Aquatic Feeding Research Articles

Effects of different traditional and commercial feed on growth, survival and proximate composition of Rohu (Labeo rohita) reared in the semi-intensive composite culture system.

This study was investigated to assess the effects of different traditional and commercial aqua feed on proximate composition, growth performance and survival rate of Labeo rohita reared in the composite semi-intensive culture system. The aqua feeds of various companies (AMG, Supreme, Aqua, Star Floating, Hi-Pro and Punjab feed) used as commercial feed. Farm made feeds were maize gluten and rice polish. For confidentiality, these feeds were randomly given code labels T1, T2, T3, T4, T5, T6, T7 and T8 which were only known to investigating staffs. There were two replicates for each treatment. In this experiment, higher growth rate was observed in T3 as compared to other treatments. Lesser weight gain was observed in the T1 ( 270.30 ± 0.5 ). The maximum body length ( 19.25 ± 2.19) was found in T3. Similarly, the minimum body length (5.97 ± 2.94) was seen in T2. FCR ratio (2.36 ± 0.01 ) was recorded in T3. Simultaneously, FCR (1.86 ± 0.002 ) was also recorded in T4 that is the perfect ratio for farmers. Higher SGR was noted in T3 (1.62 ± 0.05 ). Overall, T4 showed lesser SGR (1.05 ± 0.001 ). T4 showed the higher crude protein ( 28.66 ± 0.24 % ). In the body composition higher level of fat content was recorded in T3 ( 5.46 ± 0.33 %). These outcomes also proved that the rise in the dietary protein level and lipid content can improve the fish's body crude fats and protein level. Thus, based on growth performance, survival and proximate composition. It is concluded that T3 and T4 may be recommended for commercial culture of L. rohita.

Bio-detoxification of mycotoxin-contaminated feedstuffs: Using lactic acid bacteria and yeast

Mycotoxins contaminations in feedstuffs are one of the principal concerns worldwide nowadays, related to the fact that they may evoke health problems in animals and consequently in humans. Biodetoxification of mycotoxins by application of beneficial microorganisms (lactic acid bacteria or yeasts) is one of the well-known, relatively low-cost, easy, efficient, safe, and green approaches for the reduction of mycotoxins presence in feeds. The use of beneficial microorganisms as feed additives to remove mycotoxins is widely practiced in the industrial production of animal feed. In this overview, we aim to summarize the great potential of beneficial microorganisms as bio-detoxificant, including a summary of various reported detoxification activities of lactic acid bacteria or yeasts against mycotoxins with relevance for feedstuff. The principal focus is the detoxification of mycotoxins in livestock, poultry, and aquatic feed using beneficial microorganisms. The mechanisms of the detoxification process and effective factors in this process are also covered. This review article could be useful for biotechnologists, investigators, and animal feed manufacturers who have challenges regarding the existence of mycotoxins in feed, and help them to find the best method for feed bio-decontamination.

Comprehensive metabolomics and transcriptomics analyses investigating the regulatory effects of different sources of dietary astaxanthin on the antioxidant and immune functions of commercial-sized rainbow trout.

Astaxanthin is an important aquatic feed additive that enhances the antioxidant capacity, and immune function of rainbow trout (Oncorhynchus mykiss); however, very limited information is available on its underlying molecular mechanisms. Haematococcus pluvialis powder, Phaffia rhodozyma powder, and synthetic astaxanthin were added to the commercial feed (no astaxanthin, NA) to prepare three experimental feeds, referred to as the HPA, PRA, and SA groups, respectively, and their actual astaxanthin contents were 31.25, 32.96, and 31.50 mg.kg-1, respectively. A 16-week feeding trial was conducted on the O. mykiss with an initial body weight of 669.88 ± 36.22g. Serum and head kidney samples from commercial-sized O. mykiss were collected for metabolomics and transcriptomics analysis, respectively. Metabolomics analysis of the serum revealed a total of 85 differential metabolites between the astaxanthin-supplemented group and the control group. These metabolites were involved in more than 30 metabolic pathways, such as glycerophospholipid metabolism, fatty acid biosynthesis, linoleic acid metabolism, and arginine and proline metabolism. It is speculated that different sources of dietary astaxanthin may regulate antioxidant capacity and immunity mainly by affecting lipid metabolism and amino acid metabolism. Transcriptomic analysis of the head kidney revealed that the differentially expressed genes between the astaxanthin-supplemented group and the control group, such as integrin beta-1 (ITGB1), alpha-2-macroglobulin (A2M), diamine acetyltransferase 1 (SAT1), CCAAT/enhancer-binding protein beta (CEBPB) and DNA damage-inducible protein 45 alpha (GADD45A), which are involved in cell adhesion molecules, the FoxO signaling pathway, phagosomes, and arginine and proline metabolism and play regulatory roles in different stages of the antioxidant and immune response of O. mykiss.

The Recent Advances to Increase Nutrient Utilization of Dietary Plant Proteins by Enzyme Supplementation and Fermentation in Rainbow Trout (Oncorhynchus mykiss): A Review

Aquaculture is the fastest growing animal production sector globally. However, its sustainability heavily relies on the development of nutritionally balanced cost-effective and environmentally friendly aqua feeds for fish and crustacean species that are already being farmed or the candidate species for intensive farming in the future around the world. Therefore, feeds produced for farmed aquatic species should be highly digestible in terms of nitrogen and phosphorous contents in order to avoid excessive release of these nutrients into the water column through solid and soluble discharge. Excessive nitrogen and phosphorous in the water are the main reason of eutrophication occurring causing severe depletion of oxygen and creating hypoxia for many aquatic organisms living inside water column. Strategies like formulating aqua feeds on required DP/DE (Digestible Protein/Digestible non-protein Energy) basis for farmed species and using synthetic enzymes as feed additives in order to make plant phosphorous bioavailable for fish are being utilized by the commercial aqua feed producers around the world. Fermenting plant protein ingredients with microorganisms and using prebiotics and probiotics as feed additives are also considered a viable option to reduce the nutrient load of aquafarms since these have been shown to increase the digestibility of feed ingredients via increased gut health maintaining the optimal composition and environmental conditions for gut microbiome. In this regard, this review is intended to emphasize the importance of the sustainability efforts of aquaculture production from the perspectives of environmentally friendly aqua feed formulations and improvements based on the recent knowledge gathered for the effects of dietary external enzyme supplementation and fermentation of plant ingredients on growth and wellbeing of rainbow trout (Oncorhynchus mykiss) throughout the world.

Dietary alpha-lipoic acid boosts growth, immune-antioxidant traits, behavior, and transcriptomes of antioxidant, apoptosis, and immune-related genes to combat cold stress in Nile tilapia (Oreochromis niloticus)

Water temperature is a major environmental factor affecting fish activity, physiology, behavior, and growth. Alpha lipoic acid (ALA) has garnered much attention lately as an aqua feed supplement because of its antioxidant effects. Thus, this study aimed to assess the effect of dietary ALA on performance, hematological and immunological indices, behavior and oxidative stress, apoptosis, and genetic inflammation in Oreochromis niloticus following 60 days of cold stress. Two hundred forty fish were divided into four groups (15 fish/replicate, N = 60 fish/group). The control (CNT) and ALA groups were reared at 25 °C and fed a basal diet without any supplementation or a basal diet containing 600 mg ALA/kg diet, respectively. The cold water-stressed group (CWS) and ALA + CWS groups were reared at 18 °C and fed basal and basal diets containing ALA, respectively. The results revealed that dietary ALA supplementation significantly improved feed utilization and growth in fish. ALA also mitigated CWS-induced microcytic hypochromic anemia and hyperlipidemia. Moreover, ALA supplementation considerably enhanced the antioxidant status and boosted intestinal α amylase, lipase, protease, and serum acetylcholinesterase activity of CWS-exposed fish. Besides, ALA supplementation significantly reversed CWS-induced upregulation of proinflammatory genes, pro-apoptotic genes, heat shock protein, and proliferating cell nuclear antigen or downregulation of superoxide dismutase and catalase gene expressions in liver and spleen tissues. Furthermore, ALA supplementation reduced CWS-induced histopathological alterations in fish liver, spleen, and intestine. We can conclude that ALA (600 mg/kg diet) could be recommended as an aqua feed supplement to boost growth, antioxidant capacity, and immunity and attenuate inflammatory and apoptotic reactions of fish reared under CWS-induced.

Valorized Palm Kernel Cake and Bambaranut Meal Affects Amino Acids, Growth and Nutrient Utilization in African Catfish, <i>Clarias gariepinus</i>

The high cost of fishmeal and plant protein like soybean has necessitated the search for alternative aqua feed ingredients like proteinous agro waste products. Agro waste are cheap and plausible alternative but lacks some essential amino acids and has several anti-nutritional factors (ANF) like phytic acid, non-starch polysaccharides, high fiber, and protease inhibitors. Solid-state fermentation of the agro wastes can reduce the ANF and improve the protein and nutritional values of feed ingredients. Palm kernel cake (PKC) is a byproduct of palm kernel oil production, and it is proteinous and abundant in Nigeria. Bambaranut meal (BNM) is a neglected proteinous legume high in methionine and lysine and is abundant and cheap. Freshly produced PKC and BNM were solid-state fermented for 5 days in a bioreactor using Saccharomyces cerevisiae and used to produce five novel diets. The inclusion levels of solid-state fermented PKC: BNM per diet were as follows: F1, 450:50, F2,350:150, F3,250:250, F4,150:350, and F5,50:450. There was a control diet labeled as feed F6 which was a control. A total of 270 African catfish fingerlings of average weights distributed as follows F1, 2.63±0.06g, F2, 2.70±0.13g, F3, 2.40±0.08g, F4, 2.30±0.05g and F5, 2.70±0.09g, were acclimatized for 7 days and stocked at 15 fish per 3 replicates aquaria per treatment feed. The catfish were fed ad libitum two times daily with the treatment feeds for 70 days. Culture water was changed daily. Catfish were weighed every 14 days. The catfish that received feed F4 (PKC:BNM;150:350g) had the best specific growth rate (SGR) of 4.43±0.06% day-1, lowest food conversion ratio (FCR) of 1.01±0.07 and highest protein efficiency ratio (PER) of 1.24. The catfish fed feed F3 (PKC: BNM) 250:250g, was next to F4 with SGR, Final weight, gut volume, and gut weight were all higher for catfish receiving feed F4 followed by those fed feed F2. There were no significant differences between the PER of catfish-fed diets F2, 0.39±0.03 and F3, 0.39±0.06. The lysine and methionine content of the feed increased with inclusion of FBNM than FPKC. In conclusion, solid state fermented BNM and PKC should be included in catfish feed for optimal growth and profitability.

Morphology of gustatory organs of a crocodile newt (genus Tylototriton)

The evolutionary causes behind the development of taste discs (TDs), recognized as the only gustatory organs in metamorphosed Batrachia (Caudata and Anura), have yet to be determined. Taste buds (TBs) serve as the gustatory organs in aquatic batrachian larvae, as well as in both larval and adult caecilians (Gymnophiona) inhabiting either aquatic environments or moist terrestrial habitats. We describe the morphology of gustatory organs of adult crocodile newts (Tylototriton cf. verrucosus, Salamandridae, Caudata). Crocodile newts are semi-aquatic and exhibit increased specialization towards an aquatic feeding, distinguishing it from most members of the subfamily Pleurodelinae. Our findings confirm that TDs serve as the gustatory organs in adult T. cf. verrucosus, similarly to many batrachians. We also determined the density and sizes of TDs’ sensory zones on the tongue and palate of T. cf. verrucosus, which differs from Batrachia. In terms of micro-morphology, two types of gustatory cells (GCs) were identified in the gustatory epithelium of T. cf. verrucosus. Our literature analysis suggests that TDs were larger in anurans compared to caudate amphibians, but were also larger in aquatic/semi-aquatic than in terrestrial anurans.

Improvement of non-specific immunity, intestinal health and microbiota of crucian carp (Carassius auratus) juvenile with dietary supplementation of Bacillus coagulans BC1

Establishing beneficial intestinal microbiota using autochthonous probiotics is a promising approach for disease control and growth regulation during fish rearing. Therefore, it is crucial to identify indigenous probiotics with high application potential in aquaculture. In this study, we screened Bacillus coagulans BC1, a strain with strong application potential. After a comprehensive safety assessment, diets containing varying doses of BC1 were formulated and administered to crucian carp. Subsequently, a feeding experiment was conducted to evaluate non-specific immune response, intestinal structure, microbiota, and challenge protection rate. The results demonstrate that oral supplementation of BC1 can lead to tissue-dependent upregulation of various serum immune enzymes and IgM levels, while significantly enhancing the expression of IL-1β, IL-10, TNF-α, and TGF-β in various organs of crucian carp (p < 0.05). The BC1 diet effectively promoted intestinal morphology in crucian carp and improved resistance to Aeromonas veronii TH0426 infection. Intestinal microbiota analysis revealed that the oral addition of BC1 significantly changed the intestinal microbial community structure of crucian carp but did not clearly affect intestinal microbial diversity. Oral administration of BC1 significantly improved the relative abundance of Cetobacterium in the intestines of crucian carp; reduced the abundance of opportunistic pathogens such as Bacteroides, Vibrio and Aeromonas and effectively regulating the nutrient metabolism in intestinal microbiota. These results indicate that BC1 could regulate immune function, effectively improving the intestinal morphology and intestinal flora structure and function of crucian carp, and therefore is a potential candidate strain for aquatic feed additives.

Synthetic astaxanthin has better effects than natural astaxanthins on growth performance, body color and n-3 PUFA deposition in black tiger prawn (Penaeus monodon)

Astaxanthin is an efficient nutrition strategy to relieve oxidative stress and enhance crustacean body color. Because of technological and economic benefits, synthetic astaxanthin is favored by the aquatic feed industry. However, whether synthetic astaxanthin can achieve the effects of natural astaxanthin needs further investigation. Here, we evaluated the effects of synthetic astaxanthin and natural astaxanthin (dietary supplementation with Haematococcus pluvialis and Phaffia rhodozyma) on the growth performance, body color, fatty acid composition and antioxidant capacity of black tiger prawn (Penaeus monodon). Compared with the control group (no astaxanthin supplementation), only synthetic astaxanthin significantly increased the weight gain rate (WG) and specific growth rate (SGR), together with the elevation of feed efficiency ratio (FER). All three types of astaxanthin enhanced body color by increasing astaxanthin deposition. The highest value of (a*) in the carapace and muscle occurred in the synthetic astaxanthin group. Synthetic astaxanthin significantly increased the n-3 polyunsaturated fatty acid (n-3 PUFA) contents in muscle. As expected, different sources of astaxanthin inhibited glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities in the hemolymph and decreased the contents of reduced glutathione (GSH) and malondialdehyde (MDA) in the hepatopancreas. Correspondingly, the structure of hepatopancreas was enhanced by astaxanthin. In addition, three types of astaxanthin almost indistinguishably enhanced the ability of shrimps to resist stress caused by transportation simulation. In conclusion, these results indicate that dietary synthetic astaxanthin has a better effect than natural astaxanthin on growth promotion, body color enhancement and n-3 PUFA deposition in muscle of black tiger prawn. Hence, synthetic astaxanthin is a suitable feed additive to promote the healthy and sustainable development of the shrimp industry.

Influences of dietary sodium butyrate on growth, digestion, antioxidant capacity and health in juvenile Onychostoma macrolepis fed on high-fat diet

Butyrate is a short-chain fatty acid with growth and immune regulatory effects. The aim of this experiment was to investigate the effect of sodium butyrate (SB) on Onychostoma macrolepis fed high-fat diet. O.macrolepis (2.5 ± 0.1 g) were kept in twelve aquariums (three aquarium /treatment, fifteen fish / aquarium), fed a high-fat diet (control), and high-fat diet supplemented with 0.1%, 0.2% or 0.4% SB for fifty-six days. The results showed that the supplementation of 0.2% SB in high-fat diet significantly promoted the growth of O.macrolepis. Simultaneously, dietary SB supplementation improved lipase and trypsin activities and intestinal histological morphology of O.macrolepis consuming with high-fat diets. Furthermore, the supplementation of 0.2% or 0.4% SB in the diet enhanced serum immunity and intestinal antioxidant capacity. Additionally, the addition of 0.2–0.4% SB up-regulated the transcriptional level of peroxisome proliferators-activated receptor alpha (pparα) gene, thereby activating pparα-mediated β-oxidation and mitigating liver lipid accumulation of O.macrolepis. In summary, the addition of 0.2–0.4% SB in high-fat diet was beneficial to growth, digestion, immunity and health of O.macrolepis. This study provides a reference for SB as a functional additive of aquatic feed.

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.

Dual application of Tribonema sp. GXU-A10 for purifying molasses vinasse and promoting the growth and health of Oreochromis niloticus

Molasses vinasse (MV) is rich in nutrients and has reuse value. Hence, it could be used to cultivate microalgae. In this study, Tribonema sp. GXU-A10 strain was cultured with MV and then added to Oreochromis niloticus feed. GXU-A10 removed 90.20 % and 80.95 % of TN and NH4-N, respectively, from MV and achieved a biomass of 4.21 g/L. Adding 5 % or 10 % GXU-A10 significantly improved the WGR and SGR of O. niloticus (P < 0.05), reduced the accumulation of the lipid droplets in its liver, and facilitated the beneficial colonization of Bacteroidetes in the intestines of O. niloticus. To reduce the cost and ensure effectiveness, the recommended dosage of GXU-A10 is 3–5 % but not >10 %. These findings could promote the sustainable utilization of wastewater and microalgae resources and the development of aquatic feed additives.

MiRNA-194 targets MyD88a to regulate immune response in Cyprinus carpio after recovery from gossypol toxicity

Cottonseed meal has been one of the predominant protein feedstuffs used in aqua feed, which contains gossypol. It is well known that gossypol, a natural polyphenolic compound found in seeds, can be toxic to fish. The toxicity of gossypol persists even after a recovery period; however, the underlying mechanism remains largely unknown. To investigate the toxic mechanism of gossypol after the recovery period, Cyprinus carpio were administered a continuous oral dose of 20 mg/kg·d gossypol (gossypol acetate dose/fish weight·d) for one week, followed by a two-week recovery period. The spleen index, spleen morphology, lysozyme (LZM) activity, acid phosphatase (ACP) activity and nitric oxide (NO) concentration were obviously changed in the spleens of C. carpio after two weeks of recovery. Then, miRNA sequencing identified 22 differentially expressed miRNAs in the spleens of C. carpio two weeks after the gossypol treatment. The mRNA expression levels of immune-associated genes were significantly increased in the spleens after recovery. MiR-194 was chosen for future study through a search of existing literature and an analysis of miRNA and mRNA expression levels. To further characterize the potential target of miR-194, we identified putative miR-194 binding sites in the 3′UTR of myeloid differentiation factor 88a (MyD88a). Dual-luciferase reporter assays revealed that miR-194 downregulated the expression level of MyD88a through binding to seed-matching sequence in the 3′ UTR of MyD88a. Moreover, C. carpio were intraperitoneally administered with miR-194 antagomir. Furthermore, down-regulation of miR-194 increased the expression levels of MyD88a and some pro-inflammatory cytokines and anti-inflammatory cytokines. Altogether, the results demonstrate miR-194 can target MyD88a to regulate the immune response of C. carpio after a two-week recovery period following gossypol administration.

Genetically superior European sea bass (Dicentrarchus labrax) and nutritional innovations: Effects of functional feeds on fish immune response, disease resistance, and gut microbiota

The objective of this study was to determine if selected fish genotypes could benefit from the use of functional additives in novel aqua feed formulations to improve growth performance, gut microbiota, immune response, and disease resistance in fish. Two batches of juvenile European sea bass selected for high growth (HG; selected sires x selected dams), and wild types (WT; wild sires x selected females) were fed a “future diet” coated with three different functional additives for 12 weeks as follows: (i) 2 weeks with a high dose, followed by (ii) 10 weeks with a low dose. The functional additives tested were a mixture of probiotics (PROB), organic acids (ORG), and phytogens (PHYTO). A pathogen challenge test (Vibrio anguillarum) and a stress condition (overcrowding) were performed after each dose. At the end of the feeding experiment, fish from the HG group performed better than fish from the WT group in terms of body weight, relative growth, SGR, and DGI. The results of the two challenge tests performed after two weeks of high dose and ten weeks of low dose showed a significant effect of diet on fish survival. GALT-associated gene expression analysis revealed an interaction between the genotype and diet for il-1β in the distal gut. Finally, regarding the gut microbiota, discriminant analysis showed no clear separation between fish fed the future diet and those fed the same diet with experimental additives. Nevertheless, the relative abundance of certain taxa varied between experimental groups. For example, fish fed the ORG diet had higher relative abundance of Streptococcus in both genotypes, whereas fish fed the PHYTO diet had higher abundance of Lactobacillales. In contrast, fish fed PROB had lower abundance of Pseudomonas and Acinetobacter.

Fish Feed Processing Technology for Entrepreneurship Development in India

The objective of feeding fish is to provide the optimum nutritional requirements for good health, growth, yield while minimizing wastage to optimize profits. Though natural feed forms the main source of nutrition, supplemental feeding is necessary to obtain increased production in ponds. Therefore, a good artificial feed not only facilitate in meeting nutritional requirements but also help to maintain good water stability and acceptance by the fish. To produce supplementary feed with the desired physical characteristics, feed processing and technology has a major role to play for quality feed production. Commercial feed is mainly used by few advanced and progressive farmers while the high cost is prohibitive for the small and marginal farmers. Moreover, non-conventional ingredients are normally not used for fish feed production by aqua feed industry, resulting into increased cost of the feed in the market. Some of the limitations in using non-conventional ingredients are poor utilization by fish either due to presence of anti-nutritional factors or insufficient processing. Furthermore, the scientific information on fish feed technology of conventional and non-conventional feed ingredients are limited. Production of feed as per the requirements essentially involves industrial processing that needs to be marketed in the form highly preferred by the end-users. Hence, the entrepreneurs need to access and use technical information and technology available at the research institutes to produce the desired commercial demand. The combination of the technical knowledge, technological package and business skill would certainly ensure establishment of the successful venture of feed production to cater the demand.

The current state of research and potential applications of insects for resource recovery and aquaculture feed.

Concerns about fishmeal use and its ecological footprints must be addressed for the aquaculture industry to move on as a sustainable food production sector. Through recent research outcomes, the insect-based meals in fish diets have promise and harnessed promises for commercial applications. In this midst, the efficiency of the selected insects in valorizing biological waste, as well as the nutritional profile of the harvested insects for use in fish diets, will be the driving forces behind such an approach. More extensive research has been published on the suitability of the waste substrate, the nutritional profiling of the meals, the level of substitution, the effects on growth, the immune physiology, and the flesh quality of the animals. Previously, there are only a few reviews available in insect protein applications in aqua feed that focused particularly on the nutritional quality and substitution levels. Considering the dearth of available work, the goal of this review is to provide a more comprehensive account of the resource recovery potential of insects and its derivatives, with a special emphasis on quality as determined by substrate used and processing techniques. Suggestions and policy implications for a sustainable approach to achieving a circular bio-economy of insect farming and its application in aquaculture are discussed for progression and advancement of the existing state of the art.

Chitosan Application in Aquatic Feed and Its Impact on Fish and Shrimp Productivity

The culture of crustaceans, such as shrimp and crabs, in Indonesia has resulted in a significant increase in waste production, particularly in the form of shells and heads. This waste contains valuable components like chitin, chitosan, and carotenoids, which can be extracted and utilized in aquaculture activities. Some research results show that the use of chitosan, derived from chitin, in fish feed, is a functional polysaccharide with various biological activities, including antimicrobial, anti-inflammatory, and immune-stimulating effects. It also acts as a growth promoter in shrimp and improves the performance of farmed fish. Additionally, the inclusion of chitin and chitosan in fish feed formulations enhances digestibility, growth, and nutrient absorption. This paper provides a comprehensive review of the potential, nutritional value, and benefits of processed crustacean waste products, focusing on chitosan, and their impact on the productivity of fish in aquaculture.

Replacement of dietary fish meal by fermented soybean meal improves growth, energy metabolism, and innate immune response in Penaeus vannamei Boone, 1931 (Decapoda: Dendrobranchiata: Penaeidae)

Abstract Fishmeal (FM) is considered a preferred source of protein for aquatic feed due to its good palatability and digestibility, a balanced amino acid profile, and a low level of anti-nutritional factors (ANFs). Shortage of FM supply and increases in price, however, are major challenges faced by feed producers and aquaculture farmers. Fermented soybean meal (FSBM) has been proposed to partially replace FM because of its high nutritional value and low cost. The optimal FSBM concentration for substituting FM and effects of FSBM substitution on growth performance, energy metabolism, and immune response nevertheless remain unclear. We evaluated the effects of shrimp diets containing FSBM at 0% (FM), 25% (FSBM25), 50% (FSBM50), 75% (FSBM75), and 100% (FSBM100) on the shrimp Penaeus vannameiBoone, 1931. FSBM50 led to a significantly higher weight gain (postlarvae 1927.36 ± 46.64%, young juveniles 237.00 ± 8.25%, and juveniles 153.96 ± 2.18%) than the other experimental and control diets in different stages of the shrimp. The FM group consumed less oxygen than the experimental diet groups. FSBM75 and FSBM100 led to a significantly higher ammonia-N excretion than FM, FSBM25, and FBSM50. All experimental diet groups exhibited a significantly higher O:N ratio (8.3 ± 0.8–9.4 ± 1.7) than the FM group (7.1 ± 0.2). Shrimp fed with FSBM25- and FSBM50-containing diets exhibited an increased total hemocyte count, and FSBM25, FBSM50, and FSBM100 led to a significantly higher superoxide anion production than FSBM75 and FM. FSBM substitution in shrimp diets resulted in a significantly higher phagocytic activity than the FM diet, suggesting that FSBM substitution improves the cell-mediated immune response in shrimps. In challenge trials with white spot syndrome virus (WSSV), all experimental diets led to a higher survival rate than the FM diet, and in Vibrio parahaemolyticus challenge trials, FSBM50 led to a higher survival rate than the other experimental and control diets, indicating that FSBM substitution in shrimp diets could improve the defense capacity of shrimps against WSSV and V. parahaemolyticus.

Curcumin loaded liposome formulation: Enhanced efficacy on performance, flesh quality, immune response with defense against Streptococcus agalactiae in Nile tilapia (Orechromis niloticus).

Application of novel trend comprising antioxidant phytogenics is aiming to minimize the stress related factors and associated diseases in intensive fish culturing. Today, the concept of exploiting and protecting natural antioxidants represents a paradigm shift for the aqua feed industry. Therefore, our principal goal targeting liposome as a novel nanocarrier for curcumin is directed to attain superior performance, fillet antioxidant stability and bacterial resistance in Nile tilapia. A total of 500 Nile tilapia fingerlings (average body weight, 10.27±0.10g) assigned into five experimental groups in 25 glass aquaria of 120L capacity at the density 20 fish/aquaria. The experimental groups were supplemented with varying doses of liposomal curcumin-NPs, LipoCur-NPs (0, 5, 15, 25 and 35mg/kg diet) were reared for 12 weeks and later Streptococcus agalactiae (S. agalactiae) challenged model was performed. Inclusion of LipoCur-NPs (25 and 35mg/kg diet) had the most prominent impact on Nile tilapia growth rate and feed conversion ratio. The immune boosting outcomes post supplementing 35mg/kg diet of LipoCur-NPs were evidenced by higher myeloperoxidase, lysozyme and total immunoglobulin levels. Even after 4 weeks frozen storage, LipoCur-NPs at the dose of 35mg/kg diet prominently increased (P < 0.05) the fillet scavenging capability for free radicals (1,1-diphenyl-2-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) with an inverse reduction in lipid peroxidation biomarker (malondialdehyde). Notably, upregulation of GSH-Px, CAT, and SOD genes in fillet of 35mg/kg LipoCur-NPs fed fish coordinated with higher T-AOC and lower oxidative markers (ROS and H2O2). Post S. agalactiae challenge, higher supplementation levels of LipoCur-NPs (35mg/kg diet) greatly attenuated the expression of its vital virulence genes (cfb, fbsA and cpsA) with higher expression of Igm, CXC-chemokine and MHC genes. Concordantly, downregulation of inflammatory markers (IL-1β, TNF-α and IL-8) and upregulation of anti-inflammatory ones (IL-10 and TGF-β) were remarkably documented. Based on these findings, the innovative curcumin loaded liposome was considered a novel multitargeting alternative not only playing an imperative role in Nile tilapia growth promotion and fillet stability upon storage, but also protecting efficiently against S. agalactiae.

Efficacy of Insect Feed as Protein Source in Aqua Feed and its Impact on Growth Performance of Fish

This study aimed to evaluate the impact of using insect-based fish feed on the growth of Ctenopharyngodon idella (grass carp). A meal in powder form was produced using the larvae of blowflies. The mixture contained either 20% or 40% larvae, combined with conventional ingredients. The fish fingerlings were divided into three groups and fed with this formulated feed for 10 weeks, while ensuring that the physio-chemical parameters were within the optimum range. Various growth parameters such as mortality rate, feed conversion ratio (FCR), specific growth rate (SGR), length, and weight were measured. The results showed that fish diet based on insects greatly accelerated growth, with the group fed with 40% maggot meal growing to the largest size and length. Similarly, the group fed with 20% maggot meal also demonstrated an increased growth rate. Whereas, FCR was the highest in the group fed with 40% maggot meal. Additionally, the groups fed with maggot meal had a lower mortality rate. This study investigated the use of prepared aquatic feeds containing meals from five different insect species. It was concluded that although insect-based diets show promise as an alternative to inexpensive and unappetizing fish meal, further experimentation with different compositions of insect-based diets is needed in order to achieve optimal results. It is likely that the extensive raising and processing of insects for use as a component of fish feed would benefit aquaculture’s viability and profitability in the years to come.