High-quality Fish Meal Research Articles

Coated Crystalline Amino Acid Supplementation May Assist Higher Soybean Meal Inclusion in Diets for Nile Tilapia (Oreochromis Niloticus) With Improved Protein Assimilation and Retention

The aquaculture industry has previously relied on high-quality fishmeal (FM) to fabricate diets of excellent standards. However, plant-based proteins such as soybean are more economic for low-value fish species, for example, tilapia and carp, and fishmeal use has been significantly lessened. Previous studies have addressed standard soybean meal (SBM) sources in aquafeeds seldom addressing essential amino acid correction. An eight-week feeding trial was conducted to evaluate the replacement of fish meal with soybean meal concentrate in Nile tilapia (Oreochromis niloticus) using a semi-purified diet against a Low Temperature (LT) fishmeal as a primary reference protein. Four diets with varying levels of soybean meal were evaluated and compared to a control diet of 100 % fish meal. Three diets containing 20, 40, and 80 % soybean protein concentrate (SBPC) were examined. The fourth diet consisted of 80 % SBPC and supplementation with two essential amino acids: lysine and methionine (80SBPCAA) in a coated form. Daily growth values highlight similar rates when tilapia was fed 100FM and 40SBPC diets. No differences were observed in the final mean weights for all soybean-fed tilapia, but they were marginally lower than the 100FM control diet group. The 80SBPC diet showed the poorest feed conversion ratio (FCR) at 1.31 and protein efficiency ratio (PER) at 2.19. However, the 80SBPCAA diet showed a significantly improved percent weight gain for tilapia compared to the 80SBPC-fed tilapia. PER was significantly higher at 2.47 and had a better Apparent Net Protein Utilization (ANPU) value of 28.51 % compared to un-supplemented 80SBPC-fed tilapia (25.48 %). These results confirmed that high-quality fishmeal can be substituted by up to 40 % SBPC alone and without any detrimental effects on growth or carcass composition in juvenile tilapia. Crystalline coated essential amino acid supplementation showed marginal improvement of performance for tilapia at high SBPC inclusion level.

Effect of Japanese sandfish (Arctoscopus japonicus) meal in paste diet for Anguilla japonica in terms of growth, feed efficiency and digestibility

In this study, the effect of replacement of high-quality fish meal (HQFM) with Japanese sandfish (Arctoscopus japonicus) meal (SFM) and the utility of a viscous culture broth of Leuconostoc mesenteroides (VCL) as binding material in paste diet for Japanese eel (Anguilla japonica) was tested in terms of growth, feed efficiency and digestibility. Four experimental paste diets contained, fish meal and binding materials as, HQFM and starch (F0, control), SFM and VCL (F1), SFM and a mixture of starch and VCL (F2) and SFM and starch (F3). Each diet was formulated to be iso-nitrogenous and iso-lipidic. Each group of 10 juvenile eels with an average initial body weight of 20 ± 2.5 g were randomly distributed into 15 tanks in triplicates and fish were fed twice daily with one of the 4 experimental paste diets for 90 days. Eels fed with diet F2 exhibited good growth performance (final mean weight; 55.3±0.67 g, WGR; 169±5%), being similar to eels (55.5±0.26g, 170±7%) fed a control diet (p>0.05). In spite of iso-nitrogenous and iso-lipidic diets, the feed efficiency of F1 and F3 were inferior to other diets and the same trend was observed in growth performance also, probably due to reduced feed intake owing to poor water stability of the feeds. It should be considered that incorporation of SFM could lead to the discharge of undesirable matters such as phosphorus into the water environment, though it would contribute to lowering production costs.Therefore, further investigations are needed to improve the quality of SFM. Keywords: Fish meal replacement, Growth performance, Iso-lipidic diet, Iso- nitrogenous diet, Leuconostoc mesenteroides, Water stability.

Bacillus amyloliquefaciens CU33 fermented feather meal-soybean meal product improves the intestinal morphology to promote the growth performance of broilers

This study is aimed to select optimum keratin degradation ability from Bacillus strains for feather meal-soybean meal fermentation, and favorably water content for the strain during fermentation of feather meal-soybean meal, and finally investigate the effects of the fermented feather meal-soybean meal product (FFSMP) on growth performance, carcass trait, clinical blood biochemistry, and intestinal morphology of broilers. Thirty-six bacteria strains from soil, sewage pool, and feather waste were screened and selected Bacillus subtilis var. natto N21 (N21), B. subtilis CU14 (CU14), and B. amyloliquefaciens CU33 (CU33) with better keratinase activity and feather-degrading rate. The result of trial 1 showed that the FFSMP produced by CU33 had the optimum physiochemical characterizations, amino acid composition and feeding performance for broilers. Hence the effects of water content (45, 50, 55, and 60%) on FFMSP fermentation of CU33 were investigated in trial 2. Result showed that pH value, counts of Bacillus-like bacteria, γ-PGA, viscosity, surfactin yield and odor all significantly increased according to the water content (P < 0.05). The protease activity reached significantly highest in the 55% and 60% water content groups (P < 0.01). The broilers performance of 55% and 60% water content group were significantly higher than control group (P < 0.05) in weight gain (WG), feed intake (b) at 0 to 21-d-old and the WG, feed conversion ratio (FCR), and production efficiency factor at 0 to 35-d-old, and could reach the similar growth performance as fish meal group (P > 0.05). The fermentation groups significantly decreased urea nitrogen (P < 0.05) and increased creatinine (P < 0.05) in the blood. The fermentation groups also significantly decreased the crypt depth in the duodenum (P < 0.05) and increased villus height to crypt depth ratio of the duodenum (P < 0.05). In conclusion, CU33 shows the best degradation rate for feather and keratinase activity, and the FFSMP with a water content of 50% to 60% during fermentation is suggested. Diets supplemented with 5% FFSMP can promote the growth of broilers by improving the morphology of the duodenum and achieve the feeding effect of high-quality fish meal.

Insect meals as emerging protein source in the aquafeed sector: Emphasis on complementary effects to fishmeal, digestibility, carcass characterisation and immunomodulation in aquatic species

Insect meals received great attention in the aquafeed sector during the past decade due to the unsustainable demand for fishmeal. Desirable nutrient content, especially protein with balanced amino acids is of great importance in the use of insect meals as a viable protein source in aquafeeds. Insect meal could complement about 20-75% of dietary fishmeal in various aquatic species. They have better digestibility compared to low-quality fishmeal, oil meals/cakes, fermented plant proteins, feather meal; blood and meat meal and showed equal performance to high-quality fishmeal. Though partial substitution of fishmeal using insect meals could promote the health status, complete substitution resulted in detrimental effects in some aquatic species. This review concludes that insect meals are of great importance as a sustainable protein source and a viable complement to fishmeal in aquafeeds, thereby, helping to reduce the tremendous demand on fishmeal.Keywords: Aquafeed, Carcass characterisation, Fishmeal, Immunomodulatory effect, Insect meal

Lipolytic Effect of Staphylococcus warneri for Obtaining High-Quality Fishmeal from Fish Waste Fermentation

Lipolytic Effect of Staphylococcus warneri for Obtaining High-Quality Fishmeal from Fish Waste Fermentation

Використання беззубки звичайної (Anodonta cygnea (Linne, 1758)) як добавки до рибного корму на прикладi африканського сома (Clarias gariepinus (Burchell, 1822))

Purpose. Uzbekistan aquaculture has a huge deficit of balanced feed. In a case of feed production from local ingredients, the problem is the lack of stable source of animal protein. The purpose of this experiment was to find out how swan mussel Anodonta used as a feed additive for African catfish will affect fish growth. Methodology. Minced Anodonta was prepared as follow: mussels were collected from the bottom of ponds after fish harvesting; the collected mussels were kept in the separate aquarium; every day several mussels were taken out, their shells were opened and muscle parts were separated the (mostly mussel leg); then the separated muscle were kept for disinfection in KMnO4 solution of low concentration during 20 min and then crushed to a minced state. Feed was given to African catfish according to a special scheme at the rate of 7% of the fish weight. The control group did not receive the minced mussels and fish were fed with carp feeds.The mixed feed in the experimental group #1 consisted of 50% carp feed and 50% minced mussel. In the experimental group #2, African catfish were fed with minced mussels only. Findings. The experiment showed the clear advantage of feed containing 50% of minced clams and 50% of carp feed. The African catfish fed with this feed significantly overtook fish from the control group in weight because this feed turned out to be either the most balanced in composition or better absorbed by catfish. In the control group, the 100% mixed feed gave an increase of 83.8% in weight and 20.5% in length; in the experimental group #1, the feed (50% mixed feed : 50% minced mussel) gave an increase of 136% in weight and 31.1% in length; at the experiment #2 (100% minced mussel), the feed gave an increase of 95.5% and 20.1% in length. Originality. For the first time the swan mussel was used as a source of animal protein for African catfish.This experiment was conducted for the first time, and it was also found for the first time that the addition of minced swan mussel to the feed of African catfish contributed to a significant weight gain compared to the conventional feed:52.5% more compared to conventional feed and 40.5% more compared to pure minced swan mussel. Practical value. Aquaculturenow is in search of source of animal proteinin connection with growing global deficit of a high quality fishmeal for fish feed production. Use of bivalve mollusks Anodonta, which are also a pest in pond farms, is promising feed for obtaining physiologically determined weight gains. Key words: aquaculture, Africaт catfish (Clarias gariepinus (Burchell, 1822)), feed, animal protein, plant protein, water quality, swan mussel (Anodonta cygnea (Linne, 1758)), weight gain.

Cholecystokinin 1 and 2 in red seabream Pagrus major: molecular cloning, response to feeding, and a potential indicator of dietary protein source quality

Cholecystokinin (Cck) and peptide YY (Pyy) play important roles in digestive regulation in fish, but their function in red seabream (Pagrus major) remains obscure. Two cck complementary DNAs (cck-1 and cck-2) in red seabream were identified, and tissue distribution analysis of the genes revealed that cck and pyy were expressed throughout the digestive tract, except for stomach cck-2. After feeding, cck-1 expression significantly increased in the stomach and pyloric caeca, cck-2 expression significantly increased in the pyloric caeca and hindgut, and pyy expression increased in the pyloric caeca of red seabream. After oral administration of dietary protein, i.e., high-quality fish meal (HQFM), soy protein concentrate (SPC), or low-quality FM (LQFM), only HQFM significantly increased stomach cck-1 expression. To assess the growth of red seabream in response to different sources of dietary protein, three isonitrogenous and isoenergetic diets were formulated: HQFM, SPC with a low percentage of HQFM, and LQFM. Mean body weight was highest in the HQFM group after 6 weeks. The stomach cck-1 response to HQFM may explain the high growth in the HQFM group. Our data suggest that cck-1, cck-2, and pyy are involved in digestion. Furthermore, stomach cck-1 may be a valuable tool for evaluating the quality of dietary protein sources for red seabream.

Biochemical processes in piglets that have been receiving a new pre-starter compound feed

The feed value of modern balancing concentrates intended for compound feed to early weaned piglets is based on a combination of energy and easily digestible protein: protein-soya concentrate, potato protein, high-quality fi sh meal and dairy feeds. A protein-vitamin-mineral concentrate containing vegetable protein intended for balancing compound feed for early weaned piglets has been described in the article. It provides for the use of a component from full-fat fl axseeds, which contains polyunsaturated linolenic acid. The composition of the concentrate included pulses and oilseeds, processed by special technology for the removal of anti-nutritional substances. Data on the infl uence of pre-starter compound feed containing the developed concentrate on the body and productivity of suckling pigs have been presented. The animals from the experimental group had more intensive metabolism. The total protein content in the blood serum was in the range of 65,53–65,73 g/l, and the ratio of albumins to globulins (coeffi cient A/G) was optimal – 1,55 and 1,67. The presence of the large amount of urea and glucose in the blood (3,05–3,72 and 6,60–5,80 mmol/l, respectively) indicated that crossbred piglets had intensive synthetic processes associated with the growth of muscle tissue and internal organs. The redox processes have been intensive, which was indicated by the high content of hemoglobin in the blood at the level of 119,7–120,6 g/l and red blood cells (4,32–4,42×1012/l). The ratio of calcium to phosphorus was optimal that indicating the balanced mineral metabolism. The average daily gains in live weight of experimental animals were almost identical at the level of 253–254 g. The results indicate that the new balancing concentrate and pre-starter compound feed containing it had the favorable eff ect on the metabolism in the body of suckling piglets.

Alternative protein sources in the nutrition of farm animals

Protein requirement and its demand of farm animals became one of the critical problems in nutrition on a global scale. Protein requirement has been an explicit demand for a long period with soybean meal and animal protein, but recently there are some limitations in relation to their use and the availability of the high quality fishmeal decreases constantly. For this reason there is increased demand for finding new protein sources which could be the alternatives of soybean meal and fishmeal. Alternative protein sources can be divided into seven categories, according to their origin. In different countries, their use depends on the availability in large quantity and at reasonable price.&#x0D; There is a long tradition of using legume seeds, as alternatives of soybean. Most of them contain some anti-nutritive compounds, but it can be reduced with systematic selection. Oilseed meals are also generally use in poultry and pig nutrition, but those crude protein content varied, depending on the oil extraction technology. Green fodder and leaf protein was also proposed as alternative protein sources, but their use is limited, in particular because of the market price. The amount of bioethanol and starch industry by-products increases gradually in recent years, therefore those became alternatives of soybean meal, or in much less extend, fishmeal. However, amino acid composition of such by-products are far from optimal for poultry and pig; therefore, in the case of their use amino acid supplementation is necessary. Several novel protein sources are proposed in the last decade, such as algae or insect proteins. Recently, their availability and use is limited, but in the near future those would be alternative protein sources in monogastric animal nutrition.

The effects of increasing dietary levels of soy protein concentrate (SPC) on the immune responses and disease resistance (furunculosis) of vaccinated and non-vaccinated Atlantic salmon (Salmo salar L.) parr

Juvenile salmon, with an initial weight of 9 g, were fed three experimental diets, formulated to replace 35 (SPC35), 58 (SPC58) and 80 (SPC80) of high quality fishmeal (FM) with soy protein concentrate (SPC) in quadruplicate tanks. Higher dietary SPC inclusion was combined with increased supplementation of methionine, lysine, threonine and phosphorus. The experiment was carried out for 177 days. On day 92 salmon in each tank were bulk weighed. Post weighing eighty salmon from each tank were redistributed in two sets of 12 tanks. Salmon from the first set of tanks were vaccinated, while the second group was injected with phosphate buffer saline (PBS). Salmon were sampled on day 92 (pre-vaccination), day 94 (2 days post vaccination [dpv]/PBS injection [dpPBSinj]) and day 154 (62 dpv/dpPBSinj) of the trial for the assessment of their immune responses, prior to the performance of salmon bulk weights for each tank. On day 154, fish from each tank were again bulk weighed and then seventeen salmon per tank were redistributed in two sets of twelve tanks and intra-peritoneally infected with Aeromonas salmonicida. At Day 154, SPC80 demonstrated lower performance (weight gain, specific growth rate and thermal growth coefficient and feed conversion ratio) compared to SPC35 salmon. Reduced classical and total complement activities for salmon fed diets with over 58% of protein from SPC, were demonstrated prior to vaccination. Reduced alternative complement activity was detected for both SPC58 and SPC80 salmon at 2 dpv and for the SPC80 group at 62 dpv. Total and classical complement activities demonstrated no differences among the dietary groups after vaccination. Numerical increases in classical complement activity were apparent upon increased dietary SPC levels. Increased phagocytic activity (% phagocytosis and phagocytic index) was exhibited for the SPC58 group compared to SPC35 salmon at 62 dpPBSinj. No differences in serum lysozyme activity, total IgM, specific antibodies, protein, glucose and HKM respiratory burst were detected among the dietary groups at any timepoint or state. Mortalities as a result of the experimental infection only occurred in PBS-injected fish. No differences in mortality levels were demonstrated among the dietary groups. SPC58 diet supported both good growth and health in juvenile Atlantic salmon while SPC80 diet did not compromise salmon’ immunity or resistance to intraperitoneally inflicted furunculosis.

Growth performance and quality traits of European sea bass (D. labrax) fed diets including increasing levels of freeze-dried Isochrysis sp. (T-ISO) biomass as a source of protein and n-3 long chain PUFA in partial substitution of fish derivatives

Abstract The aim of this study was to evaluate nutrient digestibility, growth performance, biometry, dressing out parameters, fillet muscle proximate and fatty acid composition of European sea bass ( Dicentrarchus labrax L.) of nearly marketable size, fed increasing levels of a freeze-dried biomass of Isochrysis sp. (clone T-ISO) as a partial substitute for protein and lipid from fish derivatives, in diets where the level of n-3 long chain (LC) PUFA were reduced through a partial replacement of fish oil for crude palm oil. Since diets including the test ingredients could possibly result in changes of certain quality attributes, fish were also subjected to overall sensory evaluation by a trained panel of assessors according to a triangle test. Three diets were formulated to be grossly iso -nitrogenous (N, 7.5% dry matter). A preparation in which fish meal/trimmings and fish oil were the major protein and lipid sources was used as a positive control diet. Two test complete diets were obtained from the control preparation so that approximately 10 and 20% crude protein from a high quality fish meal and 18 and 36% lipids from fish oil were supplied by the dried microalgae biomass. To stress the role of Isochrysis sp. as a source of n-3(LC)PUFA, the diets including increasing levels of the microalgae biomass were made grossly iso -caloric–lipidic by replacing a part of fish oil with palm oil which is known to be virtually free from n-3 PUFA. Each diet was fed to apparent satiety to quadruplicate groups of sea bass (142 g) over 121 days. The results have shown that replacing up to 20% crude protein from fish meal with a dried Isochrysis biomass and up to 36% fish lipid for those supplied by the microalgae in a diet with reduced level of fish oil, did not adversely affect feed intake or growth performance relative to controls even if the highest substitution rate resulted in a decline (P

Spray-dried plasma promotes growth, modulates the activity of antioxidant defenses, and enhances the immune status of gilthead sea bream (Sparus aurata) fingerlings.

Terrestrial animal byproduct meals, including nonruminant blood meal and blood products, represent the largest and largely untapped safe source of animal protein available within the international market for the aquafeed industry. Spray-dried blood and spray-dried plasma (SDP) proteins have long been recognized as high-quality feed ingredients for farmed animals. In this study, we evaluated the inclusion of SDP from porcine blood (SDPP) in growing diets for gilthead sea bream. Three isonitrogenous (CP = 51.2%) and isolipidic (fat = 12.4%) diets manufactured by cold extrusion (0.8 to 1.5 mm pellet size) were prepared by substituting high-quality fish meal with 0, 3, and 6% SDPP. The diets were tested for a period of 60 d at 22°C with 4 replicates each (400-L cylindroconical tanks, 150 fish per tank, and initial density = 0.5 kg/m(3)). The SDPP inclusion in diets for gilthead sea bream fingerlings were evaluated in terms of growth performance, feed utilization, histological organization of the intestinal mucosa, activity of oxidative stress enzymes (catalase, glutathione S-transferase, glutathione peroxidase, and glutathione reductase) in the intestine, and nonspecific serum immune parameters (lysozyme and bactericidal activity). Results from this study indicated that dietary SDPP promoted fish growth in terms of BW and length; fish fed 3% SDPP were 10.5% heavier (P < 0.05) than those fed the control diet. Spray-dried plasma from porcine blood modulated the activity of the antioxidative defenses in the intestine (P < 0.05) and increased the density of goblet cells in the intestine (P < 0.05) and benefited the host by providing an effective immune barrier against gut pathogenic microbiota. The nonspecific serum immune response in fish fed diets with SDPP was greater (P < 0.05) than in fish fed the control diet. These results indicated that the inclusion of SDPP in gilthead sea bream feed could be beneficial for the fish by enhancing intestinal and serum innate immune function and the activity of antioxidative stress enzymes of the intestine and promoting growth performance.

Marine and freshwater crab meals in diets for red porgy ( Pagrus pagrus ): Digestibility, ammonia-N excretion, phosphorous and calcium retention

Abstract Two trials were conducted to evaluate the nutrient digestibility of river crab (RC) ( Procambarus clarkii ) and marine crab (MC) ( Chaceon affinis ) meals in diets for red porgy ( Pagrus pagrus ) and the effect on ammonia-N excretion and P and Ca retentions. In trial I, the apparent digestibility coefficient (ADC) of nutrients and energy contents in RC and MC meals were determined. Results showed that, the ADC values for protein, lipids, ash, dry matter and gross energy were significantly higher for MC than for RC meal. Both crab meals were efficiently digested despite their high chitin and ash contents. In trial II, red porgy were fed over 6 months with five diets: a control diet (CD) based on high quality fish meal (FM), and four diets where FM protein was replaced at a rate of 10% or 20% by protein derived from either RC or MC meal (RC10, RC20, MC10 and MC20). Replacement of the FM protein by RC or MC proteins had no effect both on protein utilisation and ammonia-N excretion rates, which ranged from 105 to 119 mg N–NH 4 + kg − 1 day − 1 for all diets. A linear increase was observed in the dietary Ca/P ratio by the increase of the dietary RC and MC meal inclusions, resulting in a reduction in the whole fish body content of P, Ca and ash with interesting similar whole body Ca/P ratio (1.59–1.63) for all treatments. Accordingly, Ca, P and ash retention rates were significantly reduced by increasing the dietary proportion of both crab meals. Moreover, a negative relationship between fish growth and final whole body Ca, P and ash contents was obtained. However, no significant differences were observed in total P excretion value (kg P t − 1 ).

Marine and freshwater crab meals in diets for red porgy (Pagrus pagrus): Effect on fillet fatty acid profile and flesh quality parameters

The present study was conducted to evaluate the effect of using river crab (Procamburus clarkii) meal (RC) and marine crab (Chaceon affinis) meal (MC) on the red porgy (Pagrus pagrus) fillet fatty acid profile and quality. Red porgy were fed during 193days with five diets: a control diet based on high-quality fish meal (CD); and four diets replacing 10% and 20% fish meal protein by protein from both RC and MC meals (RC10, RC20 and MC10, MC20). Fillet fat content resulted significantly higher in MC20 fish than the rest of diets. Feeding with both RC and MC meals slightly increased muscle contents of polyunsaturated (PUFA), arachidonic (ARA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) fatty acids and n−3/n−6 ratio as well as decreased n−9 fatty acids, although difference is only significant for the ARA content. After inclusion of both crab meals, values of atherogenicity index (AI) resulted similar among treatments while thrombogenecity index (TI) was reduced, but not significantly, reflecting the higher n−3 fatty acid content in fillets from crab diets. Sensory analysis showed that red porgy fillets of all treatments were very well appreciated with some differences detected in only MC20 fillets, which had significantly higher scores in the attributes of oily odour and flavour, cohesiveness aspect and firmness texture compared to the rest of diets. RC meal dietary inclusion did not promote any changes in sensory evaluation panel. Instrumental muscle texture did not revealed differences between treatments. Results from TBARS of raw fillets showed that the inclusion of both crab meals clearly delays lipid oxidation compared to a FM based diet, during refrigerated storage at 4°C. Thus, for 4 and 7days of storage, fillets of RC or MC diets, attained significantly lower TBARS values than those fed on CD.

Evaluation of Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae yeasts as protein sources in diets for Atlantic salmon (Salmo salar)

The use of the yeasts Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae as protein sources in diets for Atlantic salmon (Salmo salar) pre-smolts was investigated. An 89day study was conducted using triplicate groups of Atlantic salmon with 28g initial weight kept in fresh water. The dietary treatments consisted of a control diet based on high-quality fish meal (FM diet) and three experimental diets with C. utilis (CU diet), K. marxianus (KM diet) or S. cerevisiae (SC diet) yeast, substituting 40% of the crude protein (CP) from FM. There was no difference in final weight or specific growth rate (SGR) of fish fed the CU diet and the FM diet. The SC diet resulted in lower final weight and SGR, and higher average daily feed intake (ADFI) and feed conversion ratio (FCR) than the FM diet, and higher ADFI and FCR than the KM and CU diets. Fish fed the SC diet had decreased retention of nitrogen and energy, while fish fed the CU diet had increased nitrogen retention compared with those fed the FM diet. In general, feeding the SC diets gave lower digestibility of CP, amino acids, and energy compared with the FM, KM and CU diets, whereas there was no difference in nutrient or amino acid digestibility between the KM and CU diet and the FM diet. Feeding KM and SC gave higher total gut weight and higher distal intestinal weight compared with the FM diet. Plasma cholesterol level was lower for the KM and SC diets while plasma glutathione peroxidase levels were higher for the KM diet compared with the FM diet. In conclusion, feeding moderate levels of S. cerevisiae reduced growth performance and nutrient utilization, while C. utilis and K. marxianus were shown to be promising protein sources in diets for Atlantic salmon, capable of replacing 40% of the protein from high-quality fishmeal without adversely affecting growth performance, digestibility or nutrient retention.

Mixtures of lupin and pea protein concentrates can efficiently replace high-quality fish meal in extruded diets for juvenile black sea bream (Acanthopagrus schlegeli)

A 60-day feeding experiment was carried out to investigate the effects of including lupin protein concentrate (LPC) and pea protein concentrate (PPC) in multiple essential amino acid-supplemented extruded diets for black sea bream (Acanthopagrus schlegeli). Nine diets, including eight diets formulated to contain four mixtures of LPC and PPC (L/P ratio, 3:0, 2:1, 1:2 and 0:3) with two dietary inclusion levels (300 or 500g plant proteinkg−1 dietary protein) and one diet with high-quality fish meal as the sole protein source (FM diet) were fed to 18 tanks of 13-g black sea bream. Growth performance, nutrient utilization, and brush-border membrane bound maltase activities were evaluated. An average weight gain (WG) of 32.7gfish−1 and an average feed conversion ratio (FCR) of 1.13g ingested dry matter (g gain)−1 were obtained. Neither plant protein inclusion level nor L/P ratio significantly affected body composition (except ash), fish somatic indices or plasma parameters. The high inclusion of 500gkg−1 resulted in significantly higher FCR than what was obtained with 300gkg−1 inclusion. The WG, whole body ash content, and nitrogen (N) and energy retentions of these fish were, however, significantly lower than that of the fish fed diets with low plant protein inclusion (300gkg−1). The highest LPC inclusion (L/P ratio=3:0) resulted in significantly higher feed intake and FCR, and lower N retention than the treatments with less LPC, but did not affect the growth rates or energy retentions. The diet with the highest PPC inclusion resulted in significantly reduced maltase activity in distal intestine. Any combination of LPC and PPC in essential amino acid-supplemented extruded diets, accounting for up to half of dietary protein, can be used without impairing fish growth. At high inclusion, combinations with more PPC are preferred, due to less efficient feed conversion caused by the LPC.

Effect of stachyose, raffinose and soya-saponins supplementation on nutrient digestibility, digestive enzymes, gut morphology and growth performance in Atlantic salmon ( Salmo salar, L)

This study investigated the effects of raffinose, stachyose either alone or in combination, and the role of soya-saponins in combination with these oligosaccharides, in diets for Atlantic salmon on nutrient digestibilities, growth performance and morphological changes of the gastrointestinal tract. The experiment was carried out using triplicate groups of Atlantic salmon with 0.421 kg initial weight and lasted for 68 days. The experimental diets consisted of a negative control diet based on high-quality fish meal (FM), and a positive control diet containing 300 g kg −1 soybean meal (SBM), and four diets based on the negative control diet added 6.7 g kg −1 raffinose (RA), 29.5 g kg −1 stachyose (ST), a combination of the raffinose and stachyose (RA–ST), or the same combination further supplemented with 2 g kg −1 soya-saponins (RA–ST–SA). The results showed that fish fed the SBM, the positive control, had significantly higher FCR, and tended to have lower weight gain and growth rate compared to fish fed the FM-diet, while fish fed the RA, ST, RA–ST and RA–ST–SA ranked in between the two control diets. The results indicate that feeding the Atlantic salmon the RA, ST, RA–ST and RA–ST–SA did not interfere with protein or fat digestibility. None of the dietary treatments, except for the positive control, caused significant morphological changes in the liver, or mid and distal intestines.

Marine and freshwater crab meals in diets for red porgy (Pagrus pagrus): effect on growth, fish composition and skin colour

River crab (RC) meal (Procambarus clarkii) and marine crab (MC) meal (Chaceon affinis) were tested as a partial replacement for fish meal in diets for red porgy (Pagrus pagrus), and their effects on growth performance, fish proximate composition and skin colouration were evaluated. Red porgy were fed during 165 days with five diets. High-quality fish meal diet was used as a control diet (CD). Protein of fish meal in the control was replaced by increasing the dietary levels of protein derived from RC and MC by up to 10% and 20% of each of them (RC10, RC20, MC10 and MC20). Fish fed on MC20 showed the highest values in feed intake, weight gain and growth (%). No differences were found in FCR and protein efficiency ratio among the treatments. Inclusion of both crab meals in diets significantly decreased the lipid content in whole fish compared with the control animals. On the other hand, no differences in muscle composition were found between the diets. Feeding both crab meals resulted in colour improvement compared with that of the control fish, with better hue values for the RC meal group than those for the MC meal group. The crab meals tested in the present study are suitable as a partial replacement for fish meal in diets for the red porgy, with the MC meal improving growth and both crabs meals improving skin colour, with further improvements in skin colour produced in fish-fed diets containing the RC meal.

High inclusion of partially deshelled and whole krill meals in diets for Atlantic salmon ( Salmo salar)

The aim of this study was to investigate how diets containing partially deshelled or whole krill meals affected growth, digestibility of main nutrients, faecal excretion of minerals, fluoride accumulation, and organ indices and health parameters in Atlantic salmon ( Salmo salar). Three extruded diets were fed for 100 days to salmon with an average weight of 550 g, distributed into 9 tanks equipped with flow through sea water. The dietary treatments comprised a control diet based on high-quality fish meal (FM) and two experimental diets where the FM was substituted with either partially deshelled krill meal (PDKM) or whole krill meal (WKM). Shell removal reduced the chitin content from 28 to 8 g kg −1 dry matter (DM), while fluoride was only reduced from 940 to 631 mg kg −1 DM. Growth rate for fish fed WKM was significantly lower than for salmon fed control diet whereas the PDKM diet did not appear to alter growth during the first feeding period. Digestibility of lipid tended to be higher for PDKM and lower for WKM compared to the FM control. No significant difference was seen for digestibility of nitrogen, but fish fed the FM diet had higher digestibility of threonine, serine, glutamine, histidine and lysine compared to fish fed the WKM diet. No major differences in plasma were seen for triacylglycerols, free fatty acids, glucose, total protein, albumin, globulin, urea, and total bilirubin. Trypsin activities in the pyloric and mid intestine were lower in fish fed the WKM diet compared to FM. Bile acid concentration in the pyloric intestine were significantly lower in fish fed the WKM diet compared to FM and PDKM. Fish fed both diets containing krill meal had signs of mild to moderate nephrosis. To conclude, PDKM could successfully replace FM as a sole protein source for Atlantic salmon, whereas the WKM slightly reduced growth rate compared to the FM and the PDKM diet.

Substitution of fish meal by sesame oil cake (Sesamum indicum L.) in the diet of rainbow trout (Oncorhynchus mykiss W.)

The present study evaluated the nutritional value of sesame oil cake (SOC) in rainbow trout fry (initial body weight of 1.42 g) in a growth trial performed for 45 feeding days at 15 ± 1 °C. A series of five isonitrogenous (380 g digestible protein kg−1 dry matter (DM)) and isoenergetic (18.1 MJ digestible energy kg−1 DM) diets were formulated in which the digestible SOC protein progressively replaced 0%, 13%, 26%, 39% and 52% of the digestible protein of a high quality fish meal (D0-D52). Growth rate of fry significantly improved in fish fed SOC diets compared to the fishmeal control diet (D0) whatever the SOC inclusion level. This positive effect on growth was mainly related to a marked improvement of voluntary feed intake. The decrease of feed efficiency observed with increasing SOC was entirely explained by the reduction of DM and energy digestibilities with SOC incorporation. Nitrogen retention efficiency (nitrogen gain/nitrogen intake) was high (40–41%) and significantly reduced only in fish fed D52 (37%). Our results suggest that SOC can be a suitable protein source for a carnivorous fish and replace at least half of the fishmeal protein (without amino acid supplementation) without growth reduction in rainbow trout fry.