diet of Pangasius catfish juveniles having better growth, feed efficiency and nutrient utilization without affecting its survival, body indices and body composition.

A Combination of Hermetia illucens Reared on Fish Waste and Poultry By-Product Meal Improves Sensory and Physicochemical Quality of Farmed Barramundi Filets.

The proximate composition, sensory attributes, and shelf life of filets from barramundi, Lates calcarifer, were fed a fishmeal (FM) based diet (0PBM-0HI) and three test diets replacing FM protein entirely with 85% poultry by-products meal (PBM) and 15% Hermetia illucens (HI) larvae meal protein (85PBM-15HI), 80% PBM and 20% HI (80PBM-20HI) and 75% PBM and 25% HI (75PBM-25HI) were investigated. After a 56-day feeding trial, the crude protein, moisture, and ash percentage were unchanged while the crude lipid increased in barramundi filet when fed with PBM-HI-based diets. The increase in C12:0 (lauric acid) and C14:0 (myristic acid) resulted in an increase in the total saturated fatty acid while the monounsaturated fatty acid elevated due to an increase in C16:1n7 and C18:1cis + trans in the filet of the barramundi fed with a PBM-HI based diet. While the decrease in the total polyunsaturated fatty acid (PUFA) content in PBM-HI based fed barramundi filet was mainly due to a decrease in essential fatty acids including C20:5n3 [eicosapentaenoic acid (EPA)] and C22:6n3 [docosahexaenoic acid (DHA)] when compared with the 0PBM-0HI fed barramundi filet. The sensory quality was improved by PBM-HI-based diets, manifested by the highest scores given by the panelists. Texture profiles were not affected by diet but cohesiveness, gumminess, and chewiness decreased with increasing storage time. On days 1 and 8, skin brightness decreased in the skin of the barramundi fed with 85PBM-15HI and 80PBM-20HI compared with the skin of the 0PBM-0HI fed barramundi. Skin redness improved in fish-fed PBM-HI-based diets. The flesh brightness and yellowness increased significantly in barramundi when fed with PBM-HI-based diets. On days 1 and 4, the flesh brightness of the barramundi fed with PBM-HI-based diets demonstrated an increase compared with 0PBM-0HI. PBM-HI diets suppress lipid oxidation while lipid oxidation increased over the storage time. In summary, the improvement in sensory quality and color coupled with the suppression of rancidity in barramundi filets underpinned the potentiality of using the mixture of PBM and HI transformed from food waste in the barramundi diet to improve the filet quality and thus support sustainability and circular economy in aquaculture.

Growth performances and nutrient utilization efficiency of GIFT tilapia reared in floating net cages fed with bioprocessed silkworm pupae meal

A 60-day growth trial was conducted in floating cages to examine the effects of growth performances and nutrient utilization efficiency in Genetically Improved Farmed Tilapia (GIFT) tilapia fed silkworm pupae meal (SWP) and bioprocessed silkworm pupae meal (BSWP) replacing dietary fish meal protein. Seven isonitrogenous (320 g/kg crude protein) isolipidic (50 g/kg crude lipid) and isoenergetic (17 MJ/kg) experimental diets were formulated replacing fish meal protein with 0, 333.3, 666.7 and 1000 g/kg of SWP and BSWP, respectively, and referred as control, SWP 33.33, SWP 66.67, SWP 100, BSWP 33.33, BSWP 66.67 and BSWP 100. Triplicate groups of 30 GIFT tilapia juveniles with an average initial weight of 11.34 ± 0.16 g were fed with experimental diets daily thrice until apparent satiation. Among SWP and BSWP dietary groups, although weight gain was significantly (p < .05) higher in SWP 66.67, BSWP 66.67 and BSWP 100, the feed conversion ratio and specific growth rate were significantly (p < .05) higher in BSWP 66.67 than other diets including control diet. Dietary inclusion of SWP and BSWP does not (p > .05) affect the whole-body chemical and amino acid composition and haemato-biochemical responses in GIFT tilapia. It is concluded that non-processed SWP and bioprocessed SWP can completely replace dietary fish meal protein in GIFT tilapia diets. However, bioprocessed SWP at 666.7 g/kg recorded best growth performance among the diets.

Partial replacement of fishmeal by a protein‐rich product from methanotrophic bacteria in juvenile red sea bream ( Pagrus major )

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.

Lactobacillus spp. fermented soybean meal partially substitution to fish meal enhances innate immune responses and nutrient digestibility of white shrimp (Litopenaeus vannamei) fed diet with low fish meal

To accomplish the goal of sustainable aquaculture, substitution of fish meal (FM) with available and effective alternative ingredients is necessary. The present study evaluated the effects of fermented soybean meal (FSBM) substituted to FM on growth, innate immune responses, nutrient digestibility, and morphological changes in hepatopancreas of white shrimp Litopenaeus vannamei, fed a low FM diet. The FM protein was replaced by FSBM at 0%, 25% (25% FSBM), 50% (50% FSBM), 75% (75% FSBM), and 100% (100% FSBM) in the control diet (including 15% FM). Experimental diets were each fed in triplicates to juvenile shrimp with initial weight of 5.53 g in a closed recirculation system for eight weeks. Shrimp fed different diets exhibited similar (p > 0.05) growth performance and morphology in hepatopancreas. Shrimp fed the 75% FSBM diet had higher total hemocyte count than other dietary groups. Shrimp fed the 75% FSBM diet exhibited the highest phenoloxidase (PO) activity, followed by shrimp fed 50% FSBM and 100% FSBM diets, and lowest in shrimp fed the control and 25% FSBM diets. Apparent digestibility of dry matter, protein and lipid showed the highest performance in shrimp fed the 75% FSBM diet compared with other dietary treatments. Results indicate that FSBM can completely replace fish meal protein without any negative effects on growth and morphology in hepatopancreas. The adequate replacement levels is suggested at 75% to improve innate immune responses and nutrient digestibility for white shrimp.

Trypsin inhibitor reduction improves the utility of soy protein concentrate from soymilk in the diet of the juvenile red sea bream, Pagrus major

A rearing study was undertaken to investigate whether trypsin inhibitor (TI) activity reduction in soy protein concentrate (SPC) derived from soymilk can afford more replacement of fish meal (FM) protein in the diet of juvenile red sea bream, Pagrus major. A diet containing 67% FM as the sole protein source was used as the control (C). SPC products with TI activities of 36, 21 and 13 TIU/mg sample were prepared. Approximately 80% of FM protein in diet C was replaced by a combination of SPC products and corn gluten meal (4:1) and referred to as T36, T21 and T13, respectively. Aqueous krill extract (KE) was added at 1% in diets T36, T21 and T13 and termed T36K, T21K and T13K, respectively. Phytase was supplemented at 1000 FTU/kg diet in all SPC-based diets. Each of seven diets was fed to a group of 20 fish (mean weight 19 g) in triplicate twice per day to apparent satiation for 10 weeks. The final mean weight (P = 0.001), specific growth rate (SGR) (P = 0.001) and feed efficiency (FE) (P = 0.002) were significantly lower in fish fed the T36 and T36K diets than in those fed the other diets. However, there were no significant differences in final mean weight (P = 0.088), SGR (P = 0.314) and FE (P = 0.829) in fish fed diets T21, T13, T21K and T13K compared to the control diet. Although there were no significant differences in the digestibility of protein (P = 0.076) and energy (P = 0.066) among the treatments, the productive values of protein (P = 0.002) and energy (P = 0.001) were significantly reduced in fish fed the T36 and T36K diets. In contrast, a significantly lower phosphorus (P) retention efficiency (P = 0.026) in fish fed the control diet resulted in significantly higher P discharge (P = 0.001) to the environment compared with diets T21, T13, T21K and T13K. There were no major variations in hematocrit level or plasma constituents among the treatments, except glutamic oxaloacetic transaminase (GOT) and triglyceride. The results suggest that the reduction in TI activity at ≤21 TIU/mg sample (≤9.66 TIU/mg diet) in SPC from soymilk made it possible to replace 80% of FM protein without affecting growth performance and health status. Moreover, a significant reduction in P discharge suggests that ecological benefits can be achieved through improving diet utility by reducing TI activity in SPCs derived from soymilk.

Transformation of fish waste protein to Hermetia illucens protein improves the efficacy of poultry by-products in the culture of juvenile barramundi, Lates calcarifer

Promoting a circular economy via the transformation of food waste into alternative and high-value protein sources for aquaculture diets is a novel approach to developing alternative raw materials to fishmeal (FM). This approach can reduce the ecological impact on the aquatic environment and simultaneously can provide an option for sustainable food waste management. In this context, we report a 56-day trial of feeding barramundi, Lates calcarifer on four iso‑nitrogenous and iso-lipidic diets where the control (0PBM-0HI) was a FM-based diet and the other test diets replaced FM protein with mixtures of a poultry by-product meal (PBM) and a full-fat Hermetia illucens (HI) larvae meal reared on fish waste: the test diets were 85% PBM + 15% HI (85PBM-15HI), 80% PBM + 20% HI (80PBM-20HI) and 75% PBM + 25% HI (75PBM-25HI). Fish fed PBM-HI-based diets showed an equal growth rate and amino acid profile when compared to the control group. Among all serum metabolites, alanine aminotransferase and glutamate dehydrogenase decreased in fish fed PBM-HI-based diets, whilst total protein levels improved in the same diets. Serum lysozyme and bactericidal activity were unchanged which supported the observation of similar infection rates against V. harveyi. Except for the kidney and intestine, catalase activity in the serum and liver increased in fish-fed PBM-HI-based diets. In assessing the gastrointestinal mucosal morphology, the goblet cells producing neutral mucins were higher in PBM-HI-fed fish than the control. PBM-HI diets also enhanced bacterial richness and diversity and increased abundance for Lactobacillus, Clostridium, and Ruminococcus. In summary, combining full-fat HI with PBM allowed complete replacement of FM with no negative effects on growth whilst improving gut health. Such diets would be beneficial for the aquaculture industry, both ecologically and economically, as well as providing value-adding to animal waste as alternative protein sources for aquafeed production.

Effects of dietary protein substitution of fish meal with bioprocessed poultry by‐product meal on growth performances, nutrient utilization, whole‐body composition and haemato‐biochemical responses of GIFT tilapia reared in floating cages

A 60-day feeding trial was conducted to examine the effects of replacing fish meal protein with poultry by-product meal (PBM) and bioprocessed poultry by-product meal (BPBM) on growth performance, nutrient utilization, whole-body chemical and amino acid composition and haemato-biochemical responses in GIFT tilapia reared in floating cages. Seven isonitrogenous (320 g/kg crude protein), isolipidic (50 g/kg crude lipid) and isoenergetic (17 MJ/kg) experimental diets were formulated by replacing 0%, 33.33%, 66.67% and 100% of fish meal protein with PBM and BPBM respectively and referred as Control, PBM 33.33, PBM 66.67, PBM 100, BPBM 33.33, BPBM 66.67 and BPBM 100. Triplicate groups of 30 GIFT tilapia juveniles with an average initial weight of 11.28 ± 0.14 g were fed with experimental diets daily thrice until apparent satiation (08:00, 12:00 and 16:00 h). Among PBM and BPBM dietary groups, significantly (p < 0.05) higher growth performance and nutrient utilization were observed in fish fed BPBM 66.67 group compared to other treatment diets including control diet. No significant difference (p > 0.05) was observed in survival rate of GIFT tilapia fed different levels of PBM and BPBM-incorporated diets. Moreover, dietary inclusion of PBM and BPBM did not (p > 0.05) affect the whole-body chemical and amino acid composition and haemato-biochemical responses in GIFT tilapia. It is concluded that PBM and BPBM can completely replace dietary fish meal protein in GIFT tilapia diets without any negative impact on growth performances, nutrient utilization and blood haemato-biochemical responses. However, significantly higher growth performances and nutrient utilization were obtained in fish fed BPBM 66.67 diet.

Effects of replacing fish meal with soybean meal on growth performance, feed utilization and physiological status of juvenile redlip mullet Liza haematocheila

The purpose of this study was carried out to elucidate the effects of replacing fish meal (FM) with soybean meal (SBM) on growth performance, feed utilization, and physiological status of juvenile redlip mullet Liza haematocheila. Five test diets were formulated to replace FM protein by SBM at the levels of 0% (SBM0), 25 %(SBM25), 50 %(SBM50), 75 %(SBM75), or 100 % (SBM100). Each treatment was triplicated (20 fish per tank, initial average weight 5.08 ± 0.11 g fish−1). No significant differences were observed in weight gain (WG), feed efficiency (FE), and protein efficiency ratio (PER) between fish fed with SBM0 and SBM75 diets. However, the WG, FE, and PER values showed a decreased trend with fish fed diet containing more than 75 % SBM protein. The value of HSI decreased significantly with increasing dietary SBM levels. An increase of dietary SBM level linearly decreased energy retention (ER) and lipid retention (LR). Concentrations of serum triacylglycerol (TG) and total cholesterol (T−CHO) decreased significantly with increasing the dietary SBM levels. FM substitution with different levels of SBM had no statistical differences in the activities of trypsin, lipase (LPS), and amylase (AMS) on the intestine. Activities of superoxide dismutase (SOD), catalase (CAT), and glutamyl oxaloacetic transaminase (GOT) in the liver increased significantly with increasing dietary SBM levels. The content of malondialdehyde (MDA) in the liver was significant higher in fish fed SBM100 diet than other treatments. Based on the model of broken-line model of WG and FE, it showed that SBM can replace 51.18–52.46% FM in juvenile L. haematocheila.

Black Soldier Fly, Hermetia illucens as an Alternative to Fishmeal Protein and Fish Oil: Impact on Growth, Immune Response, Mucosal Barrier Status, and Flesh Quality of Juvenile Barramundi, Lates calcarifer (Bloch, 1790)

Simple SummaryFishmeal and fish oil being recognized as nutritionally balanced and preferred protein and lipid sources in aquafeeds for finfish farming. However, the limited supply, soaring prices, and depletion of wild capture fisheries have prompted the aquaculture industry to look for widely available and less expensive alternatives for fishmeal and fish oil to ensure the sustainability of aquaculture production. As an alternative to fishmeal protein and oil, black soldier fly (BSF) larvae is considered a promising candidate for its high protein, lipid and minerals content, as well as for its bioactive potential with anti-microbial, anti-fungal, and anti-viral functions. This study investigated the effects of partial substitution of fishmeal protein and fish oil with partially defatted BSF larvae protein and oil on growth performance, non-specific immunity, mucosal barrier status and muscle fatty acids composition in barramundi. The findings of the study confirmed that BSF could substitute 30% fishmeal and fish oil successfully without compromising the growth of barramundi. Further, partial replacement of fishmeal and fish oil with BSF diets improved bactericidal activity, immune-related cytokine expression, and mucin cells in both gut and skin which are an indication of improved immunity of barramundi.A feeding trial was conducted to test the effects of partial replacement of fishmeal (FM) protein and fish oil (FO) with partially defatted black soldier fly, Hermetia illucens insect protein, and oil, respectively, on growth performance, immune response, gut and skin barrier status, and flesh quality in juvenile barramundi. Four isonitrogenous and isocaloric diets used in the study were a control diet based on FM, 30% FM replaced with H. illucens protein (HiP), 30% FO replaced with H. illucens oil (HiO), and both 30% FM and 30% FO replaced with H. illucens protein and oil (HiPO). Diets were fed twice a day to satiety in triplicated groups of barramundi with an initial body weight of 1.74 ± 0.15 g per fish. At the end of the trial, growth and feed utilization indices were found insignificant (p > 0.05) between the test diets and control. A significant increase in bactericidal activity was observed in fish fed the HiP diet while serum lysozyme activity was unchanged. Stress-related heat shock proteins (HSP70 and HSP90) did not differ significantly among the test diets while immune-relevant genes (IL-1β and IL-10) were significantly upregulated in HiP and HiOP groups. The number of mucin cells were increased in the gut and skin of HiP and HiOP fed fish when compared to the control diet. The total fatty acid compositions (∑SFA, ∑MUFA, ∑PUFA, ∑n-3, and ∑n-6) in the muscles of barramundi were not significantly influenced with H. illucens protein and oil diets when compared to the control.

Effects of black soldier fly (Hermatia illucens) larvae as a fish meal replacement on growth performance, feed utilisation, morphological characters and carcass composition of Thai climbing perch (Anabas testudineus)

ABSTRACT The effects of replacing fish meal protein with different levels of black soldier fly (BSF) larvae meal (Hermetia illucens) in Thai climbing perch (Anabas testudineus) diets were assessed. Five isonitrogenous (43.69 ± 0.60%) diets were formulated to replace 0%, 25%, 50%, 75% and 100% fish meal with BSF larvae meal. Fish (1.90 ± 0.02 g) were fed at 5% body weight, twice a day for 56 days. Highest mean weight gain, average daily weight gain, specific growth rate and optimal feed conversion ratio were measured at 75% larvae meal replacement. Hepatosomatic index (HSI), visceral somatic index (VSI), crude lipid and crude protein contents in treated groups were higher than the control (P < .05). Results indicated that BSF larvae meal protein can be used to partially replace fish meal and improve growth performance and feed utilization, while increases in HSI, VSI and crude lipid content may negatively impact fish health.

The effects of replacing fish meal protein with a mixture of poultry by‐product meal and fermented soybean meal on the growth performance and tissue nutritional composition of Asian seabass ( Lates calcarifer )

The effects of fish meal (FM) protein replaced with a mixture of poultry by-product meal (PBM) and fermented soybean meal (FSBM) on the growth performance of Asian seabass (Lates calcarifer) was investigated. Seven diets were formulated to replace 0% (CON−), 0% (CON+), 20% (MPS20), 40% (MPS40), 60% (MPS60), 80% (MPS80) and 100% (MPS100) FM protein with a mixture of 60% PBM and 40% FSBM. Treatment diets except CON− contained feed attractants; each diet was randomly assigned to triplicate groups of ten 1.27 g fish for 6 weeks. The fish fed the CON−, CON+, MPS20, MPS40 and MPS60 diets showed no significant differences in weight gain percentage (WG%) and specific growth rate (SGR), whereas those fed the MPS100 diet had the lowest WG% and SGR. The crude lipid of fish muscle ranged from 66 to 71 g/kg, whereas that of fish liver ranged from 372 to 426 g/kg. The amounts of polyunsaturated fatty acid (PUFA) and n-3 LC-PUFA of fish muscle decreased as the FM protein replacement level increased. A mixture of 60% PBM and 40% FSBM would be able to substitute FM protein for up to 60% without adverse effects on the growth performance of Asian seabass.

Effect of dietary replacement of fish meal protein with crawfish shell meal ( Procambarus clarkii ) on the growth performance, digestive enzyme activity and anti‐oxidative capacity of Oujiang color common carp ( Cyprinus carpio var. color )

This study was designed to evaluate the effects of dietary crawfish shell meal (CSM) on the growth performance, digestive enzyme activity and anti-oxidative capacity of Oujiang color common carp. 180 juvenile fish (initial weight 3.0 ± 0.5 g) were assigned to the control group and the CSM25 group (fed with 25% substitution of fish meal by CSM) for 8 weeks. Results showed that significant improvement in the weight gain rate (WGR) in CSM25 group than the control (p < .05), whereas no significant change in feed conversion ratio, specific growth rate and feeding intake between the groups (p > .05). Also, no significant difference was obsevered between the groups in terms of serum biochemical index and muscle composition (p > .05). And liver superoxide dismutase, catalase, glutathione peroxidase (GPx), lysozyme (LYZ) and protease activities in CSM25 group were significantly higher (p < .05). Moreover, histological analysis indicated that width of mucosa and thickness of muscular coat in mid-intestine were significantly changed (p < .05). In conclusion, dietary supplement with CSM25 induced high oxidative stress, promote protease activities and had no negative effects on the growth performance of Oujiang color common carp. Hence, CSM may be a viable alternative protein source to reduce the demand for fish meal.

Effects of using vital wheat gluten in practical diets on growth, intestinal histopathology, proinflammation-related gene expression, and resistance of white seabream (Diplodus sargus) to Staphylococcus epidermidis infection

The current study was carried to assess the effects of using vital wheat gluten (VWG) as a fishmeal (FM) replacer in practical diets for white seabream, Diplodus sargus, juvenile. Five isonitrogenous (~ 40% CP) and isoenergetic (21 MJ/Kg diet) diets were formulated to replace FM protein by VWG protein at levels of 0.0 (CTR), 15 (VWG15), 30 (VWG30), 45 (VWG45), and 60% (VWG60). Fish (1.7 ± 0.1 g) were fed on the experimental diets in triplicated groups up to apparent satiety for 10 weeks. At the end of the feeding trial, fish of each treatment were intraperitoneally injected by pathogenic bacterium Staphylococcus epidermidis and observed for further 10 days. Results showed that only fish fed VWG45 and VWG 60 diets showed significant lower growth and feed intake relative to all other VWG groups. VWG at all inclusion levels did not significantly affect survival rate, proximate composition, or body morphometry of white seabream. The intestine architecture indicated that fish fed the VWG45 diet had mild alterations with abundant absorptive vacuole in the middle intestine, while mild to moderate pathological changes were observed in the distal portion. The intestine of fish fed VWG60 showed severe degeneration with signs of inflammation. Additionally, villi length/width and absorption area in foregut, midgut, and hindgut of white seabream were not significantly changed among CTR, VWG15, and VWG30 but these measurements were significantly lowest at the VWG60 treatment. Comparing with the CTR group, highest IL-1β and TNF-α gene expressions were observed in VWG60 followed by VWG45 groups. The phylogenetic tree indicated that VWG induced changes in muscles protein pattern especially at the VWG60 group. After the bacterial challenge, fish fed 15 and 30% VWG protein showed mild mortality as the control fish (43.3–46.7%); meanwhile fish fed the VWG60 diet were more susceptible to S. epidermidis infection showing highest mortality (63.3%). In conclusion, the present findings elucidated that the performance of white seabass was not significantly affected by partial replacement of 30% FM protein with VWG protein.

Partial fishmeal protein replacement with peptides from swine blood modulates the nutritional status, immune response, and intestinal microbiota of hybrid groupers (female Epinephelus fuscoguttatus× male E. lanceolatus)

This study investigated the effects of replacing fish meal (FM) protein with peptides from swine blood (PSB) on the growth, digestion, and absorption capacity of hybrid groupers (female Epinephelus fuscoguttatus × male Epinephelus lanceolatus). It also analyzed their inflammatory-related gene expression, and intestinal microbiota. Four isonitrogenous and isolipidic experimental feeds were formulated to replace 0% (FM), 25% (PSB25), 50% (PSB50), and 75% (PSB75) of the FM protein with PSB. Each experimental diet was fed to triplicate groups of 30 hybrid grouper juveniles for 8 weeks. No significant differences in the weight gain and specific growth rates were found among the FM, PSB25, and PSB50 groups. The intestinal digestive enzyme (lipase, amylase, trypsin, and pepsin) and brush border enzyme (Na+/K+-ATPase, creatine kinase, and γ-glutamyl transpeptidase) activities showed no significant differences among the FM, PSB25, and PSB50 groups. Meanwhile, trypsin, pepsin. Creatine kinase, and γ-glutamyl transpeptidase activities in the PSB group were significantly higher than those of the FM group. No significant differences in the expression levels of the toll-like receptor 21 (TLR21), myeloid differentiation factor 88 (MyD88), and inflammatory cytokines (TNF-α, IL-2, IL-8, and IL-10) were observed among the four groups. The intestinal microbiota results showed no significant differences in alpha diversity among the four groups. At the genus level, at the genus level, Lactobacillus relative abundance was significantly reduced in the PSB10 group compared to that in the FM group. However, no significant differences were found among the FM, PSB50, and PSB75 groups. However, no significant differences were found among the FM, PSB50, and PSB75 groups. These results demonstrated that up to 50% of the FM protein in the feed can be replaced by PSB without adversely affecting the nutritional status and inflammatory response in hybrid groupers. Replacing FM with PSB significantly influences the microbial profile but not the diversity

Physiological changes of giant grouper (Epinephelus lanceolatus) fed with high plant protein with and without supplementation of organic acid

This study was conducted to identify the effects of organic acid supplementation on 50 % replacement of fishmeal by soybean meal on the growth performance, hepatic condition and intestinal histology of giant grouper Epinephelus lanceolatus. Giant grouper juveniles were fed three different diets, 50 % fishmeal protein replacement with soybean meal (SBM50), 50 % fishmeal protein replacement with soybean meal added 1% butyric acid supplementation (SBM50 + 1%) and fishmeal diet (FM) as the control. All diets were formulated isoproteic (48 %) and isolipidic (12 %). Experimental fishes were cultured in a recirculating system and fed twice daily until apparent satiation level. Growth performance, hepatic condition and histological changes were observed in the feeding trial. Highest growth was seen in fish fed FM (p < 0.05), followed by SBM50 and SBM50 + 1% showed the lowest growth. Better feed conversion ratio (FCR) and protein efficiency ratio (PER) was also observed in fish fed FM (p < 0.05) followed by fish fed SBM50 and SBM50 + 1%. Meanwhile, hepatic superoxide dismutase activity of fish fed FM was higher, followed by SBM50 + 1% and SBM50 not significant and the thiobarbituric acid reactive substances (TBARS) of fish fed FM was significantly lower (p<0.05) followed by SBM50 + 1% and SBM50. Fish fed FM also showed significantly bigger hepatocytes (p < 0.05) and significantly higher glycogen content (p < 0.05) compared to SBM50 and SBM50 + 1%. On the other hand, inclusion of 1% butyric acid helped in mitigating intestinal inflammation caused by soybean meal although not significant. Findings from this study showed that 1% butyric acid did not help in optimizing high levels of plant based protein for giant grouper juveniles.

Effect of dietary poultry meal and oil on growth, digestive capacity, and gut microbiota of gilthead seabream (Sparus aurata) juveniles

This study aimed to evaluate the effect of replacing fish meal by poultry by-product meal (PBM) in actual commercial standard diets for gilthead seabream juveniles on growth performance, diet digestibility, digestive function, intestinal microbiota, and provide an economic analysis of using PBM in practical diets.Six isoproteic and isolipidic diets were formulated including increasing levels (from 0 to 37.5%) of PBM in replacement of fish meal, corresponding to a fish meal protein replacement in the diets up to 83%. Each diet was randomly assigned to triplicate groups of fish (IBW 63 g) and the growth trial lasted 70 days. No differences between groups were observed on growth performance, voluntary feed intake, feed efficiency, nitrogen utilization, and whole-body composition. Digestive enzymes activity and the ADC of protein, phosphorus, and energy were also not affected by dietary treatment. Regarding gut microbiota, fish fed diet PBM22.5 showed higher species richness and diversity of digesta microbiota, but no differences between groups were observed in mucosa OTUs, richness, and diversity indices. The cost of diet formulation decreased with the dietary replacement of FM by PBM, highlighting the potential of poultry by-products inclusion in commercial diets.Overall, this study indicates that dietary FM could be replaced at least up to 83% with PBM in diets for gilthead seabream juveniles without affecting growth performance and feed utilization while improving the economic efficiency of these diets.

Methanotroph (Methylococcus capsulatus, Bath) bacteria meal as an alternative protein source for Japanese yellowtail, Seriola quinqueradiata

Two trials were carried out to determine the optimal replacement level of fish meal (FM) protein by the bacterial protein meal FeedKind® (FK), in the diet of juvenile Japanese yellowtail, Seriola quinqueradiata. FK protein was produced from the methanotrophic bacteria Methylococcus capsulatus Bath, which utilizes methane as its sole carbon and energy source. In Trial 1, six diets were formulated: control diet (C) with FM as protein source; four experimental diets in which the FM of diet C was replaced at 25 (FK25), 50 (FK50), 75 (FK75) and 100% (FK100) by FK; and a final experimental diet in which 3% of FK in diet FK100 was replaced by enzyme-treated FM (EFK). In Trial 2, seven diets were prepared: control diet C similar to Trial 1; three experimental diets in which the FM of diet C was replaced at 20 (FK20), 25 (FK25) and 30% (FK30) by FK; two experimental diets in which FK from diet FK25 was replaced either by further grinding FK (FK25J) or lower digestible FK (FK25L); and experimental diet EFK in which 3% of the FK in diet FK25 was replaced by enzyme-treated FM. Fifteen (ca. 126g) or ten fish (ca. 80 g) were stocked into each of eighteen 500 L tanks in triplicates in Trial 1 and 2, respectively, fed two times daily until apparent satiation, and cultured for 8 weeks. At the end of both trials, feces were collected after feeding with chromic oxide (Cr2O3) mixed diets. In Trial 1, all growth parameters and nutrients retention efficiencies showed similar patterns and no significant differences were observed between diets C and FK25 (P > .05), though feed efficiency (FE) was reduced by 10% in the latter diet. However, other diets showed significantly lower growth performance compared to diet C (P < .05). When different lots of FK was used and feed formula was slightly adjusted in Trial 2, there were no significant differences in the growth performance, nutrients digestibility and retention efficiency, among the treatments even up to 30% FM protein replacement (P > .05). FE was also either equal to or higher in all FK-based diets compared with control group. Overall, results indicated that the FK can comprise up to 20% of total diet, replacing 30% of the FM protein in diet for yellowtail, without compromising growth performance or FE.

Substituting fishmeal with lupin Lupinus angustifolius kernel meal in the diets of cobia Rachycentron canadum: Effects on growth performance, nutrient utilization, haemato-physiological response, and intestinal health

The purpose of the study was to investigate the impacts of dietary narrow-leafed lupin Lupinus angustifolius kernel meal (LKM) on growth performance, feed utilization, digestibility, haematology, as well as liver and intestinal health of juvenile cobia Rachycentron canadum. Five isonitrogenous (crude protein around 460.0 g/kg) diets were formulated to replace 0, 200, 400, 600 and 800 g/kg of fishmeal protein with the protein from LKM designated as LKM0, LKM20, LKM40, LKM60 and LKM80, respectively. Triplicate groups of cobia were fed the respective diets for a period of 56 days. At the end of the feeding trial, growth indices expressed as final body weight (FBW) and specific growth rate (SGR) decreased following the linear and quadratic models with increasing levels of LKM. Feed intake, protein retention and energy retention followed the same trend, whereas, feed conversion ratio (FCR) and hepatosomatic index (HSI) followed a reverse trend with FBW and SGR. A significant decrease in the apparent digestibility coefficient of protein, lipid and dry matter was observed in cobia when more than 400 g/kg protein from fishmeal was substituted by LKM protein. Haematological indices such as red blood cell and haemoglobin declined significantly in fish fed with LKM60 and LKM80, while a significant increase was observed in aspartate transaminase and alanine aminotransferase. Histopathological alterations including higher lipid deposition, necrosis and vacuolization were found in the liver of fish fed higher (>600 g/kg) fishmeal protein replacement levels. Similarly, intestinal structure was affected by higher replacement level of fishmeal protein (>600 g/kg) as fold height and goblet cells decreased significantly with increasing levels of LKM. The results indicate that 200 g/kg fishmeal protein can be replaced by protein from LKM and substitution beyond that level adversely affected the growth performance of cobia.