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Agri-food system integration has the potential to increase and add value to agricultural production, reduce cost of and dependency on external inputs, generate additional income to farmers, and encourage the diversification of outputs and diets. Agri-food system integrations such as livestock-fish, poultry-fish, crop-livestock and rice-fish farming have been well documented in academic literature. However, information on fish and root, tuber and banana (RTB) crops integration is scarcely available, despite their worldwide cultural, dietary, and economic importance. This paper, which is informed by a narrative literature review and ground-truthing through key informant interviews, documents existing linkages between two agri-food systems – fish and RTB – and identifies opportunities and challenges for strengthening their integration. We found that recorded instances of fish-RTB integration are limited and predominantly discuss production-related activities. Nevertheless, initial evidence suggests that there are important livelihood-enhancing opportunities as well as environmental, and food and nutrition security benefits, which need to be considered. These include the potential to improve the nutritional status of vulnerable populations and lower the cost of fish production and thus improve the livelihoods of small-scale fish farmers. Further field-based research is recommended to explore these outcomes in more detail. [ABSTRACT FROM AUTHOR]

Enchytraeus albidus is a small euryhaline earthworm that is abundant in the supralittoral zone where it can be found in decaying seaweed. This species is readily mass‐cultured, and due to its relatively high contents of protein and polyunsaturated fatty acids (PUFAs), there has been a renewed interest in this species as an alternative source of valuable nutrients for fish feed. Here, we have investigated the influence of substrate salinity (0, 1, 2, 8, 15, 30 and 40 ppt) on reproduction, growth and nutrient content of worms. We found that intermediate salinities (8–15 ppt) of the substrate maximize biomass production as well as protein and PUFA contents of the worm tissue. In particular, we observed that the often used culturing of E. albidus in non‐saline growth medium resulted in low reproduction and biomass production. Increasing the salinity from 0 to 15 ppt resulted in a higher proportion of unsaturated fatty acids both in storage lipid and in membrane phospholipid fractions. [ABSTRACT FROM AUTHOR]

Trade credits provide financing to buyers who might not, otherwise, be able to operate a business. However, sellers may use trade credits to exploit market power and this introduces a market failure that reduces efficiency and social welfare when compared to a competitive market. The objective of this study is to investigate the costs of trade credits for fish feed to fish farmers in Bangladesh and shed light on the power relation as perceived by the farmers and feed sellers. The sources of power are determined by factor analysis. A one-way analysis of variance is used to identify the most powerful party. The results indicate that trade credits were more expensive than cash payments and even bank loans for farmers. The excess costs of trade credits indicate that feed sellers exploit their power and the identification of feed sellers as the powerful party supports this indication. Trade credits, therefore, provide gains in financing fish production that may not otherwise take place, but their costs decrease efficiency. Policymakers can increase efficiency by implementing corrective measures such as ceilings on the costs of trade credits; however, the remuneration of risk must be allowed for trade credits to prevail. [ABSTRACT FROM AUTHOR]

The conditioning and extrusion are important heat treatment process that affects the feed quality in the production of fish feed. In the mechanism research and process parameter optimization of the above process, as one of the basic thermal characteristics, specific heat is an essential parameter. The existing research about animal feed processing, mainly explores the variation of specific heat with processing parameters such as temperature and moisture content. But there is fewer research on specific heat prediction models based on nutritional composition. In order to improve the adaptability and accuracy of the model, this research comprehensively explores the influence of processing parameters (temperature, moisture content) and nutritional composition (protein content, fat content) on the specific heat of fish feed. The objectives of this investigation were to explore the thermal property of fish feed during processing, to regulate the heat supplement during conditioning and extruding, and to explore the adaptability of the existing specific heat prediction model that applied for livestock and poultry feed to fish feed that had high fat and protein content. The four main ingredients of fish feed formula were chosen, including fishmeal, soybean meal, wheat flour and soybean oil. Soybean meal and wheat were grinded using a universal grinder equipped with the 1 mm sieve, and all raw materials were passed through a 40 mesh screen. Fish meal and soybean meal were used as protein sources, and soybean oil was used as fat source. There were 9 diets with 3 crude protein levels (30%, 40%, 50%) and 3 crude fat levels (5%, 11%, 17%) to represent fish feeds with different feeding habits. DSC (Differential Scanning Calorimetry) was used to measure the specific heat of 9 diets in the temperature range of 20-120 ℃ and the moisture content range of 20%-26%, the influence rule of the above 4 factors on the specific heat was analyzed, and specific heat prediction model for 4 factors was constructed. The results showed that the specific heat of fish feed was significantly affected by moisture content, temperature, crude protein content, and crude fat content. The main order of each factor was, moisture content, temperature, crude protein content, crude fat content. The specific heat increased linearly with the increase of the water content and the crude protein content, but decreased linearly with the increase of the crude fat content. The specific heat had a non-linear relationship with temperature, which was a quadratic regression relationship. In all experiments, the specific heat of fish feed varied from 1.70 to 2.70 kJ/(kg·℃). Based on experimental data, a multiple regression model (R² =0.991) of specific heat that in relation to processing parameters (temperature and moisture content) and nutritional composition (crude protein content and crude fat content) was established. It can improve the adaptability of specific heat for livestock and poultry feed in the existing research. The prediction model can effectively predict the specific heat of fish feed within the range of this study variable. The research results can provide basic data for the establishment of heat transfer mathematical models of fish feed during conditioning and extruding, and also provide theoretical guidance for the adjustment of heat supplement parameters in the productive process. [ABSTRACT FROM AUTHOR]

Foamy, whitish appearance of the pyloric caeca, reflecting elevated lipid content, histologically visible as hypervacuolation, is frequently observed in Atlantic salmon fed high-plant diets. Lipid malabsorption syndrome (LMS) is suggested as term for the phenomenon. Earlier studies have shown that insufficient supply of phospholipids may cause similar symptoms. The objective of the present study was to strengthen knowledge on the role of choline, the key component of phosphatidylcholine, in development of LMS as well as finding the dietary required choline level in Atlantic salmon. A regression design was chosen to be able to estimate the dietary requirement level of choline, if found essential for the prevention of LMS. Atlantic salmon (456 g) were fed diets supplemented with 0, 392, 785, 1177, 1569, 1962, 2354, 2746 and 3139 mg/kg choline chloride. Fish fed the lowest-choline diet had pyloric caeca with whitish foamy surface, elevated relative weight, and the enterocytes were hypervacuolated. These characteristics diminished with increasing choline level and levelled off at levels of 2850, 3593 and 2310 mg/kg, respectively. The concomitant alterations in expression of genes related to phosphatidylcholine synthesis, cholesterol biosynthesis, lipid transport and storage confirmed the importance of choline in lipid turnover in the intestine and ability to prevent LMS. Based on the observations of the present study, the lowest level of choline which prevents LMS and intestinal lipid hypervacuolation in post-smolt Atlantic salmon is 3·4 g/kg. However, the optimal level most likely depends on the feed intake and dietary lipid level. [ABSTRACT FROM AUTHOR]

There is an urgent need to find alternatives to fish meal and fish oil in compound feeds due to their rapidly rising prices and the demand for sustainable fisheries. Spirulina, a filamentous blue‐green microalga, is an excellent source of plant protein and could replace expensive animal‐derived proteins in fish feed. Studies have evaluated the use of spirulina as a fish meal for different fish species. This paper reviews research on the effects of spirulina on the growth performance of various fish species. It is apparent that spirulina can be a highly important component of the diet of fish; it has a number of benefits, such as promoting the growth of tilapia (Oreochromis niloticus) and carp (Labeo rohita), improving the reproductive performance of yellow tail cichlid (Pseudotropheus acei) and enhancing the immune response of rainbow trout (Oncorhynchus mykiss). Recent studies have shown that spirulina can be used for treating wastewater, including effluent from fish culture activities, as it can efficiently metabolize the nutrients and remove the heavy metals contained in aquaculture effluent. Fish aquaculture could apply an integrated strategy of simultaneously treating aquaculture effluent while producing spirulina biomass to supplement fish diets. [ABSTRACT FROM AUTHOR]

This study assesses the mineral levels in water, sediment, and fishes from Ekiti State University pond, Nigeria; and investigates the metal levels in locally made and imported feeds. Four fish samples (tilapia I and II; catfish I and II) from the pond were dissected to obtain livers, gills, and tissues. The water, sediments, feeds, and fish parts were analyzed using a Flame Photometer (Corning 400) and an Atomic Absorption Spectrophotometer (Buck Scientific 210). The levels of Na, K, Ca, Fe, Cu, Zn, and Mn in the pond water are 10.00, 8.89, 3.02, 6.67, 0.03, 0.25, and 0.18 mg/L, respectively. The concentrations of Na, K, Ca, Fe, Cu, Zn, and Mn in the sediment are 2.52, 4.21, 2.72, 29.78, 0.11, 0.95, and 0.42 mg/kg, respectively. The levels of metals in the feed samples (locally made and imported) range as follows: Na (47.56 - 76.06); K (181.06 - 190.05); Ca (95.43 - 244.53); Fe (2.38 - 4.16); Cu (0.17 each); Zn (1.03 - 1.31); Mn (0.59 - 0.83 mg/kg). The concentrations of metals in the liver, gill, and tissue range as follows: Na (4.90 - 54.56); K (5.02 - 69.07); Ca (21.42 - 522.57); Fe (0.72 - 9.54); Cu (0.06 - 0.44); Zn (0.24 - 1.17); Mn (0.02 - 0.52 mg/kg). However, Cd, Pb, Cr, Ni, and Co were not detected in all the samples. The results showed that the mineral levels in the fishes are within the permissible limits of the World Health Organization (WHO) and Standard Organization of Nigeria (SON). [ABSTRACT FROM AUTHOR]

Antioxidant properties of four common green algal genera viz. Cladophora glomerata, Chaetomorpha aerea, Rhizoclonium crassipellitum, and Pithophora cleveana collected from Sunderban areas of Eastern India were tested in controlled and nutrient stress conditions. Experimental algae were exposed to growth media with variations in nitrate and NaCl salt concentrations from 0 to 1500 ppm level for a period of 21 days. A dose-dependent upregulation in total phenols, flavonoids, pigment, and antioxidant property in relation to % DPPH activity and % ferrous ion chelating activity was observed. Maximum phenol content was observed for algal biomass exposed to 1500 ppm nitrate stress conditions (52.55 ± 0.01 mg GAE/g DW-16.48 ± 0.041 mg GAE/g DW) with Rhizoclonium showing the maximum contents. In the case of total flavonoid content, maximum upregulation was noted in the hypersaline conditions and Pithophora showed the highest contents amongst all (71.8 ± 0.21 mg QE/g DW). The highest carotenoid contents were observed in 750 ppm stress condition. Optimally stressed algal biomass having maximum carotenoid levels and high antioxidant levels were selected as fish feed ingredients, based on dose- and time-dependent two-way Anova and Tukeys test (750 ppm nitrate, 7 days). The processed biomass was included as fish feed ingredient to study the nutritive effects on goldfish (Carassius auratus). Algal feed (AF) was prepared from algal biomass only, which was further mixed with the commercial feed (CF) in varying proportions to formulate three different types of value-added feed (VAF). The experimental feed (25% VAF, 50% VAF, 75%VAF and AF) were tested against commercial feed (control) for 30 days in artificially aerated static aquaria system. The feed type formulated as 50% VAF was found to be most effective in terms of skin pigmentation, growth, and antioxidant activities of experimental fishes showing almost (1.44–4-folds increase) compared to the control setup. Statistically significant results were obtained regarding nutritive properties of experimental feed and fishes using PCA and Tukeys test respectively. Body weight gain and specific growth rate also changed significantly in experimental fishes. [ABSTRACT FROM AUTHOR]

Background: Various intestinal morphological alterations have been reported in cultured fish fed diets with high contents of plant ingredients. Since 2000, salmon farmers have reported symptoms indicating an intestinal problem, which we suggest calling lipid malabsorption syndrome (LMS), characterized by pale and foamy appearance of the enterocytes of the pyloric caeca, the result of lipid accumulation. The objective of the present study was to investigate if insufficient dietary choline may be a key component in development of the LMS. Results: The results showed that Atlantic salmon (Salmo salar), average weight 362 g, fed a plant based diet for 79 days developed signs of LMS. In fish fed a similar diet supplemented with 0.4% choline chloride no signs of LMS were seen. The relative weight of the pyloric caeca was 40% lower, reflecting 65% less triacylglycerol content and histologically normal gut mucosa. Choline supplementation further increased specific fish growth by 18%. The concomitant alterations in intestinal gene expression related to phosphatidylcholine synthesis (chk and pcyt1a), cholesterol transport (abcg5 and npc1l1), lipid metabolism and transport (mgat2a and fabp2) and lipoprotein formation (apoA1 and apoAIV) confirmed the importance of choline in lipid turnover in the intestine and its ability to prevent LMS. Another important observation was the apparent correlation between plin2 expression and degree of enterocyte hyper-vacuolation observed in the current study, which suggests that plin2 may serve as a marker for intestinal lipid accumulation and steatosis in fish. Future research should be conducted to strengthen the knowledge of choline's critical role in lipid transport, phospholipid synthesis and lipoprotein secretion to improve formulations of plant based diets for larger fish and to prevent LMS. Conclusions: Choline prevents excessive lipid accumulation in the proximal intestine and is essential for Atlantic salmon in seawater. [ABSTRACT FROM AUTHOR]

Agro-industrial wastes pose great economic and environmental hazards, while the economic success of aquaculture is threatened by the unsustainability of fishmeal use. The aims of the present study were to bio-convert agro-industrial wastes through vermicomposting, and then evaluate the potential of the by-products in promoting aquaculture nutrition. Coffee husks (CH), barley wastes (BW), and kitchen wastes (KW) were pre-composted and inoculated with earthworms, Eisenia fetida, and then vermicomposted for 70 days under a controlled environment. The vermicomposting by-products, i.e., earthworms and vermicast, were amalgamated in the ratio of 1:5 into bedding and then analyzed. There were neither earthworm mortalities nor significant difference (P>0.05) in cocoons produced by E. fetida in all treatments. The earthworms grown in KW attained the highest average weight gain of 27.8±0.7g, followed by CH (24.9±0.6g) and BW (24.8±0.7g). Earthworms grown in CH and BW had significantly higher (P<0.05) nutritional attributes. All experimental wastes produced vermicast with carbon and nitrogen ratios within the preferred agronomic limit of 20. The nutritional profile of the BW bedding was comparable with that of Caridina nilotica meal and was within the recommended dietary requirements of fish. The wastes can be bio-converted through vermicomposting into various forms appropriate for providing aquaculture nutrition. [ABSTRACT FROM AUTHOR]

A 3-factor -factorial experiment (2K) was designed to produce fish feeds from mixture of pigeon pea, bambara groundnut and fish meal as major ingredients, while maize, red palm oil, salt and micro nutrient pre-mix were added as minor ingredients. The raw materials were processed into flours. The ingredients were weighed out in various ratios and mixed. The mixture was extruded; sun-dried and packaged and labeled F1-F8 and a commercial feed labeled F9 served as control. The feeds were feed to juvenile Clariasgariepinus kept in 9 separate plastic bowels and fed for 42 days. The forty-five fish of uniform weight and age were grouped into 9 and stocked in the nine artificial ponds, each pond contained five fish. The feeds were analyzed for proximate composition, while the growth performance of the fish was evaluated at the end of the feeding period. Result showed that F3 (20g pigeon pea, 20g Bambara ground nut and 16g fish meal) contains the highest protein (33.14%) and F1(20g pigeon pea, 30g bambara ground nut and 16g fish meal) the least (23.13%). F3 exhibited the highest specific growth rate (1.14%) followed by the F9 (control) which contains 1.09%. The highest weight gain (16 g) was observed in the fish fed the control feed. However, F3 and F4 (20g pigeon pea, 30g bambara ground nut and 18g fish meal) ranked next to the control with respect to growth performance. It is therefore possible to produce quality catfish feed from bend of pigeon pea, Bambara ground nut and fish meal. [ABSTRACT FROM AUTHOR]

The first part of this study evaluates the occurrence of mycotoxin patterns in feedstuffs and fish feeds. Results were extrapolated from a large data pool derived from wheat (n = 857), corn (n = 725), soybean meal (n = 139) and fish feed (n = 44) samples in European countries and based on sample analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS) in the period between 2012–2019. Deoxynivalenol (DON) was readily present in corn (in 47% of the samples) > wheat (41%) > soybean meal (11%), and in aquafeeds (48%). Co-occurrence of mycotoxins was frequently observed in feedstuffs and aquafeed samples. For example, in corn, multi-mycotoxin occurrence was investigated by Spearman’s correlations and odd ratios, and both showed co-occurrence of DON with its acetylated forms (3-AcDON, 15-AcDON) as well as with zearalenone (ZEN). The second part of this study summarizes the existing knowledge on the effects of DON on farmed fish species and evaluates the risk of DON exposure in fish, based on data from in vivo studies. A meta-analytical approach aimed to estimate to which extent DON affects feed intake and growth performance in fish. Corn was identified as the ingredient with the highest risk of contamination with DON and its acetylated forms, which often cannot be detected by commonly used rapid detection methods in feed mills. Periodical state-of-the-art mycotoxin analyses are essential to detect the full spectrum of mycotoxins in fish feeds aimed to prevent detrimental effects on farmed fish and subsequent economic losses for fish farmers. Because levels below the stated regulatory limits can reduce feed intake and growth performance, our results show that the risk of DON contamination is underestimated in the aquaculture industry.

Abstract Background A sensitive, accurate and precise method was developed and validated in regard to Council Directive 333/2007/EC, Commission Decision 657/2002/EC, ISO/IEC 17025:2005 and EURACHEM 1998 for the trace level determination of Lead (Pb), Cadmium (Cd) and Chromium (Cr) in fish feed samples using Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). Methods For method validation, selectivity, working and linear ranges, limit of detection (LoD), limit of quantification (LoQ), trueness (recovery) and precision (repeatability and reproducibility) have been assessed as performance criteria. Results The method LoDs for Pb, Cd and Cr were found to be 0.078, 0.010 and 0.022 μg/g respectively, whereas, the method LoQs were obtained at 0.156, 0.021 and 0.044 μg/g respectively. Moreover, the recovery of the analytes was 90 – 104% and the RSD values for precision were 4.90 – 9.60% respectively. Conclusions The method validation performance criteria indicate the method’s suitability for trace level quantification of Pb, Cd, and Cr in fish feed samples.

A total of 52 samples of finished fish feeds and ingredients were collected from smallholder farmers in Kenya, Tanzania, Rwanda and Uganda, and analyzed. Culture and molecular techniques were used to identify fungal isolates from the feedstock, and mycotoxin profiles were determined using liquid chromatography–tandem mass spectrometry. The most prevalent fungal species recovered in the samples was Asperigillus flavus (54.5%). Other fungal species recovered from the samples were Aspergillus tamarii (9.1%), Mucor velutinosus (9%), Phoma sp. (6.1%), Aspergillus niger (6%), Eurotium rubrum (3%) and Penicillium chrysogenum (3%). Fourteen mycotoxins were identified: aflatoxins B1, B2, G1 and G2, fumonisin B1 and B3, deoxynivalenol (DON) and acetyldeoxynivalenol (sum of 3-ADONand 15-ADON), ochratoxin A, roquefortine C, alternariol, T-2 toxin, and nivalenol. DON (92.9%), aflatoxins (64.3%) and fumonisins (57.1%) were the most prevalent within locally manufactured feeds, while no contamination was found in imported feed. Samples from Kenya were the most contaminated with aflatoxin (maximum 806.9 μg·kg−1). The high levels of aflatoxin and trichothecene type A and B contamination found in this study point to potential risks to fish performance and to the health of consumers of the fish and derived products.

Abstract Microalgae have high nutritional values for aquatic organisms compared to fish meal, because microalgae cells are rich in proteins, lipids, and carbohydrates. However, the high cost for the commercial production of microalgae biomass using fresh water or artificial media limits its use as fish feed. Few studies have investigated the potential of wet market wastewater and slaughterhouse wastewater for the production of microalgae biomass. Hence, this study aims to highlight the potential of these types of wastewater as an alternative superior medium for microalgae biomass as they contain high levels of nutrients required for microalgae growth. This paper focuses on the benefits of microalgae biomass produced during the phycoremediation of wet market wastewater and slaughterhouse wastewater as fish feed. The extraction techniques for lipids and proteins as well as the studies conducted on the use of microalgae biomass as fish feed were reviewed. The results showed that microalgae biomass can be used as fish feed due to feed utilisation efficiency, physiological activity, increased resistance for several diseases, improved stress response, and improved protein retention.

Water stability of eight samples of extruded salmon feeds was first determined by applying two gravimetric methods developed by the authors: gravimetric static and wet sieving method. Then, the conductometric method, primarily developed for investigation of nutrient leaching of feed into the water by the authors, was used for each sample. The aim of this study was to evaluate the potential of the conductometric measurement as a technique for determining water stability of extruded fish feed. In order to find any correlation between the results of two gravimetric tests and conductometric method, correlation analysis was employed. The results of static and wet sieving method were expressed as water stability index, which was expressed as the percent of remained dry matter of sample after being disintegrated in the water. The results of conductometric method were shown as conductivity curves for each sample, giving the insight in rate of nutrient leaching during the time. The obtained values of water conductivity showed no significant (p < 0.05) correlation with the results of static water method, while there was a negative significant (p < 0.05) correlation with the results of wet sieving method during first four hours of pellets soaking in water. The highest correlation coefficients were obtained within the first hour of conductivity measurement, demonstrating that proposed conductometric method had a potential to be applied as a rapid and simple method for determination and relative comparison of salmon feed water stability.[ Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III46012 and Grant no. TR31011]

Competitiveness of Local Fish Feed Manufacturing Units in Benin In Benin, fish farming is considered an effective way to supplement inland fisheries. However, its development faces the challenge of feeding fish. Most fish farmers rely on imported feed, which is very expensive, while there are local production units that also produce fish feed. This study aims to assess the competitiveness of local fish food production units to identify the factors that affect this competitiveness. Primary data were collected at 21 fish food production units in 17 districts in Benin. The data were analyzed using the Policy Analysis Matrix (PAM). The results show that the production of fish feed is financially and economically profitable. The estimated Domestic Resource Cost Ratio (DRCR) is 0.25. This means that compared to the prices the manufacturers are competitive. At contrary, imported fish feeds are quality competitive. The analysis of the sensitivity of the DRCR showed that reducing ingredient prices and increasing labor and capital productivity improve the competitiveness of manufacturers. Actors capacity building and improvement of manufacturing equipment are therefore necessary.

Screening has revealed that modern-day feeds used in Atlantic salmon aquaculture might contain trace amounts of agricultural pesticides. To reach slaughter size, salmon are produced in open net pens in the sea. Uneaten feed pellets and undigested feces deposited beneath the net pens represent a source of contamination for marine organisms. To examine the impacts of long-term and continuous dietary exposure to an organophosphorus pesticide found in Atlantic salmon feed, we fed juvenile Atlantic cod (Gadus morhua), an abundant species around North Atlantic fish farms, three concentrations (0.5, 4.2, and 23.2 mg/kg) of chlorpyrifos-methyl (CPM) for 30 days. Endpoints included liver and bile bioaccumulation, liver transcriptomics and metabolomics, as well as plasma cholinesterase activity, cortisol, liver 7-ethoxyresor-ufin-O-deethylase activity, and hypoxia tolerance. The results show that Atlantic cod can accumulate relatively high levels of CPM in liver after continuous exposure, which is then metabolized and excreted via the bile. All three exposure concentrations lead to significant inhibition of plasma cholinesterase activity, the primary target of CPM. Transcriptomics profiling pointed to effects on cholesterol and steroid biosynthesis. Metabolite profiling revealed that CPM induced responses reflecting detoxification by glutathione-S-transferase, inhibition of monoacylglycerol lipase, potential inhibition of carboxylesterase, and increased demand for ATP, followed by secondary inflammatory responses. A gradual hypoxia challenge test showed that all groups of exposed fish were less tolerant to low oxygen saturation than the controls. In conclusion, this study suggests that wild fish continuously feeding on leftover pellets near fish farms over time may be vulnerable to organophosphorus pesticides.

Animal feeds contributes to a greater percentage of the cost of production of livestock. For the increment in productivity and profit, farmers are advised to produce their feed themselves to reduce the cost of production. This work is aimed at producing a simple single unit fish feed pelletizer at a lost cost for peasant farmers. A fish feed pelletizer has been designed and constructed. It consists of hopper, screw conveyor, barrel, dies, drives system and heater. The design was carried out using engineering principles with due consideration to cost, ease of operation, serviceability, durability, and performance. It is designed to be driven by a 1.5 HP, three-phase electric motor with a heating element of 1500 W attached to the barrel surface to ensure adequate heating of the feed as they travel through the barrel. The test that determines the performance of the pelletizer was carried out which showed a throughput capacity of 17 kg/h, machine efficiency of 73.33% and a pelletizing efficiency of 90.90% with low mechanical damage of 9.10%. The cylindrical pellets size produced by the pelletizer was in the range of 2–8 mm diameter, which is suitable for fish and poultry farming. The machine was produced using locally sourced materials at a production cost of one hundred and eight thousand naira only (N 108,000.00).

This study investigated the properties of fish pellets made with plant-based ingredients intended for rainbow trout (Oncorhynchus mykiss) or other Salmonids. Plant protein from camelina meal (CMM), canola meal (CM), and isolated soybean protein (ISP) were the variable portions constituting 70% (w/w) of the seven formulations. The other 30% of ingredients included binders (7% wheat gluten protein (WGP) and 3% guar gum (GG)), 7.5% vitamins, 5% fish oil and 7.5% fishmeal. The densified pellets were made one at a time using a compaction plunger and die apparatus at 14% moisture, a die temperature of 90 °C and a compaction pressure of 112 MPa. The feed properties studied were morphology of the starting pellet powders, pellet density, durability, disintegration in water (e.g. water stability) and transverse crushing load. Results indicated the mix containing 5% CMM/5% CM/60% ISP had better durability, water stability and transverse tensile strength. The CM contributed to poor pellet performance, while the ISP produced the most favorable results. Camelina meal performed moderately well and resulted in the highest density. This study may help aqua feed producers in the selection, composition and performance of feed containing agricultural products that are more economical than current meat-based fishmeal.

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Screening has revealed that modern-day feeds used in Atlantic salmon aquaculture might contain trace amounts of agricultural pesticides. To reach slaughter size, salmon are produced in open net pens in the sea. Uneaten feed pellets and undigested feces deposited beneath the net pens represent a source of contamination for marine organisms. To examine the impacts of long-term and continuous dietary exposure to an organophosphorus pesticide found in Atlantic salmon feed, we fed juvenile Atlantic cod (Gadus morhua), an abundant species around North Atlantic fish farms, three concentrations (0.5, 4.2, and 23.2 mg/kg) of chlorpyrifos-methyl (CPM) for 30 days. Endpoints included liver and bile bioaccumulation, liver transcriptomics and metabolomics, as well as plasma cholinesterase activity, cortisol, liver 7-ethoxyresor-ufin-O-deethylase activity, and hypoxia tolerance. The results show that Atlantic cod can accumulate relatively high levels of CPM in liver after continuous exposure, which is then metabolized and excreted via the bile. All three exposure concentrations lead to significant inhibition of plasma cholinesterase activity, the primary target of CPM. Transcriptomics profiling pointed to effects on cholesterol and steroid biosynthesis. Metabolite profiling revealed that CPM induced responses reflecting detoxification by glutathione-S-transferase, inhibition of monoacylglycerol lipase, potential inhibition of carboxylesterase, and increased demand for ATP, followed by secondary inflammatory responses. A gradual hypoxia challenge test showed that all groups of exposed fish were less tolerant to low oxygen saturation than the controls. In conclusion, this study suggests that wild fish continuously feeding on leftover pellets near fish farms over time may be vulnerable to organophosphorus pesticides. [ABSTRACT FROM AUTHOR]

Use of fish meal in aquaculture is gradually becoming unsustainable due to competition, cost and ecological challenges hence the need to expand the alternative protein sources. The earthworm, Eisenia fetida is among the non‐conventional protein sources, which have been tested with relatively promising results, thanks to its high protein levels, proper amino acid profile, high reproduction rate, low mortalities, fast growth and ease of production. The feasibility of using E. fetida for commercial fish feed production depends on the fundamental knowledge of its growth and reproductive biology, as well as the production methods. On the other hand, the nutritional suitability of E. fetida is determined by its amino acid composition and meal processing methods. Therefore, this study reviews the biological, biochemical composition as well as production and processing methods, as critical aspects for sustainable production and utilization of the earthworm in commercial fish feed production. Further, the study provides some recommendations and options to provide nutritionally complete and economically viable fish feed for efficient and sustainable aquaculture production systems. [ABSTRACT FROM AUTHOR]

A feeding experiment was conducted to develop non‐fish meal and non‐fish oil diet for red seabream by using plant protein source and Schizochytrium meal which is rich in 22:6n‐3 (DHA). Three iso‐nitrogenous and iso‐lipidic experimental diets were prepared (CP 41.2% ± 0.4%, CL 16.4% ± 1%). Control diet contained both fish meal (40%) and fish oil (6%). In the second diet, fish meal was replaced by plant meals (soy protein concentrate, soybean meal, corn gluten meal) [FO]. In the third diet, fish meal and fish oil were replaced by algae meal (Schizochytrium sp. powder) and plant proteins [AO]. Duplicated groups of juvenile red seabream (8.8 g ± 1.5) were fed the experimental diets for 12 weeks to near satiation. There was no statistical difference among treatment in specific growth rate. Feed conversion ratio of AO diet group was higher than that of control. In wet basis, whole body protein level was significantly higher in AO diet than FO group while lipid content was lower than control group. In fatty acid profile, AO group had significantly lower 18:4n‐3, 20:4n‐3, 22:5n‐3 and 20:5n‐3 (EPA) level, but significantly higher 18:3n‐3 and DHA level than the other two diet fed fish. The results might suggest that further developments in microalgae diet offer a promising lipid source of n‐3 PUFA as essential fatty acid on marine fish. And it showed possibility to develop non‐fish meal and non‐fish oil feed for marine aquaculture fish by using microalgae. [ABSTRACT FROM AUTHOR]

The demand for cultured finfish has increased tremendously during the last decades, but the success of intensive farming is dependent on several factors, namely management, dietary supplementations and welfare. During the last decades, increasing demand, high price and limited supply of fishmeal have emphasized the need for alternative protein sources in aquafeeds, but plant proteins possess a series of endogenous antinutritional factors (ANFs; e.g. protease inhibitors, tannin, mimosine, phytic acid, nonstarch polysaccharides), and they must be destroyed or inactivated. Inclusion of alternative protein sources has resulted in production losses and is a concern for farmers. However, the problem with ANFs might be solved using advanced processing techniques. The present review, focusing on tropical and subtropical freshwater finfish, will discuss findings on applications of conventional methods, as well as fermentation technology for deactivation of endogenous ANFs, and the use of probiotics with ANF degrading potential when plant ingredients are included in fish feeds. [ABSTRACT FROM AUTHOR]

Food waste remains as one of the most serious environmental challenges facing the world today, with sizable quantities generated and disposed of in landfills. Accordingly, exploring solutions to mitigate the detrimental impacts of such waste becomes vital. Aquaculture, a rapidly growing industry in rural areas of developing nations, offers the potential of using this waste productively to partially replace commercial feed, which is often absent or expensive. The present study delves into new options of using plate food waste collected from local restaurants as fish feed supplementation. Food waste, collected and processed into pellets, was evaluated in an 8-week feeding trial of rabbitfish, Siganus rivulatus. Five feeding regimens were adopted in which commercial feed was substituted with waste-based feed at 0, 25, 50, 75 and 100% of daily offering. Results suggest that up to 73.2% of the commercial feed can be substituted by waste-based feed with no significant effects on survival, growth rate, feed conversion ratio, or hepatosomatic and viscerosomatic indices of the fish. There were no statistical differences among treatments with 0, 25 and 50% replacement in terms of whole-body protein and lipid content or in hematological parameters. However, at 75% substitution, there was a clear decrease in growth, whereas at 100% replacement the fish showed complete mortality. Therefore, this study demonstrates a potential solution to mitigate food waste from landfills by utilizing it as a partial replacement of commercial fish feed. This in turn decreases the cost incurred in aquaculture production. [ABSTRACT FROM AUTHOR]

In Benin, fish farming is considered an effective way to supplement inland fisheries. However, its development faces the challenge of feeding fish. Most fish farmers rely on imported feed, which is very expensive, while there are local production units that also produce fish feed. This study aims to assess the competitiveness of local fish food production units to identify the factors that affect this competitiveness. Primary data were collected at 21 fish food production units in 1 7 districts in Benin. The data were analyzed using the Policy Analysis Matrix (PAM). The results show that the production of fish feed is financially and economically profitable. The estimated Domestic Resource Cost Ratio (DRCR) is 0.25. This means that compared to the prices the manufacturers are competitive. At contrary, imported fish feeds are quality competitive. The analysis of the sensitivity of the DRCR showed that reducing ingredient prices and increasing labor and capital productivity improve the competitiveness of manufacturers. Actors capacity building and improvement of manufacturing equipment are therefore necessary. [ABSTRACT FROM AUTHOR]

Abstract Elevated levels of chlorpyrifos‑methyl have been detected in plant-based Atlantic salmon feeds. To evaluate the potential negative effects of long-term and continuous dietary exposure to chlorpyrifos‑methyl in fish, we fed juvenile Atlantic salmon three concentrations (0.1, 1.0 and 8.0 mg/kg) of the pesticide for about two months. Brain and liver tissues were collected after 30 and 67 days of exposure. Homogenized brain tissue was examined for effects on acetylcholinesterase, and brain and liver tissue from fish exposed to 8.0 mg/kg were used for transcriptional analysis (RNA-seq). The results showed a transient accumulation of chlorpyrifos‑methyl in the brain with lower levels after 67 days of exposure compared to after 30 days of exposure. In contrast, the liver showed a time-dependent accumulation pattern. No effect on acetylcholinesterase activity, the primary target of chlorpyrifos‑methyl, was seen in the brain. However, after 30 days of exposure, 98 significantly differentially expressed genes (DEGs) were found in brain tissue and 239 DEGs in liver tissue. After 67 days of exposure, two and 258 DEGs were found in brain and liver tissue, respectively. Continuous dietary exposure of chlorpyrifos‑methyl most profoundly affected mechanisms associated with protein degradation and lipid metabolism in both brain and liver. Specific for the brain, many of the significant DEGs encode proteins involved in neuron function. In conclusion, this study shows that chlorpyrifos‑methyl affects the transcription of genes involved in neurological function in Atlantic salmon brain, even at exposure concentrations below the threshold for systemic toxicity as seen from brain acetylcholinesterase inhibition. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

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Highlights • An experimental design methodology used to optimization fish feed samples analysis was applied. • The mineral composition of feed for ornamental and human consumption fishes was determined. • Microwave-assisted digestion using diluted HNO 3 is an alternative for preparation samples. • The results obtained demonstrate need for expansion of the elements to be regulated in fish feeds. Abstract This work describes the application of an experimental design in optimizing the decomposition and spectrometer operational conditions for analysis of fish feeds. The content of 22 elements (six macroelements, four microelements and eleven trace elements) in feeds for fishes (ornamental and for human consumption) was determined by inductively coupled plasma (ICP)-based methods. Limits of quantification were obtained and the values ranged between 0.02 mg kg−1 (Cd) and 76 mg kg−1 (Al). Evaluation of the methods was achieved through analysis of standard reference material, Oyster Tissue (NIST 1566b) and Tea (NCS DC 73351). Element concentrations in feed samples for ornamental fish ranged from <0.02 mg kg−1 (Cd) to 2.79% (P) and for fish breeding for human consumption from <0.02 mg kg−1 (Cd) to 2.00% (Ca). The concentrations of the elements obtained in the analyzed fish feeds were within the limits established by Brazilian and American legislation for regulated elements. [ABSTRACT FROM AUTHOR]

The government and premier fisheries research institutes of India are in pursuit to sensitize the fish farmers and entrepreneurs regarding prospects of highly promising 'culture-based fisheries (CBFs) technology' in inland waters. Some crucial aspects, key drivers and existing policy-level lacunae having implications for culture fisheries development in inland waters from fish farmers and fisheries experts perspective have been discussed. Although the technicalities encompassing fish seed and feed are discussed in Indian context, the information may be useful for other developing countries as well. The opinions from fisheries policy, vision documents, meeting proceedings, experts and stakeholders have been compiled to suggest some advanced strategies for hastening culture fisheries development in inland waters and its easier acceptability among stakeholders. Based on recommendations, a centralized fish seed and feed vigilance-cum-certification system is the need of the hour. Stakeholder extracted technicalities and ambiguities surrounding seed and feed aspects can be the basis on which these systems shall function. Periodic upgradation of policies is suggested through feedbacks obtained from stakeholders, especially fish farmers, and shall not be limited to experts only. [ABSTRACT FROM AUTHOR]

Abstract The ecological health of aquaculture water is threatened by wasted fish feed and herbicides. In order to study the effect of prometryn and fish feed on Microcystis aeruginosa growth based on Monod and Logistic functions, four different concentrations of prometryn (0, 50, 100 and 200 μg L−1) and two different dosages of fish feed (0.075 g, 0.15 g; d < 0.85 mm) were added into the culture medium, and the fish feed was the source of nitrogen and phosphorus in the MII medium. Results showed that Microcystis aeruginosa growth can be fitted well by Logistic and modified Logistic functions with 0–200 μg L−1 prometryn (R 2 = 0.981–0.998 and R 2 = 0.989–0.999, respectively). With the same concentration of prometryn, the maximum algae density (N max) of Microcystis aeruginosa calculated by both Logistic and modified Logistic functions increased with increasing dosage of fish feed and with the same dosage of fish feed, N max declined with increasing concentrations of prometryn. Inhibition of prometryn on algae growth stimulated by fish feed is of double concentration-dependence, inhibition rates (I) are lower in 0.15 g fish feed medium than 0.75 g ones generally, implying that more nutrients can alleviate the stress caused by prometryn on algae. Derived formula for the specific growth rate, growth rate and inhibition rate using modified Logistic function agreed reasonably well with measured data. Jointly application of modified Monod and Logistic functions can better describe the relationship between specific growth rates and nutrients concentrations compared to combination of Monod and Logistic functions. In addition, equations for describing variations of nutrients concentrations (PO 4 3--P and NH 4 +-N) with time were also derived based on both modified Monod and Logistic functions, which agree reasonably well with the measured data. In sum, the combination of modified Monod and Logistic functions provides a promising and robust method in studying algal growth stimulated by fish feed in incubator experiments. Highlights • Combination of modified Monod and Logistic functions is beneficial to study algae growth. • Effect of prometryn and fish feed on algae growth is of dual concentration-dependence. • Modified Logistic function could better describe algae growth. [ABSTRACT FROM AUTHOR]

The furan fatty acid (F-fatty acid) content was determined in different marine sources as well as in commercially available marine oil products that claim to be health promoting. The five F-fatty acids typically representing the majority of F-fatty acids in fish, 9M5 (9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid), 9D5 (9-(3-dimethyl-5-pentylfuran-2-yl)-nonanoic acid), 11D3 (11-(3,4-Dimethyl-5-propylfuran-2-yl)-undecanoic acid), 11D5 (11-(3,4-Dimethyl-5-pentylfuran-2-yl)-undecanoic acid), and 11M5 (11-(3-Methyl-5-pentylfuran-2-yl)-undecanoic acid) were measured as methyl esters using a gas chromatograph linked with a tandem mass spectrometer (GC/MS-MS). The results showed a significant difference in F-fatty acid levels between the different marine oil products analyzed, depending on the source of raw material. Of the 11 different Icelandic marine catches analyzed, the highest total amount of F-fatty acids was found in the farmed fish. [ABSTRACT FROM AUTHOR]

Large quantities of high protein fish meals are needed to sustain cultured species and thus the impact to marine ecosystem has been highly discussed. The aim of this study was to apply a PCR‐cloning methodology for a robust insight into the composition of commercial fish meals and feeds for farmed species of the Greek mariculture, assessing the risk posed by aquaculture to marine ecosystems but also the risk posed by commercial fish feeds to the increase in trophic level of species farmed in Greece. 89% of the sequences were identified to species level and only 11% to genus/family level. Overall, a total of 49 taxa were identified (44 fish species/taxon, five non‐fish species/taxon). Even though small pelagic fish like Engraulis sp. were the main portion, a wide range of species constituted the fish meals and feeds. Plant and animal species were also detected as an alternative protein source. Feed products employed in Greek mariculture still contain large portions of fish meals which increase the mean trophic level of farmed species causing a farming up trend. The results emphasize that such molecular methodologies are needed to certify aquafeeds allowing fish feed producers to demonstrate their commitment to sustainable aquaculture. [ABSTRACT FROM AUTHOR]

Abstract Zinc (Zn) is an element essential to all living organisms and it has an important role as a cofactor of several enzymes. In fish, Zn deficiency has been associated with impaired growth, cataracts, skeletal abnormalities and reduced activity of various Zn metalloenzymes. Fish meal and fish oil traditionally used in salmon feed preparation are being replaced by plant-based ingredients. Zinc additives are supplemented to salmon feed to ensure adequate Zn levels, promoting good health and welfare in Atlantic salmon (Salmo salar). The main objective of the present study was to evaluate Zn species found in an Atlantic salmon feed. This work describes a Zn extraction method that was optimized using a fractional factorial design (FFD), whereby the effect of six factors could be studied by performing only eight experiments. The effects of the type of extraction solution and its molar concentration, pH, presence of sodium dodecyl sulphate, temperature and extraction time on Zn extraction were investigated. Mild extraction conditions were chosen in order to keep the Zn species intact. Total Zn (soluble fractions and non-soluble fractions) was determined by inductively coupled plasma mass spectrometry (ICP-MS). The highest Zn recovery was obtained using 100 mM Tris-HCl, pH 8.5 at a temperature of 4 °C for 24 h where the total Zn in soluble fraction and non-soluble fraction was 9.9 ± 0.2% and 98 ± 6%, respectively. Zinc speciation analysis (on the soluble fractions) was further conducted by size exclusion inductively coupled plasma mass spectroscopy (SEC-ICP-MS). The SEC-ICP-MS method provided qualitative and semi-quantitative information regarding Zn species present in the soluble fractions of the feed. Four Zn-containing peaks were found, each with different molecular weights: Peak 1 (high molecular weight - ≥600 kDa), peak 2 and peak 3 (medium molecular weight – 32 to 17 kDa) were the least abundant (1–6%), while peak 4 (low molecular weight – 17 to 1.36 kDa) was the most abundant (84–95%). Highlights • Effect of six factors on Zn extraction was studied using fractional factorial design. • The soluble fractions of fish feed were characterised for Zn species. • The SEC-ICP-MS method provides qualitative and semi-quantitative information. • Four Zn-containing peaks were found in the soluble fractions of fish feed. [ABSTRACT FROM AUTHOR]

This study investigated the properties of fish pellets made with plant-based ingredients intended for rainbow trout (Oncorhynchus mykiss) or other Salmonids. Plant protein from camelina meal (CMM), canola meal (CM), and isolated soybean protein (ISP) were the variable portions constituting 70% (w/w) of the seven formulations. The other 30% of ingredients included binders (7% wheat gluten protein (WGP) and 3% guar gum (GG)), 7.5% vitamins, 5% fish oil and 7.5% fishmeal. The densified pellets were made one at a time using a compaction plunger and die apparatus at 14% moisture, a die temperature of 90 °C and a compaction pressure of 112 MPa. The feed properties studied were morphology of the starting pellet powders, pellet density, durability, disintegration in water (e.g. water stability) and transverse crushing load. Results indicated the mix containing 5% CMM/5% CM/60% ISP had better durability, water stability and transverse tensile strength. The CM contributed to poor pellet performance, while the ISP produced the most favorable results. Camelina meal performed moderately well and resulted in the highest density. This study may help aqua feed producers in the selection, composition and performance of feed containing agricultural products that are more economical than current meat-based fishmeal. [ABSTRACT FROM AUTHOR]

The influence of two dietary treatments on quality properties, like textural parameters, sensory profile, and nutritional composition of Pacú fillets (Piaractus mesopotamicus) were studied. Pacú were fed diets based on plant‐meals containing 13 g 100 g−1 fish meal (FMD) or bovine plasma protein concentrate (BPPD) as a complete replacement of fish meal. Harvested fish were filleted, kept frozen at −20C for 7 days before analysis. Chemical composition, amino acid and fatty acid profiles, and CIE‐Lab parameters of fillets were measured. Sensory characteristics and texture profile analysis (TPA) were conducted for cooked portions. Average values of TPA hardness, chewiness, and deformability modulus were higher in BPPD samples but there was no significant difference in cohesiveness between samples. In accordance with TPA, higher values of firmness and chewiness as well as less flaky muscle were detected in BPPD samples by sensory panel. However, there was no significant difference in the characteristics associated with higher freshness between samples. Total color difference was lower in BPPD samples. Differences in protein, lipid, ash, and moisture content of FMD or BPPD fillets were not found (p > .05). BPPD fillets showed higher basic and sulfur amino acids. Saturated and polyunsaturated fatty acid contents were higher in FMD fillets than BPPD. However, a significantly higher n−6/n−3 ratio for FMD fillets was observed. The higher values of textural parameters observed for BPPD cooked fillets and the lower n−6/n−3 ratio imply a better sensory and nutritional quality of fillets from fish fed with BPPD. Practical applications: A complete study is presented on how the source of protein and lipids in feed affect both the sensory profile and the nutritional composition of fillets of Pacú (omnivorous temperate freshwater fish) cultivated in the second stage of fattening. Instrumental texture analysis of the fillets is presented, identifying the indicators that match with sensorial analysis. This analysis can help the industry of aquaculture in the evaluation of new ingredients or diets for fish feeding with impact in the quality of fillets. [ABSTRACT FROM AUTHOR]

Abstract Florfenicol is one of the most-used antimicrobial agents in global fish farming. Nevertheless, in most countries, its use is not conducted in accordance with good practices. The aim of this work was to evaluate the leaching of florfenicol from coated fish feed into the water. Analytical methods were developed and validated for the quantitation of florfenicol in medicated feed and water by UHPLC-MS/MS. Florfenicol residues in the water were quantified after 5- and 15-min exposures of the medicated feed in the water at 22 and 28 °C and at pH 4.5 and 8.0. The influence of pellet size and three coating agents (vegetable oil, carboxymethylcellulose, and low-methoxylated pectin) on the leaching of the drug was also assessed. Pellet size, coating agent, water temperature, and time of exposure significantly (p < 0.05) affected florfenicol leaching, while water pH did not interfere with the leaching. Coating with vegetable oil was the most efficient method to reduce florfenicol leaching, while coating with carboxymethylcellulose presented the highest leaching (approximately 60% after 15 min at 28 °C). Thus, the coating agent has a significant effect on the florfenicol leaching rate and, consequently, on the necessary dose of the drug to be administered. Moreover, it is worth mentioning that higher florfenicol leaching will pose a greater risk to environmental health, specifically in terms of the development of bacteria resistant to florfenicol. Additional studies are needed with other polymers and veterinary drugs used in medicated feed for fish farming. Graphical abstract Image Highlights • Florfenicol leaching from medicated fish feed into water was measured for the first time. • Florfenicol in medicated fish feed and water was quantified by UHPLC-MS/MS. • Temperature, exposure time in water, pellet size influenced florfenicol leaching. • The type of coating agent also influenced the leaching of florfenicol. Our study provides support for administering the proper dose of florfenicol (FF) to the fish, as well as to estimate the environmental pollution caused by the FF leaching into water in top-coating medicated feed. To emphasize the problem we are contributing to the evaluation of new coating agents, in order to reduce the drug losses and to contribute to the responsible use of antibiotics in fish farming. [ABSTRACT FROM AUTHOR]

During the growth of population in the world, Recirculating Aquaculture Systems (RAS) are developing due to more production and less water consumption and many scientists have studied on water quality and solid removal at these systems. In this paper to study on settling pattern of solid particles on a bed of aquaculture cylindrical tanks, a tank in diameter of 2.14 m and height of 0.59 m and inlet flow using three nozzles in 8 mm diameter has implemented. Quality and quantity studies of settling patterns of solid particles in six injection location (by changing the injection location of radial alignment for three options and on the pyramid of tank for others) show that injection location by the middle location of radial length and of third station (there are 6 stations on the pyramid of the tank and each station has located at 60 degrees from the last station) created more uniform sedimentation on the bed. Also, laboratory observations show that the low density materials such as fish feed, which has a high rate of immersion are more disposed to exit due to spiral flow of cylindrical tanks.

Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of