Fish Meal Replacement Level Research Articles

Increasing levels of fishmeal replacement by defatted black soldier fly larvae meal reduced growth performance without affecting fillet quality in largemouth bass (Micropterus salmoides).

A 90-day feeding trial was conducted to evaluate the effects of replacing dietary fishmeal (FM) with defatted black soldier fly larvae meal (BSFL) on the growth performance and fillet quality of largemouth bass (Micropterus salmoides). The largemouth bass was divided into six groups (BSFL0, BSFL15, BSFL30, BSFL45, BSFL75, and BSFL100) and fed six isonitrogenous(CP 50%, 508 g/kg) and isolipid (CL 9%, 124 g/kg) diets, in which 0, 15%, 30%, 45%, 75%, and 100% of the fishmeal was replaced with BSFL, respectively. The results showed that the final body weight (FBW) and specific growth rate (SGR) of the largemouth bass decreased with increasing BSFL content, and they were significantly lower in BSFL75 than in BSFL0. The weight gain rate (WGR) decreased with increasing BSFL content and the feed conversion ratio (FCR) of largemouth bass increased with increasing BSFL content. The saturated fatty acids (SFAs) and n-3 polyunsaturated fatty acids (PUFA) contents of the largemouth bass fillet significantly decreased, and the n-6 PUFA content of the largemouth bass fillets significantly increased with increasing dietary BSFL. The fillet b* significantly decreased with increasing BSFL content. The biological parameters, fillet proximate nutrient composition, fillet amino acid composition, skin color, and fillet texture of the largemouth bass were not affected by the replacement of BSFL. Transcriptomic analysis revealed that BSFL replacement of FM affects the immune system and metabolic processes of largemouth bass through signaling pathways such as complement and coagulation cascades, the PPAR signaling pathway, cholesterol metabolism, and fat digestion and absorption. In conclusion, a replacement level lower than 45% BSFL was suggested for the overall growth and fillet quality of largemouth bass.

Dried porcine soluble augments dietary fishmeal replacement by poultry by-product meal for large yellow croaker Larimichthys crocea

Two concurrent feeding trials was conducted to assess the effects of replacing fishmeal with poultry by-product meal (PBM) and supplementing dried porcine soluble (DPS) in large yellow croaker Larimichthys crocea diets at the optimal dietary protein level. In trial I, the reference diet (F40) contained fishmeal at 400 g/kg, and 40%, 60% and 80% of the fishmeal was substituted with PBM (the diets were termed as F24, F16 and F8). In trial II, the control diet (F16D0) contained fishmeal at 160 g/kg, and DPS was added at 4, 8, 12 and 16 g/kg in F16D0 (the diets were termed as F16D4, F16D8, F16D12 and F16D16). Fish initially weighing 20.0 ± 0.2 g were fed the test diets for 10 weeks. Fishmeal replacement level significantly influenced final body weight (FBW), weight gain, feed conversion ratio, nitrogen and energy retention efficiencies, ratio of fish-in to fish-out (FIFO), feed cost, activity of superoxide dismutase and catalase in plasma and liver, activity of glutathione peroxidase in plasma, and malondialdehyde content in liver. However, neither fishmeal replacement level nor DPS supplementation level resulted in significant change in condition factor, hepatosomatic index and body composition. There were no significant differences in weight gain and FBW either between F40, F24 and F16 or between F40 and F16D0, F16D4, F16D8, F16D12 and F16D16. The FBW of F16 declined by 3.2% relative to F40, while the FBW of F16D12 increased by 10.1% relative to F16D0. This study reveals that dietary fishmeal level for large yellow croaker could be reduced to 160 g/kg by using PBM as a sole substitute, and DPS supplementation could augment dietary fishmeal replacement by PBM.

Effects of replacing fish meal with biofloc meal on growth performance, nutrients metabolism, immune response and intestinal microbiota of common carp (Cyprinus carpio)

This study investigated the effects of replacing fish meal (FM) with biofloc meal (BM) on the growth, digestion function, protein metabolism, lipid metabolism, immunity, antioxidant capacity and intestinal microbiota of common carp (Cyprinus carpio). The experiment includes two trials (a growth trial and a digestibility trial). In the growth trial, the control diet contained 20% FM. And five isonitrogenous and isolipidic diets were formulated to replace 0% (CK), 20% (BM20), 40% (BM40), 60% (BM60) and 80% (BM80) of the FM protein with BM. The five diets were fed to common carp (3.73 ± 0.01 g) for 56 days. The results indicated that the growth performance [final weight (FW), specific growth rate (SGR) and feed efficiency ratio (FER)] and digestive enzymes activities displayed a noteworthy quadratic trend with the increasing replacement level of FM with BM (P < 0.05), reaching a maximum at the BM40 group and a minimum at the BM80 group. Regression analysis of weight gain rate (WGR) against the substitution level found that the optimal level of BM replacing FM was 34.12%. The appropriate levels of BM could improve protein metabolism and lipid metabolism by regulating the expressions of related genes. Regarding the expression levels of PI3K, mTOR and HSL mRNA, they were the highest in the BM40 group and the lowest in the BM80 group, while the levels of ACC and FAS mRNA were reversed (P < 0.05). Simultaneously, the number of lipid vacuoles in the BM80 group were significantly increased than the CK group. Replacing 40% FM with BM augmented the fish immunity and antioxidant capacity, as showed by elevated the C3, C4 and IgM levels as well as CAT and SOD activities, and reduced the expression levels of NF-κB, TNF-α and Keap1 (P < 0.05). Regarding intestinal microbiota, replacing 40% FM with BM could improve the intestinal microbiota structure. The digestibility trial results showed that the apparent digestibility of protein and lipid in BM of common carp was slightly lower than FM. Conclusively, replacing 40% FM with BM could promote growth, immunity and protein metabolism of common carp, but excessive substitution level (80%) could compromise growth and hepatopancreas health.

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

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

Early nutritional programming in sterlet sturgeon (Acipenser ruthenus) with dietary soybean meal: Assessment of growth performance, body composition, and expression of GH, IGF-I, and Ghrelin genes.

This study was performed to assess the impacts of introducing diets containing different levels of soybean meal (SBM) to sterlet sturgeon (Acipenser ruthenus) larvae on growth performance, body composition, and molecular responses in the juvenile stage. The sterlet larvae (57.68 ± 0.66 mg) were weaned onto the formulated diets as follows: a control diet containing 60% fishmeal (FM), and three experimental diets with replacement levels of 15% (SBM15), 30% (SBM30), and 45% (SBM45) of FM with SBM. Then, a total of 260 fish (initial weight: 323.33 ± 11.76 mg) were fed the four different diets for 28 days in triplicates (phase 1, nutritional programming, NP). All treatments were then fed with the FM diet in phase 2 (common phase), and in phase 3 (challenge phase), all experimental groups (6.14 ± 0.08 g) were transitioned to SBM45 for 28 days. At the end of phases 1 and 2, growth performance showed no significant differences among the groups (P > 0.05), while significantly improved in SBM45 than the control at the end of phase 3 (P < 0.05). No significant differences were found among the groups in any phases for whole body composition (P > 0.05). Additionally, the total saturated fatty acids were significantly higher in SBM-based diets than FM at the end of phase 3 (P < 0.05). The mRNA of GH, IGF-I was significantly affected by variation of FM replacement level (P < 0.05). The expression level of Ghrelin was up-regulated in fish fed SBM at the end of phase 3 (P < 0.05). Our findings revealed that NP can positively enhance the adaptation of juvenile sterlet sturgeon to 45% SBM when exposed to the same diets at the larval stage. Further research is being carried out to provide valuable insights into the underlying mechanisms of digestive performance for this species.

Recycling of animal protein wastes in the formulation of feed for Labeo rohita and Mystus vittatus—a comparative evaluation

Lactic acid bacteria (LAB) are key players in the fermentation of organic wastes and their recycling as feedstuff for fish. Whey, a common dairy byproduct in India, is a cheap source of LAB and can be used to ferment animal byproducts. An experimental study was designed to explore whether the whey fermented animal protein blend (WFAPB) could be used as a fishmeal replacer in the formulation of feed for both stomach-less carp fish Labeo rohita and stomach-bearing catfish Mystus vittatus. Experiments were performed with five isoproteinous, isolipidous, and isoenergetic feeds with WFAPB replacing fishmeal (FM) by 0% (T1), 25% (T2), 50% (T3), 75% (T4), and 100% (T5). Fifteen days of laboratory experiments with these experimental feeds revealed that more than 50% FM replacement level could result in excess postprandial absorption (6 h) of some essential and non-essential amino acids in the plasma of both fish. The postprandial absorption was more in M. vittatus than L. rohita. Ninety-day experiments were conducted in outdoor cement vats to measure growths and deposition of amino acids (AA) in muscle. Regression analysis was performed to find the optimal FM replacement based on four growth parameters and fifteen AA deposition in muscle. A two-phase fuzzy methodology was used to obtain Pareto-optimal replacement levels for each fish. The results demonstrated that FM replacement levels were 7.63% and 36.79% respectively for L. rohita and M. vittatus when only four growth parameters were considered. However, based on the FM replacement level that maximized deposition of 15 amino acids and growth parameters, it was found that 12.23% and 40.02% replacement of FM by the WFAPB was ideal respectively for L. rohita and M. vittatus. The results revealed that only a fraction of both essential and non-essential amino acids absorbed in plasma could be converted into protein and deposited as bound amino acids in the muscle. It is concluded that fermentation by whey is an inexpensive, easily available, and environmentally sustainable technique to recycle animal protein in the formulation of feed for fish, and the stomach-bearing carnivorous fish are more efficient in utilizing fermented animal protein blend than the stomach-less carps.

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.

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 American cockroach (Periplaneta americana) residue could partially replace the dietary fish meal in the juvenile Nile tilapia (Oreochromis niloticus)

The American cockroach (Periplaneta americana) residue is a by-product of P. americana meal after extracting active ingredients with ethanol, and it still contains high protein, lipid, and a certain amount of active ingredients, may be a potential fish meal alternative. Five isonitrogenous and isolipidic experimental diets were formulated to replace 0%, 25%, 50%, 75%, and 100% of dietary fish meal with P. americana residue, and defined as Diet 1, Diet 2, Diet 3, Diet 4, and Diet 5, respectively. The juvenile Nile tilapia (Oreochromis niloticus) with an initial body weight of 2.98 ± 0.01 g was fed with respective diets for 10 weeks, which was conducted to investigate the effects of dietary fish meal replacement by P. americana residue on the growth performance, proximate composition, amino acid profile, metabolism, antioxidant capacity, and immunity of juvenile O. niloticus. There were no significant differences in the final body weight, weight gain rate, and specific growth rate among five diet groups, while the highest feed conversion ratio and the lowest protein efficiency ratio were recorded in Diet 4. There were no significant differences in the contents of crude protein, total lipid, ash, and total amino acid in the whole fish body among all groups. The Diet 1 and Diet 2 had higher activities of trypsin, α-amylase, and chitinase in the intestine and α-amylase in the liver. The highest serum urea content was detected in Diet 4, while the lowest liver urea content and the highest serum total protein content were detected in Diet 3. A higher liver catalase, glutathione peroxidase, and serum lysozyme activities were detected in Diet 2, and the lowest serum malondialdehyde content was detected in Diet 2. In conclusion, dietary fish meal replacement by the P. americana residue had no negative effects on the growth performance and body composition of juvenile O. niloticus, and significantly improved the antioxidant capacity and immunity, while feed utilization rate was reduced when dietary fish meal replacement levels exceeded 75%.

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.

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.

Effects of black soldier fly meal feeding on rainbow trout gut microbiota, immune-related gene expression, and Lactococcus petauri resistance

Abstract Providing a sustainable and affordable food supply is one of the most significant challenges facing the global aquaculture industry. Black soldier fly (BSF), Hermetia illucens, meal is a particularly promising alternative to animal-derived protein sources. Following a 90-day feeding experiment with four different diets containing BSF meal with increasing fish meal replacement levels of 25%, 50%, 75%, and 100%, designated as B25, B50, B75, and B100, and a control diet (B0) without BSF meal, the gut microbiota, immune-related gene expression, and Lactococcus petauri resistance of rainbow trout (Oncorhynchus mykiss) were studied. Regardless of diet, rainbow trout intestinal microbiota were different from those in water. In the intestinal mucosa, Fusobacteria, Firmicutes, and Proteobacteria were among the most prevalent taxa. Rainbow trout fed with a BSF-containing diet had a higher bacterial diversity in their gastrointestinal tract than fish fed with a control diet. The abundance of Firmicutes, Actinobacteria, and Proteobacteria increased in tandem with the replacement rate of fish meal with BSF meal. The B75-fed fish were found to be the most resistant group to L. petauri, followed by the groups fed with B100, B50, and B25. Compared to the control group, the expression of cytokines (Tgf, Il-10, Il-1β, , and Il-8) and immune-related genes (IgM, IgT, Mhc-II, and Tlr-5) increased significantly () in all fish groups fed with a BSF-containing diet. Substituting fish meal with BSF meal beyond 50% enhanced the survival rates of fish infected with L. petauri. Furthermore, BSF-containing diets boosted the immune system and cytokine-related genes in fish. Due to improved survival and immunity, rainbow trout may be fed a 50% BSF meal substituted diet without removing chitin or pre-treating BSF meal.

Overall evaluation of the replacement of fermented soybean to fish meal in juvenile white shrimp, Litopenaeus vannamei diet: growth, health status, and hepatopancreas histomorphology

This study was conducted to determine the effect of replacing fishmeal (FM) with fermented soybean meal (FSBM) for 12 weeks on the growth performance, feed utilization, immunological parameters, antioxidant enzyme assays and lipid peroxidation, digestive enzymes, and histopathological analysis of juvenile Litopenaeus vannamei (L. vannamei). By substituting 0.0%, 20%, 30%, and 40% FSBM for fishmeal (w/w), four isonitrogenous diets were generated. A total of 300 juvenile L. vannamei (1.59 ± 0.01 g) were randomly allocated to the experimental fiber tanks at a rate of fifteen shrimp per tank, with three replicates for each treatment. Growth performance and feed utilization decline considerably (P < 0.05) with increasing amounts of FM replacement with FSBM in diets. In comparison to the juveniles fed the other experimental diets, the diet containing a moderate level of FM replacement (20% FSBM) considerably enhanced growth performance and feed consumption during the feeding trial. The 20% FSBM-fed group had the highest protein content. In contrast, raising FSBM levels significantly increased lipid content (P < 0.05) compared to the control. However, there were no statistically significant differences (P > 0.05) across FSBM treatments. Hemolymph plasma total protein (TP) concentration and lysozyme activity were substantially greater (P < 0.05) in 20% FSBM compared to 40% FSBM (P < 0.05). In addition, 20% FSBM exhibits a substantial (P < 0.05) increase in the activity of antioxidant enzymes (CAT SOD, GPX, and GR). In contrast, the control and 30% FSBM groups had considerably more lipid peroxidation markers (MDA) than the 20% and 40% FSBM groups. Hepatopancreas amylase activity was considerably elevated (P < 0.05) in the control group and with 40% FSBM. In addition, hepatopancreas and intestinal protease and lipase activity increased significantly by 20% FSBM. Considerably, more B cells were present in the 40% FSBM diet than in the control diet; however, they were significantly less prevalent in the 20% and 30% FSBM diets (P < 0.05).

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.

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.

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.

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.

Dietary starch level affects nutrient digestibility, faecal waste production and characteristics in yellowtail kingfish (Seriola lalandi) depending on the level of fish meal replacement

Yellowtail kingfish have a poor faecal integrity when fed with pelleted diets which may be due to the presence of dietary starch. Moreover, whether dietary starch interacts with plant protein ingredients, is not known. In this study, we investigated the effect of dietary starch level, protein source and their interaction effect on faecal waste production and characteristics (visual appearance, faecal removal efficiency and particle size distribution (PSD)). Four diets were formulated according to a 2 × 2 factorial design (starch level × protein source). The effect of starch level was tested by either including 0% (LS - low starch, 4% starch) or 20% gelatinized wheat flour (HS - high starch, 20% starch). FM diets contained fish meal as protein source, whilst at FM/P diets approximately 65% of the fish meal was replaced by plant protein ingredients. Twelve tanks were stocked with 21 fish (mean initial weight 53 g) and fish performance, nutrient digestibility, faecal waste production and characteristics were evaluated over a 36-day experimental period. Both starch level and protein source affected the organic matter digestibility (p < 0.05). The effects of starch and protein source were additive regarding macro nutrient digestibility indicated by the absence of an interaction effect (p > 0.05). Growth was similar between the FM and FM/P at low starch diets (p < 0.05), but was reduced at the FM/P at high starch inclusion level (p < 0.05). The high starch and FM/P diets resulted in more faecal waste production (p < 0.05). Faecal integrity of yellowtail kingfish was adversely affected by starch inclusion. Fish receiving low starch diets excreted faecal pellets and short strings, while faecal waste collected from fish receiving high starch diets was classified as inconsistent. This was also reflected in a higher faecal removal efficiency and larger faecal PSD for fish receiving the low starch diets compared to the high starch diets (p < 0.05). No protein source or interaction effect was observed for faecal removal efficiency (p > 0.05). Consequently, lowering starch level and excluding plant protein ingredients reduced the amount of non-removed faeces by 71.1% and 30.6%, respectively. In summary, our study showed that the reduction of dietary starch offers possibilities to replace fish meal with plant protein ingredients without limiting growth performance in yellowtail kingfish. Moreover, lowering dietary starch level may have the potential to reduce solid loading in recirculating aquaculture systems for yellowtail kingfish.

Optimization of fish and plant production in tilapia-spinach aquaponics systems using black soldier fly larvae meal and mineral supplementation

Aquaponics is a sustainable food production system that combines aquaculture and hydroponics. Fishmeal is a common protein source in aquaponics feeds, but it is expensive and has environmental and ethical issues. Black soldier fly larvae (BSFL) are a promising alternative protein source that can be produced from organic waste. However, the optimal level of fishmeal replacement by BSFL meal and the effects of mineral supplementation on fish and plant growth, nutrient utilization, and microbial quality in aquaponics systems are not well understood. In this study, the researcher conducted three experiments to evaluate the effects of full-fat (FF) BSFL meal, defatted (DF) BSFL meal and mineral supplementation on tilapia-spinach aquaponics systems. The researcher found that FF or DF BSFL meal can replace up to 30% of fishmeal protein in tilapia-spinach aquaponics systems without compromising fish and plant growth, nutrient utilization, or microbial quality. Mineral supplementation can further enhance the performance of tilapia fed with FF or DF BSFL meal in aquaponics systems. This study provides valuable information for optimizing fish and plant production in tilapia-spinach aquaponics systems using BSFL meal and mineral supplementation as sustainable protein and mineral sources.