Levels Of Fish Meal Research Articles

Replacement of fish meal with cottonseed protein concentrate in Chinese mitten crab (Eriocheir sinensis): Nutrient digestibility, growth performance, free amino acid profile, and expression of genes related to nutrient metabolism

This study aimed to investigate the application of cottonseed protein concentrate (CPC) in Chinese mitten crabs (Eriocheir sinensis). First, the apparent digestibility coefficient (ADC) of CPC, fish meal and soybean meal were compared in crabs (21.72 ± 0.33 g). The protein ADC of CPC was 90.42%, which was significantly higher than that of soybean meal (83.16%) (P < 0.05). The ADC of Phe, Cys and Glu of CPC were significantly higher than those of fish meal, while the ADC of Ile, Leu, Lys, Met, Thr and Ala of CPC were significantly lower (P < 0.05). Second, we investigated the effects of fish meal substitution by CPC on growth performance, free amino acid profile, and expression of genes related to nutrient metabolism in crabs. Six diets were formulated by replacing 0%, 15%, 30%, 45%, 60% and 75% fish meal with CPC, namely FM, CPC15, CPC30, CPC45, CPC60, and CPC75. A total of 630 crabs (1.68 ± 0.00 g) were randomly divided into 18 tanks (3 tanks per group) and fed 3 times daily for 9 weeks. Results showed that CPC75 group significantly reduced growth performance, feed conversion efficiency, and free Ile, Leu, Lys, Met, and Thr contents in muscle (P < 0.05). The contents of free amino acids (Arg, His, Ile, Leu, Lys, Met, Phe, Thr, Val, Ala, Cys, Glu, Gly, Ser and Tyr) in hepatopancreas decreased linearly with the increase of dietary CPC level (P < 0.05). The substitution of more than 45% fish meal with CPC significantly decreased the concentration of delicious amino acids (Ala, Glu and Gly) in hepatopancreas (P < 0.05), which might adversely affect crab flavor. The expression of genes related to antioxidant capacity, protein transport, TOR pathway and lipid metabolism was significantly downregulated by increasing dietary CPC level (P < 0.05). In conclusion, based on the quadratic regression analysis of FCR and PER, the optimal replacement levels of fish meal with CPC in crab diet containing 35% fish meal were 32.36% and 35.38%, respectively. It is recommended that Ile, Leu and Thr be supplemented in addition to Met and Lys in the application of CPC.

Microalgae as fishmeal alternatives in aquaculture: current status, existing problems, and possible solutions.

Fishmeal is an indispensable ingredient for most aquatic animals. However, the finite supply and escalating price of fishmeal seriously limit its use in aquaculture. Thus the development of new, sustainable protein ingredients has been a research focus. Microalgae are potential fishmeal alternatives owing to their high protein content and balanced amino acid profile. Studies suggest that suitable replacement of fishmeal with microalgae is beneficial for fish growth performance, but excessive replacement would induce poor growth and feed utilization. Therefore, this paper aims to review research on the maximum substitutional level of fishmeal by microalgae and propose the main issues and possible solutions for fishmeal replacement by microalgae. The maximum replacement level is affected by microalgal species, fish feeding habits, quality of fishmeal and microalgal meals, and supplemental levels of fishmeal in the control group. Microalgae could generally replace 100%, 95%, 95%, 64.1%, 25.6%, and 18.6% fishmeal protein in diets of carp, shrimp, catfish, tilapia, marine fish, and salmon and trout, respectively. The main issues with fishmeal replacement using microalgae include low production and high production cost, poor digestibility, and anti-nutritional factors. Possible solutions to these problems are recommended in this paper. Overall, microalgae are promising fishmeal alternatives in aquaculture.

Growth and Hepatopancreas Health of Juvenile Chinese Mitten Crab (Eriocheir sinensis) Fed Different Levels of Black Soldier Fly (Hermetia illucens) Larvae Meal for Fish Meal Replacement.

A 56-day feeding trial assessed the effects of black soldier fly larvae meal (BSFLM) on the growth performance and hepatopancreas health of juvenile Eriocheir sinensis. Six isoproteic and isolipidic diets with 0% (FM), 10% (BSFLM10), 20% (BSFLM20), 30% (BSFLM30), 40% (BSFLM40), or 50% (BSFLM50) replacement of fish meal by BSFLM were formulated. Compared to FM, replacing 10%-40% of fish meal with BSFLM did not significantly affect the weight gain rate (WGR) or specific growth rate (SGR), while BSFLM50 significantly decreased the WGR and SGR. Crabs fed BSFLM50 had significantly lower T-AOC activity than those fed other diets, and crabs fed BSFLM30, BSFLM40, or BSFLM50 had significantly lower activities of antioxidant enzymes (SOD and GSH-Px) in the hepatopancreas than those fed FM or BSFLM10. Compared to FM, BSFLM10, BSFLM20, and BSFLM30 did not affect the relative expression of genes related to the nonspecific immunity, while BSFLM40 and BSFLM50 upregulated the relative expression of these genes. Furthermore, histological analysis showed that the hepatopancreas was deformed in the BSFLM50 group, with widened lumens and loss of basal membrane integrity. In summary, BSFLM replacing 50% of fish meal reduced growth and structural damage to the hepatopancreas. An immune response was activated when the replacement level was over 30%. Therefore, the replacement level of dietary fish meal by BSFLM is recommended to be not more than 30% of the juvenile E. sinensis feed.

THE EFFECT OF REPLACEMENT OF FISH MEAL WITH FERMENTED SOYBEAN MEAL IN THE COMBINED FEED ON THE MORPHOLOGICAL AND CHEMICAL COMPOSITION OF THE BODY OF YOUNG CLARIAS GARIEPINUS (CLARIAS GARIEPINUS)

The article examines the impact of feeding compound feed with different levels of fishmeal replacement with fermented soybean meal on the morphological and chemical composition of the body of young clary catfish (Clarias gariepinus). Experimental studies were carried out in the conditions of the experimental base of the problematic research laboratory of feed additives of the Department of Animal Feeding and Feed Technology, National University of Life and Environmental Sciences of Ukraine. A scientific and economic experiment was conducted using the method of groups of analogues lasting 56 days, which was divided into four subperiods of 14 days each. For the experiment, 600 heads of young clary catfish with an average weight of 25 grams were selected, and six groups of 100 heads each—a control group and 5 experimental ones—were formed by the analogue method. Young clary catfish were fed compound feed, which differed in the level of the introduction of fermented soybean meal. Thus, the combined feed of the control group contained 36% fish meal without the addition of fermented soybean meal EP500, while in the combined feed of group 2, the content of fish meal was reduced to 26% and 10% fermented soybean meal EP500 was added. In compound feed for group 3, the level of fish meal continued to decrease to 21%, and the level of fermented soybean meal EP500 was increased to 15%. Focusing on 100% replacement of fishmeal, the compound feed of groups 4, 5, and 6 was characterised by a 16%, 11%, and 0% content of this ingredient, while fermented soybean meal EP500 in these groups was 20%, 25%, and 36%, respectively. At the end of the experiment, the morphological and chemical composition of the body was determined by weight on ten specimens of the most typical fish. The muscle tissue of skinless fish was used to study the chemical composition. Before analysis, all samples were stored in a refrigerator. It was established that the use of compound feed with the replacement of fish meal in the feeding of young clary catfish and the introduction of fermented soybean meal into its composition at the level of 25-36% led to an increase in the weight of the carcass of the cartridge by 3.69 (р≤0.05) - 4, 12% (р≤0.01); carcass weight by 4.10 – 4.67 (р≤0.01); muscle tissue mass by 3.99 - 4.98 (р≤0.01) compared to the control group. At the same time, it should be noted that feeding compound feed with different levels of fermented soybean meal had no probable effect on the chemical composition of young clary catfish muscle tissue.

The Substitution of Fish Meal or Chicken Meal With Yeast Culture in Diets of Bullfrogs (Lithobates catesbeianus): Growth Performance, Serum Biochemical Indices, Intestinal Digestive Enzyme, Hepatic Antioxidant, and Hepatic and Intestinal Histology

The aim of this study was to reveal the effects of yeast culture replacing fish meal (FM) or chicken meal (CM) on the growth performance, serum biochemical indexes, intestinal digestive enzyme activities, hepatic antioxidant, and hepatic and intestinal histology of bullfrog (Lithobates catesbeianus). The basal diet contained 100 g/kg FM and 100 g/kg CM, and then yeast culture was used to decrease FM or CM level to 75 and 50 g/kg with yeast culture inclusion of 32 and 64 g/kg, respectively, resulting in five groups of isonitrogenous diets (control, FM75, FM50, CM75, and CM50). A total of 450 bullfrogs (45.5 ± 0.4 g initial weight) were fed the five diets for 50 days. (1) The FM50 group presented significantly lower weight gain, condition factor, hind leg index, and higher feed conversion ratio than the control group, while the other three groups of FM75, CM75, and CM50 showed no significant difference in growth performance when compared to the control group. (2) The serum triglyceride content of FM50 group was significantly lower, while the alkaline phosphatase activity was significantly higher than those of the control group. The serum total cholesterol levels were significantly lower in the CM50 group compared to the control group. (3) In intestinal digestive enzyme activities, the trypsin and α‐amylase activities in the CM75 and CM50 groups, the trypsin activity in the FM75 group, and lipase activity in the CM50 group were all significantly higher than those in the other groups. (4) The replacement of 50% FM with yeast culture (FM50 and CM50 groups) promoted the total antioxidant capacity in the liver, but compared to the control group, the intestinal villi height and muscularis propria thickness in the FM50 group were significantly lower. There was no difference (P &gt; 0.05) in liver histology among all the groups. In conclusion, in a basal diet containing 100 g/kg FM and 100 g/kg CM, 32.0 and 64.0 g/kg yeast cultures could successfully replace 25% of dietary FM and 50% of dietary CM without negative effects on the growth performance, serum biochemical indexes, and hepatic and intestinal health of bullfrogs.

Effects of replacing fishmeal with different proportions of mixed protein source in the diet of largemouth bass (Micropterus salmoides)

Fishmeal is an important protein source for largemouth bass (Micropterus salmoides). However, the production of fishmeal is decreasing each year and the price of fishmeal is rising. Therefore, it is necessary to find new high-quality and suitable protein sources. This study used a mixed animal protein source (chicken meal:blood meal:shrimp meal:brewer's yeast = 50:12.5:25:12.5) to replace fishmeal. Using a 48 % fishmeal group as the control, five diets with different fishmeal levels (FM48, FM44, FM40, FM36, FM32) were established to determine the effects on largemouth bass growth performance, liver health and intestinal health. There were no significant differences in the percentage weight gain, specific growth rate, feed conversion rate, and condition factor of largemouth bass, but the hepatosomatic and viscerosomatic indexes were significantly decreased when the dietary fishmeal level was reduced to 40 %. The content of taurine, glycine, and histidine was significantly reduced in the muscle of largemouth bass fed the FM32 diet compared with those fed the FM48 and FM44 diets. Mixed protein feed reduced the total bile acid content and increased the low-density lipoprotein cholesterol content in the plasma of largemouth bass. The replacement of fishmeal with the mixed protein source inhibited the expression of tnf-α and caspase 3 and enhanced the expression of apoa1 in the liver, as well as enhancing the protein expression of FXR and SREBP and inhibiting the protein expression of P-PPARA in the liver. The intestinal pparα expression was suppressed when dietary fishmeal was replaced. When dietary fishmeal decreased, the mucosal folds height and muscle layer thickness also decreased. In conclusion, partial replacement of fishmeal with the mixed protein source did not affect the growth performance, while lipid metabolism and intestinal health were negatively affected when dietary fishmeal levels were below 36 %.

Functional Effects of Hydrolyzable Tannins on the Growth, Health Status, and Hepatopancreas Histology of Pacific White Shrimp Penaeus vannamei Reared under Commercial Pond Conditions

In the present study, the functional effects of hydrolyzable tannins (HT) extracted from the sweet chestnut tree Castanea sativa were evaluated either by directly incorporating them into the diet or by using a top-dressing application on the growth, body composition, total hemocyte counts, lysozyme activity, and histomorphological condition of the hepatopancreas of Pacific white shrimp Penaeus vannamei. Shrimp was confined in hapa nets installed within commercial outdoor ponds for 90 days. Eight experimental diets included a basal formulated diet (BD) with varying inclusion levels of HT (BD-0%, BD-0.1%, BD-0.2%, and BD-0.3%), a low fish meal (FM) diet with reduction on the inclusion level of FM from 10% to 7.5% and labeled as LFM 0.3% HT, a top-dressing HT application (TC) on basal diet (BDTD-0.4% HT), and a commercial diet (CDTD-0% HT and CDTD-0.4% HT). The final body weight (FBW), percentage weight gain (PWG), thermal growth coefficient (TGC), average daily growth (ADG), and feed conversion ratio (FCR) were significantly better in the group of shrimp fed with BD-0.3% HT compared to BD-0% HT. The administration of CD-0.4% HT was able to enhance the growth performance of shrimp compared to BD-0% HT and CD without HT. Higher protein and fat contents were found in the body of shrimp fed with graded levels of HT compared to shrimp fed with BD or CD without HT. Numerically, the direct inclusion and top-dressing process of HT increased the total hemocyte count and lysozyme activity in shrimp. Both BDTD-0.4% HT and CDTD-0.4% HT were also able to support a better hepatopancreatic condition with reference to histomorphology and integrity. These results indicated that BD-0.3% HT inclusion could significantly improve the growth performance and prevent the alteration in health and histomorphological condition of the hepatopancreas of shrimp P. vannamei cultured in hapa nets under commercial farm conditions, but also 0.4% HT could be used as a supplementation dosage for the top-dressing process in diets.

Efficacy of an Insect-Based Diet with Addition of Probiotics on Growth, Proximate Composition, Enzymatic Efficiency, and Immune Response of Nile Tilapia

Insects are potential alternative protein sources to replace fish meal (FM) in aqua feed. The role of insect species as replacements in the aqua industry has been a hot debate in the current era. The present study evaluated the influence of FM replacement with insect-based meals (black soldier fly (BSF) and maggot fly) in the feed of Nile tilapia. Eight diets with graded replacement levels of FM were formulated along with basal diet as T0 (control group having basal diet), T1 (25% maggot meal (MM) with 2% probiotics), T2 (50% MM + 2% probiotics), T3 (75% MM + 2% probiotics), T4 (100% MM + 2% probiotics), T5 (25% BSF meal (BSFM) + 2% probiotics), T6 (50% BSFM + 2% probiotics), T7 (75% BSFM + 2% probiotics), and T8 (100% BSFM + 2% probiotics). Fish having an initial body weight of 7 g were fed on formulated feed for 16 weeks. Growth parameters, including weight, length, feed conversion ratio, specific growth rate, and survival rate, were observed weekly, and significant ( p &lt; 0.05 ) results were attained up to 75% replacement level with no adverse effect on growth. However, at 100% replacement of FM, fish growth was retarded. Maximum survival rate was observed in T1 and T5 and minimal in T4 and T8. Body composition, including crude protein, fat, moisture, and ash, showed significant ( p &lt; 0.05 ) results. Similarly, digestive enzyme (protease, lipase, and amylase) activity was measured at the end of the trial. Fish in T1 and T5 groups had the highest digestive enzyme activity, which slightly decreased with the inclusion of insect-based meals and probiotics. Statistically significant ( p &lt; 0.05 ) results were observed for antioxidant enzyme activity in catalase, glutathione peroxidase, and superoxide dismutase. The most vigorous immune response was shown in T1 and T5, with higher white blood cells and high levels of IgM. The present research showed that FM could be replaced with BSF meal and MM with probiotics up to 50% for better fish health performance; however, 75% replaced FM without compromising growth and health status.

Effect of replacing fish meal with chicken gut meal on growth, immune parameters, and metabolism of juvenile Fat Greenling Hexagrammos otakii

AbstractObjectiveChicken gut meal (CGM) is reasonably priced and rich in nutrients and can become a new source of protein in the diets of major aquatic products, such as fish and shrimp.MethodsAn 8‐week feeding trial was conducted to comprehensively investigate the beneficial effects of CGM on juvenile Fat Greenling Hexagrammos otakii. Juveniles (1.58 ± 0.06 g [mean ± SE]) were fed with different levels of CGM in replacement of fish meal (FM) in the basal diet: 0% (CGM0), 25% (CGM25), 50% (CGM50), 75% (CGM75), and 100% (CGM100) replacement, representing a dietary CGM level of up to 40 g/kg.ResultThe results showed that the percent weight gain; specific growth rate; feeding rate; feed conversion ratio; hepatosomatic index; and apparent digestibility coefficients of dry matter, protein, and lipid were significantly improved among the experimental groups. Moreover, the activities of superoxide dismutase and catalase were significantly increased in the CGM25 and CGM50 groups, respectively. The activities of acid phosphatase and alkaline phosphatase were significantly decreased in the CGM75 and CGM100 groups. Triglycerides and total cholesterol were significantly increased in the CGM50 and CGM75 groups, respectively. Fish in the CGM100 and CGM75 groups had significantly higher activities of aspartate aminotransferase and alanine aminotransferase than the control. Moreover, the relative expression levels of the fatty acid synthase and acetyl‐coenzyme A carboxylase alpha genes were significantly increased in the CGM75 and CGM100 groups, while the gene expression levels of hormone‐sensitive lipase and peroxisome proliferator‐activated receptor alpha were significantly decreased.ConclusionIn summary, the optimal replacement level of FM with CGM was shown by curve equation analysis to be 61.30%, and their dosages were 24.52 and 15.48 g/kg, respectively.

Replacing fishmeal with cottonseed protein concentrate in practical diet of largemouth bass (Micropterus salmoides): Growth, flesh quality and metabolomics

The study estimated the effect of substituting fishmeal with cottonseed protein concentrate (CPC) in practical diets on growth performance, flesh quality and metabolomics of largemouth bass (Micropterus salmoides). In a basal diet with fishmeal inclusion of 400 g/kg, five diets were formulated with CPC inclusion to isoproteicly replace 0%, 15%, 30%, 45% and 60% of dietary fishmeal, correspondingly, the fishmeal inclusion was 400 g/kg (FM40), 340 g/kg (FM34), 280 g/kg (FM28), 220 g/kg (FM22), 160 g/kg (FM16), respectively. Then, the five diets were fed to largemouth bass with initial body weight of 75.0 g for 12 weeks. The results showed that 15% and 30% of dietary fishmeal could be successfully replaced by CPC without significant effects on the weight gain (WG) and feed conversion ratio (FCR), while the WG was decreased and FCR was increased when 45% and 60% of dietary fishmeal were replaced by CPC (P < 0.05). With the increase of replaced fishmeal level by CPC, the flesh hardness and the content of heat-insoluble collagen showed a significantly negative linear trend (P < 0.05), while flesh drip loss (at 12th h and 24th h), n-6 polyunsaturated fatty acid, total free amino acids and flavor amino acids contents showed a significantly positive linear trend (P < 0.05). FM22 and FM16 groups showed lower flesh hardness and higher drip loss (24th h) than FM40 group (P < 0.05). In muscle histology and metabolomics, FM16 group presented higher myofiber density and lower myofiber diameter than FM40 group. A total of 97 differential metabolites were detected between FM16 and FM40 groups, which mainly enriched in pathways as biosynthesis of amino acid, protein digestion and absorption, D-arginine and D-ornithine metabolism, histidine metabolism, alanine, aspartate and glutamate metabolism. Conclusively, in a practical diet containing 400 g/kg fishmeal, CPC could replace 30% fishmeal (120 g/kg) without significant impacts on growth, flesh composition, texture, flavor and muscular tissue structure, and high fishmeal replacement (≥ 45%) decreased growth performance and flesh quality of largemouth bass.

Comparative evaluation of soybean meal vs. extruded soybean meal as a replacer for fishmeal in diets of olive flounder (Paralichthys olivaceus): Effects on growth performance and muscle quality

A 56-day feeding trial was performed to compare the impacts of replacement of dietary fishmeal by soybean meal (SM) or extruded soybean meal (ESM) on the growth performance and muscle quality of olive flounder (Paralichthys olivaceus) (initial weight: 6.32 ± 0.01 g). Nine isonitrogenous and isolipidic diets were prepared by substituting 0% (FM, control), 12% (SM12/ESM12), 24% (SM24/ESM24), 36% (SM36/ESM36) and 48% (SM48/ESM48) of fishmeal with SM or ESM respectively. Results indicated that contents of anti-nutritional factors (trypsin inhibitors, glycinin and β-conglycinin) in ESM were significantly lower than those in SM. The weight gain rate, specific growth rate, feed efficiency ratio, protein efficiency ratio, activities of intestinal trypsin and lipase, as well as expressions of myogenic regulatory factors (myf5, myod and mrf4) and protein synthesis-related genes (akt, pi3k, tor and s6) in fish muscle decreased linearly and quadratically with increasing replacement levels of dietary fishmeal by SM or ESM. Expressions of mstn and protein degradation-related genes (foxo1, murf-1, mafbx, capn2 and ctsl) in muscle showed a trend opposite to growth parameters responding to dietary SM or ESM levels. Significant differences in all the above parameters were observed in the SM36, SM48 and ESM48 groups, accompanied by the declines in contents of most muscle free amino acids. The increase of dietary fishmeal replacement level by SM linearly and quadratically decreased muscle hardness, water holding capacity (WHC), pH and total collagen content. Markedly lower values were found in the SM36 and SM48 groups. However, ESM could replace up to 36% of dietary fishmeal without significantly impacts on above muscle quality parameters. Additionally, reduced myofiber density and sarcomere length were observed in the SM36, SM48, ESM36 and ESM48 groups. However, at the same substitution level, dietary ESM relieved the effects of SM on myofiber morphology to some extent. In conclusion, according to broken-line regression on SGR, the optimal replacing level of fishmeal by SM and ESM for olive flounder was 22.07% and 34.39% respectively. The improved replacement level of fishmeal by ESM, in terms of fish growth, muscle hardness and WHC, may be due to the fact that dietary ESM alleviated the adverse impacts of SM on digestive enzyme activity, muscle growth-related genes expression, muscle pH, collagen content and myofiber morphology of fish.

Effects of a free amino acid mixture in replacing dietary fishmeal and reducing Nile tilapia (Oreochromis niloticus) production costs

To encourage aquaculture sustainability and lower fish production costs, fish products need to be substituted with sustainable ingredients in aquafeeds. Toward this goal, we examined whether a natural mix of highly concentrated free amino acids could alleviate the negative effects of low–fish meal (FM) diets on Nile tilapia in terms of growth performance and nutrient utilization. In the present study, a 2 × 3 factorial design with two FM levels (5 % and 10 %) was used to prepare the experimental diets and three levels of Kera-Stim® 50 (KS), a free amino acid mixture, was supplemented (0 %, 0.25 %, and 0.5 %). Nile tilapia fish (average initial body weight of 20 g) were cultured in 18 cages and provided with one of the six diets for eight weeks. We found that dietary KS supplementation significantly increased the growth performance parameters including final body weight, weight gain, and specific growth rate compared with the diets without KS supplementation (P < 0.05). Moreover, KS supplementation had a substantial positive effect on the feed conversion ratio (P < 0.05). Interestingly, not only the low-FM diets but also the diets supplemented with KS had a positive effect on the economic conversion ratio and economic profit index, suggesting increased economic efficiency. Furthermore, lysozyme, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase activity levels were significantly increased by supplementing low-FM diets with KS (P < 0.05). KS and low-FM diets increased the whole-body levels of ash, fat, and crude protein (P < 0.05). Moreover, KS supplementation increased the levels of polyunsaturated fatty acids, such as arachidonic acid (20:4 n6) and docosahexaenoic acid (C22:6 n3). We concluded that supplementing a natural free amino acid mix to a low-FM diet can mitigate negative nutritional effects and achieve optimum fish performance without compromising growth performance or revenue-to-cost ratios.

Application prospect of replacement of fish meal with spray-dried egg meal in diets for swimming crab (Portunus trituberculatus)

An 8-week feeding trial was conducted to evaluate the effects of replacing fish meal with spray-dried egg meal (SEM) on growth performance, anti-oxidative capacity, mTOR pathway, and cholesterol metabolism in juvenile Portunus trituberculatus. The results showed that the highest percent weight gain was observed in crabs fed diet with 10% replacement of fish meal with SEM. Essential amino acids in the muscle and hepatopancreas significantly decreased with the increase of dietary replacement levels of fish meal with SEM. The lowest content of MDA in hepatopancreas was occurred at those fed diet with 40% replacement of fish meal with SEM, the activities of T-AOC, GSH-PX and content of GSH in hepatopancreas significantly increased with dietary SEM replacement fish meal increasing from 10% to 50%. The expression of akt, eif4e1a, eif4e2, eif4e3, and 4ebp1 significantly up-regulated, however, the expression of tor was showed significantly linear down-regulated, and the highest expression of akt, eif4e2 and 4ebp1 were found in crabs fed diet with 20% replacement of fish meal with SEM, the highest expression of eif4e1a was observed in those fed diet with 10% replacement of fish meal with SEM, the highest expression of eif4e3 was occurred in crabs fed diet with 30% replacement of fish meal with SEM. In cholesterol metabolism, the expression of abcg1 and lrp2 significantly down-regulated and the expression of npc1 significantly up-regulated with increase of replacement level of fish meal with SEM. The content of T-CHO in hemolymph and hepatopancreas significantly linear increased. In conclusion, based on quadratic broken-line regression analysis of PWG against the dietary replacement of fish meal with SEM, the optimal replacement level of fish meal with SEM was estimated to be 15.94% for juvenile swimming crab.

Hermetia illucens larvae meal as an alternative protein source in practical diets for gilthead sea bream (Sparus aurata): A study on growth, plasma biochemistry and gut microbiota

The effects of dietary Hermetia illucens (HI) larvae meal on growth, plasma biochemistry and gut microbiota was tested in gilthead sea bream. Four isonitrogenous and isolipidic extruded diets (50% protein; 14% lipid) with different levels of HI larva meal (0% CTRL, 5% HI5, 10% HI10, and 15% HI15) in partial substitution to fish meal (FM) were administered to triplicate fish groups over 113 days. Diets were designed to partially replace FM, using FM level for practical application. No significant differences (p > 0.05) were observed in terms of final body weight, specific growth rate (SGR), feed intake (FI), feed conversion rate (FCR) as well as feed efficiency parameters such as protein efficiency ratio (PER), gross protein efficiency (GPE), gross lipid efficiency (GLE). At the end of the trial there were not significant differences on growth, feed intake, feed conversion rate and protein efficiency. Among over 20 plasma parameters analyzed, HI inclusion level reduced iron (Fe), potassium (K), creatinine (CREA), aspartate aminotransferase (AST), alanine amino transferase (ALT), creatine kinase (CK), alkaline phosphatase (ALP), lactate dehydrogenase (LDH). The reduction of AST, ALT and ALP might suggest a potential beneficial role of HI for liver integrity and functionality. Concerning gut microbiome (GM) layout, HI was able to induce a shift in the GM structure at any inclusion level considered compared to the control diet increasing the abundance of Bacillaceae (mainly Bacillus and Oceanobacillus) and Paenibacillaceae (Paenibacillus). Taxa that can be involved in chitin degradation and has been recently recognized as novel probiotics for aquaculture. In conclusion, the results of feed intake, growth, feed utilization and plasma biochemistry indicate that HI larvae meal can be successfully incorporated up to 15% in practical aquafeed diets to partially replace FM without any negative effects on growth and feed efficiency. Beyond being a valid alternative protein source for fish meal replacement in this species, it displays gut health functional properties already at low inclusion level.

Haematological responses of replacement levels of fish meal with chicken offal in catfish (Clarias gariepinus) diets

Fish demand by consumers keeps increasing, yet constraints to the production of fish are encountered, the commonest of which is the high cost and difficulty in acquiring fish feeds in Nigeria. The objective of this study was to determine the effect of the formulated test diets of 40% protein concentrate using varying levels of chicken offal diets on the haematological parameters of the African Catfish (Clarias gariepinus). The chicken offal was used to replace fish meal at inclusion levels of 0% (control, treatment A), 25% (treatment B), 50% (treatment C), 75% (treatment D) and 100% (treatment E) respectively. Three hundred (300) fingerlings of average length, 8.12±0.48 cm, and average weight, 3.68±0.00 g, were stocked in concrete tanks. Fish were fed at 5 per cent body weight for 8 months. Physicochemical parameters including; water temperature (°C), pH, dissolved oxygen and ammonia were monitored every four days and maintained within acceptable ranges for fish culture. Data obtained were analysed using analysis of variance (ANOVA). Results showed haemoglobin (Hb), Packed cell volume (PCV), Mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular volume (MCV) to be statistically different (ANOVA, p&lt;0.05) between the treatments, although no significant difference (ANOVA, p&gt;0.05) was observed in white blood cell (WBC), Mean Corpuscular haemoglobin (MCH) and erythrocyte sedimentation rate (ESR). Haematological parameters results were within the ranges for fish well-being. Chicken offal were suitable as partial replacement at (25, 50, 75 and 100%) for fish meal, it enhanced the hematological performance of C. gariepinus due to its mineral components.

Effect of replacing dietary fish meal protein with combined animal meals on the growth performance of olive flounder (Paralichthys olivaceus)

The effect of various levels of fish meal (FM) protein substitution with combined animal meals on the growth and feed utilization of olive flounder (P. olivaceus) was elucidated. A total of 630 juvenile olive flounder averaging 12.5 g was distributed to 21 tanks, with 3 tanks per diet. A two-way ANOVA experimental design was adopted, incorporating two replacement sources [combined plasma powder and chicken by-product meal (PC), and combined plasma powder and tuna by-product meal (PT)] and three FM replacement ratios (25%, 50%, and 70%). A control (Con) diet contained 70% FM. In the Con diet, 25%, 50%, and 70% FM protein were substituted with PC and PT, labeled as the PC25, PC50, PC70, PT25, PT50, and PT70 diets, respectively. Fish were hand-fed to apparent satiation twice a day for 56 days. Upon completion of the feeding experiment, both dietary replacement source and ratio significantly affected the weight gain (WG), specific growth rate (SGR), and feed consumption of fish (P < 0.001 for all). The PT replacement source achieved better WG, SGR, and feed consumption than the PC replacement source. Additionally, dietary increased FM replacement ratio reduced WG, SGR, and feed consumption. WG, SGR, and feed consumption of fish fed the PC25 and PT25 diets were comparable to fish fed the Con diet, but superior to fish fed all other diets, except for feed consumption of fish fed the PT50 diet. None of proximate composition, AA profiles, plasma parameters as well as selected innate immunity (lysozyme and SOD activities) of fish was influenced by dietary treatments. In conclusion, up to 25% of FM protein (35.7% of FM replacement) in a 70% FM-based diet could be successfully substituted with PC and PT without negatively affecting growth, feed consumption and utilization, proximate composition, AA profiles, and selected innate immunity (lysozyme and SOD activities) of olive flounder.

Dried porcine soluble benefits to increase fish meal replacement with soy protein concentrate in large yellow croaker Larimichthys crocea diet

AbstractThe effect of dried porcine soluble (DPS) supplementation on replacement of dietary fish meal with soy protein concentrate (SPC) for large yellow croaker, Larimichthys crocea, was assessed in a feeding trial conducted in inshore net pens. Five isoproteic and isolipidic diets were tested. A basal diet (BD) contained 400 g/kg fish meal, and SPC was used as an alternative ingredient to replace 40% (F24) and 60% (F16) of the fish meal in BD at an equal protein basis. DPS was added at 5 g/kg in F24 (FD24) and F16 (FD16). Fish weighing 33.6 ± 7.4 g were fed with the test diets in 1.5 × 1.5 × 2 m net pens for 9 weeks. The fish meal replacement level significantly affected weight gain, feed conversion ratio, phosphorus retention efficiency, body phosphorus content, and ratio of fish meal consumption to fish production (RCP), while the DPS supplementation level significantly affected weight gain. The weight gain of fish fed FD24 was higher than that of fish fed F16, while no significant difference was found in weight gain between fish fed BD and fish fed FD24, F24, FD16 and F16. The feed cost, RCP and phosphorus waste of fish fed BD were higher than those of fish fed FD24, F24, FD16 and F16. Fish fed FD24 exhibited the best production performance, and the production performance of fish fed F24 and FD16 was close to that of fish fed BD. The present study indicates that the fish meal level in large yellow croaker diet could be lowered to 240 g/kg with SPC alone as a fish meal substitute, and could be further reduced to 160 g/kg by supplementation of 5 g/kg DPS. Therefore, DPS supplementation can benefit to increase fish meal replacement with SPC in large yellow croaker diet.

Single cell protein from methanotrophic bacteria as an alternative healthy and functional protein source in aquafeeds, a holistic approach in rainbow trout (Oncorhynchus mykiss) juveniles

Bacterial single cell protein (BSCP) obtained from methanotrophic bacteria was tested as an alternative protein source to fishmeal (FM) in compound diets for rainbow trout (Oncorhynchus mykiss) juveniles (initial body weight, BW = 11.3 ± 0.2 g, mean ± standard deviation). Different levels of FM replacement (0, 25, 50, 75 and 100%) by a BSCP (0, 3.75, 7.5, 11.25 and 15% of Uniprotein® Aqua) were tested in isoproteic (crude protein: 42%) and isolipidic (crude fat: 21%) extruded diets. The trial was divided in two different parts, a nutritional trial that lasted 83 days during which the impact of experimental diets was evaluated in terms of key performance indicators (KPIs) associated to fish growth performance and feed utilization, which was followed by a challenge with a pathogenic bacterium (Aeromonas salmonicida subsp. salmonicida) to evaluate the immunological competence of fish fed the experimental diets (15 days). At the end of the nutritional trial, somatic growth in terms of body weight (BW) responded quadratically (P < 0.05) to the dietary inclusion of BCSP with the lowest BW values (183.4 ± 4.5 g) recorded in fish fed 100% FM replacement with BSCP, whereas the rest of dietary groups showed similar BW values (191.3–201.2 g). Feed intake was not affected by the level of FM replacement by BSCP, whereas feed conversion ratio (FCR) slightly increased with increasing levels of BSCP (P < 0.05), even though the lowest FCR values were found in fish fed 50% FM replacement by BSCP (0.79 ± 0.01) in comparison to the control group (0.81 ± 0.01). When using quadratic linear regression, the optimal dietary FM replacement by BSCP in terms of BW values was estimated as 41.7%. The nutritional quality of the fillet was not altered with experimental diets; all dietary groups showed similar amino acid levels as well as their content in HUFA n-3 and n-6 that remained unaltered (P > 0.05) and lipid nutritional indexes (P > 0.05). No negative effects were observed in the histological organization of the liver nor the proximate intestine, neither in the lipid peroxidation levels nor activity of antioxidative stress enzymes in the liver from fish fed increased inclusion levels of BSCP (P < 0.05). The replacement of FM by the tested BSCP obtained from methanotrophic bacteria did not cause an imbalance or dysbiosis in the intestinal microbiota in rainbow trout regardless of the level of FM replaced. The replacement of FM by BSCP at 50% improved disease resistance in rainbow trout exposed to furunculosis when compared to the control diet (cumulative mortality = 83.3 ± 7.2% vs. 49.2 ± 15.6%; P < 0.05), which suggested that this ingredient may also have some immunomodulatory properties that would protect fish from infections, although their mode of action deserves further attention. Current results indicated that the tested BSCP from methanotrophic bacteria is a safe, functional, and sustainable alternative protein source for aquafeeds.

Affecting mechanism of Chlorella sorokiniana meal replacing fish meal on growth and immunity of Litopenaeus vannamei based on transcriptome analysis

The purpose of this study was to analyze the affecting mechanism of Chlorella sorokiniana meal replacing fish meal on the growth performance and immune function of Pacific white shrimp, Litopenaeus vannamei by transcriptomics analysis. In a control diet containing 560 g % /kg fish meal, chlorella was used to replace 0 %, 20 %, 40 %, 60 %, 80 % and 100 % of dietary fish meal to form six iso-nitrogenous and iso-lipidic diets (C0, C20, C40, C60, C80, C100). The six diets were fed to white shrimp (1.37 ± 0.02 g) for 8 weeks. Compared to the control group, the final body weight (FBW), specific growth rate (SGR) and feed efficiency (FE) of the C20 group were significantly improved (P < 0.05). There was no significant difference in growth performance between the C40 group and the C0 group (P > 0.05). When the replacement level of fish meal by chlorella was ≥ 60 %, the FBW, SGR and FE of shrimp were significantly decreased (P < 0.05). In the analysis of the hepatopancreatic transcriptome, the amount of differentially expressed genes (DEGs) in C20, C40, C60, C80 and C100 groups were 322 (176 up and 146 down), 482 (246 up and 236 down), 804 (487 up and 317 down), 1080 (684 up and 396 down) and 1262 (827 up and 435 down), respectively, when compared to the C0 group. GO Term and KEGG pathway enrichment analysis of DEGs showed that DEGs between the C20 and C0 groups were significantly enriched in chitin binding and inositol metabolism processes. Several immune-related signaling pathways were also enriched, including the C-type lectin receptor pathway, complement and coagulation cascades, the B-cell receptor pathway, and most of these genes were up-regulated in the C20 group. Compared to the C0 group, DEGs in C40, C60, C80 and C100 groups were significantly enriched in lysosomal, protein digestion, and absorption pathways. In addition, in the C80 and C100 groups, the DEGs were also significantly enriched in lipid catabolism process. The high replacement of fish meal with chlorella meal affected the absorption and utilization of nutrients by regulating the signaling pathways related to protein digestion and absorption, and aggravated lipid catabolism of the body, thereby affecting the growth of shrimp. The high replacement of fish meal might also affect the homeostasis of shrimp cells and reduce immunity through the lysosomal signaling pathway. In summary, the low replacement of fish meal (20 %) with chlorella meal significantly improved the growth performance of Litopenaeus vannamei, which might be realized through activating the C-type lectin receptor signaling pathway to regulate immune function of the body, but the high substitution of fish meal (≥ 60 %) reduced the growth performance and immunity by affecting the lysosomal signaling pathway.

Aquatic product hydrolysates increase rearing performance in red seabream (Pagrus major), fed a low fish meal diet, in both controlled and stressed conditions: From growth to stress responses

Although aquaculture industry has made great efforts to reduce the levels of fish meal (FM) in aquaculture feeds, further efforts and investigations are still needed to increase aquaculture production, which has more than tripled in the last two decades. This study was implemented to Six replicate groups of fish (24.6 ± 0.1 g) were fed one of the experimental diets to apparent satiety twice daily for 15 weeks; half of them were subjected to a daily net chasing stress for 1 min in the morning, 1 h before feeding. At the end of the feeding trial, fish were challenged with Edwarselia tarda injection. LFM diet resulted in comparable growth and feed efficiency performance to HFM group. However, significant impairments were observed in apparent digestibility coefficients, condition factor, hematocrit and serum super oxide dismutase activity. Fish fed LFM showed much lower resistance to E. tarda challenge. Both TH and SH resulted in enhanced fish nutritional and health performance with significant improvements in growth performance, feed efficiencies, digestibility, serum non-specific immunity and gut morphometric parameters. Fish fed TH and SH also exhibited the highest survival after E. tarda challenge. Principal component analysis (PCA) showed significant differences between stress and dietary groups for dimension 1 (33.3% of the variability), which was mostly characterized by growth and health variables. SH and TH coordinates were significantly higher on dimension 1 compared to HFM and LFM ones. Daily repeated stress affected most of measured performance parameters of all dietary groups with very few interactions. The stressed fish groups fed TH or SH showed lower cortisol levels compared to those fed HFM and LFM (p < 0.01). Strong correlations were observed between feed efficiency and fish gut morphometrics as quantified by villi length, enterocyte height and goblet cell density. Dietary supplementation of aquatic protein hydrolysates such as TH and SH appeared to be essential for maintaining good fish performance when they were subjected to a daily husbandry stressor or to an infectious challenge.