Fish Meal Research Articles

Effects of replacing fish meal with pork meal and supplementing with crystalline amino acids and fish oil on growth performance, body composition, enzyme activity, intestinal morphology, and immune response of Penaeus monodon

IntroductionThe present study aimed to evaluate the effects of substituting fish meal with pork meal in feed on the growth performance, feed utilization, intestinal morphology, and immune function of Penaeus monodon.MethodsA total of 600 uniformly sized juvenile shrimp with an initial weight of 1.20 ± 0.03 g were randomly assigned to four groups, with each group consisting of six replicates of 25 shrimp each. Fish meal protein was replaced with 0%, 5%, 10%, and 15% pork meal, and crystalline amino acids and fish oil were supplemented accordingly. The groups were designated as P0, P5, P10, and P15, and the study duration was 70 days.ResultsResults indicated no significant difference in specific growth rate (SGR) between the P5 and P10 groups compared to the P0 group. However, the SGR in the P15 group was significantly lower than that in the P5 and P10 groups. Feed conversion rates (FCRs) for the P5 and P10 groups were comparable to the P0 group, whereas the P15 group showed a significantly higher FCR than the other groups. There were no significant differences in whole body composition among all the groups. Apart from alanine, the amino acid composition of muscles did not differ significantly among all the groups. Results of enzyme activity in plasma revealed that the replacement of fish meal with pork meal reduced levels of aspartate aminotransferase (AST) and superoxide dismutase (SOD). Specifically, levels of AST in the P5 and P15 groups were significantly lower compared to the P0 and P10 groups. Histological examination of midgut tissues showed that villus height initially increased and then decreased with higher replacement ratios. The P5 group had the highest villus height, while the P15 group had the lowest villus height. Analysis of gene expression related to liver immune functions indicated that genes in TLR signaling pathway were significantly elevated in the P15 group compared to the other groups.DiscussionIn conclusion, even with the supplementation of crystalline amino acids and fish oil, pork meal should not replace more than 10% of fish meal in the feed of P. monodon to maintain optimal growth and feed efficiency.

A taste for growth: Rapeseed lecithin improves the feed intake of post‐juvenile rainbow trout (Oncorhynchus mykiss)

AbstractFeed formulations low in fish meal and fish oil can decrease feed intake and nutrient digestibility. Dietary application of lecithins could improve growth performance and nutrient digestibility; however, knowledge about specific lecithins and their effects in post‐juvenile fish is lacking. This study evaluated the effects of a commercially available rapeseed lecithin mixture on growth performance, feed intake, and nutrient digestibility of post‐juvenile rainbow trout (77.1 ± 12.1 g). A commercially based diet low in fish meal served as the control, while in the remaining three diets, fish oil was replaced with lecithin by 50%, 100% with lecithin, or 100% with a mixture of equal amounts of lecithin and rapeseed oil. Fish were fed to apparent satiation twice per day for 56 days. At the end of the trial, growth parameters, health parameters, nutrient digestibility, and filet coloration were assessed. Overall growth and feed intake were significantly elevated in all lecithin diets compared with the control group. The nutrient digestibility of all diets containing lecithin was similar to the control, and no differences in health parameters were detected. Filet coloration was significantly improved in diets of 100% fish oil replacement. Rapeseed lecithin can act as a feed attractant in fish meal and fish oil‐reduced diets.

Manures base on Oreochromis niloticus for agricultural use

ABSTRACT Objective: Oreochromis niloticus (Tilapia) meal was evaluated as a source of nutrients in agriculture, through a composting process mixed with a zero tillage soil. Design/methodology/approach: Two manures were formulated, mixing flour and soil at a 30:70 ratio (mass/mass w:w) respectively. Compost A was maintained at 60 days of composting (ddc), compost B at 30 days. The phytotoxicity of the manures was evaluated as percentage of germination in Solanum lycopersicum (tomato) seeds. Results: The N-P-K ratio (% dry mass) was 1.90-2.06-0.30 for manure A (60 ddc), and 2.60-2.24-0.34 for B (30 ddc). On germination, 100% concentration; manure A had 44.9% and B 19.6%, compared to the control. For concentration of 10% it was 93.7 and 111.4%, manure A and B, respectively. Limitations on study/implications: It is necessary to carry out more phytotoxicity tests. In this experiment, dilutions were made in the manures to increase germination. Findings/conclusions: The use of manure based on tilapia meal in agriculture is proposed in the future and in this way take advantage of the waste from fish processing. Keywords: Fish meal, compost, tomato, soil improver

A critical review on heavy metal contamination in aquatic food webs by edible fish species: a special case concerning Bangladesh.

Heavy metals (HMs) are ubiquitous in terrestrial and aquatic environments due to unplanned industrial waste discharge, the release of untreated wastewater, and improper mining activities. In particular, the concentrations of HMs are found to be higher in aquatic environments. As a result, the aquatic biota was heavily affected by HM contamination. This critical review aims to understand the sources and toxicity of HMs in commercial fish species, explore their ecological exchange, and examine the related human health challenges in Bangladesh. A modified PRISMA review technique is used in this paper to analyze the current status and research limitations of HM studies in Bangladesh fish species and their toxicity within aquatic food webs. Briefly, we searched several keywords to explore the research trend of HM concentrations and toxicity in fish species. Furthermore, potential toxicity and risk assessment of HMs through the aquatic food chain in Bangladesh were explored. On the other hand, a cross-tabulation approach was used to process the toxicity findings of HMs. Previous studies indicate that fish species can possess comparatively higher HMs than river water due to ecological exchange factors, including bioaccumulation and biotransformation. This review focuses on Bangladesh, highlighting areas for improvements and the need for further study to achieve a transparent understanding of HM deposition in fish species and the sustainable management of aquatic food chain toxicity.

The impact of quality certificates on sustainable food production: An analysis of selected systems in Poland

This study evaluates the influence of quality certificates on sustainable food production in Poland, considering economic, social, and environmental dimensions. Analyzing 25 different certificates, the research explores their criteria, procedures, and costs across various food product categories, including meat, fish, and plant-based products. The study provides a detailed review of certification processes, from initiation to audits and inspections. It identifies both commonalities and differences among certificates, each addressing unique aspects such as environmental impact, worker rights, and product origins. Despite the diversity in standards and procedures, the study underscores the need for standardized international criteria to improve transparency and meet consumer expectations, highlighting the significant role of quality certificates in advancing sustainable food production.

Effects of fish meal replacement with composite proteins source on growth performance, antioxidant capacity and swim bladder quality of chu’s croaker (Nibea coibor)

Collagen, as a commercial functional protein, is widely applied in food, cosmetics, biomedicine and other industries, and swim bladder is regarded as an ideal source of raw materials due to its rich collagen content. Chu’s croaker (Nibea coibor), as an economical fish that can produce high-grade swim bladder, is popularly farmed, however, its high fishmeal demand limits the development of the feed industry. Therefore, it is worth thinking about how to reduce the use of fish meal without affecting the swim bladder quality. Given that, an 8-week feeding trial was conducted to investigate the effects of fish meal partially replaced (0.0%, 5.0%, 10.0%, 15.0%, 20.0%) with composite proteins (CPs, consisted of corn protein meal and hydrolyzed feather meal) on growth, antioxidant capacity and swim bladder quality (texture and collagen deposition) of chu’s croaker. Results showed that although growth performance decrease with the increase of CPs’ replacement level, it did not compromise the swim bladder quality. Specifically, 5% - 10% CPs did not affect the growth significantly, but can improve antioxidant capacity, protein content, collagen synthesis and texture quality of swim bladder. The enhancement of swim bladder texture, including hardness, chewiness, springiness, and adhesiveness may be caused by changes in the expression of related genes, such as colga1t1, col12a1, cyp27a1, etc. These results indicated that appropriate fish meal replaced by CPs could be applied during aquaculture practice after comprehensive consideration of feed cost, growth rate and quality of swim bladder. This study provides support for the development of cost-effective feed formulations that improve the sustainability and economic viability of chu’s croaker culture.

Effects of Replacing Fish Meal with Rubber Seed Cake on Growth, Digestive, Antioxidant and Protein Metabolism of Juvenile Asian Red-Tailed Catfish (Hemibagrus wyckioides)

An 8-week feeding trial was conducted to assess the impact of replacing fish meal (FM) with rubber seed cake (RSC) on growth performance, digestive enzyme activity of the gut, antioxidant capacity and protein metabolism-related parameters of plasma and liver in juvenile Asian red-tailed catfish (Hemibagrus wyckioides) with an average body weight of 3.21 g. Four isonitrogenous (41.08 ± 0.17) and isolipidic (10.07 ± 0.11) diets were formulated, incorporating RSC at a level of 0%, 15%, 30%, and 45% (w/w) to progressively replace FM. Dietary inclusion of 15–30% RSC did not significantly affect growth performance (p > 0.05). However, the replacement of FM with RSC resulted in linear reductions in intestinal trypsin and amylase activities, with a significant reduction in intestinal amylase activity observed at the 45% RSC inclusion level. Dietary inclusion of 30–45% RSC decreased plasma glutamate dehydrogenase and aspartate aminotransferase activities, but increased plasma adenosine monophosphate deaminase and hepatic γ-glutamyltransferase activities. This may indicate that the high substitution of FM by RSC may affect the homeostasis of amino acid metabolism. Dietary inclusion of 15% RSC did not affect serum and hepatic antioxidant enzyme activities; however, dietary inclusion of 45% RSC significantly increased plasma malondialdehyde level, but decreased catalase activity. Furthermore, dietary inclusion of 30–45% RSC significantly increased hepatic lactate dehydrogenase activity. These results demonstrated that replacing a portion of FM with RSC is feasible, and dietary inclusion of 15% RSC did not have significant adverse effects on growth performance, digestive function and antioxidant capacity of H. wyckioides.

Replacement of fish meal with full fat Hermetia illucens modulates hepatic FXR signaling in juvenile rainbow trout (Oncorhynchus mykiss): exploring a potential role of ecdysteroids

Replacement of fish meal with full fat Hermetia illucens modulates hepatic FXR signaling in juvenile rainbow trout (Oncorhynchus mykiss): exploring a potential role of ecdysteroids

Evidence of polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs) in wild fish species from the remote tropical marine environment, South China Sea

Polybrominated diphenyl ethers (PBDEs) and their alternatives (e.g., dechlorane plus (DPs) and decabromodiphenyl ethane (DBDPE)) are ubiquitous in various environmental media. However, limited data is available on these chemicals in edible fish species from the wide-open South China Sea (SCS). In the present study, ten legacy PBDEs and three substitutions (DBDPE and two DPs) were analyzed in 16 wild fish species sampled from the open SCS to investigate their spatial and species-specific variations. The results showed that the total concentrations of PBDEs, DBDPE, and DPs in fish samples were in the range of 1.69 to 47.6, not detected (nd) to 21.0, and nd to 3.80 ng/g lipid weight (lw), respectively. BDEs 47, 209 and 100 were the dominant target PBDE congeners, representing 49.2%, 17.2% and 9.93% of the total PBDE concentrations, respectively. Higher concentrations of PBDEs, DBDPE, and DPs were found in fish species from the Wanshan Archipelago compared to those from the Mischief Reef and the Yongxing Island, suggesting the significant influence of anthropogenic activities. Species-specific differences in levels of PBDEs were observed, with the order of bathydemersal > demersal > pelagic ≈ reef-associated > benthopelagic species. The average fanti value of all fish samples was 0.68, suggesting commercial DP products as a contamination source. The levels of PBDEs, DPs, and DBDPE in fish samples were relatively low compared with those from other locations around the globe. Finally, the health risks concerning the ingestion of BDEs 47, 99, 153 and 209 via fish consumption collected from the SCS are negligible.

Implementation of GMP and SSOP in Making Fish Chili Sauce

Chili Sauce is a famous food. Fish Chili Sauce made contains 10% fermented Tuna fish meat, to give a different taste. To get the quality of Fish Chili Sauce. The purpose of this study is to be able to apply the principles of Good Manufacturing Practice (GMP) and Sanitation Standard Operational Procedures (SSOP) in making fish Chili sauce. This study uses a Descriptive Method to see the Implementation of GMP and SSOP in Making Fish Chili Sauce. In each Principle of GMP and SSOP implementation, Objective and Subjective Microbial (TPC) and E.coli analysis will be carried out. The results of the study showed that the nutritional value of Fish Chili Sauce is Water 44.735%, Protein 4.595%, Fat 25.72%, Carbohydrate 4.1%, Ash 20.85%, pH 4.50 and TPC 2.4 x 10 4. With an Average Organoleptic Value of Taste 6.1 (Like), Aroma 6.5 (Like), Color 5.8 (Like), Texture and Overall Acceptance 6.2 (Like). The results of the Escherichia coli test from raw materials, equipment and also Fish Sambal showed Qualify.

Dietary full-fat or defatted black soldier fly larvae can replace protein sources with no detrimental effect on growth performance or intestinal health of nursery pigs.

This work aimed to determine the effects of dietary full-fat or defatted black soldier fly larvae (BSFL) to replace protein sources on growth performance, blood parameters, intestinal morphology, and intestinal microbiota in nursery pigs and to investigate the effects of dietary defatted BSFL at up to 30% at the expense of protein sources on growth performance in nursery pigs. In Exp. 1, a total of 36 barrows with an initial body weight of 7.0kg (standard deviation = 0.8) were allotted to 3 dietary treatments in a randomized complete block design with 4 replicate pens per treatment and 3 barrows per pen. A corn-soybean meal (SBM)-whey-based control diet was prepared with soy protein concentrate and fish meal as additional protein supplements. Two additional diets were prepared to include 20% full-fat BSFL or 20% defatted BSFL to replace soy protein concentrate and fish meal to maintain the same energy and nutrient concentrations in all diets. In the 28-day feeding trial, pigs fed the diet containing defatted BSFL tended to consume more feeds (P < 0.10) than other groups during days 14 to 28 and the overall period. On day 28, the serum blood urea nitrogen in pigs fed the control diet was less (P < 0.05) than that fed the full-fat or defatted BSFL, but fecal score and jejunal morphology did not differ among the treatment groups. Relative abundance of Mycoplasma in the ileal digesta was less (P < 0.05) in the pigs fed the diet containing full-fat or defatted BSFL compared with the control group. In Exp. 2, a total of 192 pigs with an initial body weight of 7.8 (standard deviation = 1.2kg) were randomly allotted to one of 4 dietary treatments in a randomized complete block design with 6 replicate pens per treatment and 4 barrows and 4 gilts per pen. A control diet was mainly based on corn, SBM, fermented SBM, fish meal, and spray-dried plasma protein. Three additional diets were prepared to contain 10%, 20%, and 30% defatted BSFL to replace SBM, fermented SBM, fish meal, and spray-dried plasma protein to maintain for the same energy and nutrient concentrations. Average daily gain, average daily feed intake, gain:feed, and fecal score were not affected by increasing dietary defatted BSFL. Overall, dietary black soldier fly larvae did not compromise growth performance or intestinal health in nursery pigs. Black soldier fly larvae can be used in nursery pig diets to replace other protein sources without negative effects.

Bioconversion of insect protein biomass into a fishmeal alternate for freshwater fish, Oreochromis mossambicus (Peters, 1852) diets

Abstract The demand for alternative fishmeal has increased significantly in recent years due to the expansion of the fishing industry. Therefore, insect proteins are becoming more popular as an alternative low-cost bio-source for fish than plant-based fish feeds. In the present study, a dietary mixture of insect protein powder derived from four Indian grasshopper species, namely Oxya hyla hyla, Atractomorpha crenulata, Oxya japonica japonica, and Phlaeoba infumata (insect meal, IM) was substituted for conventionally used fishmeal (FM) in the diet formulation for growing Mozambique tilapia, Oreochromis mossambicus (Peters, 1852) fingerlings. Three formulated diets with IM were prepared, with FM substituted at the rates of 25%, 50%, and 75%, respectively, with a control diet with no IM but only 20% FM. All dietary treatments were administered to tilapia fingerlings for 60 days under laboratory conditions. IM-incorporated diets outperform FM-incorporated diets in growth and digestibility due to their higher food conversion ratio for IM. In terms of growth and survivability in tilapia fingerlings, a 75% replacement of FM with IM demonstrated the most significant efficacy. According to the findings, mixed insect powder derived from four grasshopper species can be used as a partial replacement for FM in formulating the compound fish diet for tilapia fingerlings.

The effect of experimental diets incorporating fermented soybean meal on growth metrics and utilization of nutrients in broiler chickens

The aim of this study was to explore the impact of fermented soybean meal (FSBM) on the nutritional quality of feed, growth performance indicators, and nutrient utilization in broiler chickens, aiming to overcome the challenges associated with locally produced soybean meal stemming from anti-nutrients and variations in nutritional quality. The study methodology included assessing growth performance metrics through two-way ANOVA statistical analysis and evaluating nutrient utilization in broiler chickens. Results indicated that broiler chickens fed with FSBM exhibited superior performance, displaying the highest average weekly weight gain (452 grams), optimal feed conversion ratio (1.39), extended intestinal length (225 cm), increased intestinal weight (297.5 grams), and heightened activity of digestive enzymes compared to other treatment groups throughout the feeding trials. The results of this study suggest that FSBM’s better digestibility helps broiler chickens grow faster. This makes it a possible replacement for animal protein sources like fish meal in poultry feed production, which is good for both local poultry feed producers and consumers.

Bovine bone meal combined with dephenolized cottonseed protein is an effective fishmeal substitution in Trachinotus ovatus feed: A comprehensive evaluation of growth, muscle quality, and intestinal digestion physiology

To investigate the feasibility of substituting fishmeal (FM) with a combination of bovine bone meal (BBM) and dephenolized cottonseed protein (DCSP), a mixture (consisting of 60 % BBM and 40 % DCSP) was used to replace varying FM levels in Golden pompano (Trachinotus ovatus) feed. Five isoproteic (47 %) and isolipidic (12 %) experimental diets were formulated, with FM levels set at 30 %, 24 %, 18 %, 12 %, and 6 % (namely Control, FM24, FM18, FM12, and FM6). To compensate for the reduced FM content, BBM and DCSP were used as substitutes, and DL-methionine and L-lysine were added to maintain the dietary amino acid balance. Following a 63-day trial, results showed that the growth of FM24, FM18 and FM12 groups did not exhibit significant differences compared to the Control group, while those of FM6 group considerably decreased. The biochemical composition of whole fish did not display significant differences among the five groups, while the muscle protein contents of the FM12 group were higher than the Control group. Most of the muscle texture properties were positively modified in the FM 12 and FM 6 groups. With the substitution ratio increase, the contents of serum total protein, albumin, total amino acids, and cholecystokinin were elevated, while serum peptide YY contents decreased. In addition, intestinal trypsin, NaK-ATPase, and alkaline phosphatase activities in FM18, FM12, and FM6 groups decreased, and lipase activities exhibited the opposite trend. The transcription levels of genes related to amino acid-sensing receptors (asct2 and snat2) were down-regulated with increasing dietary FM substitutions, while the expression levels of appetite regulation factors (pept1, cck, and ghrl) were up-regulated. In conclusion, the FM content in the diet of T. ovatus can be reduced to 12 % through the utilization of a combination of BBM and DCSP, with no adverse effects observed on growth performance, biochemical composition, or muscle texture.

Rethinking Freshwater Cage Aquaculture: A Case in Ghana

Lakes around the world, including Ghana’s Lake Volta, are facing insidious threats from pollutants due to high dependency on aquatic ecosystems. Cage aquaculture is expanding across Africa because of its potential to address food insecurity, provide livelihoods, and boost local economies. However, the uncontrolled expansion of cage aquaculture can have significant negative impacts on water resources, including environmental footprints that threaten biodiversity. Given the intensification of cage aquaculture for tilapia farming on Lake Volta, we advocate for a transition to inland-integrated aquaculture systems that promote circularity. Strengthening stakeholder collaboration is essential for enhancing competence in mapping inland aquaculture areas, identifying eco-friendly alternatives and reinforcing aquaculture regulations, with particular emphasis on cage culture on Lake Volta. These strategies can reduce the pressures imposed by tilapia cage farms on the lake while promoting best management practices. Additionally, capacity building must be an ongoing process to address knowledge gaps, including the development of effective preparedness plans executed during emergencies. The ongoing pollution from illegal mining in the Black Volta River, a tributary of Lake Volta, along with endemic diseases in the lake, further compounds fish health and welfare issues. This underscores the urgent need to implement inland transition strategies to protect the lake, mitigate disease spread, and ensure safe fish food production.

Evaluating Inclusion of Commercial Pistachio By-Product as a Functional Ingredient in Rainbow Trout Fishmeal and Plant Meal-Based Diets

To meet the growing demand for sustainable aquaculture, plant proteins are being explored as alternative sources in fish diets. However, some plant proteins can have adverse health effects on fish, prompting research into functional feed ingredients to mitigate these issues. This study investigated pistachio shell powder (PSP), rich in antioxidants, as a functional feed ingredient for rainbow trout (Oncorhynchus mykiss). The effects of PSP inclusion (0%, 0.5%, 1%, 2%) on growth performance, intestinal health, and gut microbiota were assessed in fish fed either a fishmeal (FM) or plant meal (PM) diet over a 12-week feeding period. The results indicated that PSP inclusion at 1% significantly (p &lt; 0.05) improved weight gain and growth performance in FM treatments, with no impact on growth in PM treatments. No significant differences were observed in other growth parameters, intestinal morphology, or oxidative stress markers, although a trend toward the downregulation of inflammatory genes was noted in PM treatments at 2% PSP inclusion. PSP inclusion did not significantly alter gut microbiota alpha diversity but affected beta diversity at the 0.5% level in the FM treatments (p &lt; 0.05). Differential abundance analysis of gut microbiota revealed taxa-specific responses to PSP, particularly the genus Candidatus arthromitus, increasing in relative abundance with PSP inclusion in both the FM- and PM-based treatments. Overall, PSP inclusion up to 2% did not have significant adverse effects on the growth, intestinal health, or antioxidant status of rainbow trout.

Effects of dietary fish meal replacement by Periplaneta americana meal on growth, metabolism, intestinal health and resistance against Aeromonas hydrophila of Micropterus salmoides

An 8-week culture experiment was conducted to investigate the effects of partial replacement of fish meal (FM) with Periplaneta americana meal (PAM) on growth performance, body composition, serum biochemical parameters, intestinal health and resistance against Aeromonas hydrophila of largemouth bass, Micropterus salmoides. A total of 450 healthy largemouth bass with an initial body weight (IBW) of 14.55±0.09 g were randomly divided into five groups. Five experimental diets were prepared by replacing 0 % (P0), 15 % (P15), 30 % (P30), 45 % (P45) and 60 % (P60) of the FM in the basal diet with PAM, respectively. The results showed that final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) were no significant difference in P15 and P30 compared with the control group (P > 0.05). Crude protein of whole fish body was significantly increased and crude lipid was significantly decreased in all PAM groups (P < 0.05). In the P30, the antioxidant enzyme activities were significantly higher than those in the control and other experimental groups, and malondialdehyde (MDA) was significantly decreased (P < 0.05). The activities of α-amylase and pepsin increased significantly in P15 and P30 and decreased significantly in P45 and P60 (P < 0.05). Lipase was significantly increased in all groups except P15 than in the control group (P < 0.05). There were no significant differences in villus height (VH), crypt depth (CD), and muscle thickness (MT) among all groups (P > 0.05), but villus width (VW) was significantly decreased in P45 and P60 (P < 0.05). The relative expression of IL-10 and TGF-β1 were first up-regulated and then down-regulated, while IL-8 was opposite (P < 0.05). The relative expression of Casp3, Casp9 and IFN-γ were significantly up-regulated in P45 and P60 (P < 0.05). After injecting A. hydrophila, all groups of largemouth bass experienced mortality, but cumulative mortality was lowest in the P30. In conclusion, PAM can partially replace FM in the diet of juvenile largemouth bass. The replacement of no more than 30 % is unlikely to adversely affect growth performance, and can increase the crude protein content of the whole fish body, and is beneficial to intestinal health.

Effect of dietary glycerol monolaurate supplementation on gene expression, intestinal mucosa and microbiota of juvenile black sea bream (Acanthopagrus schlegelii).

Glycerol monolaurate (GML) is a chemical compound derived from the combination of lauric acid and glycerol, exhibiting potent antimicrobial properties. An eight-week feeding trial was conducted to evaluate the effects of dietary supplementation of Glycerol Monolaurate (GML) on juvenile black sea bream. The control diet included 24% fish meal, while five additional diets were formulated with increasing GML concentrations: 0.01% (GML1), 0.02% (GML2), 0.04% (GML3), 0.08% (GML4), and 0.16% (GML5). Each diet was assigned to triplicate tanks. At the end of the experiment, serum immune and antioxidant in liver were non-significantly different among the groups. The relative gene expression of IGF-1 and GH in liver was statistically higher in the GML3 treated. The relative gene expression of IL-1, TGF, TNF-1, CCK, CLDN1, CASS-3 and GPR41 in intestine were statistically higher in the GML3 group. The photomicrographs of transmission electron microscope of the intestine were also studied. The GML supplemented groups had longer brush borders. The cells seemed to be joined by an intact junctional complex without visible intercellular spaces. The observed variations in phyla, class, and genus did not demonstrate statistical significance. Proteobacteria, Cyanobacteria, Firmicutes and Actinobacteria in the phylum, and Oxyphotobacteria, Bacteroidia, Holophagae and Negativicutes in the class, Brevundimonas, and Achromobacter in the genera were all substantially increased with higher levels of GML supplementation. Based on these results, it is suggested that glycerol monolaurate (GML) may serve as a potential dietary supplement for promoting different gene expression and intestinal health in black sea bream.

The on growth, histology of intestinal and hepatopancreas of using black soldier fly (Hermetia illucens) larvae meal in the diets of Pontastacus leptodactylus juvenile

ABSTRACT In 60 days of feeding, a trial was conducted to evaluate the effects on liver, gut histology, and growth performance of using defatted black soldier fly Hermetia illucens (BSF) larvae meal as a fish meal (FM) protein alternative in the diet of Pontastacus leptodactylus. Fish meal protein was replaced with BSF meal protein at 0%, 20%, 40%, 60%, 80%, and 100%. Six hundred crayfish with an initial weight of 0.033 g were randomly divided into 24 experimental groups with four repetitions. There were no significant differences observed in cheliped, molting numbers, or survival rates between the groups (p > .05). However, adding more than 60% BSF to feeds caused pathological findings in the hepatopancreas,and the intestines. The results of this study showed that 40% defatted BSF meal can be used as a protein source replacement for fish meal protein without affecting the survival rate and growth of P. leptodactylus juveniles.

MrFeed Pro50 FF supplementation improves growth of Largemouth Bass fed a diet containing 160‐g/kg fish meal

AbstractObjectiveThis study aimed at evaluating the role of a novel commercial product, MrFeed Pro50 FF (MP50), as a functional ingredient with which to formulate low‐fish‐meal diets for Largemouth Bass Micropterus nigricans.MethodsSeven test diets were examined. A reference diet (RD) contained 400‐g/kg fish meal, and a control diet (C) was formulated by replacing 60% of the fish meal in RD with poultry by‐product meal. The other five diets were formulated by adding MP50 to C at 5.0 (D50), 7.5 (D75), 10.0 (D100), 12.5 (D125), or 15.0 (D150) g/kg. Fish (initial body weight = 9.2 ± 0.1 g) were fed the test diets for 8 weeks.ResultThe MP50 supplementation level significantly affected weight gain, final body weight, carbon retention efficiency, energy retention efficiency (ERE), hepatosomatic index (HSI), viscerosomatic index (VSI), the ratio of fish meal consumption to fish production (RCP), and carbon waste. The weight gain of fish fed D50, D75, and D100 was greater than that of fish fed C and D150. The ERE was greater in fish fed D50 and D100 than in fish fed C and D75. The HSI and VSI were greater and nitrogen and carbon wastes were lower for fish fed D50 and D100 than in fish fed C. Fish fed D50, D75, and D100 exhibited greater weight gain and lower RCP values compared with fish fed RD. The weight gain of fish fed RD did not significantly differ from the weight gain of fish fed C, D125, and D150, confirming that the minimum fish meal level could be reduced to 160 g/kg.ConclusionThis study indicates that MP50 at 5.0–10.0 g/kg can be used as a functional ingredient in low‐fish‐meal diets for Largemouth Bass.