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Society is becoming more demanding with aquaculture's environmental footprint and animal wellbeing. In order to potentially mitigate these concerns, feed formulations could be based on eco-efficient (circular economy-driven) or organic ingredients. This study aimed to investigate the growth performance, feed utilization, and health status of juvenile Nile tilapia (Oreochromis niloticus) when fed with such feeds. The growth trial lasted for 8 weeks, and fish had an initial weight of 31.0 ± 0.5 g (mean ± SD). Fish were fed until visual satiation, in quadruplicate, with one of three isonitrogenous and isoenergetic experimental feeds: a commercial-like feed without fishmeal (PD), a diet based on ingredients compatible with organic certification (ORG), or a feed formulated using circular economy-driven subproducts and emergent ingredients (ECO). Fish fed ECO showed a tendency for decreased feed intake, while ORG fish significantly reduced their intake compared to those fed PD. Consequently, fish fed ECO (62.7 ± 5.4 g) exhibited almost half the growth than those fed PD (107.8 ± 6.1 g), while ORG fish almost did not increase their weight (32.7 ± 1.3 g). ECO and ORG diets had a lower digestibility for protein, lipid, and energy when compared to PD. Feed utilization of fish fed ECO or ORG was also lower than those fed PD. From the health-related genes analyzed, only glutathione reductase (gsr) showed statistically significant differences, being more expressed in fish-fed ECO than those fed PD. Thus, even when such novel formulations induced extreme effects on voluntary feed intake, their impact was noted only in fish growth, but not in robustness. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish meal (FM) is considered the primary protein source in fish feed, but the most expensive ingredient, which ultimately increases feed cost. Application of a substitute for FM in fish feed can lower feed cost, but it commonly leads to reduced palatability and lowered feed consumption of fish. Jack mackerel meal (JMM) has been reported to be an effective attractant and/or stimulant in the olive flounder diet. This study revealed that inclusion of 50% jack mackerel meal (JMM) at the expense of FM in the olive flounder (Paralichthys olivaceus) diet replacing 50% FM with duck by-product meal (DBM) lowered feed cost, but improved feed consumption and growth performance and economic return to the farmer. The results of this study will help olive flounder producers to improve their profitability. This experiment was performed to evaluate the inclusion impact of various levels of jack mackerel meal (JMM) in olive flounder (P. olivaceus) feeds substituting 50% FM by duck by-product meal (DBM) on growth, feed availability, and economic efficiency. Seven experimental diets were prepared. The control (Con) diet contained 60% FM. Fifty percent FM in the Con diet was substituted with DBM, and then the graded levels (0%, 10%, 20%, 30%, 40%, and 50%) of JMM were added instead of FM, named the DJ0, DJ10, DJ20, DJ30, DJ40, and DJ50 diets, respectively. All feeds were assigned to triplicate fish groups. At the end of 56 days' feeding, fish fed the DJ40 and DJ50 diets exhibited comparable weight gain and specific growth rate to fish fed the Con diet. Higher feed consumption was observed in fish fed the Con, DJ40, and DJ50 diets compared to fish fed the DJ0 and DJ10 diets. Lower feed conversion ratio was observed in fish fed the Con diet compared to fish fed the DJ0, DJ10, DJ20, and DJ30 diets. Furthermore, the DJ50 diet led to the highest economic profit index (EPI). In conclusion, inclusion of 50% JMM in the olive flounder diet replacing 50% FM with DBM seems to be the most recommendable dietary treatment based on growth and feed consumption of olive flounder and EPI. [ABSTRACT FROM AUTHOR]

The main cost in aquaculture production is feed, so management practices and feeding strategies aim to optimize both feed intake and efficiency. This study aimed to evaluate the growth performance of beluga, Huso huso, affected by periodic changes in dietary protein sources and hence identify possible innovative feeding strategies toward more efficient use of dietary protein. This study was designed with two experimental diets, namely fish meal (diet A) and plant protein blend (diet B) (protein 40%, fat 16%), which were used in different food schedules for feeding beluga (initial weight 82.08 ± 4.1 g) during 8 weeks. The experimental treatments included: continuously feeding a fish meal diet (A); continuously feeding a plant protein diet (B); alternating between diet A in the morning and diet B in the afternoon (A am/B pm); alternating between diet B in the morning and diet A in the afternoon (B am/A pm); and alternating between diet A for one day and diet B for one day (1A/1B). At the end of the eight‐week trial, superior growth performance and feed utilization were respectively observed in fish receiving A, Bam/Apm, and Aam/Bpm diets compared with the remaining treatments. The specific activity of trypsin and chymotrypsin was significantly high in fish fed Aam/Bpm and Bam/Apm. Feeding the fish‐meal‐based diet (A) continuously, led to decreased protein and increased fat deposition in the carcass. Among the mixed feeding schedules, the highest cost‐saving was recorded with the Aam/Bpm and Bam/Apm schedules. Based on economic analysis, applying Aam/Bpm and Bam/Apm schedules led to the reduced cost of beluga production compared with the other treatments. Therefore, the optimal feeding schedules for beluga are Aam/Bpm and Bam/Apm, which should be used as a practical feeding guideline for H. huso production. [ABSTRACT FROM AUTHOR]

In aquaculture, fishmeal is consumed in large quantities. Utilizing non-fishmeal protein sources to replace fishmeal in aquaculture feed and developing low-fishmeal feed has become a hot topic in current aquaculture industry research and development. However, non-fishmeal protein sources contain some anti-nutritional factors that can affect the application of low-fishmeal feed and to some extent, restrict the development of low-fishmeal feed. Adding exogenous enzyme preparations to low-fishmeal feed can effectively improve the digestibility of low-fishmeal and degrade the antinutritional substances in non-fishmeal protein sources, thereby enhancing the feeding value of low-fishmeal feed. The article analyzes the application value of feed enzyme preparations in aquaculture feed and reviews their application effects in low-fishmeal aquaculture feed, aiming to provide references for the efficient development of low-fishmeal feed. [ABSTRACT FROM AUTHOR]

Aquaculture contributes to the sustainable development of food security, marine resource conservation, and economy. Shifting aquaculture feed from fish meal and oil to terrestrial plant derivatives may result in cost savings. However, many carnivorous fish cannot be sustained on plant-derived materials, necessitating the need for the identification of important factors for farmed fish growth and the identification of whether components derived from terrestrial plants can be used in feed. Herein, we focused on the carnivorous fish leopard coral grouper (P. leopardus) to identify the essential growth factors and clarify their intake timing from feeds. Furthermore, we evaluated the functionality of starch, which are easily produced by terrestrial plants. Results reveal that carbohydrates, which are not considered essential for carnivorous fish, can be introduced as a major part of an artificial diet. The development of artificial feed using starch offers the possibility of increasing the growth of carnivorous fish in aquaculture. [ABSTRACT FROM AUTHOR]

Aquafarms should reduce the use of fishmeal and fish oil in nutritional feed. One such accessible and relatively inexpensive food component that could successfully meet the challenge posed by aquaculture is algae. The objective of the present study was to evaluate the algae meal inclusion of Chlorella and Spirulina sp. in a diet for rainbow trout, evaluating its effects on fish growth, histological parameters and fillet quality. Experiments were carried out to replace 50% and 100% of fishmeal with Spirulina sp. and Chlorella vulgaris in feed for rainbow trout (Oncorhynchus mykiss W.) cultured in a recirculation system. At the end of the experimental period, the highest mean live weight was measured in rainbow trout fed a feed containing 50% algal meal in the feed. The absorptive vacuolization of cells was increased the most and lamina propria was average thickened when fed 50% algae diets. Fat droplets in the hepatocytes were larger in the 50% algae meal fed group, and their nuclei were replaced in the peripheral zone of the cells. Substitution of fishmeal with 50% algal meal in fish feed resulted in a 36.44% reduction in the lipid content of rainbow trout fillets compared to control fish. [ABSTRACT FROM AUTHOR]

Research has focused on alternative plant materials or additives that can be used instead of fish meal due to limited stocks and increased feed prices, although it is important for carnivorous fish species. Taurine is a functional amino acid supplemented to low fish meal diets to improve the growth performance of fish. In this study, eight experimental diets with 0%, 0.5%, 1% and 2% ratios of taurine supplemented (T0, T0.5, T1 and T2) high (HFM) and low fish meal (LFM) diets were prepared (defined as HFMT0, HFMT0.5, HFMT1, HFMT2, LFMT0, LFMT0.5, LFMT1 and LFMT2). The experiment was carried out in twenty-four 400 L rectangular fiberglass tanks conducted in a marine water system, and fish (initial mean weight of 23.5 g) were stocked in each tank. The nutrition trial was carried out for 90 days with three replicates. Meagre fed with the HFMT1 diet had a higher final mean weight (FMW) and specific growth rate (SGR) than fish fed with HFMT0 and all LFM diets. Including taurine in all LFM diets also enhanced growth performance. The FMW and SGR of fish fed the LFMT0.5 diet were similar when compared to HFMT0 (P>0.05) and increased compared to that of other LFM diets with taurine (P<0.05). Meagre fed the LFM0.5 diet had a lower feed conversion rate (FCR) than those provided for all HFM diets, although there was no significant difference between treatments. Dietary taurine has decreased the hepatosomatic index (HSI), viscerosomatic index (VSI) and total ammonia-nitrogen excretion (TAN), irrespective of taurine and fish meal levels. Including dietary taurine at both fish meal levels enhances the number of red blood cells (RBC) and whole-body amino acids of meagre. The most remarkable conclusion of this study is the inclusion of taurine in low fish meal diets improved growth performance and profitability in meagre, and the level of 0.5% has been recommended. [ABSTRACT FROM AUTHOR]

Simple Summary: Simple Summary: Protein ingredients play a significant role in pet food and have been brought into focus by pet owners, which drives up the annual cost of protein sources for the pet food industry. Protein resources are a crucial part of human food. However, there is a global shortage of protein-rich food, particularly animal protein. Researching the nutritional value and metabolic properties of various protein sources is essential for the pet food industry to make environmentally sustainable pet food. Using the beagles as the model animal and the difference method, we evaluated the energy value of six protein ingredients, including fish meal, meat and bone meal, corn gluten meal, soybean meal, mealworm meal, and yeast extract, and compared the effects on biological potency. There is a correlation between the chemical composition and the effective energy of protein ingredients. This study also provided recommended predictive energy equations for protein ingredients in dog food. This study evaluated the nutrition composition, the nutrient digestibility, and the energy value of six protein ingredients used in pet food by the difference method in six beagles within a 7 × 6 incomplete Latin square design. The results showed that the apparent total tract digestibility of gross energy (GE) and organic matter (OM) in beagles fed the fish meal (FM) and corn gluten meal (CGM) diets was higher than for those fed the meat and bone meal (MBM), soybean meal (SBM), mealworm meal (MM), and yeast extract (YE) diets (p < 0.05). The digestible energy (DE), metabolizable energy (ME), and net energy (NE) of the MM diet were greater than the other diets, and MBM was the lowest (p < 0.05). The ME of protein ingredients was positively correlated with organic matter and negatively correlated with the ash content. The NE of protein ingredients was positively correlated with the crude protein content and negatively correlated with the ash content. The study resulted in predictive energy equations for protein ingredients that were more accurate than the NRC's predictive equation of ME when the ash content of the ingredient was more than 30% DM. In conclusion, the nutrient digestibility and energy value of corn gluten meal were similar to those of fish meal and those of soybean meal were similar to yeast extract. All predictive energy equations for six protein feedstuffs had slight differences with measured energy values. [ABSTRACT FROM AUTHOR]

Using stable isotope analysis, we assessed the relative contributions of the main protein contributors fishmeal, soya and sunflower meal to mature abalone muscle and gonad tissue over 1 year. Prerequisites for the use of stable isotope mixing models were established in this species. The δ13C and δ15N discrimination factors and turnover rates were influenced by diet composition, and there were tissue‐specific and sex‐specific differences. Abalone were fed the two combination diets (fishmeal–soya and fishmeal–sunflower meal) grew at similar rates. However, feed was most efficiently utilised in abalone fed a combination of fishmeal and soya. The relative contribution of fishmeal, soya and sunflower meal to female and male abalone tissue growth fluctuated throughout the 1‐year study. Overall, fishmeal contributed over 50% of the gonad (54%–82%) and muscle (54%–84%) tissue growth in females. Similarly, fishmeal contributed over 50% of gonad tissue growth of male abalone, ranging from 59% to 87%, while the contribution to meat tissue growth in males ranged from 44% to 94%. These findings support the importance of laboratory studies when using stable isotope analysis and mixing models for nutrient allocation in aquaculture. [ABSTRACT FROM AUTHOR]

Simple Summary: The United Nations' goals for sustainability, like Zero Hunger by 2030, urge us to find new ways to produce food without harming nature. As traditional resources for feed, like soymeal and fishmeal, become scarcer and more expensive, exploring alternative protein sources is one options. Research on using insect meal instead of fishmeal shows promise in terms of animal growth and feed efficiency. This paper assesses the socio-economic benefits and costs of production of insect meal to substitute fishmeal in feed, while also focusing on factors that would affect performance most. The study evaluates the economic value of insect-based products, waste, and greenhouse gas reduction as socio-economic benefits. Data from laboratory trials and case studies on black soldier fly and yellow mealworm reveal negative balances of socio-economic benefits and costs; however, it is possible that upscaling and more effective technologies could move this positively. Changes in nutrient market values could also shift the balance as well as prevent impact on marine ecosystems from reduction fishery; this was not evaluated but could contribute to the overall outcome. Thus, although the current assessment shows a negative balance, it does not necessarily mean that the production of insect meal for feed is not beneficial for society in the long term. Sustainability targets set by the United Nations, such as Zero Hunger by 2030, encourage the search for innovative solutions to enhance food production while preserving the environment. Alternative protein sources for feed, while conventional resources like soymeal and fishmeal become more expensive and scarcer, is one of the possibilities. Studies on substituting fishmeal with insect meal show promising results in terms of animal growth and feed efficiency. This paper aims to assess the socio-economic benefits and costs of insect meal substituting fishmeal in feed and to highlight the factors influencing performance most. The study evaluates the economic value of insect-based products, waste reduction, and reduced greenhouse gas emissions as socio-economic benefits. It combines empirical data derived from laboratory trials and two case studies covering black soldier fly (Hermetia illucens) and yellow mealworm (Tenebrio molitor). Current analyses reveal negative socio-economic balances, emphasizing that reduction of operating and investment costs through upscaling and technological advancements can give a positive move, as well as factors such as current market valuations for nutrients can change significantly. Thus, a negative balance at the moment does not mean that insect rearing, and larva processing are not desirable from a long-term socio-economic perspective. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish meal is commonly used as the main protein source in fish feeds, but its high price has restricted the use of fish meal. Thus, looking for a substitute with an inexpensive and sustainable source for fish meal in fish feeds is highly needed. Nevertheless, replacement of fish meal with an alternative source in fish feeds commonly reduces the palatability of diets, leads to reduced feed intake, and lowers growth performance. Our previous study reported that up to 20% of fish meal could be substitutable with chicken by-product meal in the feed of rockfish without deteriorating their growth and feed intake. This study evaluates the impact on growth and feed availability from including jack mackerel meal in rockfish diets which otherwise replace 20% fish meal with chicken by-product meal. With fish fed a 55% fish-meal-based diet, the inclusion of 60 and 80% jack mackerel meal in low-fish-meal diets achieved superior weight gain, specific growth rate, and feed consumption. Furthermore, compared to an 80% inclusion level, the slightly but not significantly higher economic profit index was obtained in rockfish fed the low-fish-meal diet with 60% jack mackerel meal in diets. Therefore, the manipulation of jack mackerel meal as feed enhancer in the low-fish-meal diet, which otherwise replaces 20% fish meal with chicken by-product meal, could improve the growth performance and feed consumption of rockfish. This study was conducted to elucidate the impact on the growth and feed availability of rockfish (Sebastes schlegeli) from including jack mackerel meal (JMM) in feeds which otherwise substitute 20% fish meal (FM) with chicken by-product meal (CBM). Six formulated feeds were designed to be isonitrogenous and isolipidic. Specifically, 55% FM was included in the control (Con) diet. In the Con diet, 20% FM was substituted by CBM, and then the graded levels (0, 20, 40, 60, and 80%) of JMM were included instead of FM, named as the C20J0, C20J20, C20J40, C20J60, and C20J80 diets, respectively. Five hundred and forty juvenile rockfish (initial weight of 11.2 g) were assigned to 18 tanks. All experimental feeds were fed to triplicate groups of rockfish twice daily for 8 weeks. Superior weight gain, specific growth rate (SGR), and feed intake of rockfish fed the C20J60 and C20J80 diets compared to rockfish fed the Con and C20J0 diets were observed. However, the feed utilization, biological indices, proximate composition, amino acid profiles, and blood chemistry of the rockfish were not affected by the dietary treatments. The slightly but not significantly higher economic profit index and growth performance were obtained in the C20J60 diet compared to the C20J80 diet. In conclusion, the C20J60 diet was the most recommendable treatment based on the improvement in growth performance (weight gain and SGR) and feed intake of rockfish, and the highest economic return to farmers. [ABSTRACT FROM AUTHOR]

Background: Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the host. Gossypol, a toxic component in cottonseed meal (CSM), caused intestinal injury in fish or other monogastric animals. It has been demonstrated that probiotics administration benefits the intestinal barrier integrity, but the efficacy of probiotics in maintaining intestinal health when the host is exposed to gossypol remains unclear. Here, a strain (YC) affiliated to Pediococcus pentosaceus was isolated from the gut of Nile tilapia (Oreochromis niloticus) and its potential to repair gossypol-induced intestinal damage was evaluated. Results: A total of 270 Nile tilapia (2.20 ± 0.02 g) were allotted in 3 groups with 3 tanks each and fed with 3 diets including CON (control diet), GOS (control diet containing 300 mg/kg gossypol) and GP (control diet containing 300 mg/kg gossypol and 108 colony-forming unit (CFU)/g P. pentosaceus YC), respectively. After 10 weeks, addition of P. pentosaceus YC restored growth retardation and intestinal injury induced by gossypol in Nile tilapia. Transcriptome analysis and siRNA interference experiments demonstrated that NOD-like receptors (NLR) family caspase recruitment domain (CARD) domain containing 3 (Nlrc3) inhibition might promote intestinal stem cell (ISC) proliferation, as well as maintaining gut barrier integrity. 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS) revealed that addition of P. pentosaceus YC altered the composition of gut microbiota and increased the content of propionate in fish gut. In vitro studies on propionate's function demonstrated that it suppressed nlrc3 expression and promoted wound healing in Caco-2 cell model. Conclusions: The present study reveals that P. pentosaceus YC has the capacity to ameliorate intestinal barrier injury by modulating gut microbiota composition and elevating propionate level. This finding offers a promising strategy for the feed industry to incorporate cottonseed meal into fish feed formulations. [ABSTRACT FROM AUTHOR]

Over the last 500 years, Europe (excluding Russia) consumed over 2500 million tonnes of ocean biomass. This is based on detailed historical data that we provide for human consumption per capita which was stable from 1500 to 1899 and tripled in the twentieth century. In the last 300 years, cod and herring dominated human seafood consumption. Whaling for non-food uses peaked in the 1830s and declined as cetaceans became scarce. Seafood consumption increased rapidly after 1900, and by the late 1930s, annual marine consumption in Atlantic Europe reached 7 million tonnes of biomass, facilitated by the globalisation of whaling. Atlantic European consumption, including fishmeal for animal feed, peaked at more than 12 million tonnes annually in the 1970s, but declined thereafter. The marine footprint of Atlantic Europe was significant well before modern fisheries statistics commenced. Our findings can inform future assessments of ocean health and marine life's importance for human society. [ABSTRACT FROM AUTHOR]

Background: The present study aimed to determine the immune and stress responses of juvenile GIF tilapia fed with Ulva seaweed meal supplemented diet. Methods: The study was undertaken with different inclusion levels of Ulva seaweed meal (USM) such as raw (UR) and fermented (UF) Ulva meal (UR-5, UR-10, UR-15, UF-5, UF-10 and UF-15% of diet) and control feed (C) for a period of 60 days. Result: GIF tilapia fed with fermented Ulva meal at a 10% inclusion level in their diet showed the highest growth (41.43 g). Immune parameters such as catalase activity (CAT), super oxide dismutase (SOD), respiratory burst activity (RBA), myeloperoxidase activity (MPA) and serum protein value (SPV) showed significant increases in fish fed with Ulva meal incorporated diet followed by UF-5, Ulva Raw (UR) 5%, control (C), UF-15, UR-10 and UR-15 diet respectively. Decreased glucose level was recorded in GIFT fed with fermented Ulva meal at 10% inclusion level followed by UF5, UR5, control diet, UF15, UR10 and UR15 diet. Increased plasma cholesterol, triglyceride, GPx activity, GRA activity and GST activity were recorded in GIFT tilapia fed with fermented Ulva meal at 10% inclusion level followed by UF5 diet, UR5 diet, control diet, UF15 diet, UR10 diet and UR15 diet. GIFT fed with fermented Ulva meal at a 10% inclusion level in their diet exhibited the highest growth performance (41.43 g) followed by UF5 (41.07±0.43 g), UR5 (39.65±0.36 g), control (39.09±0.20 g), UF15 (38.67±0.26 g), UR10 (38.47±1.47 g) and UR15 (35.77±0.35 g) diet. GIF tilapia fed with UF10 diet showed lowest FCR (1.34±0.00), highest SGR (0.99±0.00) and PER (2.37±0.07) followed by UF5 diet, UR5 diet, control diet, UF15 diet, UR10 diet and UR15 diet. One-way ANOVA data analysis and followed by Tukey's test for conducting pair wise comparisons at significance level of 0.05. GIFT tilapia fingerlings had significant differences (P<0.05) among the different experimental diets. From the present experiment, it could be concluded that, Ulva meal incorporation at 10% in the diets increases immune responses in GIF tilapia. [ABSTRACT FROM AUTHOR]

The experimental approach was designed for analyzing the nutritional evaluation of formulated feed by replacing conventional fish meal used in fish diet with Padina gymnospora supplementation under laboratory feeding conditions for 45 days on growth indices in brackishwater euryhaline fish, Etroplus suratensis. Proximate composition of control and experimental algal formulated feed was assessed. An increase was observed in the body weight and growth indices of the experimental fishes fed with supplemented algal diets. The analysis determined better growth performance index in those fishes fed on a the formulated diet. [ABSTRACT FROM AUTHOR]

Hunger affected 278 million people in Africa in 2021, and in Kenya, the proportion of the population unable to afford a healthy diet is 81%. To combat hunger and increase resilience throughout the food system, spirulina (Arthrospira platensis) has been shown to have remarkable properties. The main aim of this study is to investigate whether protein from spirulina is a suitable alternative to protein sourced from fish meal in fish feed for juvenile Nile tilapia (Oreochromis niloticus). In a trial investigating the use of spirulina biomass for fish feed on juvenile Nile tilapia, it has been proven that tilapia fingerlings fed diets with spirulina, replacing up to 30% of fish meal protein, were not affected in terms of growth performance compared to the fish fed the commercial diet. This shows that, nutritionally, protein from spirulina can replace fish meal protein fed to juvenile Nile tilapia. This offers promising opportunities for enhanced food and nutrition security. If produced affordably, spirulina can have a significant impact on the income level of low-income fish farmers in Kenya, who often spend more than 50% of their income on commercial fish feed. Affordability can be made possible if small-scale farmers can produce spirulina using animal manure that is available on the farm instead of using highly priced commercial fertilizer. The additional environmental benefits of spirulina include carbon dioxide sequestration and the removal of nitrogenous and phosphorous waste from the wastewater. Spirulina can therefore increase the sustainability of a whole food system. [ABSTRACT FROM AUTHOR]

Aquaculture has been one of the fastest-growing sectors in agriculture and plays an important role in supplying high quality proteins for humans. Genetic improvement for important traits is essential for increasing aquaculture production. The aquaculture of Asian seabass (Lates calcarifer) has become important in Southeast Asia and Australia and has expanded to other countries. In Singapore, a breeding program was initiated in 2004, aimed at improving growth rates, high omega-3 content, and disease resistance within Asian seabass populations. Many genomic resources have been developed to achieve these goals. The breeding program was established with a broodstock of 549 broodfish collected from the wilds of Indonesia, Thailand, Malaysia, and Singapore. Through four generations of family-based selection, utilizing a combination of conventional selective breeding, molecular parentage analysis, marker-assisted selection, and genomic selection techniques, three distinct elite lines of Asian seabass were successfully established. Each line consisted of approximately 200 broodfish. These lines were selected for growth, higher omega-3 content, and disease resistance, respectively. These traits have been improved without dramatically reducing genetic variation. This review provides a comprehensive overview of the methodologies adopted and status of the genetic improvement of the above-mentioned traits. Concurrently, certain gaps in the existing body of research have been identified. In the future, additional traits related to the ability to use feeds with reduced fishmeal, as well as adaptation to climate change and resistance against emerging diseases should be included in the breeding program. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish meal is widely used as a feed ingredient in formulated feeds for marine fish species due to its high nutritional value and palatability. However, the increasing cost and limited availability of fish meal highlight the high need to look for an alternative protein source for fish meal in fish feeds to achieve sustainable aquaculture. Tuna by-product meal, derived from the tuna canning process, shows promise as a viable substitute for fish meal in fish feeds. This study aimed to investigate the effect of replacing fish meal with tuna by-product meal on the growth of red sea bream. The findings of this study suggested that 40% fish meal replacement with tuna by-product meal is viable without compromising growth, feed consumption, and feed utilization, while simultaneously providing the highest economic return for fish farmers. The effect of substituting fish meal (FM) by tuna by-product meal (TBM) on growth and feed availability of red sea bream (Pagrus major) was investigated. Six experimental diets were crested to be isonitrogenous (51.5%) and isolipidic (14.5%). The control (Con) diet contained 55% FM. FM substitution in the Con diet was made in increments of 20 percentage points (20, 40, 60, 80, and 100%), named as the TBM20, TBM40, TBM60, TBM80, and TBM100 diets, respectively. Juvenile red sea bream were stocked into 18, 300 L flow-through tanks (50 fish/tank). Red sea bream were hand-fed with each diet until satiation for 8 weeks. No statistical differences in weight gain, specific growth rate (SGR), and feed consumption were found among red sea bream fed the Con, TBM20, and TBM40 diets. Furthermore, feed utilization of fish fed the TBM20, TBM40, TBM60, and TBM80 diets was comparable to red sea bream fed the Con diet. The biological indices, biochemical composition, and hematological parameters of fish were not statistically altered by dietary FM replacement with TBM. The greatest economic profit index was achieved in the TBM40 diet. In conclusion, the replacement of 40% FM with TBM in red sea bream diet appears to be the most recommendable approach without producing retarded growth and feed availability, but maximizing EPI to farmers. [ABSTRACT FROM AUTHOR]

Objective: Protein is needed for chicken growth, but high protein consumption causes a low protein efficiency ratio and causes feed prices to be expensive. Therefore, the immunological potential of fermented snail meat hydrolysate in local chickens was studied for feed supplements in low-protein rations to reduce costs. Materials and Methods: The research used snail meat hydrolysate resulting from submerged fermentation with starter culture from rice washing water. Using hydrolysates as a fishmeal substitute to reduce the protein content of male local chicken diets. Hydrolysate is mixed into the formulated ration: P0 = 12% fish meal in feed without hydrolysate added, P1 = 8% fish meal in feed plus 5 ml hydrolysate/kg feed; P2 = 4% fish meal in feed plus 10 ml hydrolysate/kg feed; and P3 = Feed without fish meal plus 15 ml hydrolysate/kg feed. The study used completely randomized study parameters, namely the production performance of 200 chickens and the immune system (including lymphoid organs and hematological status) of 60 chickens. Results: Snail meat hydrolysate (10 ml/kg) can replace the reduction in the use of fish meal from 12% to 4% in ration formulation without reducing production performance and has no negative effect on the immune system. Conclusion: Snail meat hydrolysate has the potential to be used as an immune antibiotic to replace the use of fishmeal in the development of low-protein dietary formulations without affecting production performance or negatively affecting the chicken's immune system. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the efficiency of an integrated multi-trophic aquaculture (IMTA) system comprising co-cultured fed fish and organic extractive species representing three distinct trophic levels as well as the impact and potential utilization of two commercially available fish feeds made up of 35% fish meal (FM) and 20% fish meal (LFM) ingredients, using a multi-indicator assessment approach. Significant alterations were observed in growth performance indicators (GPIs), water and sediment quality indices, toxicity tests and biomarkers within the IMTA system. The fish survival, weight gain (WG), and specific growth rate (SGR) were higher in the IMTA system with significantly lower feed conversion ratios (FCRs) and higher feed efficiency (FE) in comparison to the fed fish monoculture system. Yet, organic filter feeders displayed 100% survival, and increased shell growth, while deposit feeders exhibited successful survival and significant weight gain. In the comparison between FM-IMTA and LFM-IMTA, fed fish in FM-IMTA showed higher WG, SGR, and FE with lower FCR. Environmental parameters like temperature, oxygen, and nutrient concentrations fluctuated but generally improved in the IMTA system, indicating lower mesotrophic conditions. Sediment fatty acid profiles differed between systems and toxicity assessments, which suggested a lower impact in IMTA and FM-IMTA systems. The sediment microbial community displayed high similarity within IMTA systems and between FM-IMTA and LFM-IMTA. These findings underscore the potential of IMTA systems for sustainable aquaculture, emphasizing improved growth performance and reduced environmental impact, particularly when using fish meal feeds. [ABSTRACT FROM AUTHOR]

Alternative protein sources to replace fish meal in aquaculture feeds are continuously sought after. The fish meal industry is unsustainable, from an economic point of view and because of its impact on wild aquatic ecosystems. This review presents the use of gastropod species (class Gastropoda) in aquaculture feeds. Gastropods have been studied for their potential use in aquaculture feeds, mainly as an alternative source of protein to fish meal. Gathered studies from various databases encompass gastropods nutritional value, and their performance in rearing aquatic organisms. Fish meal replacement with meals sourced from gastropods is closely analysed in this paper. Synthesized information from this review will benefit future research on this subject. [ABSTRACT FROM AUTHOR]

Fish meal is commonly used as a protein source in fish feeds due to its high protein content. However, the supply of fish meal is becoming uncertain due to decreased stocks caused by climate change and overexploitation. Consequently, researchers are exploring less expensive alternatives to replace fish meal in fish feeds. This experiment aimed to determine the effects of replacing fish meal with a combination of soybean meal (SBM) and fermented fish (FF) in the diet on the growth performance and feed utilization of juvenile Asian seabass (Lates calcarifer Bloch, 1790). Six isonitrogenous (40%) and isolipidic (5%) experimental diets were formulated. Fish meal was replaced with 0% and 10% of SBM in diet 1 (D1) and diet 2 (D2), respectively. In the other four diets, FM was replaced by gradual levels of SBM and FF as follows (%SBM/%FF): 20/10, 20/20, 30/10, and 30/20 (designated as diet 3-diet 6; D3-D6). A commercial feed was used as a comparative diet (D7). Fish, with an initial weight of 3.32-3.33 g, were fed twice daily until satiation for 90 days. The final body weight (FBW), specific growth rate (SGR), and feed intake (FI) of fish fed D1 were significantly difference (p<0.05) but did not significantly differ from those of fish fed D2 and D3. Similarly, the FBW, SGR, and FI of fish fed D3 were not significantly different from those of fish fed D7. In conclusion, fish meal can be replaced by a combination of 20% SBM and 10% FF in the diet for juvenile Asian seabass without any adverse effects on growth performance, body indices and feed utilization. [ABSTRACT FROM AUTHOR]

The growing scale of plastic pollution causes a devastating impact on the aquatic ecosystem. The people largely depend on animal-based food for their protein requirements. In this study, we analysed 10 different fish meal samples and 20 feed samples used in farming to understand the level of microplastic (MPs) contamination and estimate the amount of MPs ingested by farmed fish, shrimp, and chicken through feed. The abundance of MPs in fish meal samples ranges from 210 ± 98.21 to 1154 ± 235.55 items/kg. The fish meal produced from dried fish is more prone to MPs contamination than that produced from fresh fish. In the case of fish feed, MP abundances range from 50 ± 22.36 to 160 ± 36.57 items/kg in shrimp feeds, 60 ± 26.74 to 230 ± 52.32 items/kg in fish feeds and 90 ± 25.11 to 330 ± 36.12 items/kg in chicken feeds. The exposure rate of MPs is higher in the grower- and finisher-stage feeds than in the starter feed. Fiber-shaped MPs of size 100–500 μm with PE and PP polymers were predominantly found in fish meal and feed samples. EDAX analysis showed the presence of Cr, Cd, Ti, Ni, Cu, As, Al, Pb, Hg, Cd, Ti, Fe, Ca, K, and Si in fish meal samples and Ca, Na, Zn, Cu, Ni, Cl, Al, Si, S, Pb, Cd, Ti, Cr, Mg and Fe in feed samples. The possible level of exposure of microplastic particles was calculated based on MP contamination in feed, feed consumption rate, and body weight. We estimated an MP exposure level of 531-1434 items/kg feed for farmed shrimp, 234–4480 items/kg feed for fishes, and 3519–434,280 items/kg feed for chicken. This study concludes that fish meal and feed are one of the important exposure routes of MPs to the farmed animals. [Display omitted] • Abundance of MPs in fish meals and farmed animals feed was studied. • MP abundance in fish meal ranges from 210 ± 98.21 to 1154 ± 235.55 items/kg. • MP abundance in animal feed ranges from 50 ± 22.36 to 330 ± 36.12 items/kg. • MP exposure through poultry feed ranges from 3519 to 434,280 items/kg. • Exposure via shrimp feed is 531-1434 and via fish feed is 234-4480 items/kg. [ABSTRACT FROM AUTHOR]

Gossypol, a naturally occurring compound found in cottonseed meal, shows promising therapeutic potential for human diseases. However, within the aquaculture industry, it is considered an antinutritional factor. The incorporation of cottonseed meal into fish feed introduces gossypol, which induces intracellular stresses and hinders overall health of farmed fish. The aim of this study is to determine the role of General control nonderepressible 2 (gcn2), a sensor for intracellular stresses in gossypol-induced stress responses in fish. In the present study, we established two gcn2 knockout zebrafish lines. A feeding trial was conducted to assess the growth-inhibitory effect of gossypol in both wild type and gcn2 knockout zebrafish. The results showed that in the absence of gcn2 , zebrafish exhibited increased oxidative stress and apoptosis when exposed to gossypol, resulting in higher mortality rates. In feeding trial, dietary gossypol intensified liver inflammation in gcn2 −/− zebrafish, diminishing their growth and feed conversion. Remarkably, administering the antioxidant N-acetylcysteine (NAC) was effective in reversing the gossypol induced oxidative stress and apoptosis, thereby increasing the gossypol tolerance of gcn2 −/− zebrafish. Exposure to gossypol induces more severe mitochondrial stress in gcn2 −/− zebrafish, thereby inducing metabolic disorders. These results reveal that gcn2 plays a protective role in reducing gossypol-induced oxidative stress and apoptosis, attenuating inflammation responses, and enhancing the survivability of zebrafish in gossypol-challenged conditions. Therefore, maintaining appropriate activation of Gcn2 may be beneficial for fish fed diets containing gossypol. • Zebrafish lacking Gcn2 showed a significant increase in mortality when exposed to gossypol. • Gcn2 deficiency exacerbated oxidative stress and apoptosis in response to gossypol exposure. • Zebrafish deficient in Gcn2 exhibited more severe liver inflammation upon dietary gossypol exposure. [ABSTRACT FROM AUTHOR]

Chicken eggs can be a significant source of human PFAS exposure. A survey of PFAS in commercial eggs from larger farms across Denmark showed the absence or low contents of PFAS in free-range and barn eggs. However, organic eggs from eight farms collected in September 2022 had a similar profile of nine PFASs with a predominance of odd over even carbon length PFCAs. Farm 11–13 e.g. had egg yolk ng/g concentrations of PFOA 0.07 ± 0.02; PFNA 0.37 ± 0.04; PFDA 0.13 ± 0.00; PFUnDA 0.22 ± 0.04; PFDoDA 0.06 ± 0.02; PFTrDA 0.15 ± 0.04; PFTeDA 0.02 ± 0.02; PFHxS 0.10 ± 0.04; PFOS 2.62 ± 0.11. Normalised to PFOS, the relative sum of other PFAS showed no difference between the eight organic egg samples, but significant differences between mean individual PFASs (p = 1.4E-25), reflecting a similar profile. The PFAS found in two fishmeal samples with the same origin as the fishmeal used for the organic feed production, could account for the contents in the eggs via estimated transfer from the feed. Furthermore, the estimated transfer from concentration in feed to concentration in egg increased with the carbon length of the PFCA. Exposure (95th percentile) of ∑4PFAS (PFOA, PFNA, PFHxS, PFOS) solely from consumption of 311 g ∼ 5–6 organic eggs/week was for children 4–9 years 10.4 ng/kg bw, i.e. a significant exceedance of the tolerable weekly intake of 4.4 ng/kg bw established by the European Food Safety Authority. Based on the PFAS exposures from organic egg consumption, the organic egg producers decided voluntarily to cease adding fishmeal to the feed. Since the feed-to-egg half-lives are ≤1 week for PFOA, PFOS, and PFHxS, the removal of fishmeal as a feed ingredient should eliminate PFAS after 1–2 months. This was demonstrated in analyses of ten organic egg samples collected by the authorities without PFAS in eight and with 0.1 and 0.4 ng/g ∑4PFAS in two samples. [Display omitted] • Similar PFAS profiles in organic eggs from large farms across Denmark. • Fishmeal in organic feed with related PFAS profile is a PFAS source in eggs. • Replacing fishmeal in organic feed almost eliminated PFAS in organic eggs. • Fishmeal might be a significant indirect source of human exposure to PFAS. [ABSTRACT FROM AUTHOR]