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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]

Soybean meal (SBM) is the most widely used source of high-quality plant protein within the feed industry. Raw soybeans are conventionally processed to reduce antinutritional factors, enhance protein bioavailability and improve the overall quality of the final feed product. New high-oleic (HO) cultivars with enhanced unsaturated fatty acids are being utilized in the production of HO SBM for use in the animal feed industry. However, no studies to date have examined the impact of HO SBM on feed formulation and processing of aquaculture feeds. Therefore, we aimed to determine the quality of feed for juvenile domesticated striped bass (Morone saxatilis) using SBM prepared from HO or normal-oleic (NO) soybeans and extrusion-expeller processing. The following four soybean meals were used in our experimental diets: solvent-extracted defatted normal oleic (SENO), full-fat normal oleic (FFNO), extruded-expelled defatted normal oleic (EENO), or full-fat high oleic (FFHO). These meals replaced half of the fishmeal (FM) normally included in a nutritionally complete marine finfish diet. Physico-chemical feed variables and chemical composition were determined during feed production. Data were analyzed using one-way ANOVA and means were separated using Tukey's t-test. The specific mechanical energy of the diet was reduced with the addition of full-fat SBMs during the extrusion process. All finished fish diets were of similar high quality with high pellet durability index and protein content (P > 0.05). This suggested that using different types SBM, including high oleic, to replace 50 % of the fish meal in a floating feed for juvenile domesticated striped bass does not adversely affect the feed quality or nutritional content. • Dry extrusion of soybeans as full fat meal or as extruded and expelled meal produces the meal between particle size ranges of 1128–1177 µm. • Inclusion of different types of soybean meal in the fish feed formulation had a significant effect on the specific mechanical energy of the extrusion process. • The fat levels in the soybean meals inversely affected the pellet diameter. • Over 90 % of the fish feeds could float in water for 30 minutes and is indicative of the suitability of the soybean meals used in this study for producing floating feeds. [ABSTRACT FROM AUTHOR]

Farmers and researchers in developing countries are evaluating the use of fish meal in broiler diets due to high cost and product variability. This study evaluated the effects of replacing fish meal with either soybean meal or poultry by-product meal on broiler performance and total feed cost per kilogram of gain. Three dietary treatments were manufactured to contain soybean meal and fish meal, soybean meal or soybean meal, and poultry by-products meal. Diets were balanced for lysine and fed in mash form. A total of 900 1-day-old male Cobb 500 broilers were randomly assigned to pens with 25 chicks per pen and reared for 42 d. Overall, 42 d broilers fed fish meal diets had lower body weights (P ≤ 0.05) compared to those fed soybean meal and poultry by-products meal diets but adjusted feed conversion ratio was similar (P ≥ 0.05) for all treatments. Replacing fish meal with either soybean meal or poultry by-products meal resulted in higher body weights and average daily feed intake but similar adjusted feed conversion ratio for all birds and lower feed cost per kilogram of gain. [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]

Although aquaculture industry has made great efforts to reduce the levels of fish meal (FM) in aquaculture feeds, further efforts and investigations are still needed to increase aquaculture production, which has more than tripled in the last two decades. This study was implemented to Six replicate groups of fish (24.6 ± 0.1 g) were fed one of the experimental diets to apparent satiety twice daily for 15 weeks; half of them were subjected to a daily net chasing stress for 1 min in the morning, 1 h before feeding. At the end of the feeding trial, fish were challenged with Edwarselia tarda injection. LFM diet resulted in comparable growth and feed efficiency performance to HFM group. However, significant impairments were observed in apparent digestibility coefficients, condition factor, hematocrit and serum super oxide dismutase activity. Fish fed LFM showed much lower resistance to E. tarda challenge. Both TH and SH resulted in enhanced fish nutritional and health performance with significant improvements in growth performance, feed efficiencies, digestibility, serum non-specific immunity and gut morphometric parameters. Fish fed TH and SH also exhibited the highest survival after E. tarda challenge. Principal component analysis (PCA) showed significant differences between stress and dietary groups for dimension 1 (33.3% of the variability), which was mostly characterized by growth and health variables. SH and TH coordinates were significantly higher on dimension 1 compared to HFM and LFM ones. Daily repeated stress affected most of measured performance parameters of all dietary groups with very few interactions. The stressed fish groups fed TH or SH showed lower cortisol levels compared to those fed HFM and LFM (p < 0.01). Strong correlations were observed between feed efficiency and fish gut morphometrics as quantified by villi length, enterocyte height and goblet cell density. Dietary supplementation of aquatic protein hydrolysates such as TH and SH appeared to be essential for maintaining good fish performance when they were subjected to a daily husbandry stressor or to an infectious challenge. • FM reduction may result in an impaired fish health status despite good growth • APH mitigate stress adverse effects • APH help to reduce FM and antibiotic uses [ABSTRACT FROM AUTHOR]

Fishmeal (FM) replacement using cost-effective blends of complementary ingredients is commonly used in carnivorous marine fish diets for economic and sustainable purposes. The use of functional compounds such as prebiotics or functional ingredients is a nutritional strategy in low FM diets to maximize growth and feed utilization, as well as reducing enteropathies caused by plant proteins, in particular soybean meal (SBM) that can induce enteritis in Totoaba macdonaldi juveniles. Therefore, this study was conducted to evaluate the effects of glutamine (Gln) and agavin (AGA) as a novel prebiotic or a combination of both on growth parameters, digestive capacity, whole-body proximate composition, gut health, and sustainable and economic indexes in totoaba juvenile fed low FM (17%) diet for 56 days. Juvenile totoaba with an initial weight of 168 ± 4 g were fed one of four isoproteic and isolipidic diets formulated with poultry by-product meal and FM in a 2:1 ratio and 24% of SBM. For the control basal diet (SBM), no Gln or AGA was added. The other three experimental diets consisted of the basal diet with either 1.5% glutamine (GLN), 1% prebiotic agavin (AGA), or 1.5% glutamine and 1% agavin (Gln + AGA) supplementation. Fish fed the Gln diet significantly improved growth, feed utilization and increased trypsin, total alkaline proteases, and L-aminopeptidase activities. Additionally, an enhanced brush border height (BBH) in the distal intestine was observed in the Gln group, suggesting improved intestinal health compared to the rest of the treatments. However, no significant synergistic effect was observed in fed fish the Gln + AGA diet. Interestingly, no signs of enteritis among the fish fed the four experimental diets was observed. These results suggest that fish with an initial size of 168 g are less susceptible to the adverse effects of SBM compared to previous studies. The inclusion of 1.5% dietary glutamine is recommended in totoaba diets with low FM containing 24% of SBM. Since the fish fed the diet supplemented with glutamine + agavin resulted in intermediate values for the parameters evaluated, it is recommended to evaluate different levels of agavin in combination with glutamine or perform longer bioassays using immunological or environmental challenges to aid in elucidating potential benefits of these functional compounds and their synergistic effects. • Addition of 1.5% glutamine in totoaba diets improved growth, feed utilization, and increased intestinal brush border height. • Combining dietary glutamine with agavin resulted in small synergistic effects and should be further evaluated. • Dietary glutamine increases sustainability by reducing the fishmeal dependency and improving fish intestinal health. • Results suggest totoaba juveniles with larger initial weight are less susceptible to dietary SBM induced adverse effects. [ABSTRACT FROM AUTHOR]

The growth of aquaculture and the increasing demand of farmed fish have led to a rise in the price of fishmeal and fish oil used in fish feeding during the last years. The experimental use of insect meal as a sustainable alternative to fish meal has recently grown. Insects are easy to rear, have a small ecological impact and have high protein content. The present work analyzes through a Discrete Choice Experiment method, the preferences and willingness to pay of Spanish consumers towards an aquaculture production system based on this protein source as ingredient in aquafeed, using the gilthead seabream as a case study. It also analyzes the information level of consumers about aquaculture and their perceptions towards its environmental impact compared to other animal production systems. This study also summarizes research advances regarding the insect meals as substitutes or complements for fish meals focusing on fish species of interest in Spain and Europe. Special emphasis was made on the limitation of their use, its impact towards the conversion feed ratio and its main nutritional problems for fish feeding, such as fatty acids and chitin. The studies showed that the use of insect meal, in particular, from the black soldier fly (Hermetia illucens), the common housefly (Musca domestica) and the mealworm (Tenebrio molitor) as an alternative of feeding in aquaculture seems to be promising both at technical-productive level and at consumer acceptance level. Results showed that Spanish consumers were willing to pay a premium for this type of fish compared to fish produced with the current feeding systems. Furthermore, the gilthead sea bream fed with insect meal was the most valued regarding its environmental impact compared to the current fish feeding systems. However, taste expectation for this fish type still low, highlighting the importance of including hedonic evaluation studies for further research. • Labelled Discrete Choice experiment was used to analyze feed preference in fish. • Spanish consumers are willing to accept fish fed with insect meal alternative. • Aquaculture is perceived as the most environmental friendly animal production system. • Consumers perceived the fish fed with insect meal with lower environmental impact. [ABSTRACT FROM AUTHOR]

• The slaughter method could be a viable alternative to the T-cannula technique. • Nutritional value of selected protein sources fed to pigs under 20 kg BW was estimated. • S50, HP300 and CDCP could replace fish meal after adding moderate fat and AA. The digestible energy (DE) and metabolizable energy (ME) content (Exp.1), and apparent or standardized ileal digestibility coefficients (AIDC or SIDC) of crude protein (CP) and amino acid (AA) (Exp.2) in Soyppt-50% (S50), Hamlet Protein 300, (HP300), concentrated degossypolized cottonseed protein (CDCP), Palbio 50 RD (P50) and fish meal fed to piglets were estimated. In Exp.1, 36 barrows (10.19 ± 1.35 kg BW) were randomly divided into 6 diets with 6 pigs per diet. A basal diet and 5 diets containing 800 g/kg basal diet and 200 g/kg of each test protein ingredient were prepared. In Exp.2, 38 barrows (12.61 ± 1.45 kg BW) were randomly allotted to 1 of 6 diets with 6 pigs except for N-free diet (n = 8). 5 diets containing each of test protein ingredient as the sole source of AA and a N-free diet were formulated. At the end of the trial, ileal digesta of each pig was collected using the slaughter method. Results indicated that S50 contained more DE (16.28 MJ/kg) (P < 0.05) than CDCP (15.79 MJ/kg) and P50 (15.16 MJ/kg), but less (P < 0.05) than HP300 (16.53 MJ/kg) and fish meal (16.59 MJ/kg). The ME content in CDCP (14.68 MJ/kg) was less (P < 0.05) than in S50 (14.47 MJ/kg), HP300 (15.77 MJ/kg) and fish meal (15.63 MJ/kg), but greater (P < 0.05) than in P50 (13.11 MJ/kg). P50 had lower (P < 0.05) AIDC or SIDC of CP and most indispensable AA compared with other protein ingredients. AIDC or SIDC of CP and most indispensable AA in HP300 and CDCP were no differences, but greater (P < 0.05) than in other protein ingredients. S50 and fish meal had similar AIDC or SIDC of CP and most indispensable AA. In summary, S50, HP300 and CDCP had promising potential to replace fish meal in piglet diet after adding appropriate amount of fat and crystalline AA. [ABSTRACT FROM AUTHOR]

Abstract This research evaluated the effect of the simultaneous substitution of fish meal and fish oil at 0, 30, 50, 70 and 100% (termed SS0, SS30, SS50, SS70 and SS100, respectively) with both Spirulina (Arthrospira platensis) and linseed oil. The effect on growth, colour, fatty acid (FA) profile, and liver and muscle antioxidant response in mullets (Mugil liza) were evaluated. A full substitution was not possible due to a final body weight reduction (p < 0.05). The colorimetric analyses showed an improvement in fillet colouration (p < 0.05). Also, we found a saturation of carotenoids in muscle at 30% substitution. The content of highly unsaturated fatty acids - HUFA (DHA, EPA and ARA) in muscle diminished as the substitution level increased and, at the same time, the level of these FAs in the diet diminished. We found interesting evidence of elongation from 18:3n-3 to 20:3n-3 when substitution with linseed oil levels was above 50% but no desaturation to 20:4 or 20:5n-3 was found, which could insinuate a certain n-3 HUFA requirement under the experimental conditions. Moreover, we noted an increase in the antioxidant capacity up to the treatment SS70; the SS100 treatment showed a diminution in the antioxidant capacity. It is concluded that a partial inclusion of Spirulina and linseed oil (50%) is possible, and that this replacement can increase antioxidant responses, improve its growth performance and can modulate the mullets fillet quality without affecting negatively fillet fatty acid content. Graphical abstract Mugil liza juveniles were fed diets with different levels of simultaneous substitution (SS) of fish meal and fish oil with Spirulina and linseed oil. Unlabelled Image Highlights • Simultaneous substitution of fishmeal and fish oil with Spirulina and linseed oil was assessed using Mugil liza juveniles • Partial inclusion of Spirulina and linseed oil (50%) is possible without hampering Mugil liza survival and growth • Full simultaneous substitution is not feasible probably as a result of the lack of some essential amino acids • We have found evidence of fatty acid elongation in the muscle of mullets. [ABSTRACT FROM AUTHOR]

Abstract This study was conducted to examine the effects of fish meal (FM) replacement by rice protein concentrate (RPC) supplemented with xylooligosaccharides (XOS) on the growth, intestinal digestive and absorptive capabilities and amino acid metabolism of blunt snout bream. Fish were randomly divided into six groups, and were fed with the control diet (containing 10% FM), the RPC diet (FM entirely replaced by RPC) and the RPC diet supplemented with 0.5, 1.5, 2.3 and 3% XOS, respectively, for 8 weeks. Fish fed the RPC diet obtained significantly lower values in daily growth index, feed efficiency ratio, nitrogen and energy retention and plasma concentrations of methionine, leucine, phenylalanine, lysine and histidine compared to the control. However, the supplement of 1.5% XOS restored these parameters to the levels similar to the control group. Fish fed the RPC diet showed no statistical difference in intestinal lipase, alkaline phosphatase and Na+K+-ATPase activities compared to the control group, but exhibited lower protease, carboxypeptidase A, aminopeptidase N and γ-glutamyl transpeptidase activities. However, these effects were reserved with the administration of 1.5% XOS. Also, the transmission electron microscopy analysis showed a significantly lower microvilli length in the mid-intestine of fish fed the RPC diet compared to the control, but it improved significantly with the supplementation of XOS. Hepatic activities of alanine transaminase, aspartate aminotransferase and glutamate dehydrogenase were significantly lower in fish fed the RPC diet compared to the control, but they improved with the supplementation of 1.5% XOS. Similarly, fish fed the RPC diet obtained relatively low expression levels of the target of rapamycin (TOR) and ribosomal protein S6 kinase 1 but higher expressions of eukaryotic translation initiation factor 4E-binding protein 2 in the intestine, liver and muscle. Opposite trend was observed in fish fed the RPC diet supplemented with 1.5% XOS. Overall, these results showed that RPC supplemented with 1.5% XOS could completely replace FM in the feed of blunt snout bream without any adverse effect on the growth performance, intestinal enzymes activities, gut morphology, amino acid metabolism and TOR signaling. Highlights • FM replaced by RPC led to a significant reduction in growth, feed utilization and AA metabolism. • The supplementation of 1.5% XOS restored these parameters to the levels similar to the control. • Excessive XOS levels led to compromised growth, feed utilization and AA metabolism. [ABSTRACT FROM AUTHOR]

Abstract An 8-week feeding trial was conducted to evaluate the effect of fish-meal replacement on growth performance, protein synthesis and immune response of juvenile Pacific white shrimp, Litopenaeus vannamei reared at low salinity (7‰). Five isonitrogenous and isolipidic diets were formulated to contain graded levels (25, 20, 15, 10 and 5%) of fish-meal. High quality alternative solutions were performed, crystalline amino acids, phytase, mannan oligosaccharides and some micro-nutrients were supplemented in the low fish-meal diets. Each diet was randomly assigned to triplicate tanks, each tank with 30 shrimp (mean weight 0.3 g), the shrimp were fed 3 times a day. Weight gain and survival were decreased with the decreasing dietary fish meal levels. When dietary fish-meal decreased, the gene expression of TOR, Raptor and eIF4E2 in hepatopancreas were decreased with the decreasing fish meal levels, eIF4E2 in intestine was decreased while 4E-BP was increased with the decreasing fish meal levels. The mRNA level of SOD in hepatopancreas decreased, and the expression of GPx and CAT increased with the decreasing FM levels. The Toll pathway was affected by dietary FM levels, the expression of Toll2, TNFSF, MyD88, Rho and p38 in intestine were increased with the decreasing FM levels. The results indicated that at low salinity condition, fish meal level lower than 15% would inhibit the protein synthesis and harm to the health of shrimp. Graphical abstract Unlabelled Image Highlights • Reduced the fish meal content in the diet would significantly affected the survival of white shrimp reared at low salinity. • The protein synthesis of white shrimp might be affected by the dietary fish meal levels. • Immune response, especially for Toll pathway, might be affected by dietary fish meal levels. [ABSTRACT FROM AUTHOR]

Abstract An 8-week feeding trial was carried out to evaluate the effects of replacing fish meal (FM) with housefly (Musca domestica) maggot meal (HFMM) on growth, antioxidant capacity, digestive enzymes activity, and gut health of bullfrog Rana (Lithobates) catesbeiana. A basal experimental diet was formulated using FM and soybean meal as the major protein sources, then four other diets were produced by replacing 25, 50, 75 or 100% of FM with HFMM (FM, HFMM25, HFMM50, HFMM75 and HFMM100 diets). Each diet was fed to triplicate groups of bullfrog (34.1 ± 1.10 g) to apparent satiation twice daily. No significant linear or quadratic trends were observed between FM replacement level and growth, feed utilization and survival rate (P > 0.05). A significant negative linear trend was detected between the incremental levels of HFMM and apparent digestibility coefficients (ADCs) of dry matter, protein and lipid, while positive linear and quadratic trends were found in ADC of phosphorous (P < 0.05). A negative linear trend was observed between whole-body ash content and HFMM level. Positive linear and quadratic trends were found between serum aspartate aminotransferase, alkaline phosphatase and lysozyme activities and incremental HFMM levels. Liver superoxide dismutase and catalase activities were increased linearly, and total antioxidant capacity was enhanced both linearly and quadratically by incremental levels of HFMM. In contrast, a negative linear trend was found in liver malondialdehyde concentration. A significant positive quadratic trend was found between intestinal protease, lipase and amylase activities and incremental levels of HFMM. Histological observations revealed a significant negative linear trend between HFMM level and villus height and muscular thickness. Gut microbiota analysis showed no significant changes in the operational taxonomic unit (OTU) diversity and richness indices among treatments. Positive linear and quadratic trends were found between incremental HFMM levels and expression of liver HSP70 and IGF-Ι and intestinal TNF-α, IL-1ß, IL-8 and IL-17 genes. The findings in this study showed that although growth performance was not significantly affected by total replacement of FM with HFMM, nutrients digestibility and gut health could be adversely influenced at higher replacement levels. Highlights • Housefly maggot meal was evaluated as a fish meal replacer in bullfrog diets. • Total replacement of fish meal did not lead to detrimental effects on growth. • Gut health was adversely affected at higher replacement levels. • Housefly maggot meal inclusion enhanced antioxidant capacity and immune response. [ABSTRACT FROM AUTHOR]

Highlights • A new alternative to classic fishmeal production is proposed, using the pH shift method. • The pH shift process is proposed as an efficient method of working with high bone-low meat sources, such as fishery byproducts. • Protein yield is affected by the treatment that is applied during the pH shift process. • Proximate composition of the pH shift produced protein concentrates is also subject to treatment. Abstract There is a strong need in animal production for sustainable protein sources used in feed. The aim of the present study was to evaluate the potential of the pH-shift process as a method to concentrate proteins from complex bone-rich herring (Clupea harengus) by-products. By-product parts (frame, head, guts), protein solubilization pH (pH 2.8 or 11.3) and separation g-force (800 or 8000 g) were varied. The findings revealed that protein recovery yields of up to 60% were obtained and that higher protein yield was obtained from the alkaline than the acid process. By-product part and g-force had no significant impact on protein yield. Protein levels reached in the concentrates were 75–80 % (dw basis). Protein concentrates contained a similar amino acid profile as have been reported for fishmeal, with ∼40% essential amino acids and up to 7.8% and 2.8% of lysine and methionine. Residual levels of LC n-3 PUFA as well as calcium, magnesium, potassium and phosphorous were also found in the produced protein concentrates which could be an added value. Acid produced concentrates were particularly high in calcium potassium and phosphorous. Provided a careful evaluation, the pH-shift process could become a successful alternative to classic fish meal production for increasing the use of fish by-products for production of protein ingredients for feed. [ABSTRACT FROM AUTHOR]

Work was undertaken to investigate the potential use of housefly (Musca domestica) larvae reared on broiler manure as a source of nutrition for poultry production in the United Kingdom. Nutritional analysis showed that larvae have a high (>45% dry wt.) protein content and a favorable amino acid profile that is rich in key amino acids, such as lysine and methionine. A broiler digestibility trial was carried out to determine the apparent ileal digestibility coefficients (AIDC) and true ileal digestibility coefficients (TIDC) of amino acids (AA) from insect larval meal (ILM) from M. domestica and fishmeal (FM) in broiler chickens. This was calculated using multiple linear regression technique based upon 3 inclusions of each protein source in a semisynthetic diet. One-hundred-forty-four day-old male (Ross 308) broilers were fed from hatch on a commercial starter diet for 20 days. Experimental diets were fed from d 21 to 28, and feed intakes were measured daily. On d 28, the trial was terminated, ileal digesta were collected for the determination of AIDC and TIDC of AA, and inflammatory responses (gizzard erosion and eye discharge) were measured. No significant differences were observed in digestibilities between protein sources for any AA. Furthermore, ILM feeding did not induce gizzard erosion or eye discharge at any inclusion. These results provide strong evidence to suggest that ILM of the common housefly can provide a successful alternative protein source to FM in broiler diets. [ABSTRACT FROM AUTHOR]

[Display omitted] • Physiological effects from supplementation of blue mussel meal (BM) were investigated. • Inclusion of BM in salmon diet maintained the n-3 PUFA level in the salmon fillet. • Inclusion of BM in mouse diet improved the n-3/n-6 PUFA ratio in mouse liver. • No BM-induced adverse effects were observed in the mouse model of obesity. Alternative feed ingredients for farmed salmon are warranted due to increasing pressure on wild fish stocks. As locally farmed blue mussels may represent an environmentally sustainable substitute with a lower carbon footprint, we aimed to test the potential and safety of substituting fish meal with blue mussel meal in feed for Atlantic salmon. Salmon were fed diets in which fish meal was partially replaced with blue mussel meal in increments, accounting for up to 13.1 % of the ingredients. Fillets from the salmon were subsequently used to prepare obesity-promoting western diets for a 13-weeks mouse feeding trial. In a second mouse trial, we tested the effects of inclusion of up to 8% blue mussel meal directly in a meat-based western diet. Partial replacement of fish meal with blue mussel meal in fish feed preserved the n-3 polyunsaturated fatty acid (PUFA) content in salmon fillets. The observed blue mussel-induced changes in the fatty acid profiles in salmon fillets did not translate into similar changes in the livers of mice that consumed the salmon, and no clear dose-dependent responses were found. The relative levels of the marine n-3 fatty acids, EPA, and DHA were not reduced, and the n-3/n-6 PUFA ratios in livers from all salmon-fed mice were unchanged. The inclusion of blue mussel meal in a meat-based western diet led to a small, but dose-dependent increase in the n-3/n-6 PUFA ratios in mice livers. Diet-induced obesity, glucose intolerance, and hepatic steatosis were unaffected in both mice trials and no blue mussel-induced adverse effects were observed. In conclusion, our results suggest that replacing fish meal with blue mussel meal in salmon feed will not cause adverse effects in those who consume the salmon fillets. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the use of novel ingredients such as green pea protein and Ascophyllum nodosum , a brown seaweed for the replacement of fish meal in feeds suitable for organic production. The growth, feed utilization and fillet composition of gilthead seabream were examined under a lab scale trial and based on the results a large-scale field trial was conducted in the facilities of Galaxidi marine farms in order to compare a novel feed with a typical commercial feed suitable for organic production. Final weight, growth rate and somatic indices of the fish fed these alternative ingredients did not show significant differences compared to the control group fed the commercial diet. Muscle protein content was higher in the fish fed the higher inclusion level of green pea protein, whereas lipid content was lower in both experimental diets. Fatty acid composition, in terms of n-3 and n-6 polyusaturated (PUFA), eicosapentanoic (EPA) and docosahexaenoic (DHA) acid content was higher in the muscle of the fish fed the experimental diets. In the case of the liver, the fatty acid profile reflected the feed composition, and the fish fed the diet with an inclusion of 19% green pea protein showed a lower content of protein and a higher content of n-6 PUFA, and monounsaturated fatty acids (MUFA). In view of the results obtained, the ingredients assayed in this study could be used in organic feed formulations as alternatives to fish meal obtained from trimmings since no negative effects were detected neither on fish growth, muscle composition, fish health nor end product quality and nutritional value. • Green Pea Protein can be included up to 25% in organic feeds for gilthead sea bream Sparus aurata • Seabream growth and conversion using this new organic ingredient are similar to those obtained using a commercial feed • The addition of seaweed meal as a supplement can also contribute to the growth, health status and final composition of organic gilthead sea bream. [ABSTRACT FROM AUTHOR]

A 59-days feeding trial was carried out to estimate the effects of fish meal replacement by defatted black soldier fly larvae meal (DBSFLM) on growth performance, antioxidate enzyme activities, digestive enzyme activities, hepatopancreas and intestinal morphology in Jian carp ( Cyprinus carpio var. Jian) juveniles (initial mean body weight, 34.78 g). Five isolipidic (5.29 ± 0.04%) and isoprotein (40.69 ± 0.11%) diets were formulated by replacing 0%, 25%, 50%, 75%, 100% fish meal (FM) protein with graded DBSFLM levels of 0%, 2.6%, 5.3%, 7.9% and 10.6%. Each diet was randomly assigned to triplicate groups of 20 fish per aquarium. Fish were fed three times daily to apparent satiation. The results showed that the growth performance and nutrients utilization of fish in five groups were not different ( P > 0.05). The hepatopancreas lipid and serum cholesterol content of treated groups was significantly lower than that of the control group ( P < 0.05). With increasing dietary DBSFLM level, the activity of the CAT significantly increased. No significant differences in the activity of intestinal protease, lipase and diastase were observed among dietary groups ( P > 0.05). The histological examination of intestine showed that when 75% or more FM protein was replaced, apparent pathological changes for example tissue disruption were observed in intestine, and relative gene expression of HSP70 in hepatopancreas significantly increased ( P < 0.05). The histological examination of hepatopancreas sections showed less vacuolated with lipid deposits in treatment groups compared with control group. These results suggested that the growth of Jian carp was not affected by dietary DBSFLM, while it boosted antioxidant status of Jian carp by higher CAT activity. However, dietary stress and intestinal histopathological damage was observed when the replacement levels exceeded 75%. The study demonstrates that it is suitable to replace up to 50% of dietary FM protein with DBSFLM. [ABSTRACT FROM AUTHOR]

This study comprised a 2 × 2 factorial array of dietary treatments offered to male Ross 308 broiler chicks from 15 to 28 days post-hatch. The dietary treatments consisted of a sorghum-soybean meal diet in which either sorghum was partially substituted by maize starch (200 g/kg) or soybean meal was partially substituted by fishmeal (175 g/kg). Growth performance, nutrient utilisation, digesta retention times in four small intestinal segments, starch and protein (N) digestibility coefficients and disappearance rates (g/bird/day) and starch:protein disappearance rate ratios in four small intestinal segments were determined. The partial substitution of soybean meal by fishmeal had the more profound effects on the parameters assessed as fishmeal inclusions improved weight gain by 12.1% (1260 versus 1124 g/bird, P < 0.001) and FCR by 8.13% (1.299 versus 1.414, P < 0.001). This substitution significantly enhanced starch digestibility coefficients in four small intestinal segments culminating in an increase of 18.9% (0.937 versus 0.788; P < 0.001) in the distal ileum. The partial substitution of soybean meal by fishmeal significantly increased digesta retention time in the small intestine from 210 to 289 min. Starch digestibility was significantly correlated with growth performance (weight gain, FCR) and energy utilisation (AME, ME:GE ratios, AMEn) and these parameters were all significantly enhanced by the fishmeal substitution. Consideration is given to the possible mechanisms whereby the partial substitution of soybean meal by fishmeal promoted starch digestibility and energy utilisation and growth performance. Instructively, starch:protein disappearance rate ratios in the proximal jejunum were quadratically related to weight gain (r = 0.849; P < 0.001) and FCR (r = 0.838; P < 0.001) such that a ratio of 3.59:1 would generate the maximum weight gain of 1265 g/bird and a ratio of 3.88:1 would generate the minimum FCR of 1.287. These relationships emphasise the importance of digestive dynamics and in these examples there was an ideal balance between the bilateral bioavailabilities of starch and protein. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (BSFL) meal, produced from the larvae of Hermetia illucens, has shown promise as a fish meal (FM) replacement in diets for rainbow trout, catfish and tilapia, but has not been examined as an alternative protein source in shrimp diets. Six isonitrogenous (35% crude protein, as fed) and isoenergetic (16.7 kJ available energy g − 1 of diet) diets containing graded levels of BSFL as replacements for protein from menhaden FM were fed to juvenile (1.24 g ± 0.01; mean ± SE) Pacific white shrimp, Litopenaeus vannamei . Diet 1 (the control) was formulated similar to a commercial shrimp diet containing 25% menhaden FM and 23% soybean meal. Diets 2–6 were formulated as a dose-response series that progressively replaced protein from menhaden FM with BSFL meal at inclusion rates of 7%, 14%, 21%, 28%, and 36% of diet; this equated to progressively replacing 16.5% of dietary protein provided by menhaden FM. Diets were fed to juvenile shrimp stocked into eighteen 110-L saltwater aquaria (30 ppt) (three replicates per dietary treatment) at a density of 15 shrimp per aquarium (50/m 2 ) for 63 days. Nonlinear and spline regression analysis of responses indicated that the maximum level of BSFL meal inclusion varied significantly with the response being modeled. Generally, without modification of the ingredient or replacement diet nutrient profiles, 95% to 100% of most growth responses, i.e., shrimp final weight, weight gain, specific growth rate, and food conversion, could be obtained if replacement of FM by BSFL meal was limited to < 25% of the diet, depending on performance measure. Similarly, 95% or greater of maximum whole-body protein and lipid content could be achieved when BSFL inclusion was restricted to < 29% and 15%, respectively. Comparison of amino acid profiles in the test diets with recent requirement estimates for limiting amino acids in BSFL meal also suggest future strategies for increasing dietary substitution of FM with BSFL. [ABSTRACT FROM AUTHOR]

The salmon feed composition has changed the last decade with a replacement of traditionally use of fish oil and fishmeal diets with vegetable ingredients and the use decontaminated fish oils, causing reduced concentrations of dioxins and dioxin-like PCBs in farmed Norwegian Atlantic salmon. The development of novel salmon feeds has prompted the need for prediction on dioxins and dl-PCB concentrations in future farmed salmon. Prediction on fillet dioxins and dl-PCB concentrations from different feed composition scenarios are made using a simple one-compartmental transfer model based on earlier established dioxin and dl-PCB congener specific uptake and elimination kinetics rates. The model is validated with two independent feeding trials, with a significant linear correlation (r 2 = 0.96, y = 1.0x, p < 0.0001, n = 116) between observed and predicted values. Model fillet predictions are made for the following four scenarios; (1) general feed composition of 1999, (2) feed composition of 2013, (3) future feed composition with high fish oil and meal replacement, (4) future feed composition with high fish oil and meal replacement and decontaminated fish oil. Model predictions of fillet dioxin and dl-PCB concentrations from 1999 (1.05 ng WHO 2005 -TEQs kg −1 ww) and 2013 (0.57 ng WHO 2005 -TEQs kg −1 ww) are in line with the data observed in national surveillance programs of those years (1.1 and 0.52 ng WHO 2005 -TEQs kg −1 ww, respectively). Future use of high replacement and decontaminated oils feeds gave predicted fillet concentrations of 0.27 ng WHO 2005 -TEQs kg −1 ww, which is near the limit of quantification. [ABSTRACT FROM AUTHOR]

Fish from aquaculture has the ability to meet consumer demand for a healthy and sustainable diet. The environmental footprint of fish farming depends largely on the method of production. Trout production in the temperate climate zone in open flow-through systems using the natural hydraulic gradient of streams as freshwater supply is energy efficient relative to more intensive systems. To investigate the possibility of reducing global warming potential, eutrophication potential, acidification potential, and ozone layer depletion associated with rainbow trout (Oncorhynchus mykiss) production in southern Germany, a comprehensive dataset collected under the typical farm framework was analyzed and a cradle-to-gate life cycle assessment was conducted. The impact of feed source (plant- and fish-based) was analyzed, as well as that of photovoltaic panels installed over the production area. Calculated emissions per kg fish live weight were 1.18 kg CO 2eq , 7.89e−8 kg CFC 11eq , 0.00552 kg SO 2eq, and 0.0257 kg PO 4eq. Full covering of the production area with photovoltaic panels, compared to the current ∼40% coverage, was estimated to provide a reduction of 1.04 kg CO 2eq, resulting in emissions of 0.773 kg CO 2eq per kg fish live weight. Feeds containing 35% and 61.8% fishmeal were associated with lower emissions compared to 100% plant-based, with a reduction in GWP of 0.79 kg CO 2eq in the 61.8% fishmeal variant. Results showed that the use of photovoltaic panels can significantly reduce rainbow trout culture impact on the analyzed environmental impact categories. Feed containing fishmeal has a lower impact on the analyzed environmental impact categories. Alternatives such as insect meal and sustainable plant alternatives should be the focus of future research. • Investigation of environmental impact of trout reared in flow-through systems • Typical farm approach with scenarios differing in energy and feed use • Main emissions come from the use of oxygen and feed • Increasing photovoltaic system use on farm lowers farm emissions • Increased fishmeal content in feed decreases the ecological impact of the farm [ABSTRACT FROM AUTHOR]

Dioxins and dioxin-like polychlorinated biphenyls (dl-PCBs) in fish fillet counteract the health benefits of fish products. In this study, food waste was used as a protein alternative to replacing fishmeal commonly used in the commercial fish feed, aiming to cultivate Sabah grouper with acceptable levels of dioxins and dl-PCBs. The concentrations of dioxins and dl-PCBs, as well as the fish growth performance, were compared between the fish groups fed with food waste-based feed (FWBF) and commercial feed (Nanyu®, control). The results showed that the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) (1.22 pg/g dry weight (d.w.)) and non-ortho-dl-PCBs (13.0 pg/g d.w.) were significantly lower (p < 0.05) in the FWBF than in the control feed (commercial feed) (PCDDs: 2.35 pg/g d.w.; non-ortho-dl-PCBs: 27.2 pg/g d.w.). The growth performance of the fish group fed with the FWBF was comparable to that fed with the control feed. There were no significant differences between the WHO 2005 -TEQ values of different fish fillets (1.00, 1.11, and 1.10 pg WHO 2005 -TEQ/g d.w. for FWBF group, control feed group, and local market fish, respectively). Based on the guidelines provided by European Food Safety Authority (ESFA) and U.S. Environmental Protection Agency (USEPA), the fish fed with the FWBF were safe for human consumption (hazard index values: 0.284–0.522; cancer risk range: 2.59–2.97 × 10−5). The findings of this study suggest that food waste could serve as an alternative protein source for cultivating Sabah grouper with acceptable levels of dioxins and dl-PCBs. [Display omitted] • The food waste-based diet reduced 50% of fishmeal in traditional feed for grouper. • Cultured Grouper were safe for consumption based on levels of dioxins and dl-PCBs. • Safety of food waste for Grouper farming was assessed for the first time. • The food waste-based diet was suitable for cultivating quality Sabah grouper. [ABSTRACT FROM AUTHOR]

The Atlantic salmon farming industry has progressively decreased the proportion of fishmeal used in commercial diets due to rising costs and sustainability concerns. A variety of alternate proteins have been identified to partially replace fishmeal; however, very little research has described the effect of feeding alternate protein, fishmeal-free diets to Atlantic salmon, particularly post-smolts cultured in recirculation aquaculture systems (RAS). Therefore, a 6-month study was conducted to compare the effects of feeding a fishmeal-free diet (FMF) versus a fishmeal-based diet (FM) on post-smolt Atlantic salmon performance, water quality, and waste production rates in six replicated RAS. Experimental diets were fed to Atlantic salmon (281 ± 5 g to begin) in triplicate RAS. Protein ingredients used in the FMF diet included mixed nut meal, poultry meal, wheat flour, and corn protein concentrate; while the FM diet contained menhaden meal, poultry meal, soy protein concentrate, and blood meal proteins. Fish oil derived from whiting fish trimmings was used in the FMF diet to establish a wild fisheries input to farmed fish output ratio of 0:1; while menhaden oil was the primary lipid source for the FM diet. Both diets were formulated with approximately 42% crude protein and 27% crude fat. Each RAS was operated with flushing rates that created an average system hydraulic retention time of 20 days (5% system volume flushed daily) and a mean feed loading rate of 3.2 kg feed/m 3 of daily make-up water volume. Atlantic salmon growth, survival, and feed conversion ratios (FCR) were unaffected ( P > 0.05) by diet. At the conclusion of the study, Atlantic salmon fed the FMF and FM diets were 1.716 ± 0.076 and 1.720 ± 0.065 kg; cumulative survival was >99% for both; and average FCR was 0.89 ± 0.03 and 0.90 ± 0.02, respectively. The FMF diet resulted in greater total phosphorous (TP), carbonaceous biochemical oxygen (cBOD), and total suspended solids (TSS) mass per kg feed in the effluent ( P < 0.05). The FMF and FM diets produced 0.009 ± 0.001 v. 0.006 ± 0.001 kg TP/kg feed; 0.079 ± 0.005 v. 0.056 ± 0.005 kg cBOD/kg feed; and 0.297 ± 0.028 v. 0.221 ± 0.032 kg TSS/kg feed, respectively. A significantly higher percentage of TSS was captured by radial flow settlers of RAS receiving the FMF diet compared to capture by settlers associated with the FM diet. Mass balance data, radial settler removal efficiency, and observations of flushed solids suggested that the FMF diet produced fecal matter with better settling characteristics. Lower TSS and true color values ( P < 0.05), indicative of clearer water, were measured in RAS receiving the FMF diet. Total phosphorous (most of which was dissolved) was 4 times greater in the culture water of RAS that received the FMF diet, e.g., 4.3 ± 0.1 mg/L v. 0.9 ± 0.0 mg/L for the FM Diet. This was the first research attempt to formulate a fishmeal-free diet for Atlantic salmon with this ingredient profile and one of few studies to demonstrate uncompromised Atlantic salmon performance when feeding a diet without fishmeal. [ABSTRACT FROM AUTHOR]

The aim of the present research was to investigate the potential use of the phototrophic microalgae Phaeodactylum tricornutum ( P. tricornutum ) as a fish meal replacement in diet for Atlantic salmon, Salmo salar . Two experiments were designed with fish meal based control diets and dried whole cells P.tricornutum replacing fishmeal in the ratios 3%, 6% and 12% (experiment one) and 3 and 6% (experiment two). Experiment one was a digestibility study lasting for 21 days, investigating effects of inclining level of P. tricornutum on apparent digestibility (ADC) of nutrients and energy. Experiment two was investigating ADC's of nutrients and energy, growth performance and nutrient retention in salmon fed for 82 days. The results from experiment one showed a linear reduction in ADC of dry matter (DM; P = 0.02), lipid ( P < 0.0001), and protein ( P = 0.04) with increasing level of algae biomass in the diet. The ADC of starch increased ( P < 0.05) with algae inclusion level in both experiments. For experiment two, no effects were observed on digestibility of DM, lipid, protein, energy or ash, with 3 and 6% algae replacing fish meal. Neither was growth or feed conversion affected by 3 and 6% algae replacing fish meal. Increasing inclusion level of algae biomass caused an increase in whole body lipid. The ADC of saturated fatty acids was higher in fish fed 3% alga biomass compared to the 6% group. There was no difference in ADC or retention of n -3 fatty acids. In conclusion, the two experiments showed that P. tricornutum can replace up to 6% of the fish meal without adverse effects on nutrient digestibility, utilization of the feed and growth performance. Statement of relevance Microalgae are potential omega-3-contributing feed ingredients [ABSTRACT FROM AUTHOR]

An experiment was conducted to evaluate the effect of two salmon protein hydrolysates on growth performance and intestinal morphometry in broiler chickens. Two different Atlantic salmon protein hydrolysates (SPH) from viscera were produced, one without the addition of exogenous enzymes and the other with added papain+bromelain during hydrolysis. The hydrolysates were included at 5% and 10% in both the starter and grower diets for broiler chickens. Additionally, one fish meal diet (FM) and a plant protein-based (PP) diet were included as controls in each period. Immediately after hatching, 5282 Ross308 broiler chickens were allotted to 66 pens and fed the starter diet from days 0–9 and the grower diet from days 10–28. Growth performance data were recorded for the starter period, early grower period (days 10–20) and late grower period (days 21–28), and duodenum, jejunum and ileum were sampled at day 10 for morphometric analysis. Inclusion of 10% SPH in the diet increased average daily gain (ADG) ( P <0.05) compared with the broiler chickens fed the PP, FM and 5% SPH diets. Using contrast statistical analysis, the gain to feed ratio (G:F) was significantly higher in the groups fed the 10% SPH diets compared with the groups fed the PP and FM diets in the starter period. Also, ADG values were higher for the 5% SPH diet groups compared with the groups fed the FM (FM vs. 5% SPH, P <0.001) and PP (PP vs. 5% SPH, P =0.015) diets in the starter period. In the grower period, the impact of SPH inclusion on ADG diminished compared with the FM diet group; however, broiler chickens fed the PP diet did not reach the same final live-weight as broiler chickens fed the marine protein diets. There was a tendency towards longer villi in the duodenum and ileum, as well as larger villi absorption area in the ileum, of broiler chickens fed marine proteins compared with those fed the PP diet. No adverse effect on mortality or litter quality was detected when salmon protein hydrolysates were included in the broiler chicken diet. In conclusion, addition of salmon protein hydrolysates to broiler chicken starter diets improved growth performance compared with the PP and FM diets. Additionally, starter diets with inclusion of marine proteins tended to improve the small intestinal development in broiler chickens compared to a plant protein-based diet. [ABSTRACT FROM AUTHOR]

Four isoproteic/isolipidic plant protein-based diets were formulated to assess the lasting effects of feed additives and low fish meal (FM) and fish oil (FO) diet formulations on gilthead sea bream growth performance. FM was included at 23% in the control diet (D1) and at 3% in the other three diets (D2, D3, D4). Added oil was either FO (D1) or a blend of vegetable oils replacing 58% (D2) and 84% (D3, D4 diets) of FO. A commercial sodium butyrate preparation (NOREL, 70-BP) was added to the D4 diet at 0.4%. Each diet was allocated to triplicate groups of juvenile fish fed to satiety over an 8-month feeding trial (May–December). All fish grew efficiently from 15 g of initial body weight to 296–320 g with an overall feed efficiency (FE) of 0.95–1.01, although fish fed D3 and D4 diets showed transient growth impairments over the course of the first four weeks of the trial. Data on biometric indexes, whole body composition, haematology and blood biochemistry revealed a strong effect of sampling time in fish sampled at mid-summer (August) and late autumn (December). In contrast, the diet effect was mostly reduced to a few blood parameters. Low inclusion levels of FM reduced plasma haemoglobin levels (D2, D3), but these effects were reversed by butyrate supplementation (D4). The same phenomena occurred for total cholesterol with the highest circulating concentration of choline and IGF-I in fish fed the D4 diet during their summer growth spurt. At the transcriptional level, gene expression profiling of liver and skeletal muscle with a PCR-array of 87 growth markers provided additional evidence for an overall well-growth condition in all of the experimental groups. Up to 73 genes were found at detectable levels in the liver tissue, but only 13 were differentially expressed. Likewise, 84 genes were actively transcribed in the skeletal muscle, but only nine were differentially expressed in at least one experimental group. Butyrate supplementation reversed the up-regulated expression of inflammatory cytokines (TNFα) and muscle markers of cellular morphogenesis and protein breakdown (CDH15, CAPN3, PSMA5, PSMB1, UBE2N) in the muscle of fish fed the extreme D3 diet. These results support the use of low FM/FO diets alone or supplemented with feed additives, which have the potential to improve or reverse metabolic steady-states. Statement of relevance Butyrate effect on low fish meal/fish oil diets. [ABSTRACT FROM AUTHOR]

A 12-week experiment was conducted to determine the effect of dietary duckweed (Lemna minor) on growth performance, body composition and fatty acid profiles of juvenile Nile tilapia (Oreochromis niloticus). Five isonitrogenous (30 % crude protein) diets were prepared with the inclusion of dry ground L. minor at 0 %, 5 %, 10 %, 15 % and 20 % of diet dry weight. Each diet was randomly allocated to triplicate tanks stocked with juvenile tilapia that had an initial mean weight of 2.00 ± 0.01 g. The juvenile tilapia were reared in a flow-through system with each diet fed twice a day at a total ratio of 5 % body weight per day. While weight gain and specific growth rate (SGR) were generally higher, and food conversion ratio (FCR) generally lower in fish fed the control diet than fish fed L. minor, there were no significant differences in these performance parameters between tilapia fed L. minor at 15 % inclusion and fish fed the control diet. Survival ranged from 80 % to 96 % and was significantly higher in fish fed the control diet. Dietary L. minor significantly reduced whole-body total lipid contents and increased moisture contents. The dietary inclusion of L. minor significantly increased the proportions of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) in muscle, with eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids increasing by over 10-fold from 0.5 % each of total fatty acids, respectively, in fish fed the control diet to 5 % each in fish fed 20 % L. minor. Since the inclusion of L. minor increased the contents of 18:3n-3, but not EPA and DHA in the diets, this indicates that the increased proportions of EPA and DHA in the muscle of tilapia fed L. minor was due to endogenous biosynthesis of LC-PUFA with the conversion of dietary 18:3n-3 to EPA and DHA. Therefore, the present study indicated that dietary inclusion of 15–20 % L. minor in feeds for Nile tilapia can significantly improve the omega-3 fatty acid profile of muscle for human consumers, with only minor effects on growth and feed utilization. These findings demonstrated the potential for the utilization of L. minor as an ingredient to increase omega-3 LC-PUFA, EPA and DHA, contents of farmed tilapia while reducing the use of fish oil and fish meal in tilapia feeds. • Use of plant-derived protein and oil in fish feeds have increased. • α-linolenic acid (ALA; 18:3n-3) is abundant in certain freshwater aquatic plants. • EPA and DHA were increasing with the graded increase in dietary L. minor. • L. minor meal can improve the nutritional quality of farmed tilapia. [ABSTRACT FROM AUTHOR]

Microalgae exhibit diverse and high nutritional value, and therefore, have a huge potential application as a raw material for the preparation of aquafeeds. This study was conducted to evaluate the effects of low-level replacement of dietary fishmeals by algal meals comprised of Schizochytrium limacinum (SL) and Nannochloropsis salina (NS) individually and in combination in the diet of juvenile largemouth bass (LMB, Micropterus salmoides). Five isonitrogenous, isolipidic, and isoenergetic diets with fishmeal-based diets as control, and four experimental diets with replacement by individual 4% SL (4SL), individual 4% NS (4NS), 2% SL combined with 2% NS (2SL + 2NS) and 4% SL combined with 4% NS (4SL + 4NS) were formulated. Five hundred juvenile fish (average weight 8.72 ± 0.10 g) were evenly distributed to five groups with quadruplicate each, in twenty fiberglass tanks and fed for eight weeks. Our results showed that there were no significant difference in weight gain, special gain rate, hepatosomatic index, viscerasomatic index, conditioning factor, and the whole-body composition among the five groups (p > 0.05). However, feed intake and feed conversion ratio in the 4NS treatment were significantly higher (p < 0.05) compared with the control. Further, lipid content and intraperitoneal fat ratio in the liver of the 4NS and 4NS + 4SL groups were significantly decreased, suggesting that NS may reduce visceral fat accumulation in LMB. The serum superoxide dismutase (SOD) activity of LMB in the 4NS group was significantly increased compared with the control (p < 0.05). However, malondialdehyde (MDA) content in the liver of the 4NS group and intestine of the 4SL + 4NS group was significantly lower than that in the control (p < 0.05). Replacement with 4% SL significantly increased docosahexaenoic acid, polyunsaturated fatty acids (PUFAs), and n-3 PUFA proportions in the liver. Further, SL alone or in combination with NS increased the n-3 to n-6 ratio of PUFAs in the liver and muscle, creating more balanced unsaturated fatty acids. The fillet texture was significantly enhanced by taste and flavor. Nevertheless, the present study verified the successful addition of SL and NS algal meals to fish feed, which exhibited excellent potential to replace fishmeals and fishoil, respectively, as protein and lipid sources. • Effects of fishmeal replacement by algal meals on largemouth bass were evaluated. • Low-level substitution had no negative effect on growth or whole-body composition. • Fishmeal replacement (4%) with Nannochloropsis salina decreased lipid deposition. • Fishmeal replacement (4%) with Schizochytrium limacinum increased docosahexaenoic acid. [ABSTRACT FROM AUTHOR]

The use of insects in animal feed appears to be an efficient approach that contributes to solving the environmental issues related to leftover disposal; however, it has not been approved in some countries due to concerns about pathogenic infections. This study aimed to evaluate the feasibility of long-term substitution of fish meal in poultry feed with organic defatted black soldier fly larvae (BSFL) meal prepared from BSFL raised on leftovers. The 87 Julia laying hens (178-day-old) were allotted in a completely randomized design with three treatments (29 layers in each treatment). The laying hens were fed maize grain and soybean meal-based diet containing either 3% fish meal, 1.5% fish meal and 1.5% BSFL meal, or 3% BSFL meal supplements for 52 wk (541-day-old). Results showed that substituting fish meal with BSFL meal had no effect on the laying rate, feed intake, and feed conversion ratio of laying hens, and only the complete replacement (3% BSFL meal) significantly increased the body weight of laying hens. In terms of egg quality, there was no significant effect on eggshell parameters (weight, thickness, and strength), albumen weight, yolk height, yolk color, and Haugh unit. However, both half (1.5% fish meal and 1.5% BSFL meal) and complete substitution of fish meal increased yolk weight (P < 0.01) and egg weight (P < 0.05). In conclusion, even if BSFL were fed leftovers and the meal was defatted with organic solvents, it can be used as a poultry feed ingredient without any adverse effect. Moreover, the complete substitution of fish meal with BSFL meal may be a feasible way to effectively contribute to the laying hens' performances and poultry farming costs. In addition to fish meal, the replacement of soybean meal with BSFL meal may also needs to be further studied for the extensive BSFL meal application in poultry feed. [ABSTRACT FROM AUTHOR]

The addition of n-3 polyunsaturated fatty acids (PUFA) to the diet of ruminants can benefit the reproductive process in the female. The current study was conducted to assess the effect of a short period of feeding a diet that included fish meal and oil on the progesterone (P 4 ) and insulin (INS) profile, and on reproductive variables including estrous onset, pregnancy and prolificacy in virgin ewes artificially inseminated by laparoscopy (AIL). Forty-two Dorset ewes were assigned into two experimental groups: These groups were no supplementation (CON; n =21) and a group supplemented with fish meal and oil (4 and 0.8%; FMO; n =21). Ewes were fed the experimental diets for 15 days, beginning four days before inserting sponges for estrus synchronization and ending the day the vaginal sponges were removed. Each ewe received 0.8 kg d −1 feed in individual pens. Ewes were pre-synchronized with prostaglandin F 2α and later synchronized with chronolone sponges for 11 days. When sponges were removed, the ewes received 200 IU of eCG. The AIL began 48 h after sponge removal and estrus detection. The time of estrus onset was different among groups ( P <0.05; CON: 35.1±2.1; FMO: 41.0±1.8 h). No differences were found in P 4 (FMO: 3.8±1.2; CON: 3.5±1.4 ng mL −1 ) or INS concentrations in serum (FMO: 0.12±0.02; CON: 0.13±0.03 ng mL −1 ). Adding fish meal and oil to the diet did not affect pregnancy percentage (FMO: 52%; CON: 55%), but it did affect the prolificacy index (FMO: 1.63; CON: 1.25) ( P <0.05). It was concluded that the addition of fish meal and oil to the diet of virgin ewes over a short period time delayed onset of estrus and enhanced prolificacy. [ABSTRACT FROM AUTHOR]

A 60–70% increase in consumption of animal products is expected by 2050. This increase in the consumption will demand enormous resources, the feed being the most challenging because of the limited availability of natural resources, ongoing climatic changes and food–feed–fuel competition. The costs of conventional feed resources such as soymeal and fishmeal are very high and moreover their availability in the future will be limited. Insect rearing could be a part of the solutions. Although some studies have been conducted on evaluation of insects, insect larvae or insect meals as an ingredient in the diets of some animal species, this field is in infancy. Here we collate, synthesize and discuss the available information on five major insect species studied with respect to evaluation of their products as animal feed. The nutritional quality of black soldier fly larvae, the house fly maggots, mealworm, locusts–grasshoppers–crickets, and silkworm meal and their use as a replacement of soymeal and fishmeal in the diets of poultry, pigs, fish species and ruminants are discussed. The crude protein contents of these alternate resources are high: 42–63% and so are the lipid contents (up to 36% oil), which could possibly be extracted and used for various applications including biodiesel production. Unsaturated fatty acid concentrations are high in housefly maggot meal, mealworm and house cricket (60–70%), while their concentrations in black soldier fly larvae are lowest (19–37%). The studies have confirmed that palatability of these alternate feeds to animals is good and they can replace 25–100% of soymeal or fishmeal depending on the animal species. Except silkworm meal other insect meals are deficient in methionine and lysine and their supplementation in the diet can enhance both the performance of the animals and the soymeal and fishmeal replacement rates. Most insect meals are deficient in Ca and its supplementation in the diet is also required, especially for growing animals and laying hens. The levels of Ca and fatty acids in insect meals can be enhanced by manipulation of the substrate on which insects are reared. The paper also presents future areas of research. The information synthesized is expected to open new avenues for a large scale use of insect products as animal feed. [ABSTRACT FROM AUTHOR]

Ascorbic acid (Vitamin C - VC) is one of the essential micronutrients required for normal growth and physiology of fish. In this research, the optimum dietary VC requirement of juvenile hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) was evaluated in a comparative feeding trial and subsequent oxidative stress test. Six isoenergetic (340 kcal/kg), isoproteic (49%) and isolipidic (7%) experimental diets were supplemented with graded amounts of L-ascorbyl-2-polyphosphate (analyzed VC concentrations of 76, 86, 104, 126, 137 and 152 mg/kg dry matter) and hand-fed to fish (initial weight of 15 ± 0.1 g/fish (means ± S.D.)) in three replicate cages twice a day (08:00 h and 16:30 h) to apparent satiation for 7 weeks. Percent weight gain (WG%), together with the VC concentrations in liver and head kidney, were elevated with increasing dietary VC contents, reaching a plateau in the VC137 treatment. The optimal dietary VC requirement of hybrid grouper was estimated to be 148 mg/kg dry matter based on broken-line regression analysis of WG%. Serum immunoglobulin M (IgM) concentrations and the relative mRNA expression of hepatic insulin-like growth factor-1 (IGF-1) displayed a similar variation tendency as WG%. At the transcriptional level, the activity of Nrf2-Keap1 pathway was up-regulated by VC supplementations, with the VC104 treatment showing the highest value. In summary, the optimal dietary VC requirement for the highest value of WG% of juvenile hybrid grouper was 148 mg/kg dry matter, and appropriate dietary VC supplementation improved oxidation resistance and serum IgM concentrations of the fish. • VC affects growth and expression of hepatic IGF-1 of hybrid grouper. • At the transcriptional level, the activity of Nrf2-Keap1 pathway was up-regulated by VC supplementations. • Optimal VC requirement of hybrid grouper fed low fishmeal diets was 148 mg/kg. [ABSTRACT FROM AUTHOR]

To evaluate the effects of feeding frequency (FF) and dietary protein/carbohydrate (P/CH) ratios on appetite regulation of gilthead seabream, two practical diets were formulated to include high protein and low carbohydrate (P50/CH10 diet) or low protein and high carbohydrate (P40/CH20 diet) content and each diet was fed to triplicate groups of fish until visual satiation each meal at a FF of 1, 2, or 3 meals per day. Feed intake and feed conversion ratio were higher in fish fed 2 or 3 meals than 1 meal per day and in fish fed the P40/CH20 than the P50/CH10 diet. The specific growth rate was only affected by FF, being higher in fish fed 2 or 3 meals per day than 1 meal per day. Expression of the cocaine-amphetamine-related transcript, corticotropin-releasing hormone , ghrelin receptor-a (ghsr-a), leptin , and neuropeptide y in the brain, cholecystokinin (cck) in the intestine, and leptin and ghrelin in the stomach was not affected by FF or dietary P/CH ratio. This is the first time that ghrelin cells were immune-located in the stomach of gilthead seabream. Fish fed 3 meals per day presented lower cck expression in the brain than those fed twice per day and higher hepatic ghsr-b expression than those fed once per day. Fish fed P40/CH20 diet presented higher hepatic leptin expression than those fed P50/CH10 diet. In conclusion, present results indicate that feeding a P40/CH20 diet at 3 meals a day seems to decrease the satiation feeling of gilthead seabream compared to fish fed higher P/CH ratio diets or fed 1 or 2 meals a day. [Display omitted] • No major interactions on appetite control were reported between feed frequency and dietary protein to carbohydrate ratios. • Fish fed 3 times per day and a P40/CH20 diet presented a lower satiation feeling. • Stomach immunopositive ghrelin cells were not affected by feeding frequency or protein/carbohydrate ratio. [ABSTRACT FROM AUTHOR]

Abstract: Lipid content and composition in aquafeeds have changed rapidly as a result of the recent drive to replace ecologically limited marine ingredients, fishmeal and fish oil (FO). Terrestrial plant products are the most economic and sustainable alternative; however, plant meals and oils are devoid of physiologically important cholesterol and long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic (ARA) acids. Although replacement of dietary FO with vegetable oil (VO) has little effect on growth in Atlantic salmon (Salmo salar), several studies have shown major effects on the activity and expression of genes involved in lipid homeostasis. In vertebrates, sterols and LC-PUFA play crucial roles in lipid metabolism by direct interaction with lipid-sensing transcription factors (TFs) and consequent regulation of target genes. The primary aim of the present study was to elucidate the role of key TFs in the transcriptional regulation of lipid metabolism in fish by transfection and overexpression of TFs. The results show that the expression of genes of LC-PUFA biosynthesis (elovl and fads2) and cholesterol metabolism (abca1) are regulated by Lxr and Srebp TFs in salmon, indicating highly conserved regulatory mechanism across vertebrates. In addition, srebp1 and srebp2 mRNA respond to replacement of dietary FO with VO. Thus, Atlantic salmon adjust lipid metabolism in response to dietary lipid composition through the transcriptional regulation of gene expression. It may be possible to further increase efficient and effective use of sustainable alternatives to marine products in aquaculture by considering these important molecular interactions when formulating diets. [Copyright &y& Elsevier]

Abstract: Polycyclic aromatic hydrocarbons (PAHs) contaminations in Ghanaian smoke-cured fish are known to be in high levels. This may be linked to the recent upsurge of cancer cases among the population because PAHs are well-known carcinogens. A modified traditional kiln fitted with charcoal filters to remove PAHs by adsorption from the smoke before it contacted the fish being smoke-cured was designed. Smoke-curing was done for 4 h with three most used smoke wood types- in Ghana namely acacia, sugarcane bagasse and mangroves. The smoking was done with no charcoal filter and compared to smoking with two types of activated charcoals fitted to the designed traditionally modified kiln. PAHs in smoke-cured fish samples (n = 108) using the designed system were analysed using Varian GC/MS (3800-GC) system. The mean total PAHs levels in the experimental smoked fish samples analysed ranged from 212.56 to 472.98 μg/kg in samples smoke cured with – activated charcoal filters. The mean percent reductions (efficiency of Kiln) were 21–69%. The mean Benzo[a]pyrene levels in all fish cured using the modified traditional kiln with charcoal filters in place were below the Turkish Codex's maximum limit of 2.0 μg/kg. An ANOVA analysis conducted at 95% CL showed statistically significant differences (P < 0.05) in PAH levels between smoking with no charcoal filters and those with charcoal as filters. No statistical significant differences (P > 0.05) were obtained between the two smoking processes with charcoal filters. Fish obtained from the modified traditional kiln were of good organoleptic quality (moisture content < 65% as recommended) and the use of charcoal filters in fish smoking should be encouraged. [Copyright &y& Elsevier]

Abstract: A constraint for the expansion of cobia aquaculture is the availability of high quality formulated diets which reduce or eliminate fish meal (FM) protein. Therefore, the nutritive value of a novel soybean cultivar, Navita™ (Navita, non-genetically modified and selectively bred soy), and regular, commodity soybean meal (SBM, de-hulled, defatted, roasted and solvent-extracted) was evaluated for cobia, Rachycentron canadum via separate digestibility and growth trials. In the first experiment Navita's apparent digestibility coefficients (ADC) were higher than those of SBM for nearly every nutrient evaluated. Crude protein ADCs were 82 and 69% for Navita and SBM, respectively. Apparent DC for amino acids ranged from 68 to 109% for Navita whereas, amino acid ADCs for SBM varied from 42 to 98%. The feeding trial utilized fish of a size that more closely resembles commercial cobia stocking (1.8kg), and was conducted over a 91-day period. Experimental diets (iso-nitrogenous and iso-energetic) were formulated such that 67% of the FM protein in the reference diet was replaced by either a combination of SBM+soy protein concentrate (SPC, Solae Profine®) labeled MXSB-diet, or by a combination of SPC+Navita; Navita-diet, hereafter. A fourth experimental diet had 80% of the FM protein replaced by a combination of Navita+SPC and was identified as Navita-high. No significant differences (P >0.05) were observed in fish fed the experimental diets for feed conversion ratio, protein efficiency ratio, feed efficiency, mean daily intake, gross protein intake, gross energy intake, visceral somatic index, muscle ratio, and hepatosomatic index. Fish fed the Navita-high diet had the lowest fish in:fish out ratio (FIFO) at 0.9±0.16. These results indicate that Navita meal can be incorporated at very high levels in the diet of marine carnivorous fish such as cobia with no detriment to performance, making it a prime candidate for FM replacement in aquafeeds. [Copyright &y& Elsevier]

Abstract: Plant protein sources have been identified to have the greatest potential to replace fish meal protein in aquafeeds. However, plant ingredients contain significant quantities of carbohydrates, and the ability of fish to utilize dietary carbohydrates as energy sources for growth is limited. Included in the carbohydrate group, cellulose is not tolerated by most fish. In the present study, the grass carp, a typical herbivorous fish, fed with duckweed was selected to study the effect of exogenous cellulase on the growth. The results of 2-month feeding experiment showed that the cellulase promoted the growth of grass carp. In addition, the cellulase increased various digestive enzyme activities, such as cellulase, amylase and protease but not the lipase activity. Meanwhile, the polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) analysis indicated that the intestinal microbiota of fish fed with the supplemental cellulase changed in bacteria species and density. Band patterns derived from control and cellulase samples showed a low degree of similarity when analyzed by cluster analysis. Some bands were unique to control samples, whereas other bands were obtained only with samples of the cellulase group. The 16S rRNA gene sequencing identified that Proteobacteria and Firmicutes were the two dominant groups, and the emergence of certain bacterial strains including Bacilli and Sphingomonas may contribute to the digestion of cellulose. The former researches and this paper results suggest that the endogenous cellulase is far from sufficient to fully digest the ingested fiber, so cellulase should be developed as a kind of aquatic additive. [Copyright &y& Elsevier]

Atlantic salmon fed low fish meal feeds supplemented with zinc (Zn) were studied in two feeding trials. In trial I, Atlantic salmon parr were fed six graded Zn levels (40 to 249 mg kg−1 as ZnSO 4) for 8 weeks in freshwater followed by a 4-week seawater phase. In trial II, Atlantic salmon post-smolt were fed for 10 weeks in SW with 10 dietary Zn levels (45 to 280 mg kg−1), either as ZnSO 4 or Zn-glycinate. Growth was unaffected by dietary Zn in both trials. Dietary Zn affected concentration of Na + and K+ ions in plasma, branchial and intestinal expression of sodium potassium ATPase, tissue and body Zn status, and cataracts. Seawater transfer significantly reduced apparent availability, body and tissue levels of Zn due to increased endogenous Zn loss. Atlantic salmon post-smolt in seawater improved body and tissue Zn status with increasing dietary Zn levels, irrespective of the Zn source. Body or tissue saturation of Zn occurred at dietary Zn levels between 137 and 156 mg kg−1 with smolts in freshwater and 181 to 218 mg kg−1 in SW post-smolts. Dietary Zn levels below 180 mg kg−1 in low fish meal feeds compromised the Zn status and welfare of Atlantic salmon in seawater. • Impact of dietary Zn and seawater transfer was studied in Atlantic salmon. • Atlantic salmon in seawater have lower Zn availability and increased endogenous Zn loss than in freshwater. • Dietary Zn affects osmoregulatory responses in Atlantic salmon smolt. • Zinc sulfate and zinc chelate of glycine have similar availability to Atlantic salmon in seawater. • Reduction in maximum dietary Zn levels to 150 ppm in salmon feeds will affect the health and welfare in seawater. [ABSTRACT FROM AUTHOR]

Balantidium ctenopharyngodoni Chen, 1955 is an intestinal ciliate identified from the hindgut of grass carp (Ctenopharyngodon idella). Although it was described quite a long time ago, its epidemiologic features and growth characteristics remain poorly understood. In the present study, the investigation of B. ctenopharyngodoni presence was conducted in different age groups of grass carp, and we also developed a self-made medium (BCM medium) to cultivate B. ctenopharyngodoni in vitro. In the grass carp fed on plant-based diets, balantidia were not identified before the age-1, whereas they were identified in fish above the age-1. In the fishes fed on the granular fish meal we did not identify any balantidia regardless of the age of the fish (age-1+ or age-2). BCM medium was effective for in vitro cultivation of B. ctenopharyngodoni , and polysaccharides were an essential nutrient for its growth. We also proposed potential infection mechanisms of B. ctenopharyngodoni in the grass carp above two summers of age. • The prevalence and intensity of Balantidium ctenopharyngodoni in grass carp (juvenile to adult) were investigated. • B. ctenopharyngodoni can be cultivated in the BCM medium, which mainly contains starch, serum and intestinal bacteria. • The potential infection mechanisms of B. ctenopharyngodoni were proposed. [ABSTRACT FROM AUTHOR]

Largemouth bass is a carnivorous fish commercially important for freshwater aquaculture worldwide, however, the optimal feeding regime for the fish reared in pond has not been established. The present study examined feed intake, growth, feed utilization, body composition and waste outputs of largemouth bass fed at different feeding frequencies in pond and in-pond-raceway (IPR). Two 10-week feeding trials (I and II) were conducted simultaneously. Fish were fed at 1, 2, 3 or 4 meal d−1 in pond (trial I), and were fed at 2 or 3 meal d−1 in either pond or IPR (trial II). The initial body weight was 43.0 ± 0.2 g fish−1. In trial I, weight gain increased with increasing feeding frequency from 1 to 3 meal d−1, but no significant difference was found in weight gain between fish fed at 2, 3 and 4 meal d−1. The lowest retention efficiencies of nitrogen (NRE) and phosphorus (PRE) and the highest feed intake and phosphorus waste occurred in fish fed at 4 meal d−1. In trial II, no significant difference was found in weight gain between fish fed at 2 and 3 meal d−1 in IPR, while NRE, PRE and energy retention efficiency (ERE) were lower in fish fed at 3 meal·d−1 than in fish fed at 2 meal d−1. Weight gain, NRE, PRE and ERE were lower, while feed intake, body lipid content, wastes of nitrogen, phosphorus and carbon were higher, in fish reared in IPR than in fish fed at the same feeding frequency in pond. The present study indicates the optimal feeding frequency was 3 meal d−1 for largemouth bass reared in pond, and 2 meal d−1 for the fish reared in IPR. According to production performance, the IPR should not be an appropriate grow-out system for commercial largemouth bass farming. • The optimal feeding frequencies for largemouth bass reared in pond and IPR were determined. • Growth, feed utilization efficiency and waste outputs of the fish reared in pond and IPR were evaluated. • IPR should not be an appropriate system for commercial largemouth bass farming. [ABSTRACT FROM AUTHOR]

Abstract: The nutritional contribution of the dietary nitrogen, carbon and total dry matter supplied by fish meal (FM), soy protein isolate (SP) and corn gluten (CG) to the growth of Pacific white shrimp Litopenaeus vannamei was assessed by means of isotopic analyses. As SP and CG are ingredients derived from plants having different photosynthetic pathways which imprint specific carbon isotope values to plant tissues, their isotopic values were contrasting. FM is isotopically different to these plant meals with regards to both, carbon and nitrogen. Such natural isotopic differences were used to design experimental diets having contrasting isotopic signatures. Seven isoproteic (36% crude protein), isoenergetic (4.7kcal g−1) diets were formulated; three diets consisted in isotopic controls manufactured with only one main ingredient supplying dietary nitrogen and carbon: 100% FM (diet 100F), 100% SP (diet 100S) and 100% CG (diet 100G). Four more diets were formulated with varying mixtures of these three ingredients, one included 33% of each ingredient on a dietary nitrogen basis (diet 33FSG) and the other three included a proportion 50:25:25 for each of the three ingredients (diets 50FSG, 50SGF and 50GFS). At the end of the bioassay there were no significant differences in growth rate in shrimps fed on the four mixed diets and diet 100F (k =0.215–0.224). Growth rates were significantly lower (k =0.163–0.201) in shrimps grown on diets containing only plant meals. Carbon and nitrogen stable isotope values (δ13C and δ15N) were measured in experimental diets and shrimp muscle tissue and results were incorporated into a three-source, two-isotope mixing model. The relative contributions of dietary nitrogen, carbon and total dry matter from FM, SP and CG to growth were statistically similar to the proportions established in most of the diets after correcting for the apparent digestibility coefficients of the ingredients. Dietary nitrogen available in diet 33FSG was incorporated in muscle tissue at proportions representing 24, 35 and 41% of the respective ingredients. Diet 50GSF contributed significantly higher amounts of dietary nitrogen from CG than from FM. When the level of dietary nitrogen derived from FM was increased in diet 50FSG, nutrient contributions were more comparable to the available dietary proportions as there was an incorporation of 44, 29 and 27% from FM, SP and CG, respectively. Nutritional contributions from SP were very consistent to the dietary proportions established in the experimental diets. [Copyright &y& Elsevier]

Abstract: The role of dietary protein source on growth performance and lipid metabolism in European sea bass (Dicentrarchus labrax) was investigated, by the evaluation of fat content in different tissues, plasma metabolites, liver lipogenic activity and fatty acid composition of dorsal muscle tissue. Five isonitrogenous (490gkg−1 crude protein dry-matter basis) and isolipidic (170gkg−1 lipid dry-matter basis) diets with graded levels of wheat gluten, soybean and pea meal in substitution of fish meal were evaluated in European sea bass (initial body weight 23.9±0.1) for 96days. There was a significant difference (p<0.05) in dorsal muscle and liver lipid contents. Plasma glucose and cholesterol levels decreased significantly (p<0.05) as diet included soybean and wheat gluten meal (p<0.05). The composition of fatty acids in muscle triacylglycerols and phospholipids was affected by vegetable sources as n−6 PUFA percentage was significantly increased and n−3 PUFA percentage was significantly decreased (p<0.05), without modifying EPA/DHA ratio, when wheat gluten and pea meal were included in the diet. The results confirm that the quality and quantity of vegetable protein source could affect lipid metabolism and lipid content in the dorsal muscle of the European sea bass and suggest the possibility of manipulation of the diet for commercial purpose. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to identify physicochemical properties of fishmeal (FM) with impact on specific mechanical energy, starch gelatinization, pellet durability and pellet hardness. The effects of variation in 18 physicochemical properties were assessed based on standardized extrusion, drying and coating conditions. Multivariate models (R 2 =0.907–0.970) were established based on partial least squares regression. Increased level of specific mechanical energy was associated with decreased water-holding capacity (P=0.008), decreased cumulative mean particle size (P=0.020), increased value of flow-figure (P<0.001), increased degree of protein hydrolysis (P<0.001) and increased level of the water soluble protein fraction with molecular weight less than 0.2kDa (P=0.022). Improved degree of starch gelatinization was associated with decreased water-holding capacity (P<0.001) and increased degree of protein hydrolysis (P<0.001). The variation in FM physicochemical properties resulted in a large span in pellet hardness (4.9–133.4N) covering the range from poor to high physical quality. Improved hardness was associated with decreased water-holding capacity (P=0.069), decreased pH (P=0.001), decreased level of non-soluble protein (P<0.001), increased level of salt (P=0.002), and increased level of the water soluble protein fractions with molecular weight 5–6kDa (P<0.001), 20–35kDa (P<0.001) and above 60kDa (P=0.006). The underlying physical and chemical mechanisms are discussed. The study documents the complexity of FM as a protein ingredient with significant impact on the extrusion process, starch gelatinization and physical pellet quality. The FM specifications normally used on the world commodity market inadequately describe the technical quality of a FM. [Copyright &y& Elsevier]

Abstract: Salmon protein hydrolysate (SPH) is made from fresh by-products from farmed salmon that are minced and acidified to hydrolyse proteins into peptides and free amino acids. The objective of this study was to evaluate SPH in young pigs compared to soy protein concentrate (SPC), fish meal (FM) and combinations hereof. Five diets were composed, all fulfilling the nutrient recommendations for young pigs. All diets contained 172gsoybeanmeal/kg. One diet was supplemented with 123gSPH/kg, and equivalent protein was supplied as SPC or FM in two other diets. Two diets were composed by combining half the amount of SPH and SPC or half the amount of SPH and FM. One week after weaning, one hundred individually housed pigs were allocated to one of five diets (n =20) and fed ad libitum for four weeks. Pigs fed the SPH and SPH+FM diets ate 12–14% more (P<0.05) than pigs fed the SPC diet, but the results on gain and feed utilization was not significantly different among treatments. No differences were observed in faeces characteristics when scored by visual judgment during two 5-d periods. In conclusion, pigs responded equally to diets containing SPH and FM, and SPH resulted in greater feed intake than SPC. [Copyright &y& Elsevier]

The objective of this study was to determine amino acid digestibility of 4 feedstuffs [soybean meal (SBM), canola meal, fish meal, and meat and bone meal (MBM)] using the precision-fed cecectomized rooster assay (PFR), the standardized ileal assay (SIAAD), and a newly developed precision-fed ileal broiler assay (PFC). For the PFR, cecectomized roosters were precision-fed approximately 30 g of feed sample, and excreta were collected 48 h postfeeding. For the SIAAD, 16-d-old broilers were fed a semipurified diet containing the feed samples as the oniy source of protein from 17 to 21 d, with ileal digesta collected at 21 d. For the PFC, 22-d-old broilers were precision-fed 10 g of feed sample mixed with chromic oxide, and ileal digesta were collected at 4 h postfeeding. Digestibility coefficients were standardized using a nitrogen-free diet for the SIAAD and PFC and using fasted roosters for the PFR. There were generally no consistent differences in standardized amino acid digestibility values among assays, and values were in general agreement among assays, particularly for SBM and MBM. Differences did occur among methods for amino acid digestibility in fish meal; however, these differences were not consistent among methods or amino acids. The results of the study indicated that all 3 bioassays are acceptable for determining the amino acid digestibility of SBM, canola meal, MBM, and fish meal for poultry. [ABSTRACT FROM AUTHOR]

Abstract: The development of cost-effective and growth-promoting diets for Florida pompano (Trachinotus carolinus L.) is necessary for a feasible pompano aquaculture industry in the United States. However, research efforts to reduce the utilization of marine ingredients in aquatic feeds are needed to accomplish such a goal. Three independent growth trials were conducted to evaluate the replacement of fishmeal in the diet of Florida pompano. The basal diets were formulated to contain 40% crude protein and 10% lipid using solvent extracted soybean meal and corn gluten as the primary and fixed protein sources. In Trial I (10weeks) the basal diet containing 15% fishmeal (FM15) was modified by the isonitrogenous replacement of fishmeal with poultry by-product meal resulting in diets containing 10% (FM10), 5% (FM5) and 0% (FM0) fishmeal. In Trial II (12weeks), the FM0 diet was supplemented with methionine (M), lysine (L), and taurine (T), serving as the basal diet (MLT) for the evaluation of potential limitations in these amino acids. By deleting individual amino acids, test diets without methionine (LT), lysine (MT) or taurine (ML) supplements were formulated. In Trial III (8weeks), the FM0 diet from Trial I served as the basal diet (0% Tau) for the evaluation of potential limitations in taurine. Fish in replicate tanks (n=3) were fed one of the randomly assigned test diets two times daily. The total replacement of fishmeal in Trial I resulted in depression of fish performance while the performance of fish offered test diets with 5–15% fishmeal did not differ significantly. Reductions in weight gain (from 338.1 to 260.4%), feed efficiency (from 0.53 to 0.40), protein and energy retention (from 19.6 to 12.4% and from 20.4 to14.2%, respectively) were observed in fish fed the FM15 and FM0 diets, respectively (P<0.05). In Trial II, growth performance of pompano did not change (P>0.05) by the removal of supplemental methionine, lysine or taurine from the FM0 diet albeit, numerically the removal of taurine produced the smallest fish. In Trial III, the supplementation of taurine to the FM0 diet at 0.75g/100 (0.75% Tau) improved the weight gain (from 587.7 to 773.3%), feed efficiency (from 0.50 to 0.64), and protein retention (from 20.5 to 24.3%) of pompano (P<0.05). Based on these results, we concluded that poultry by-product meal is a good alternative ingredient for fishmeal in the diet of Florida pompano and that this species appears to have a minimum dietary requirement for taurine. [Copyright &y& Elsevier]

Abstract: The intention of this study is to investigate the effect of fish meal soluble protein quality on growth and protein utilisation of Atlantic salmon fed very low fish meal diets. For this purpose stickwater (SW) was separated during herring meal production, fractionated following successive micro- ultra- and nano-filtration steps and reintroduced in the press cake (PC) in order to produce 4 reconstituted fish meals containing different molecular size soluble protein mixes. The SW fractions used for the production of the experimental fish meals were: 1) the micro-filtration (MF) retentate, 2) the ultra-filtration (UF) retentate, 3) the nano-filtration (NF) retentate and 4) the nano-filtration permeate. Four very low fish meal experimental diets were prepared containing 25gkg−1 super prime fish meal and 50gkg−1 diet of one of the 4 experimental fish meals produced. A positive control diet was prepared containing 300gkg−1 diet super prime fish meal. Three more diets were prepared containing 25gkg−1 diet super prime fish meal and 50gkg−1 diet PC. Two of them were supplemented with either crystalline taurine, or crystalline hydroxyproline, up to the levels present in the high fish meal control diet. The experimental diets with the SW fractions contained similar levels of water soluble protein (WSP), which were higher than in the PC diets and lower than in the control. All diets were iso-nitrogenous, iso-lipidic and iso-energetic and were fed to 8 triplicate groups of salmon (80 fish per group of initial body weight 133g), for 69days. High growth rates and low fish in-fish out ratios (FIFO) were achieved in salmon fed all the very low fish meal diets. Feed intake, fish body growth, whole body protein content, protein gain and morphometry were significantly affected by the inclusion of the different SW fractions in the low fish meal diets. The medium size peptides (UF retentate) induced significant increase in feed consumption in salmon and supported higher fish growth compared to the highest (MF retentate) or the lowest molecular weight peptides (NF permeate) where both feed intake and fish growth were reduced. The fish fed the diet containing the NF permeate had significantly lower growth compared to the diets containing the other SW fractions. We did not find any benefits for salmon performance by the supplementation of taurine or hydroxyproline alone to the low WSP PC diets. The present work gives evidence on the multi-dimensional effects of the different marine water soluble components on fish performance. In order to identify novel, high added-value, water soluble marine compounds, advanced large scale separation technologies must be further developed and applied in studies investigating specific functional effects that these compounds may have on fish and other organisms. [Copyright &y& Elsevier]

Abstract: The use of carob seed germ meal (CG) as a substitute for fish meal was evaluated in fingerlings (average weight 10g) of gilthead sea bream fed isonitrogenous (46% Crude Protein, CP) and isolipidic (19.5% Crude Lipid, CL) diets containing four CG levels (0, 17, 34 and 52%). The duration of the trial was 83days. The diets were tested in triplicate, and the fish were fed to satiation twice daily. The apparent protein and energy digestibility coefficients decreased in response to the dietary inclusion of CG. The decreases in the values of the ADC ranged from 93% for the 0 diet to 80% for the 52 diet. The amount of digestible Arg in the diets increased with the inclusion of CG, from 3.2g Arg 100g−1 in the 0 diet to 4.81g Arg 100g−1 in the 52 diet. The digestible Arg content increased in the diets because the amounts of the remaining digestible amino acids decreased. The fish reached weights of 72, 72, 69 and 53g on the 0, 17, 34 and 52 diets, respectively. The 52 diet gave the lowest specific growth rate (SGR, 1.95%day−1) relative to those found for the other three diets (2.32%day−1). The 52 diet produced the least satisfactory results for feed intake (FI) and the food conversion ratio (FCR) (2.23g 100gfish−1 day−1 and 1.38, respectively). The efficiency of retention of His, Phe and Leu in the fish fed the 52 diet showed the lowest values (17.3, 25.5 and 28.5%, respectively), but the efficiency of retention of Met in the fish fed the 52 diet showed the highest value (48.2%). In the distal intestine and liver, histological alterations were found in the fish fed the 34 and the 52 diets. In fish fed the 52 diet, the mucosal fold was significantly shorter and thinner and exhibited a smaller number of goblet cells. These changes could affect nutrient uptake by modifying the digestibility of the diet. The histology of the liver did not show severe degradation in any treatment. The results of the present experiment demonstrated that CG can be included at levels up to 34% in diets for short term feeding of gilthead sea bream without any adverse effects on fish growth and nutritive parameters. [Copyright &y& Elsevier]

Abstract: Yellowtail (Seriola quinqueradiata) is the most important cultured marine fish in Japan. Dietary fish meal for yellowtail in aquaculture was replaced with 0.0%, 15.4% and 100.0% Antarctic krill meal (KM0, KM15, and KM100) and with 0.0%, 15.4%, and 100.0% low-fluoride krill meal (LFK0, LFK15 and LFK100). The fish was fed to duplicate fish groups for 92d (KM trial) or 75d (LFK trial), and fish growth was monitored. Dietary fluoride (F−) concentrations (mgkg−1) were 110, 160, and 580 (KM0, KM15, and KM100, respectively) and 98, 120, and 190 (LFK0, LFK15, and LFK100, respectively). The growth during the experimental period, weight gain, feed intake, specific growth rate, and feed efficiency in fish fed the KM100 diet were markedly lower than the other experimental groups, which showed no marked differences in growth performance. After the experiment, dorsal muscle fluoride concentrations in each group were below the detectable limit (1mgkg−1), but vertebral bone fluoride concentrations increased with increasing proportion of KM to 655 (KM0), 870 (KM15), and 2150 (KM100) mgkg−1. With increasing LFK in the feed, vertebral bone fluoride concentrations (mgkg−1) increased slightly from 500 (LFK0) to 655 (LFK15), and 695 (LFK100). No histopathological changes were detected in the liver tissue in any experimental group. It has been reported that the fluoride bioavailability was reduced with increasing water hardness, however, the dietary fluoride derived from KM exoskeleton accumulates in vertebral bones of marine fish with growth inhibition, as has already been shown for freshwater fish. Vertebral bone fluoride concentrations in two krill-eating Antarctic marine fish in the wild were 33000mgkg−1 (Champsocephalus gunnari) and 15000mgkg−1 (Notothenia rossii), but they did not show any adverse effect of growth. Therefore, fish bone fluoride accumulation apparently depends on fish species rather than the salinity of the habitat. Consequently, krill exoskeleton must be removed during the processing of Antarctic krill if indeed these krill are to be used as fish feed. However, LFK can completely replace dietary fish meal without apparent adverse effects. [Copyright &y& Elsevier]

Abstract: A 2×3 factorial experiment was conducted to evaluate the effect of partial substitution of dietary fish meal with soybean meal and citric acid (CA) supplementation on growth, food utilization, muscle composition and nutrient digestibility of Beluga, Huso huso. Three isonitrogenic and isoenergetic diets, as SBM1 (soybean meal protein (SBP):fishmeal protein (FP)=1:3), SBM2 (SBP:FP=2:3) and SBM3 (SBP:FP=1:1) containing two levels of CA (0 and 30gkg−1) were fed to triplicate groups of fish for 8 weeks. The results revealed that adding CA increased (P<0.05) the weight gain (WG), specific growth rate (SGR) and protein efficiency ratio (PER) and decreased (P<0.05) food conversion rate (FCR) whereas partial substitution of fishmeal with soybean meal decreased (P<0.05) growth performance. Partial replacement of fishmeal with SBM (P=0.021) as well as CA supplementation (P=0.019) and their interaction (P<0.001) affected hepatosomatic index (HSI). No differences (P>0.05) were observed for viscerosomatic index (VSI) among treatments (P>0.05). No differences (P>0.05) were detected in moisture, protein of muscle sample among treatments, but lipid content was reduced (P<0.05) while ash content increased (P=0.035) by CA. Soybean meal decreased (P<0.05) nutrient digestibility, whereas CA improved apparent protein and phosphorus (P) digestibility (P=0.011 and P<0.001 respectively). No interaction (P<0.05) between levels of SBM and CA was found on these parameters. Results of the present study indicate that Beluga has a limited ability to utilize SBM as a protein source in practical diets whereas CA can improve growth and nutrient utilization in Beluga. [Copyright &y& Elsevier]