Levels Of Fish Meal Research Articles

Replacement of Dietary Fishmeal by Black Soldier Fly Larvae (Hermetia illucens) Meal in Practical Diets for Juvenile Tench (Tinca tinca)

The development of specific diets for the juvenile stage is a main target for culture intensification of tench (Tinca tinca). Aquafeeds still rely heavily on the use of fishmeal (FM) but concerns about economic and ecological sustainability make the use of alternative protein sources necessary. Insect meals are considered a promising substitute to replace FM. In a 90-day experiment, 6 diets with different replacement levels of FM by partially defatted black soldier fly larvae meal (BSFLM): 0%, 15%, 30%, 45%, 60% and 75%, were tested on juvenile tench. Survival rates were high (95.8–100%) without differences between treatments. Diet with 45% FM replacement allowed for best growth performance in terms of total length (TL = 66.4 mm) and weight (W = 4.19 g), without differences with 60% and 75% of replacement. A cubic relationship was evidenced between the level of FM replacement and growth. From the regression equations, the estimated optimal level of FM replacement was 47% (356 g BSFLM kg−1 diet). Externally visible deformities were always under 0.05%. The whole-body lipid content of the fish had a significantly negative linear regression with BSFLM (r2 = 0.80). The content of the essential amino acids (EAA) arginine, leucine, lysine, phenylalanine, methionine, and threonine in diets decreased with dietary BSFLM inclusion. However, it did not have a negative effect on growth performance, suggesting that EAA requirements were covered. The amount of essential amino acids in whole-body juveniles was similar independently of the diet provided. The results allow considering BSFLM as a sustainable protein source for juvenile tench feeding.

Squid industry by-product hydrolysate supplementation enhances growth performance of Penaeus monodon fed plant protein-based diets without fish meal

The poor growth of aquatic animals fed with diets containing high plant proteins has been attributed to low diet acceptability and feed value. Supplementation of protein hydrolysate, with high contents of free amino acids and soluble low molecular weight peptides, may increase the acceptability and feed value of a plant protein-based diet. In the present work, squid processing by-products were enzymatically hydrolyzed and used as a supplement in a plant protein-based diet, without fish meal, of Penaeus monodon to fully maximize the utilization of this marine resource. The hydrolysate was incorporated at 0, 0.5, and 1% levels in P. monodon diets containing 0 and 10% fish meal levels. Growth, digestive enzyme activities, muscle growth-, gut pro-inflammatory and immune-related gene expressions, and muscle morphometric measurements were evaluated as biological indices in an 8-week feeding trial. The squid by-product hydrolysate produced in the present study contains 90.25% protein, 5.84% lipid, and 3.91% ash, and has a molecular weight of 3.76 kDa. Supplementation at 1% hydrolysate in the experimental shrimp diet without fish meal resulted in the highest growth performance associated with increased feed intake, efficient feed and nutrient conversion and retention, enhanced digestive enzyme activities, upregulation of muscle growth- and immune-related genes, and suppression of the gut pro-inflammatory gene. The growth promotion is also linked with a significant increase in muscle mean fiber area, which suggests hypertrophic growth in shrimp. Generally, the supplementation of 1% squid by-product hydrolysate supported the growth of P. monodon fed on a plant protein-based diet without fish meal.

Evaluation of Meat Meal as a Replacer for Fish Meal in Diet on Growth Performance, Feed Utilization, Chemical Composition, Hematology, and Innate Immune Responses of Olive Flounder (Paralichthys olivaceus)

This study aims to evaluate the dietary replacement effect of various levels of fish meal (FM) with meat meal (MM) on the growth, feed utilization, chemical composition, hematological parameters, and innate immune responses of olive flounder. A total of 360 juvenile fish (initial weight of 14.7 g) were randomly assigned to 18 flow-through containers. The control (MM0) diet included 65% FM. Then, 10%, 20%, 30%, 40%, and 50% FM in the MM0 diet were replaced with MM, referred to as the MM10, MM20, MM30, MM40, and MM50 diets, respectively. The fish were hand-fed to satiation daily for 56 days. Weight gain, the specific growth rate, the feed efficiency ratio, and the protein efficiency ratio of fish fed the MM0 diet were statistically greater than those of fish fed the MM30, MM40, and MM50 diets, but not statistically different from those of fish fed the MM10 and MM20 diets. To incite the maximum values of weight gain and the specific growth rate (SGR) of the fish, an estimated 7.0% of FM substitution with MM in diets was required according to regression analysis. However, the feed consumption, protein retention, hematological parameters, and innate immune (superoxide dismutase and lysozyme activities) responses of the fish were not statistically impacted by the dietary replacement levels of MM for FM. In conclusion, the feed ingredient grade of MM can substitute FM by up to 20% in the diet without causing any negative impact on the growth, feed consumption, feed utilization, or innate immune responses of olive flounder.

Fish Meal Replacement by Mixed Plant Protein in the Diets for Juvenile Yellow Catfish Pelteobagrus fulvidraco: Effects on Growth Performance and Health Status.

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%.

Evaluation of Krill Meal in Commercial Diets for Juvenile Swimming Crab (Portunus trituberculatus).

An 8-week feeding trial was carried out to assess the effect of dietary krill meal on growth performance and expression of genes related to TOR pathway and antioxidation of swimming crab (Portunus trituberculatus). Four experimental diets (45% crude protein and 9% crude lipid) were formulated to obtain different replacements of fish meal (FM) with krill meal (KM); FM was replaced with KM at 0% (KM0), 10% (KM10), 20% (KM20), and 30% (KM30); fluorine concentration in diets were analyzed to be 27.16, 94.06, 153.81, and 265.30 mg kg-1, respectively. Each diet was randomly divided into 3 replicates; ten swimming crabs were stocked in each replicate (initial weight, 5.62 ± 0.19 g). The results indicated that crabs fed with the KM10 diet had the highest final weight, percent weight gain (PWG), and specific growth rate (SGR) among all treatments (P < 0.05). Crabs fed with the KM0 diet had the lowest activities of total antioxidant capacity (T-AOC), total superoxide dismutase (SOD), glutathione (GSH), and hydroxyl radical scavenging activity and had the highest concentration of malondialdehyde (MDA) in the hemolymph and the hepatopancreas (P < 0.05). In the hepatopancreas, the highest content of 20:5n-3 (EPA) and the lowest content of 22:6n-3 (DHA) were shown in crabs fed with the KM30 diet among all treatments (P < 0.05). With the substitution level of FM with KM gradually increasing from 0% to 30%, the color of the hepatopancreas changed from pale white to red. Expression of tor, akt, s6k1, and s6 in the hepatopancreas was significantly upregulated, while 4e-bp1, eif4e1a, eif4e2, and eif4e3 were downregulated with dietary replacement of FM with KM increasing from 0% to 30% (P < 0.05). Crabs fed with the KM20 diet had notably higher expression of cat, gpx, cMnsod, and prx than those fed with the KM0 diet (P < 0.05). Results demonstrated that 10% replacement of FM with KM can promote growth performance and antioxidant capacity and notably upregulate the mRNA levels of genes related to TOR pathway and antioxidant of swimming crab.

The Effects of Two-Stage Fermented Feather Meal-Soybean Meal Product on Growth Performance, Blood Biochemistry, and Immunity of Nursery Pigs

The keratinase-producing microbes can readily change the feather waste into more bioavailable peptides and amino acids. This study aimed to improve two-stage fermented feather meal-soybean meal product (TSFP) quality with five selected Bacillus strains and Saccharomyces cerevisiae Y10, as well as investigate the effects of TSFP on growth performance, blood biochemistry, and immunity of nursery pigs. In trial 1, 100 hybrid piglets (Duroc x KHAPS) were randomly assigned to dietary supplementation of 5% fish meal or 5% TSFP prepared with 0, 32, 40, or 48 h in the first-stage fermentation. The results showed that the body weight (BW), average daily gain (ADG), and feed conversion ratio (FCR) of fermented groups were significantly better than the unfermented group (p &lt; 0.05) at weeks 0 to 3 and 0 to 5. The ADG of 32-hr and 48-hr TSFP groups were better than the unfermented group (p &lt; 0.05) at weeks 3 to 5. In trial 2, 80 hybrid piglets (Duroc × KHAPS) were randomly assigned into 5% fish meal or different supplementation levels of TSFP (32-hr first-stage fermented time) at 0, 2.5, or 5%. The 5% TSFP group had better BW, ADG, FCR, and PEF than the 0% group (p &lt; 0.05) at weeks 0 to 5. Furthermore, the ex vivo mitogen-induced lymphoblastogenesis, the interferon-γ production, the oxidative burst activity, and the IgG production of the 5% TSFP group were higher than the fish meal group (p &lt; 0.05). In conclusion, the first-stage fermentation time can be shortened from 48 h to 32 h using selected Bacillus strains in TSFP production when supplemented at 5% of the diet for nursery pigs shows the best growth performance and immunity.

The Effect of The Use of Fish Flour as a Source of Protein in Complete Feeds on The Digestivenes of Fat, Crude Fiber and Nitrogen-Free Extract in Bali Cattle Fattened

The research has been carried out for 3 months, starting from May 13 to August 13, 2021 in the experimental cage of the Faculty of Agriculture, University of Timor, while the analysis of digestibility of fat, crude fiber, and Extract Material Without Nitrogen (EMWN) at the Chemistry Laboratory of the Faculty of Animal Husbandry, University of Nusa Cendana. The purpose of this study was to determine the effect of using fish meal as a protein source in a complete feed on the digestibility of fat, crude fiber, and EMWN in fattened male bali cattle. The method used in this study was a completely randomized design (CRD) which consisted of 3 treatments and 5 replications so that there were 15 experimental units. The treatments were: T1= Natural grass 30% + Milled corn 42% + Rice bran 13% + Brand Pollard 11% + Fish meal 4%, T2= Natural grass 30% + Milled corn 42% + Rice bran 9% + Brand Pollard 11% + fish meal 8%, T3=. Natural grass 30% + Milled corn 42% + Rice bran 5% + Brand Pollard 11% + fish meal 12%. The variables tested included Fat Digestibility (%), Crude Fiber Digestibility (%) and EMWN Digestibility%. The results of analysis of variance showed that digestibility of crude fat and digestibility of crude fiber had a significant effect (P&lt;0.05) and digestibility of EMWN had no significant effect (P&gt;0.05) on the percentage of digestibility of fat produced T1: 19.06%; T2; 34.11%; T3: 69.31%, digestibility of crude fiber produced T1: 42.13%; T2: 29.02%; T3: 18.52% and the resulting EMWN T1: 65.01%; T2: 60.28%; T3: 62.31%. It can be concluded that the use of completed feed prepared with fish meal containing 12% protein increased the crude fat digestibility value but the crude fat digestibility was lower when compared to 4% fish meal and 8% in fattened bali cattle. Meanwhile, the digestibility of EMWN was not affected by the use of different levels of fish meal in complete feeds.

Growth performance of Clarias gariepinus (Burchell, 1822) fed with varying substitution levels of fish meal with cattle hoof meal

Fifteen weeks (105 days) feeding trial was conducted to determine growth response and economic benefit of replacing fishmeal with cattle hoof meal (CHM) in the diets of African catfish (Clarias gariepinus) juveniles. Five isonitrogenous diets containing 42% crude protein were formulated in which CHM replaced fishmeal at 0%, 25%, 50%, 75% and 100% (coded as D2, D3, D4, D5 and D6 respectively). A commercial feed (D1) was used as reference diet. Two hapa partitioned into six treatments of three replicates each embedded in a concrete pond of 5m by 3m by 2m was used for the experiment. The fish were fed at 3% body weight three times daily between the hour of 6.00 am and 7.00am, 2.00 pm and 3.00pm, and 10.00 pm and 11.00 pm. The feeding ration was adjusted every three weeks after weighing. The mean of the monitored physico chemical parameters of the water in the experimental tank were pH (7.12), temperature (28.25oC), oxygen (5.77mg/l), ammonia (0.04mg/l), nitrite (0.04mg/l), nitrate (0.03mg/l) and bicarbonate (5.45mg/l). The proximate composition of cattle hoofs meal were 33.75% moisture content, 66% dry matter, 58.06% crude protein, 2.75% crude fibre, 3.25% crude lipid, 0.91% ash content and 1.78% Nitrogen free extract. Feeding trials indicated that all fish consumed the experimental diets actively. Fish fed with the commercial feed had the highest mean weight gain (204g), followed by those fed with the experimental diet with 25% of CHM (D3) (181g). The fish fed with the control diet with no cattle hoofs meal (D2) had lower mean weight gain compared to the fish fed with 25% CHM. The fish fed with 50% CHM, 75% CHM and 100% CHM exhibited a decreasing weight gain (148.60g, 143.73g and 129.00g respectively) as the substitution level of the CHM meal increased. The fish fed with 25% cattle hoof meal (D3) had the best growth performance and feed utilization proficiency (specific growth rate 2.58, relative growth rate 1403, protein efficiency ratio 1.67 and feed conversion ratio 1.47) among the fish fed the formulated diets (D2, D3, D4, D5 and D6). There was no significant difference (p˃0.05) in the survival value of fish fed with all the experimental diets. The fish fed with D3 had the best net profit (₦46.53) followed by D6 (₦45.63), D1 (₦42.54), D5 (₦41.61), D4 (₦31.49) and D2 (₦20.59) in decreasing order. This study revealed that CHM can replace fishmeal at a lower cost and efficient diets for Clarias gariepinus. The best result was produced at the substitution level of 25% inclusion of CHM. It is recommended that CHM be included in the feed of Clarias gariepinus at 25% for optimum growth performance and reduced cost of production.

High replacement of fishmeal by Chlorella meal affects intestinal microbiota and the potential metabolic function in largemouth bass (Micropterus salmoides).

Microalgae have beneficial effects on the performance of fish as additives and they are becoming a promising alternative to fishmeal as macronutrient ingredients. However, the impact on the fish intestinal microbiome and the function, caused by microalgae as protein sources in diets, remains unclear. This study aimed to determine the composition and potential function of the intestinal microbial community of largemouth bass (Micropterus salmoides) fed diets at five replacement levels (0, 25, 50, 75 and 100%) of fishmeal by Chlorella meal in a basal diet (400 g kg−1) after 8 weeks. The results showed significant decreases in unique amplicon sequence variants in the intestine at the higher levels of fishmeal replacement. At 50% of fishmeal replacement, dietary inclusions of Chlorella meal had no impact on species richness and Shannon diversity and the community structure of the intestinal microbiota. However, high levels of fishmeal replacement (75 and 100%) significantly induced intestinal community disturbance and diversity loss in largemouth bass. Responding to the high fishmeal replacement level, the dominant genus Cetobacterium and Pleslomonas sharply increased and several taxa from Lactobacillus decreased significantly. Functional data predicted by PICRUSt revealed that nutrition-related metabolism was dominant in the intestinal microbiota of fish fed all the five diets, although some potential functions, particularly amino acid and lipid metabolisms, and energy metabolism, were upregulated firstly, and then downregulated in fish fed diets with the increase of dietary Chlorella meal. Meanwhile, certain pathways were not enriched in intestinal microbiome until up to 75% of fishmeal replacement, such as carbohydrate metabolism, and cofactors and vitamins metabolism. To conclude, this study reveals that fishmeal replacement (50%) by Chlorella meal at the level of 237 g kg−1 in diets is feasible for largemouth bass without impairing the microbiome structure and the metabolism function, providing an alternative strategy for evaluating the possibility of fishmeal replacement by microalgae in aquafeeds.

An Evaluation of Replacing Fishmeal with Chlorella Sorokiniana in the Diet of Pacific White Shrimp (Litopenaeus Vannamei): Growth, Body Color, and Flesh Quality.

This study was conducted to investigate the effects of replacing fishmeal (FM) with Chlorella sorokiniana on growth and flesh quality of Pacific white shrimp, Litopenaeus vannamei. A control diet was formulated to contain 560 g/kg FM, and then chlorella meal was used to replace 0% (C-0), 20% (C-20), 40% (C-40), 60% (C-60), 80% (C-80), and 100% (C-100) of dietary FM, respectively. The six isoproteic and isolipidic diets were fed to shrimp (1.37 ± 0.02 g) for 8 weeks. The results showed that weight gain (WG) and protein retention (PR) of C-20 group were significantly higher than those of C-0 group (P < 0.05), while no significant differences were observed in WG and PR between C-0 and C-40 groups (P > 0.05). When the replaced level of FM by chlorella meal reached 60%, the WG of shrimp decreased and feed conversion ratio (FCR) increased significantly (P < 0.05). The quadratic regression analysis indicated that substituted fishmeal levels with chlorella meal were 20.50% and 28.25%, respectively, to obtain the highest WG and lowest FCR. In C-40 and C-60 groups, the body surface presented higher redness than the control (P < 0.05). No significant differences in the whole body and muscle composition, SOD, T-AOC, GSH-PX activities, MDA contents, total collagen content, steaming loss, texture property, free delicious amino acids contents, PUFAs, and n-3/n-6 PUFAs in flesh were observed among the three groups of C-0, C-20, and C-40 (P > 0.05). Compared to the control group, C-60, C-80, and C-100 groups showed lower flesh hardness, chewiness, shear force, and higher steaming loss and resilience (P < 0.05). There were no significant differences in serum TP, TG, GLU, and ALB contents, boiling loss, freezing loss, total free amino acids, SAFs and MUFAs among all the groups (P >0.05). Conclusively, in a diet containing 560 g/kg FM, chlorella meal could replace 40% dietary FM without negative effects on the growth and flesh quality, while increase the body redness of white shrimp.

Olfaction and gustatory senses promote feeding through different pathways in yellowtail, Seriola quinqueradiata

For sustainable aquaculture, the replacement of dietary fishmeal with plant protein is becoming more common because fishmeal resources are limited. However, in the case of carnivorous fish such as yellowtail (Seriola quinqueradiata), reducing the dietary fishmeal level often causes low feed intake. Improving feed intake is important in the use of a non- and low-fishmeal diet. However, little is known about the mechanisms that regulate feeding in yellowtail. The relationship between appetite, feeding behaviour, and food intake needs to be examined to elucidate the mechanisms of feeding regulation. The senses of smell (olfaction) and taste (gustation) are important for feeding in fish. However, it is unclear how each of these senses stimulates feeding behaviour, appetite, and feed intake. In this study, the effects of olfactory and gustatory stimuli on feeding behaviour, brain expression of neuropeptide Y (NPY), and feed intake in yellowtail were investigated using a strong olfactory stimulant (alanine, Ala) and a strong gustatory stimulant (proline, Pro). By using observation tanks, feeding behaviour was divided into ‘search’ and ‘bite’. Ala promoted ‘search’ feeding behaviour and significantly decreased npy mRNA expression in the olfactory bulb and telencephalon as the olfactory centre and hypothalamus as the appetite centre. No increment in feed intake was found in the Ala-supplemented diets compared to the control diet. Meanwhile, Pro increased npy mRNA expression in the gustatory centre (cerebellum), promoted ‘bite’ feeding behaviour, and increased feed intake. Odour stimulation promoted ‘search’ through npy mRNA expression but was not reflected in feed intake. Taste stimulation promoted ‘bite’ through npy mRNA expression, which increased feed intake. Thus, olfactory and gustatory senses may promote feeding through different pathways in the yellowtail. These results will contribute to increasing the feeding amount of non- and low-fishmeal diet in the feed of yellowtail towards sustainable aquaculture.

Utilization of Biang Fish Flour (Ilisha elongata) as an Enrichment Material for Sago Noodles Nutrient Value.

This study aims to determine the appropriate concentration of lead fish meal for enriching the nutritional value of sago noodles favored by consumers. The method used is an experimental design using Completely Randomized (CRD) with 4 concentration levels of lead fish meal, namely, 4% without a lead fish meal (M0), 6% (M1), 8% (M2), and 10% (M3). The analysis of sago noodles was performed and proximate by the AOAC method; amino acids by HPLC; fatty acids by GC; and minerals by HPLC. The results of the showed that the study getting the best treatment was a concentration of 8% (M2) with the characteristics of whole sago noodles' appearance: attractive, grayish-white color; a distinctive aroma of sago noodles with a hint of fish; a specific taste typical of sago noodles and fish prickly taste; delicious; slightly chewy texture. Sensory evaluation with a taste value of 8.9, an aroma of 8.6, a visual value of 8.9, and a texture value of 8.8. Its nutritional content is 5.58% protein content, air 22.35%, ash 1.69%, fat 1.41%, and carbohydrates 68.29%. The proximate values are protein 5.58%, water content 22.35%, ash 1.69%, fat content 1.41%, and carbohydrates (different) 68.29%. The mineral content is Ca.P.I, Mg, Zn, and Fe. Amino acids consist of 8 types of essential amino acids, namely, histidine, arginine, threonine, valine, alanine, methionine, isoleucine, leucine, phenylalanine, and 7 types of nonessential amino acids, namely, aspartic acid, glutamic acid, serine, glycine, tyrosine. Its fatty acid profile has 13 components of unsaturated fatty acids and 17 components of saturated fatty acids.

Effects of replacing dietary fish meal with enzyme-treated soybean meal on growth performance, intestinal microbiota, immunity and mTOR pathway in abalone Haliotis discus hannai

In addition to eliminating most of the anti-nutritional factors in soybean meal, enzyme-treated soybean meal (ESBM) can also increase the proportion of small peptides. It was found that ESBM can replace fish meal (FM) either partially or completely in diets for some fish and shrimp species. In the present study, the effects of replacing dietary FM with ESBM on growth performance, intestinal microbiota, immunity and mTOR pathway in abalone Haliotis discus hannai (initial weight: 16.75 ± 0.09 g) were investigated after a 100-day feeding trial. Five experimental diets were designed to replace 0%, 25%, 50%, 75% and 100% of dietary FM by ESBM, which were named as ESBM0 (control), ESBM25, ESBM50, ESBM75 and ESBM100, respectively. Results showed that ESBM could replace up to 75% of FM in the diet without significant effect on the weight gain rate (WGR, 118.05%–124.16%) of abalone. The increasing dietary ESBM levels significantly decreased the trypsin activity from 418.52 to 286.52 U/mg protein in the digestive gland. No significant differences in the contents of total cholesterol (T-CHO), ammonia (BLA) and malondialdehyde (MDA) in cell-free hemolymph were observed among the groups with replacement levels of dietary FM by ESBM from 0% to 75%. Excessive replacement level of FM with ESBM (ESBM100) significantly increased the MDA content (2.33 nmol/mg prot.) and pro-inflammatory-related gene expression in digestive gland. Compared with the control group, the mTOR pathway in muscle was significantly upregulated in the ESBM75 group. The digestive gland in the ESBM100 group contained more golden refractile spherules than those in the other groups. The abundance of intestinal microbes such as Halomonas, Zobellella and Bacillus was decreased in the ESBM100 group. In conclusion, up to 75% of replacement of dietary FM by ESBM had no negative effects on the growth performance, intestinal microbiota, immunity and mTOR pathway of abalone.

Dietary brewer's spent yeast enhances growth, hematological parameters, and innate immune responses at reducing fishmeal concentration in the diet of climbing perch, Anabas testudineus fingerlings.

A 60-day feeding trial was conducted to optimally reduce the fishmeal level in climbing perch (Anabas testudineus) fingerling diet using a dietary brewer’s spent yeast biomass (BSY) based diet. In this study, five isonitrogenous (35% CP) and isocaloric (19.15 MJ/Kg) feeds were prepared by replacing 0 (BSY0), 25% (BSY25), 50% (BSY50), 75% (BSY75) and 100% (BSY100) of fishmeal protein using BSY protein. A total of 225 numbers of uniform-sized climbing perch fingerlings (3.29 ± 0.09 g) were randomly stocked in the 15 rectangular FRP (Fiber-reinforced plastic) tanks (150 L capacity). The experimental fish were fed twice daily at 4% BW for the first fortnight and later reduced to 3% BW based on satiation. At the end of the feeding trial, the weight gain (WG) of fish increased with the increasing BSY incorporation rates corresponding to fishmeal content and peaked at 77.88%, and beyond that, WG decreased. Food conversion ratios decreased as dietary BSY levels increased and peaked at 76.28%. All other growth and feed utilization parameters followed a similar trend of weight gain. Hepatosomatic index (HSI) and viscerosomatic index (VSI), A:G ratio, serum catalase activity, and monocytes were unaffected and the total serum protein, albumin, globulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), respiratory burst activity, lysozyme levels, myeloperoxidase activity, hemoglobulin, red blood cells, white blood cells, neutrophils, eosinophils, lymphocytes, and gut protease activities were increased significantly (P < 0.05) with the increasing replacement levels and peaked between 25 and 75%. The serum SOD activity and total platelets were decreased, whereas the serum uric acid and gut amylase activities were increased significantly to the increasing levels of FM replacement in the diets (P < 0.05). Among treatments, the BSY100 resulted in an overall poor growth response combined with relatively reduced values in nearly all biochemical parameters. The whole-body composition was nearly unaffected. The integrated biomarker response of various biochemical indicators from the different treatments has shown that the 50% fishmeal protein can be optimally replaced by BSY, which would cause an 18% reduction in the Economic conversion ratio (ECR) and −270.28 gCO2e– reduction in carbon footprint value per kg of climbing perch fingerlings production.

Zootechnical performance, immune response, and resistance to hypoxia stress and Vibrio harveyi infection in Pacific white shrimp (Litopeneaus vannamei) fed different fishmeal diets with and without addition of sodium butyrate

The dietary effect of a chemically protected sodium butyrate, Butirex®C4 (BU), on growth performance, digestive enzymes activity, immunity, gut microflora, and resistance against hypoxia stress and infectious disease were studied in Pacific white shrimp fed different levels of fishmeal (FM) diets in earthen outdoor ponds. Nine isonitrogenous and isolipidic experimental diets were formulated to contain different levels of FM (45 %, 30 %, and 15 %) and enriched with the incremental levels of BU (0, 0.3%, and 0.6%). After 60 days, the shrimp fed diets containing 45% and 30 % FM along with 0.3 % and 0.6 % BU, respectively, showed higher levels of final weight and weight gain, while, the group fed diet with 15 % FM free from BU showed the highest level of feed conversion ratio. The levels of protease and trypsin activity significantly decreased in the group fed 15 % FM without BU, while the administration of BU improved the digestive enzymes activity in low FM diets. The total hemocyte count, phenoloxidase, and lysozyme were negatively affected by decreasing levels of FM in the diets, but BU-supplemented diets improved these parameters. The dietary administration of BU increased lactic acid bacteria and decreased total Vibrio sp. counts in the intestine of shrimp fed different levels of FM. Although the diets with low levels of FM had no significant effect on the hypoxia stress tolerance, the cumulative mortality was decreased in the low FM groups fed with different BU levels. The mortality of shrimp against Vibrio harveyi infection was notably decreased in BU-added groups compared to the groups that did not receive BU in their diets. Overall, dietary BU administration at 0.6 % mitigates the adverse impacts of the diets with the lowest FM (15 %) on overall performance and immunity in Pacific white shrimp.

Replacement of dietary fishmeal by cottonseed protein concentrate on growth performance, feed utilization and protein metabolism of large yellow croaker Larimichthys crocea

A 90-day feeding trial was conducted to evaluate the effects of cottonseed protein concentrate (CPC) replacing dietary fishmeal on growth performance, feed utilization and protein metabolism of large yellow croaker (initial body weight: 191.60 ± 1.36 g). Seven iso-nitrogenous and iso-lipidic experimental diets were formulated by replacing 0%, 15%, 30%, 45%, 60%, 75% and 100% of dietary fishmeal with CPC. The experimental diets were named as CPC0, CPC15, CPC30, CPC45, CPC60, CPC75 and CPC100, respectively. Results showed that when CPC replacement level was less than 60%, there were no significant differences in survival, weight gain rate, feed intake, feed conversion ratio, protein efficiency ratio, hepatosomatic index, visceral somatic index and condition factor of large yellow croaker compared with those in the CPC0 group (P > 0.05). The dorsal muscle proximate compositions and amino acid profiles were not significantly affected by dietary CPC replacement levels (P > 0.05). Compared with those in the control group, digestive and absorptive enzymes activities in the intestine and liver in the CPC75 and CPC100 groups decreased significantly (P < 0.05). The perimeter ratio, muscularis thickness and villus height in the intestine decreased linearly with increasing replacement levels of dietary fishmeal by CPC (P < 0.05). Compared with those in the CPC0 group, the mRNA levels of mammalian target of rapamycin, ribosomal protein S6, eukaryotic translation initiation factor 4E in the muscle were down-regulated with increasing dietary CPC levels, and while the expressions of eukaryotic translation initiation factor 4E-binding protein, general amino acid control nonderepressible 2 and eukaryotic translation initiation factor 2 α were up-regulated. Take the growth performance, feed utilization and protein metabolism into account, 60% of dietary fishmeal could be replaced by CPC in large yellow croaker.

Replacement of dietary fish meal with Clostridium autoethanogenum meal on growth performance, intestinal amino acids transporters, protein metabolism and hepatic lipid metabolism of juvenile turbot (Scophthalmus maximus L.)

Clostridium autoethanogenum meal (CAM) is a novel single-cell protein, which is produced from bacteria using carbon monoxide (CO) as sole carbon source. To evaluate the efficiency of CAM as an alternative for dietary fish meal, a 56-days growth experiment was performed on juvenile turbot (Scophthalmus maximus L.) with initial average weight of 9.13 ± 0.02 g. Six iso-nitrogenous (crude protein, 51.0%) and iso-lipidic (crude lipid, 11.5%) diets were formulated with 0%, 15%, 30%, 45%, 60% and 80% dietary fish meal protein substituted by CAM protein, which were designated as CAM0 (the control group), CAM15, CAM30, CAM45, CAM60 and CAM80, respectively. Results showed that no significant differences were observed in survival rate (over 97.50%) among different dietary treatments (p > 0.05). The specific growth rate (SGR) was not significantly affected when replacement levels of dietary fish meal with CAM were less than 45% (p > 0.05). The feed intake (FI) was significantly linear reduced with increasing dietary CAM (p < 0.05), whereas no significant differences were observed in feed efficiency ratio (FER), protein efficiency ratio (PER) and protein retention (PR) among different dietary treatments (p > 0.05). With increasing dietary CAM, lipid retention (LR) and carcass lipid tended to be increased in both significantly linear and quadratic patterns (p < 0.05). The apparent digestibility coefficient (ADC) of crude protein and some essential amino acids, including threonine, valine, lysine, histidine and arginine, showed significantly linear increase with increasing dietary CAM (p < 0.05). Furthermore, with the increase of dietary CAM, the gene expression of intestinal peptide and amino acids transporters was first up-regulated and then down-regulated with significantly quadratic pattern (p < 0.05), peaking in fish fed with diets CAM30 or CAM45, which was similar to the expression of genes related protein degradation in muscle. For genes related to protein metabolism in liver and muscle, the expression of mammalian target of rapamycin (mtor) was not significantly affected by dietary CAM, while the general control nonderepressible 2 (gcn2) tended to be first up-regulated and then down-regulated with significantly quadratic pattern (p < 0.05). Apart from that, the lipid metabolism of turbot was also affected by high dietary CAM, evidenced by increased expression of hepatic genes related to lipogenesis as well as reduced expression of genes related to lipid oxidation and lipid transport. In conclusion, CAM can replace up to 45% fish meal protein in diet for juvenile turbot without significantly adverse effects on growth performance. But excessive dietary CAM would result in significant growth reduction, and excessive lipid deposition may also occur in fish fed diets with high levels of CAM.

Effects of dietary fishmeal levels on adenosine triphosphate-related compounds and freshness of raw and cooked muscle in large yellow croaker Larimichthys crocea

A comparative study on the adenosine triphosphate (ATP)-related compounds and freshness of raw and cooked muscle in wild and farmed large yellow croaker (Larimichthys crocea) was performed. The two groups of farmed fish (189.87 ± 0.89 g) were fed two diets containing 44% (CF) and 25% (LF) of fish meal (FM) for 82 days, respectively. Results showed that the contents of ATP, adenosine diphosphate (ADP), adenosine monophosphate (AMP) and inosine 5′-monophosphate (IMP) were highest in raw and cooked muscle of wild fish, while these values were lowest in raw and cooked muscle of fish fed LF. Conversely, wild fish had the lowest inosine (Ino) and hypoxanthine (Hx) contents in raw and cooked flesh, while the LF group had the highest levels of Ino and Hx in raw and cooked flesh. Fish fed CF had significantly higher amounts of ATP, ADP and IMP in raw muscle, ATP and AMP in cooked muscle than those in the LF group (P < 0.05). The above results allowed wild fish to have the lowest K and Ki values, closely followed by fish fed CF, and the LF group have the highest values in raw and cooked muscle (P < 0.05). Meanwhile, cooking significantly decreased ATP, ADP and IMP contents, while increased AMP and Ino levels, inducing significantly higher K and Ki values in cooked muscle of all the treatments (P < 0.05). In conclusion, lower dietary FM level could decrease the contents of IMP and its precursors, and increase the degradation products of IMP in muscle, leading to the declines in umami and freshness. The stronger umami of wild large yellow croaker could be related to the higher precursors and lower degradation products of IMP in fillets.

Effects of Decreasing Fishmeal as Main Source of Protein on Growth, Digestive Physiology, and Gut Microbiota of Olive Flounder (Paralichthys olivaceus).

Simple SummaryThe demand for fishmeal is increasing due to aquaculture development, but the supply is unstable. This indicates the need to reduce the fishmeal content in the feed and develop an optimal fish-feed formulation through substitutes. However, most studies on reducing fishmeal content in feed were conducted at the laboratory level. In this study, the application of a low-fishmeal diet as feed to olive flounder was evaluated in terms of growth-related factors, digestive physiology, and microbiota raised for five months in a fish farm using four feed formulations- FM70 [control (CON), 70% fishmeal], FM45 (45% fishmeal), FM35A (35% fishmeal), and FM35B (35% fishmeal + insect meal). There was no difference in growth-related factors, digestive physiology, and gut microbiota diversity compared with the CON-fed fish. Therefore, reducing the fishmeal content of the feed by up to 35% does not adversely affect growth and physiological characteristics under farm conditions.In olive flounder (Paralichthys olivaceus), growth performance, expression of growth-related factors, digestive physiology, and gut microbiota were assessed under farm conditions in the fish fed diets with low levels of fishmeal. Four experimental diets were prepared, FM70 [control (CON), 70% fishmeal], FM45 (45% fishmeal), FM35A (35% fishmeal), and FM35B (35% fishmeal + insect meal), and fed to the fish for five months. The CON-fed fish had the highest plasma GH, but IGF-1 and hepatic IGF-1 mRNA expression of the olive flounder fed diets with low-fishmeal levels did not significantly differ among diets. The intestinal villus length, muscular thickness, and the number of goblet cells were statistically similar, and ocular examination of hepatopancreas showed no discernable difference in all experimental diets. The chymotrypsin content of FM35B-fed fish is significantly lower, but trypsin and lipase contents are similar. The diversity of gut microbiota did not differ among groups, although the FM35B group had a higher composition of Firmicutes. Thus, a diet with reduced fishmeal content and several alternative protein sources can be used as feed ingredients in feed formulation for olive flounder reared under typical aquaculture farm conditions.

Effects of Bacillus subtilis DSM 32315 (Gutcare®) on the growth performance, antioxidant status, immune ability and intestinal function for juvenile Litopenaeus vannamei fed with high/low-fishmeal diets

This study was conducted to investigate the effects of dietary Bacillus subtilis DSM 32315 (Gutcare®) supplementation on the growth performance, antioxidant status, immune ability and intestinal function in juvenile Litopenaeus vannamei fed with high/low-fishmeal diets. A 4 × 2 two-factor design was formulated with graded dietary Gutcare® and fishmeal levels. Specifically, four Gutcare® supplemental levels (0, 0.05%, 0.15% and 0.3%) were added under two fishmeal diets (20% and 5% fishmeal levels). Each diet was randomly assigned to five replicate groups of 30 juvenile Pacific white shrimp that were stocked in fiberglass tanks. The results indicated no significant inhabitation on the growth performance, hepatopancreas antioxidant capacity, immune response and intestinal function at 5% fishmeal compared with 20% fishmeal. Shrimp fed with Gutcare® supplementation regardless of high/low-fishmeal diets exhibited higher growth performance, antioxidant- and immune-related enzyme activities (P < 0.05) compared with that 0% Gutcare® supplementation. However, none of the treatments found significant differences in feed efficiency and survival. The mRNA expression levels of Cu/Zn superoxide dismutase, heat shock protein 70, glutathione peroxidase, prophenoloxidase and lysozyme were significantly up-regulated (P < 0.05) at shrimp fed with Gutcare®. Moreover, the results of mid-intestine morphology showed a significant increase with the addition of Gutcare®, and the highest height and thickness of intestinal epithelium occurred at shrimp fed 0.15% Gutcare®. Bacterial community composition showed that shrimp fed with the graded Gutcare® significantly increased the abundance of Firmicute and reduced the relative abundance of Vibrio (P < 0.05). In conclusion, 5% fishmeal supplementation with well-balanced amino acid composition had no adverse effect on the growth performance of L. vannamei when compared with the 20% fishmeal. Dietary Gutcare® significantly enhanced immunity and antioxidant capacity, and improved intestinal function of L. vannamei. The positive effect of Gutcare® at 5% fishmeal diet provided a possibility for reducing fish meal in the commercial diets of Pacific white shrimp.