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A great deal of attention has been paid to the replacement of the high levels of fishmeal present in commercial diets by alternative animal and vegetable protein sources. There are some contradictory data on the effects of partial or... more
A great deal of attention has been paid to the replacement of the high levels of fishmeal present in commercial diets by alternative animal and vegetable protein sources. There are some contradictory data on the effects of partial or total replacement of dietary fishmeal especially regarding vegetable protein sources. The effect of technological treatments applied to the vegetable materials and the quality of the control diets are the reasons for these contradictory results. A ten week growth trial was conducted to study the effect of partial or total replacement of fishmeal by plant proteins in diets for rainbow trout. For this purpose, four practical diets were formulated: a fishmeal-based control diet, which included a brown fishmeal as the only protein source (diet C1); another diet where 5% of the brown fishmeal protein was replaced by a fishmeal protein concentrate (CPSP; diet C2); and two other diets where 50% (diet C50) and 100% (diet C100) of the fish meal protein was replaced by plant protein sources (soybean meal, fullfat soybean and corn gluten meal). The results of the growth trial showed that 50% of the fishmeal protein can be replaced by vegetable protein sources with no adverse effects on growth and feed utilization when diet C1 was used as control. However, using diet C2 as control, weight gains of trout fed the other diets were all significantly lower. Nitrogen and phosphorus balances were also estimated and results are discussed regarding the effect of diet quality on environmental impact.
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Dietary conjugated linoleic acids (CLA) have been shown to alter growth rates and reduce body fat storage by altering the activity of key enzymes involved in lipid metabolism, in several species, but have not been evaluated in rainbow... more
Dietary conjugated linoleic acids (CLA) have been shown to alter growth rates and reduce body fat storage by altering the activity of key enzymes involved in lipid metabolism, in several species, but have not been evaluated in rainbow trout. A 12-week growth trial was conducted with rainbow trout juveniles, having an initial weight of 5.3±0.03 g (mean±S.D.). Fish were fed
Research Interests: Biology, Aquaculture, Body Composition, Fisheries Sciences, Lipid metabolism, and 15 moreEnzyme, Nutrient, Rainbow trout, Growth rate, Enzyme activity, Body Fat, Nutrient Utilization, Oncorhynchus Mykiss, Feed Efficiency, Whole Body, Feed Intake, Conjugated linoleic acid, Feed Conversion, Adverse effect, and Growth index
... Pongmaneerat, J. and Watanabe, T., 1993. Effect of extrusion processing on the utilization of soybean meal diets for rainbow trout. Nippon Suisan Gakkaishi, 59: 14071414. ... Nutritional evaluation of brown fish meals as a protein... more
... Pongmaneerat, J. and Watanabe, T., 1993. Effect of extrusion processing on the utilization of soybean meal diets for rainbow trout. Nippon Suisan Gakkaishi, 59: 14071414. ... Nutritional evaluation of brown fish meals as a protein source in diets for rainbow trout. Bull. ...
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This manuscript describes and evaluates the FEEDNETICS model, a detailed mechanistic nutrient-based model that has been developed to be used as a data interpretation and decision-support tool by fish farmers, aquafeed producers,... more
This manuscript describes and evaluates the FEEDNETICS model, a detailed mechanistic nutrient-based model that has been developed to be used as a data interpretation and decision-support tool by fish farmers, aquafeed producers, aquaculture consultants and researchers. The modelling framework comprises two main components: (i) fish model, that simulates at the individual level the fish growth, composition, and nutrient utilization, following basic physical principles and prior information on the organization and control of biochemical/metabolic processes; and (ii) farm model, that upscales all information to the population level. The model was calibrated and validated for five commercially relevant farmed fish species, i.e., gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and Nile tilapia (Oreochromis niloticus), using data sets covering a wide range of rearing and feeding conditions. The...
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The apparent digestibility coefficients (ADCs) of differently processed okara meals were assessed in Nile tilapia diets: dried okara not autoclaved (FOK), dried okara autoclaved (AOK), okara hydrolyzed with Alcalase (ALOK) or Cynara... more
The apparent digestibility coefficients (ADCs) of differently processed okara meals were assessed in Nile tilapia diets: dried okara not autoclaved (FOK), dried okara autoclaved (AOK), okara hydrolyzed with Alcalase (ALOK) or Cynara cardunculus proteases (CYOK), and hydrolyzed okara fermented with lactic bacteria: Lactobacillus rhamnosus R11 (CYR11OK) or Bifidobacterium animalis ssp. lactis Bb12 (CYB12OK). Okara processing significantly affected nutrient digestibility: dry matter ADC was highest in CYR11OK (80%) and lowest in FOK (40%). The lowest protein digestibility was observed in CYR11OK (72%), and the highest in AOK (97%) and CYOK (91%), evidencing the effectiveness of the autoclave and the use of C. cardunculus proteases to increase okara protein bioavailability. The inclusion of up to 20% of AOK or CYOK did not affect fish growth, nutrient utilization, or whole body composition of Nile tilapia. The flesh quality (color, pH, water activity, cohesiveness, elasticity and resili...
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Abstract Glycerol is an inexpensive source of dietary energy, although its inclusion in compound feeds has been barely investigated in fish. The effects of dietary refined glycerol inclusion on growth performance, nitrogen and energy... more
Abstract Glycerol is an inexpensive source of dietary energy, although its inclusion in compound feeds has been barely investigated in fish. The effects of dietary refined glycerol inclusion on growth performance, nitrogen and energy balance, as well as its digestibility and intestinal digestive enzyme activities was studied in rainbow trout. Fish (initial BW 20.2 ± 0.1 g, mean ± SE) were divided into nine tanks (1.66 kg m−3), each one assigned to the experimental diets, in triplicates. Fish were fed twice a day to apparent satiation for 60 days three diets including 0, 25, or 50 g kg−1 of refined glycerol (G0, G25, and G50, respectively) with similar digestible protein to energy ratios (22 mg kJ−1). A digestibility trial was conducted in parallel to the growth trial by using a Choubert System to collect feces, in triplicates. Refined glycerol was well digested (ADCglycerol > 99.7%) when included up to 50 g kg−1. Specific growth rate (SGR) decreased as glycerol inclusion levels increased in the diet (P = 0.029). Feed intake was enhanced with increasing dietary inclusion levels of glycerol (P = 0.013). The feed efficiency decreased linearly as the glycerol inclusion levels increased in the diet, reflected in a higher FCR ratio, particularly in the G50 group compared to the G0 or G25 groups (1.04 ± 0.02, 0.90 ± 0.02 and 0.91 ± 0.02, respectively). Total ammonia nitrogen excretion rate (TANER) was measured in trout at the end of the growth trial, displaying increased values with higher dietary glycerol inclusion levels (P
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Abstract Concerns about antibiotic use led to stricter legislations and overall better practices in aquaculture production. However, depletion time periods in tissues vary greatly with different antimicrobials, fish species, or... more
Abstract Concerns about antibiotic use led to stricter legislations and overall better practices in aquaculture production. However, depletion time periods in tissues vary greatly with different antimicrobials, fish species, or experimental setup. In the present work, five drugs (sulfadiazine (SDZ), trimethoprim (TRI), flumequine (FLU), oxolinic acid (OXO), and oxytetracycline (OTC)) were incorporated into medicated feed, and their retention in European seabass muscle tissues assessed. Juveniles were placed in 300 L tanks at 18 °C and were manually fed with medicated feeds for a 7 day period (two concentrations per antimicrobial, ranging from 6 to 220 mg kg−1, which were based on previous studies on the occurrence of these antimicrobials). Residues were analyzed through a multi-class quantification method (UHPLC-MS/MS). Data on residues concentration through time followed a one-compartment model, with TRI concentrations above the established Maximum Residue Level (MRL) throughout the experiment. Similarly, OTC concentrations at the highest dose were also above 100 μg kg−1 up to 14 days after the medication period. Results obtained for TRI may indicate the presence of a dose dependency for this antimicrobial. FLU concentrations in muscle samples were the lowest through time (Cday7 of 279.70 and 386.63 μg kg−1, for prophylactic and therapeutic treatments, respectively). Half-life values of 14.37, 10.87, 5.36, 7.20, and 27.22 h (prophylactic treatment), and 20.95, 8.41, 5.61, 11.22, and 17.99 h (therapeutic treatment), were determined for SDZ, TRI, FLU, OXO, and OTC, respectively. Withdrawal times of 0, 2, and 5 days were determined for FLU, OXO, and SDZ, but sampling times for OTC and TRI should be longer, since antimicrobial concentrations were above the MRL 14 days after the end of the feeding period with medicated feed. Therefore, special attention should be given since they are the most used antibiotics in aquaculture and European seabass plays a major part in human nutrition in the Mediterranean region.
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Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout... more
Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficien...
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Probiotic administration can be a nutritional strategy to improve the immune response and growth performance of fish. The current study aimed to evaluate the effects of a probiotic blend (Bacillus sp., Pediococcus sp., Enterococcus sp.,... more
Probiotic administration can be a nutritional strategy to improve the immune response and growth performance of fish. The current study aimed to evaluate the effects of a probiotic blend (Bacillus sp., Pediococcus sp., Enterococcus sp., Lactobacillus sp.) as a dietary supplement on growth performance, feed utilization, innate immune and oxidative stress responses and intestinal morphology in juvenile Nile tilapia (Oreochromis niloticus). The probiotic was incorporated into a basal diet at three concentrations: 0 g/kg (A0: control), 3 g/kg (A1: 1.0×106 colony forming unit (CFU)/g) and 6 g/kg (A2: 2.3×106 CFU/g diet). After 8 weeks of probiotic feeding, weight and specific growth rate where significantly higher in fish-fed A1 diet than in fish-fed A0. Alternative complement in plasma was significantly enhanced in fish-fed A2 when compared with A0. The hepatic antioxidant indicators were not affected by probiotic supplementation. Villi height and goblet cell counts increased significan...
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Probiotic administration is associated with the enhancement of host resistance to environmental and nutritional stressors, improving survival and growth rates. This study was carried out to evaluate the effects of dietary supplementation... more
Probiotic administration is associated with the enhancement of host resistance to environmental and nutritional stressors, improving survival and growth rates. This study was carried out to evaluate the effects of dietary supplementation of Bacillus subtilis and Bacillus cereus toyoi on growth performance, innate immune responses and gut morphology of two trout species feeding a commercial diet high in soybean meal. A commercial probiotic (4.2 × 109 CFU g−1 of additive) was supplemented to the experimental diets at 0% (control), 0.03% (P1; 6 × 103 CFU g−1 of diet) or 0.06% (P2; 1.5 × 106 CFU g−1 of diet) and fed to brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) for 9 and 20 weeks respectively. Rainbow trout showed significantly better growth performance than brown trout, regardless of the dietary treatment. No effect of dietary probiotic supplementation was detected on growth performance, body composition or innate immune parameters (plasma lysozyme, alternative complement and peroxidase activities). In both species, after 9 weeks, intestinal lamina propria and submucosa were widened, with increased presence of inflammatory cells, significantly higher in groups fed probiotics. This inflammatory process, with villi and enterocytes noticeably damaged compared with the control group, was more pronounced in brown trout. Under the current trial conditions, the B. subtilis + B. cereus toyoi had no positive impact in either trout species, on the contrary a harmful effect was observed.
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Determination of sex is vital in establishing the identity of human remains and has always been a challenge for forensic pathologists, particularly when a fingerprint recovered from crime scene does not match with any of those available... more
Determination of sex is vital in establishing the identity of human remains and has always been a challenge for forensic pathologists, particularly when a fingerprint recovered from crime scene does not match with any of those available in the records. The present study was conducted on 100 males and 100 females of South Indian Population, aged between 18 and 81 years, to study the possibility of differentiation of gender using fingerprint ridge density. For calculating the finger print ridge density, the upper portion of the radial border of each print was chosen and the epidermal ridges in a defined area counted. Results show that women have a significantly higher fingerprint ridge density than men. Application of Baye's theorem suggests that a fingerprint having ridge density of 14/25mm2 is more likely to be that of a female. Discriminant analysis on the study data could derive formulae to predict the sex using fingerprint ridge density. The results show that fingerprint ridge density can be used as a tool for sex determination.
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ABSTRACT A vitamin E extraction method for rainbow trout flesh was optimized, validated and applied in fish fed commercial and Gracilaria vermiculophylla-supplemented diets. Five extraction methods were compared. Vitamers were analyzed by... more
ABSTRACT A vitamin E extraction method for rainbow trout flesh was optimized, validated and applied in fish fed commercial and Gracilaria vermiculophylla-supplemented diets. Five extraction methods were compared. Vitamers were analyzed by HPLC/DAD/fluorescence. A solid-liquid extraction with n-hexane, which showed the best performance, was optimized and validated. Among the 8 vitamers, only α- and γ-tocopherol were detected in muscle samples. The final method showed good linearity (>0.999), intra- (<3.1%) and inter-day precision (<2.6%), and recoveries (>96%). Detection and quantification limits were 39.9 and 121.0 ng/g of muscle, for α-tocopherol, and 111.4 ng/g and 337.6 ng/g, for γ-tocopherol, respectively. Compared to the control group, the dietary inclusion of 5% G. vermiculophylla resulted in a slight reduction of lipids in muscle and, consequently, of α- and γ-tocopherol. Nevertheless, vitamin E profile in lipids was maintained. In general, the results may be explained by the lower vitamin E level in seaweed-containing diet.Practical Applications: Based on the validation results and the low solvent consumption, the developed method can be used to analyze vitamin E in rainbow trout. The results of this work are also a valuable information to fish feed industries and aquaculture producers, which can focus on improving seaweed inclusion in feeds as source of vitamin E in fish muscle and, therefore, taking full advantage of all bioactive components with an important role in fish health and flesh quality.
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Research Interests: Physiology, Biology, Diet, Medicine, Serotonin, and 15 moreDopamine, Cortisol, Brain, Blood Glucose, Stress response, Animals, Synaptic Transmission, Amino Acids, Amino Acid Profile, Physiological Stress Markers, Biochemistry and cell biology, Plasma Glucose, High protein, hydrocortisone, and Stress Physiological
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Research Interests: Biology, Aquaculture, Muscle, Functional Food, Body Composition, and 15 moreFisheries Sciences, Growth performance, Sensory Analysis, Rainbow trout, Fatty Acid, Sensory properties, Body Weight, Biological activity, Market Size, Oncorhynchus Mykiss, Level, Control Group, Conjugated linoleic acid, Feed Conversion, and Fatty acid profile
Research Interests: Zoology, Biology, Fish Biology, Aquaculture, Multidisciplinary, and 15 moreMaize, Fish Meal, Fisheries Sciences, Soybean, Nile Tilapia, Growth performance, Animal Protein, Rainbow trout, Oreochromis niloticus, Oncorhynchus Mykiss, Weight Gain, Feed Intake, Nutrient Balance, Specific Growth Rate, and Digestible protein
... Gomes Texeira, 4000 Porto, Portugal bInstituto de Ciencias Biomedicas, 4000 Porto, Portugal Departamento de Zootecnia, Universidade de Vila Real, 5000 Vila Real, Portugal Abstract A 12-week feeding trial was conducted with 38 g... more
... Gomes Texeira, 4000 Porto, Portugal bInstituto de Ciencias Biomedicas, 4000 Porto, Portugal Departamento de Zootecnia, Universidade de Vila Real, 5000 Vila Real, Portugal Abstract A 12-week feeding trial was conducted with 38 g rainbow trout to evaluate the effect of 20 ...
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... 2004. RESEARCH ARTICLE. Maria José Saavedra 1* Sandra Guedes-Novais 1 Anabela Alves 1 Paulo Rema 2 Marta Tacão 3 António Correia 3 Antonio Martínez-Murcia 4. ... A incidência maiordas resistências recaíram sobre: amoxicilina,... more
... 2004. RESEARCH ARTICLE. Maria José Saavedra 1* Sandra Guedes-Novais 1 Anabela Alves 1 Paulo Rema 2 Marta Tacão 3 António Correia 3 Antonio Martínez-Murcia 4. ... A incidência maiordas resistências recaíram sobre: amoxicilina, carbenicilina ea ticarcilina. ...
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The effects of graded levels (0 %, 0·5 %, 0·75 and 1 %) of dietary conjugated linoleic acid (CLA) were assessed on 97 g rainbow trout. Fish were fed to satiation twice a day for 12 weeks. At the end of the experiment, all groups of fish... more
The effects of graded levels (0 %, 0·5 %, 0·75 and 1 %) of dietary conjugated linoleic acid (CLA) were assessed on 97 g rainbow trout. Fish were fed to satiation twice a day for 12 weeks. At the end of the experiment, all groups of fish weighed more than 250 g and no significant differences were detected in growth performance, feed conversion, nutrient or energy utilisation or body composition between treatments. A decrease in liver lipid content resulted from including CLA and was accompanied by a reduction in malic enzyme activity. The muscle saturated acid and PUFA content did not vary between dietary treatments, despite the increasing concentration of stearic acid and CLA. In the liver, however, both fractions increased significantly with dietary CLA. Moreover, the MUFA decreased significantly in both muscle and liver. CLA was incorporated into tissue lipids, with levels in flesh (2·1–4·2 %) being 2-fold higher than in liver (0·8–1·9 %). In muscle, the percentage of cis-9, trans...
Research Interests: Nutrition and Dietetics, Skeletal muscle biology, British, Animal Production, Animal Husbandry, and 12 moreFatty acids, Animal Feed, Animals, Body Composition, Taste, Rainbow trout, Food Sciences, Cambridge University, Chemical Composition, Oncorhynchus Mykiss, Conjugated linoleic acid, and Dietary fats
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Research Interests: Aquaculture, Muscle, Functional Food, Body Composition, Fisheries Sciences, and 15 moreGrowth performance, Sensory Analysis, Rainbow trout, Fatty Acid, Sensory properties, Body Weight, Biological activity, Market Size, Oncorhynchus Mykiss, Level, Time Course, Control Group, Conjugated linoleic acid, Feed Conversion, and Fatty acid profile
ABSTRACT
The most frequent infectious diseases that affect fish are those of bacterial origin. In European sea bass fish farms (Dicentrarchus labrax) are included Vibrio spp., Pasteurella piscicida and Myxobacter spp. In addition to these, it is... more
The most frequent infectious diseases that affect fish are those of bacterial origin. In European sea bass fish farms (Dicentrarchus labrax) are included Vibrio spp., Pasteurella piscicida and Myxobacter spp. In addition to these, it is also possible to find, although lesser frequently, other pathogenic agents such as Pseudomonas spp., Aeromonas spp., Staphylococcus epidermis, Streptococcus spp. and Enterobacter spp. The presence of these micro-organisms in fish farms contributes for a significant decrease in fish production and subsequent loss of profitability in these aquaculture units. The use of antibiotics may therefore be necessary as a prophylactic measure although their systematic utilization leads to the development of strains of antibiotic resistant bacteria. Bearing that in mind, a survey was conducted on the susceptibility of isolated strains of bacteria found in juvenile European sea bass. It was concluded that chloranphenicol and tetracycline are two important antibiot...
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Two separate trials were performed to evaluate the effects of adding various sources of carotenoids on survival and growth of goldfish (Carassius auratus) larvae and juveniles. In the first trial (Trial A), larvae (initial body weight:... more
Two separate trials were performed to evaluate the effects of adding various sources of carotenoids on survival and growth of goldfish (Carassius auratus) larvae and juveniles. In the first trial (Trial A), larvae (initial body weight: 3.4 ± 0.7 mg) were fed four microparticulate diets (MP) from first feeding to day 28. Diets were formulated to contain a constant level of pigments (45mg kgG ) from different sources of carotenoids 1(Chlorella vulgaris, Spirulina platensis and synthetic pigment astaxantin). All treatments were tested in triplicate as well as a fasted control group. In the second growth trial (Trial B), a fifth diet, containing Haematococus pluvialis biomass (45 mg kgG ; diet Hp), was also tested. Diets were fed to homogenous groups 1 of 45 juvenile C. auratus (1.7 ± 0.1g), in triplicate. Water temperature was maintained at 25 ± 1°C during the 12 weeks long trial. High survival rates were recorded in both studies. Furthermore, there were no significant differences amon...
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The influence of two commercial probiotics on the growth, innate immune parameters and intestinal morphology of rainbow trout (Oncorhynchus mykiss) juveniles (initial weight: 16.4 ± 0.4 g) was evaluated. Two probiotic types: A,... more
The influence of two commercial probiotics on the growth, innate immune parameters and intestinal morphology of rainbow trout (Oncorhynchus mykiss) juveniles (initial weight: 16.4 ± 0.4 g) was evaluated. Two probiotic types: A, multi-species (Bacillus sp., Pedicoccus sp., Enterococcus sp., Lactobacillus sp.) and B, mono-species (Pediococcus acidilactici) were tested at two levels each (A1: 1.5 g.kg(-1), 8.6 × 10(5) CFU.g(-1); A2: 3 g.kg(-1), 1.6 × 10(6) CFU.g(-1); B1: 0.1 g.kg(-1), 2.6 × 10(4) CFU.g(-1); B2: 0.2 g.kg(-1), 7.2 × 10(4) CFU.g(-1)) versus an unsupplemented diet (C). Diets were distributed to sextuplicate tanks, three times a day to visual satiation for 8 weeks. Growth performance and immune responses (plasma lysozyme, ACH50, peroxidase and head kidney respiratory burst) were determined at 4 and 8 weeks of feeding. Body composition and intestine morphology were determined at the end of the feeding trial. At 8 weeks, the lower dose of multi-species probiotic (A1) improved...
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ABSTRACT The efficacy and tolerance of a novel microbial 6-phytase were investigated in rainbow trout, Oncorhynchus mykiss, and Nile tilapia, Oreochromis niloticus. Reference diets were sufficient in available phosphorus (P). The test... more
ABSTRACT The efficacy and tolerance of a novel microbial 6-phytase were investigated in rainbow trout, Oncorhynchus mykiss, and Nile tilapia, Oreochromis niloticus. Reference diets were sufficient in available phosphorus (P). The test diet limiting in available P was supplemented with phytase at 500, 1000, or 2000 phytase units/kg feed. The enzyme was effective in increasing total P apparent digestibility coefficient in relation to increasing the dose of phytase in rainbow trout and Nile tilapia. Zinc apparent digestibility improved in relation to phytase supplementation in rainbow trout. P release due to phytase supplementation ranged from 0.06 to 0.18% P/kg feed in rainbow trout and from 0.13 to 0.26% P/kg feed in Nile tilapia. A 58-d performance trial was conducted to evaluate tolerance of fish to phytase supplementation. Dietary treatments consisted of a basal diet without phytase or supplemented with 2000 and 200,000 phytase units/kg feed. Results indicate that this novel microbial 6-phytase is well tolerated by fish. Significant improvements for growth as well as feed conversion ratio were observed when the phytase was fed at 2000 phytase units/kg feed. This phytase is proven efficient in releasing P from phytate and could be added when plants are used for fish meal replacement in diets for salmonid and omnivorous fish.
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ABSTRACT The apparent digestibility coefficients (ADCs) of four seaweeds, Porphyra dioica, Ulva spp., Gracilaria vermiculophylla and Sargassum muticum, were evaluated in rainbow trout and Nile tilapia. Porphyra, Ulva and Gracilaria were... more
ABSTRACT The apparent digestibility coefficients (ADCs) of four seaweeds, Porphyra dioica, Ulva spp., Gracilaria vermiculophylla and Sargassum muticum, were evaluated in rainbow trout and Nile tilapia. Porphyra, Ulva and Gracilaria were produced in land-based integrated multi-trophic aquaculture (IMTA). This production method resulted in increased protein content when compared to wild specimens and to the wild-harvested Sargassum. For both, trout and tilapia, the ADC of the experimental diets was generally lower than the reference diet, though in trout, protein digestibility of Gracilaria diet was similar to the reference diet (90%). In terms of the calculated seaweed ADC, the results vary significantly according to the seaweed and fish species. In trout, protein ADC of Gracilaria (88%) was significantly higher than all other seaweed (66–80%). Best lipid ADC was recorded for Gracilaria (97%), although not significantly different from Porphyra (94%). In tilapia, protein ADC was higher for Ulva (63.4%) and Sargassum (65.1%) than for the other seaweed. In lipid ADC, Gracilaria was significantly lower (82%) compared to all other test seaweed (91–95%). Overall trout seems to digest better Gracilaria, whereas tilapia does better with Ulva and Sargassum. The results demonstrate that IMTA-seaweed can be considered good ingredients for fish feed.
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Apparent digestibility, deposition and retention of carotenoids in the muscle of rainbow trout, Oncorhynchus mykiss, were investigated comparing the feeding of pigments from Chlorella vulgaris against commercially available pigments at... more
Apparent digestibility, deposition and retention of carotenoids in the muscle of rainbow trout, Oncorhynchus mykiss, were investigated comparing the feeding of pigments from Chlorella vulgaris against commercially available pigments at two different total lipid contents (15% and 20% lipid). Algal biomass (ALG) was included in rainbow trout diets and muscle pigmentation was compared to that obtained in trout fed diets