Search Results (68)

An alternative fish feed (ALT) replacing 50% of the fishmeal with poultry byproduct meal and insect meal and total fish oil with microalgae, poultry, and salmon byproducts oils was tested for 300 days on 900 gilthead seabream (Sparus aurata) with an initial body weight of 17.1 ± 1.8 g (mean ± SD) of unselected (REF) and selected (HG) genotypes. Using in situ, histochemistry, and immunohistochemistry techniques, we assessed the immune response by characterizing IgT and IgM immunoglobulins, CD3ε⁺ T lymphocytes, and eosinophilic granular cells (EGCs) along the digestive system. IgT mRNA⁺ cells were concentrated in the second part of the digestive tract, while IgM⁺ predominated in the first and occasionally showed intraepithelial localization. CD3ε⁺ and EGCs were most prominent in the midgut. The diet affected IgT and IgM mRNA⁺ cells mainly in the initial part of the digestive tract. For CD3ε⁺, the diet only affected the initial and final parts, while the ALT diet increased EGC abundance across the middle compartments. Genetic selection had minimal effect on IgT⁺ and CD3ε⁺ cells, affecting only the first compartments. The REF group showed higher IgM⁺ cell abundance in specific regions, while EGCs differed between genotypes, favoring anterior accumulation in HG and ileocecal abundance in the REF group. Full article

The use of eco-organic ingredients as a source of protein in aquaculture diets needs important attention due to the growing demand for organic seafood products. The present study evaluated the effects of fish meal substitution by different organic ingredients on the growth, body composition, retention efficiency, enzyme activity, and nutrient digestibility of white shrimp Penaeus vannamei. The four dietary formulations tested were formulated with organic ingredients and the fish meal was replaced by the following organic protein meals: Iberian pig viscera meal (PIG), trout by-product meal (TRO), insect meal (FLY), and organic vegetable meal (WHT), in addition to a control diet (CON) that included 15% fish meal. A growth trial was carried out for 83 days, raising 1 g shrimp to commercial size (20 g). Shrimp were stocked at 167 shrimp/m³ (15 individuals per 90 L tank). The results showed that the growth obtained by shrimp fed with TRO (19.27 g) and PIG (19.35 g) were similar in weight gain to the control diet (20.76 g), while FLY (16.04 g) and WHT (16.73 g) meals resulted in a significant lower final weight. The FLY diet showed significantly lower protein digestibility (68.89%) compared to the CON, PIG, TRO, and WHT diets, and significantly higher trypsin activity (0.17 mU/g) compared to shrimp fed with the PIG, TRO, and WHT diets. Shrimp fed with WHT have a significantly lower body weight percentage of protein (19.69%) than shrimp fed with the WHT and TRO diets, and some significant differences in dietary aminoacidic levels affecting amino acid body composition. These results indicate that Iberian pig viscera and trout by-product meal can successfully replace fish meal in Pacific white shrimp aquaculture. Full article

Restaurants and open markets generate considerable quantities of organic waste. Converting these residues into poultry feed ingredients offers a sustainable disposal route. This study aimed to evaluate the nutritional and sensory viability of a novel feed complement formulated from Bonito fish meal (Sarda chiliensis chiliensis) and Única potato peel flour (Solanum tuberosum L. cv. Única). This study was conducted in three phases: (i) production and nutritional characterization of the two by-product flours; (ii) formulation of a 48:52 (w/w) blend, incorporated into broiler diets at 15%, 30%, and 45% replacement levels over a 7-week trial divided into starter (3 weeks), grower (3 weeks), and finisher (1 week) phases; and (iii) assessment of growth performance (weight gain, final weight, and feed conversion ratio), followed by a sensory evaluation of the resulting meat using a Check-All-That-Apply (CATA) analysis. The Bonito fish meal exhibited 50.78% protein, while the Única potato peel flour was rich in carbohydrates (74.08%). The final body weights of broiler chickens ranged from 1872.1 to 1886.4 g across treatments, and the average feed conversion ratio across all groups was 0.65. Replacing up to 45% of commercial feed with the formulated complement did not significantly affect growth performance (p > 0.05). Sensory analysis revealed that meat from chickens receiving 15% and 45% substitution levels was preferred in terms of aroma and taste, whereas the control group was rated higher in appearance. These findings suggest that the formulated feed complement may represent a viable poultry-feed alternative with potential sensory and economic benefits, supporting future circular-economy strategies. Full article

A two-factorial experiment was conducted to evaluate the potential for improving the palatability and utilization of tuna by-product meal (TBM) as a replacement for fish meal (FM) via supplementing the diet of juvenile greater amberjack (Seriola dumerili) with powdered salmon roe liquid (PSRL). FM protein in the control diet (C) was partially replaced with TBM at levels of 25% (T25R0) and 40% (T40R0). PSRL was then added at 5% and 10% to both the T25R0 and T40R0 diets, resulting in the formulations T25R5, T25R10, T40R5, and T40R10. After a 6-week rearing period, during which groups of 30 juveniles (mean initial weight of approximately 1.7 g) were stocked in 500 L tanks, there were no significant differences in the final mean weight, weight gain, or specific growth rate among fish fed diets C, T25R0, and T25R5. However, the other experimental diets showed significantly lower values compared to the C diet (p < 0.05). PSRL supplementation did not significantly enhance either palatability or feeding rate in TBM-based diets (p > 0.05). Two-way ANOVA indicated that only FM replacement with TBM had a significant effect on the growth parameters mentioned above (p < 0.05). A significantly lower whole-body crude lipid content was observed in all test diets compared to that in the C diet, resulting in significantly lower lipid retention efficiency in all test groups except T25R5 and T25R10 (p < 0.05). These results suggest that 25% of FM protein can be replaced with TBM protein in the diet of juvenile greater amberjack, but PSRL does not effectively address the palatability issues associated with TBM-based diets. Full article

Aquaculture advancement depends on alternative raw materials to reduce reliance on fishmeal (FM) and fish oil (FO) from extractive fisheries. Strategies like restricted feeding reduce costs and improve sustainability by minimizing feed waste and enhancing water quality, while selective breeding boosts growth and adapts fish to innovative diets. However, these measures may affect quality and shelf life. Gilthead seabream selected for high growth or non-selected were fed in 500 L tanks for 300 days until apparent satiety (AS) or with food restrictions (85AS or 65AS) using a control diet with low FM and FO balanced with vegetable ingredients, and an alternative diet (ALT) where FM was substantially replaced with insect, poultry by-product, feather, and porcine blood meals, while FO was completely replaced by microalgae, poultry, and salmon by-product oils. The ALT diet improved EPA + DHA levels, n-3/n-6 ratio, and fillet hardness. The selected fish outperformed the non-selected ones in growth and were more resilient to ALT diet and feeding restrictions. The 85AS feeding strategy optimized fillet quality by preventing lipid accumulation and muscle adaptations, as observed with the other feeding strategies. Combining sustainable feed formulations, genetic selection, and moderate feed restriction enables a viable, long-term strategy for high-quality, environmentally responsible seabream farming. Full article

A combination of meat meal (MM) and chicken byproduct meal (CBM) were evaluated as fish meal (FM) replacers in the diets of juvenile red seabream (Pagrus major). The control diet was formulated with 60% FM (CON). Four other diets were designed by reducing the FM levels to 45, 30, 15, and 0% by adding 14, 28, 42, and 56% MM and CBM in a 1:1 ratio to compensate for the reduced protein level (designated as MC14, MC28, MC42, and MC56, respectively). Red seabream (averaging 4.57 g) were distributed among 15 fiberglass tanks (40 fish/tank) and assigned to one of three replicates of the diet. After an eight-week long feeding trial, the growth performance of the fish fed the CON, MC14, and MC28 diets were comparable with the control group, and were significantly higher than the MC42 and MC56 groups. Feed utilization was significantly higher in the MC28 group compared to the other groups. The lowest growth and feed utilization were observed in the MC56 group. Serum lysozyme and SOD activities were significantly reduced when the dietary FM level decreased. Plasma total cholesterol levels were significantly reduced when the FM level was decreased in the diets, exhibiting a significant linear trend. The CON group exhibited a significantly higher cholesterol level compared to the MC42 and MC56 groups. The muscle amino acid profile was not significantly affected. The muscle myristic acid (14:0) was significantly decreased, while the palmitic acid (16:0) level increased with the increase of MM and CBM in the diets. Therefore, the results indicate that the combination of MM and CBM can be used to replace 50% of the FM from the red seabream diets without negative influences compared to a diet containing 60% FM. Full article

This study was conducted to investigate the effects of the addition of dried mealworm, hydrolyzed mealworm, fermented poultry by-product meal (FPBM), and hydrolyzed fish soluble protein (HFSP) on the growth performance, nutrient digestibility, fecal score, and blood profiles of weaning pigs. A total of 40 (21-day-old) weaned piglets ([Yorkshire × Landrace] × Duroc) with an initial average body weight (BW) of 7.14 ± 1.29 kg were randomly assigned to one of four treatments for 35 days. There were four treatment groups with five replicates and two pigs (male and female) per pen. The dietary treatment included TRT1, a basal diet + 10% dried mealworm; TRT2, a basal diet + 10% hydrolyzed mealworm; TRT3, a basal diet + 10% fermented poultry by-product meal (FPBM); and TRT4, a basal diet + 10% hydrolyzed fish soluble protein (HFSP). The inclusion of FPBM in weaning pig diets had a significant effect on the blood profile with blood urea nitrogen (BUN) levels (p < 0.05), but not on other blood profiles of serum IGF-1, IgG, and IgA concentrations. BUN concentration decreased in response to the dietary inclusion of FPBM (p = 0.019). BUN concentration decreased and was at its lowest with FPBM (6.3 mg/dL), followed by hydrolyzed mealworm (7.3 mg/dL), while increasing with dried mealworm and HFSP (8.5 mg/dL). There was no significant difference in the growth performance, nutrient digestibility, and fecal score of piglets fed a basal diet with dried mealworm, hydrolyzed mealworm, FPBM, and HFSP. Hence, the addition of fermented poultry by-products in weaning pigs’ diets decreases the blood urea nitrogen, without any detrimental effect on performance, nutrient digestibility, or fecal score. Full article

Fish meal (FM) and fish oil (FO) are vital components commonly used in feed formulations. However, their supply, which generally comes from capture fisheries, is being exhausted, necessitating the exploration of sustainable alternatives. In a two-part study, the first part evaluated the FM and FO derived from smoked salmon by-product (SSBP) over a 12-week accelerated shelf-life test, comparing their lipid oxidation, amino acid, and fatty acid profiles to those of commercial whitefish meal and oil. In the second part, the SSBP FM and FO were then included in three experimental feeds at 25%, 50%, and 100% inclusion levels. These feeds were tested on juvenile striped bass (Morone saxatilis) cultured in a recirculating aquaculture system (RAS). The results indicated that the quality of SSBP FM and FO was lower than the commercial product (less amino acids (23.98% vs. 60.30%) and omega-3 fatty acids (9.46% vs. 26.6%), respectively). SSBP FO exhibited high initial peroxide value (21.00 ± 0.00 meq/kg oil), with gradually increasing total oxidation value and p-Anisidine value during storage. Regarding the feeding trial, all fish showed signs of Mycobacterium marinum infection after one month. While there was no significant difference in feed palatability (p > 0.8559), the feed conversion ratio was less efficient for the 100% SSBP feed (1.44 ± 0.14) compared to commercial feed (1.36 ± 0.13), but these differences were not statistically significant. This study suggests that SSBP FM and FO can be used as supplements at lower levels (25% and 50%) without negatively affecting growth, feed efficiency, or survival. Our findings may be useful for enabling beneficial collaborations between smoked salmon processors, feed manufacturers, and striped bass farmers, therefore contributing to sustainability in aquaculture practices. Full article

Fish meal (FM) replacement is essential for sustainable aquaculture development. This study investigated the effects of FM replacement with poultry by-product meal (PBM) on growth performance, hepatic and intestinal health and ammonia nitrogen stress resistance in mandarin fish (Siniperca chuatsi). A 52-day feeding trial was conducted using PBM to replace fish meal at levels of 0%, 17.5%, 35.0%, 52.5% and 70.0%. The results showed that FM replacement with PBM did not influence growth performance in mandarin fish. Moderate PBM replacement (≤35.0%) did not harm liver health and enhanced the intestinal structure. However, excessive replacement (≥52.5%) caused hepatocyte damage, reduced antioxidant capacity and decreased survival under ammonia nitrogen stress. Notably, 70% PBM replacement led to severe hepatic lipid accumulation, inhibiting fatty acid β-oxidation and triglyceride hydrolysis pathways. Furthermore, high PBM levels (≥52.5%) also reduced intestinal muscularis thickness, downregulated tight junction proteins and induced inflammation. In conclusion, while PBM replacement does not hinder growth, maintaining levels below 35.0% (PBM ≤ 28.5%) is essential for preserving hepatic lipid metabolism, intestinal health and antioxidant defense in mandarin fish. Full article

The current experiment is conducted to determine the effects of chicken by-product meal (CBM) as a fish meal (FM) replacer in diets, with or without the inclusion of jack mackerel (Trachurus japonicus) meal (JMM), on the growth and feed availability of rockfish (Sebastes schlegeli). A two-way ANOVA experimental design [FM replacement level (FMRL, 25% and 50%) × JMM inclusion (without and with)] was adopted. The control (Con) diet contained 55% FM. In the Con diet, 25% and 50% of FM were substituted with CBM, either without or with the inclusion of 22% JMM, referred to as the CBM25, CBM50, CBM25J, and CBM50J diets, respectively. A total of 375 juvenile fish were distributed into 15 tanks with triplicates. The 25% FM replacement diets led to significantly (p < 0.003 and p < 0.004, respectively) greater weight gain and specific growth rate (SGR) of rockfish than the 50% FM replacement diets. Furthermore, the CBM-replaced diets with JMM inclusion led to significantly (p < 0.003 and p < 0.002, respectively) greater weight gain and SGR of fish compared with those without JMM inclusion. Weight gain and SGR of rockfish fed the Con and CBM25J diets were significantly (p < 0.001 for both) greater than those of fish fed the CBM25, CBM50, and CBM50J diets. However, neither dietary FMRL nor JMM inclusion had significant (p > 0.05) effects on feed consumption, blood chemistry, or the biochemical composition of rockfish. In conclusion, 25% of FM could be replaced with CBM in the 55% FM-based diet, including JMM, without adverse effects on the growth, feed availability, blood chemistry, or biochemical composition (proximate composition and amino and fatty acid profiles) of rockfish. Full article

The poultry industry relies heavily on soybean meal to feed egg-laying chickens, but its high cost and price instability necessitate the exploration of more affordable and reliable alternatives. Fish bone meal, a nutritious byproduct from fish processing, offers high-quality protein and essential minerals, making it a promising addition to poultry diets. In this study, 240 Hy-Line Brown laying hens (31 weeks old, average weight 1.90 ± 0.1 kg, egg laying 11 weeks) were randomly assigned to two dietary treatments for 12 weeks: one group received a regular diet, while the other was fed a diet containing 3% fish bone meal. Each treatment included 12 replicates with 10 hens per replicate, and all birds were maintained under identical environmental conditions using a completely randomized experimental design. The results showed that hens fed the fish bone meal diet produced more eggs (p < 0.05) and had heavier yolks (p < 0.05) compared to the control group. Furthermore, intestinal health indicators, including villus height and crypt depth, were significantly improved (p < 0.05), along with enhanced immune markers (p < 0.05) in the fish bone meal group. However, no significant differences were observed in other egg quality parameters or feed conversion efficiency between the two groups (p > 0.05). These findings demonstrate that fish bone meal can improve egg production, yolk quality, intestinal health, and immune function in laying hens. Full article

Fish waste (FW) serves as an underutilized resource in agriculture, especially among small-scale processors. The trimmings and skins generated during the manufacturing of smoked salmon often end up in landfills due to insufficient quantities and logistical challenges to promote upcycling. An additional consideration is the high fat and mineral content in the smoked Atlantic salmon (Salmo salar) used for this study. We tested the feasibility of technology that small-scale processors can adapt to upcycle smoked salmon by-products into fish meal (FM) and fish oil (FO). A two-phase decanter centrifuge was optimized by manipulating acceleration, differential speed, flow rate, weir disc diameter, sample temperature, and the number of decanter runs. FW, processed through the decanter three times, produced FM with the least fat content compared to other trials. The optimized FM contained 74.09% protein, 8.56% fat, 15.41% ash, and 0.20% salt. FO production involved running a 9:1 water-to-by-product dilution through a three-phase clarifier centrifuge, followed by batch centrifugation and storage. Proximate, amino acid, and fatty acid profiles of the produced FM and FO aligned with industry standards. This study highlights a potentially sustainable solution for small-scale processors to transform FW into high-quality FM and FO, reducing waste and supporting sustainable resource recovery. Full article

Aquafeed production is a fast-growing industry, seeking novel, cost-efficient raw materials to diversify traditional ingredients like fish meal and oil. Insects, particularly BSF larvae, convert by-products and waste into value-added biomass. In this study, by-products and co-products from two major fish-transforming industries in the Iberian Peninsula, i.e., tuna heads (THs) and codfish frames (CFs), hydrolysates of THs and CFs, and TH oils, were supplied to BSF larvae to improve their profile in n-3 fatty acids (FAs), namely EPA and DHA, and their protein/amino acid content. By testing the replacement levels of a control diet with by-products and co-products, we evaluated the amount of n-3 FA that could be added to BSF larval tissues. The results showed that high levels of a hydrolysed diet negatively impacted larval survival. In addition, parameters such as the moisture, protein content, and viscosity of the substrate affected bioconversion rates. Nevertheless, BSF fed with these diets contained high levels of lysine (5.8–8.4%, dry weight (DW)), methionine (1.5–2.4%, DW), and n-3 FA (14.4% DW: EPA 6.7% and DHA 7.1%). These findings suggest that BSF can effectively convert fish by-products into a nutrient-rich biomass for aquafeeds, supporting the diversification of raw material sources and promoting a circular bioeconomy. Full article

A 56-day feeding experiment was carried out to evaluate the effects of substituting fish meal (FM) with chicken by-product meal (CBM) in diets on the growth and feed utilization of rockfish (Sebastes schlegeli). Six experimental diets were formulated to be isonitrogenous and isolipidic. The control (Con) diet included 55% FM. In the Con diet, 10%, 20%, 30%, 40%, and 50% of FM was replaced with CBM, named as the CBM₁₀, CBM₂₀, CBM₃₀, CBM₄₀, and CBM₅₀ diets, respectively. A total of 540 juvenile fish were distributed into 18 tanks (30 fish per tank and 3 tanks per diet) and fed to apparent satiation two times daily for 56 days. The weight gain and specific growth rate of rockfish fed the CBM₁₀ and CBM₂₀ diets were comparable to rockfish fed the Con diet. The feed consumption of rockfish fed the Con and CBM₁₀ diets was significantly (p < 0.001) higher than that of fish fed all other diets, except for the CBM₂₀ diet. However, protein retention, biometric indices, chemical composition, amino acid profiles, and plasma and serum parameters of rockfish were not significantly influenced by dietary FM substitution with CBM. The Con, CBM₁₀, and CBM₂₀ diets showed superior (p < 0.001) economic profit index (EPI) compared to the CBM₃₀, CBM₄₀, and CBM₅₀ diets. Conclusively, FM up to 20% could be substituted by CBM in diets without impairing growth, feed availability, chemical composition, amino acid profiles, and blood parameters of rockfish grown from 2.5 g to 12.5 g. However, the long-term effects of CBM substitution or the potential use of combined CBM and other alternative protein sources for FM in rockfish diets are needed in future. Full article

A two-way {dietary substitution source [chicken by-product meal (CBM), meat meal (MM), and tuna by-product meal (TBM)] × substitution level (25% and 50%)} ANOVA experimental design was adopted. The control (Con) diet included 55% FM. In the Con diet, 25% and 50% of FM were substituted with CBM, MM, and TBM, with the inclusion of 22% JMM exhibiting strong attractiveness for rockfish, named CBM25J, CBM50J, MM25J, MM50J, TBM25J, and TBM50J diets, respectively. All experimental diets were assigned to triplicate groups of fish. A total of 525 juvenile fish were distributed into 21 flow-through tanks. The CBM- and TBM-substituted diets achieved greater weight gain and specific growth rates (SGRs) of rockfish than the MM-substituted diets. Moreover, dietary 25% FM substitutions achieved greater weight gain and SGRs of rockfish than dietary 50% FM substitutions. Weight gain and SGRs of rockfish fed the Con, CBM25J, and TBM25J diets were superior to those of rockfish fed the CBM50J, MM50J, and TBM50J diets. Dietary 25% FM substitutions exhibited higher rockfish feed consumption than dietary 50% FM substitutions. None of the proximate compositions, amino and fatty acid profiles, or blood chemistry of the fish were significantly different among dietary treatments. The highest EPI was observed in the CBM25J diet. Conclusively, a 25% FM substitution with CBM, MM, and TBM with the inclusion of 22% JMM in the 55% FM-based diet could be made without reducing the growth and feed consumption of rockfish. Finally, the CBM25J diet produced the highest weight gain and SGRs of rockfish, as well as the highest economic return to farmers. Full article