Effects of Spirulina platensis as a feed additive on growth and coloration of blue dolphin cichlids (Cyrtocara moorii Boulunger, 1902)

This study was carried out to investigate the effects of replacing fish meal with dietary Spirulina as a feed supplement on the growth performance and coloration of blue dolphin cichlids (Cyrtocara moorii). Five isonitrogenous (47% crude protein) and isocaloric (17.36 kJ/g digestible energy) diets were for formulated to replace FM with 0, 5, 10, 15 and 20% Spirulina (designated as Control, SP5, SP10, SP15 and SP20 respectively) and fed to the fish (initial body weight, 3.15 ± 0.01 g). Fish were randomly distributed into fifteen 120 L aquariums (26.5 ± 1.00°C), 15 fish per aquarium. The diets were tested in triplicate for 12 weeks. Experimental groups were fed twice daily (09:00 and 17:00) by hand to satiation. At the end of the feeding trial, significantly (p < 0.05) higher weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and lower feed conversion ratio (FCR) were observed in fish fed the SP10 diet when compared to the SP20 diet. There was no significant difference in these parameters between the other groups. The skin coloration of blue dolphin cichlid fed a diet containing Spirulina meal was enhanced. The best coloration was observed in the SP15 group. These impressions were objectively validated by chemical determinations of carotenoids extracted from fish skins and passed statistical tests of significance. The study findings show that Spirulina meal does not diminish growth rates except at very high levels.     

Effects of dried fairy shrimp Streptocephalus sirindhornae meal on pigmentation and carotenoid deposition in flowerhorn cichlid; Amphilophus citrinellus (Günther, 1864) × Cichlasoma trimaculatum (Günther, 1867)

We investigated the effects of dried fairy shrimp Streptocephalus sirindhornae meal (FS) on skin pigmentation and carotenoid deposition in flowerhorn cichlid. Six experimental diets including three treatments of FS at 10% (FS10), 20% (FS20) and 30% (FS30), two dried Spirulina sp. meal (SP) at 6% (SP6) and 12% (SP12), and a control diet (a basal diet without FS or SP) were offered for 90 days. The results demonstrate an increase in the flowerhorn cichlid skin pigmentation from alternative carotenoid feeding. Fish fed the FS diet displayed higher (P ≤ 0.05) chroma and redness values than those fed with a SP diet. The hue value (measure for skin pigmentation) was high when fish were fed with FS20 for 30 and 60 days (P ≤ 0.01). However, fish also showed high hue values when fed for 90 days with FS10 (P ≤ 0.01). The FS20 treatment gave better results than other treatments in terms of total carotenoid, canthaxanthin, astaxanthin and β‐carotene concentration in the skin and musculature. The optimum level of FS in flowerhorn cichlid diets for achieving the highest skin pigmentation was 20%.     

Dietary Spirulina (Arthrospira platensis,Gomont, 1892) improved the flesh quality and shelf life of rainbow trout (Oncorhynchus mykiss,Walbaum, 1792) fed fish meal or plant‐based diet

This study was carried out to determine the effects of fish meal or plant‐based diets with supplementation of dietary Spirulina (4%) on shelf life of rainbow trout, Oncorhynchus mykiss. Rainbow trout (initial weight: ~135 g) were fed four experimental diets (fish meal‐based FM, plant meal‐based‐PM, Spirulina included at 4% of fish meal‐based‐FM/S or plant meal‐based PM/S) for 12 weeks. After the feeding trial, trout were stored on ice at 4°C for 0, 5, 10, 15 and 20 days. The chemical, microbiological and sensory analyses of fish were subjected to each sampling days for flesh quality evaluation. TBA of supplemented dietary Spirulina was lower than that non‐supplemented dietary Spirulina. pH values of all groups decreased significantly between days 0 and 20 during the storage period (p < 0.05). Luminosity (L*) value of all groups increased with time in storage period. Fish fed Spirulina supplemented diets showed an increased red/green tonality (a*) (p < 0.05) compared with fish fed non‐Spirulina supplemented diets. In the end of the storage period, the total coliforms values of fish fed with PM/S diet lower than that of other all diets. In conclusion, dietary Spirulina could be allowed the shelf life of the rainbow trout to be extended.     

Effects of fish oil and partial fish meal substitution with oilseed oils and meals on growth performance, nutrient utilization and health of the rainbow trout Oncorhynchus mykiss

A feeding trial was conducted to investigate the effects of the replacement of dietary fish meal and fish oil with oilseed meals (soybean or canola) and canola oil on growth, nutrient utilization, body composition, diet digestibility and hematological parameters of rainbow trout Oncorhynchus mykiss. Seven diets were used; the control diet (designated FM) contained fish meal and fish oil as the main protein and lipid sources. For the experimental diets, 40% of fish meal protein was substituted with soybean meal, canola meal or a soybean/canola meal mixture, and these diets (designated SM, CM and SCM, respectively) contained fish oil as the lipid source. Three additional diets (SM?+?CO, CM?+?CO and SCM?+?CO) were formulated with the same vegetable protein meals but with fish oil replaced by canola oil. Fish were fed twice daily to apparent satiation for 11?weeks. The growth of fish fed the CM?+?CO diet was significantly lower than that of fish fed the FM, SCM, SM?+?CO and SCM?+?CO diets. The feed conversion ratio (FCR) was significantly better in fish fed the FM and SCM?+?CO diets than in fish fed the CM and CM?+?CO diets. Furthermore, feed intake was significantly lower for fish fed the CM?+?CO diet than in fish fed the SCM diet, and lipid digestibility of the CM?+?CO diet was significantly lower than that of all other diets. No significant differences of body composition were observed. Circulating leukocyte levels, leukocyte ratios and serum lysozyme activity remained unaffected by dietary treatment. However, it was observed that fish fed the CM?+?CO diet displayed hematocrit levels significantly lower (P?<?0.05) than that of fish fed the other diets. The results indicate that when diets contain either fish oil or canola oil, canola meal and soybean meal can be incorporated into rainbow trout feeds at a combined 32% inclusion level (replacing 40% of fish meal protein) without inducing significant negative effects on growth, nutrient utilization or health.     

Replacement of dietary fish meal by soybean meal supplemented with crystalline methionine for Japanese seabass (Lateolabrax japonicus)

Two 8‐week feeding trials were conducted to evaluate soybean meal (SBM) as a fish meal substitute in diets for Japanese seabass, Lateolabrax japonicas. In trial I, a control diet (C) contained 400 g kg^?1 fish meal, and 20%, 40%, 60% and 80% of the fish meal were replaced with SBM, supplied with 3 g kg^?1 DL‐methionine and 2 g kg^?1 L‐lysine (S20, S40, S60 and S80). In trial II, 60% and 80% of the fish meal in diet C were replaced with SBM, supplied with DL‐methionine at 3 g kg^?1 (S60, S80) or 6 to 7 g kg^?1 (RS60, RS80). The feed intake was lower in fish fed diet C than in fish fed diets S20, S40, S60 and S80 (trial I). No significant differences were found in the weight gain, nitrogen retention efficiency and body composition between fish fed diets C, S20, S40 and S60 (trial I), between fish fed diets S60 and RS60 or between fish fed diets S80 and RS80 (trial II). This study indicates that dietary fish meal level for Japanese seabass can be reduced to 160 g kg^?1 by using SBM as a fish meal substitute.     

Gastrointestinal and hepatic enzyme activities in juvenile silvery-black porgy (<Emphasis Type="Italic">Sparidentex hasta</Emphasis>) fed essential amino acid-deficient diets

As amino acids (AAs) are vital molecules in the metabolism of all living organisms and are the building blocks of enzymes, a 6-week feeding trial was conducted for determining the influence of dietary essential amino acid (EAA) deficiencies on pancreatic, plasma, and hepatic enzyme activities in silvery-black porgy (initial weight 4.7?±?0.01 g) juveniles. Eleven isoproteic (ca. 47%) and isoenergetic (ca. 20.5 MJ kg^?1) diets were formulated including a control diet, in which 60% of dietary nitrogen were provided by intact protein (fish meal, gelatin, and wheat meal) and 40% by crystalline AA. The other 10 diets were formulated by 40% reduction in each EAA from the control diet. At the end of the experiment, fish fed with threonine-deficient diet showed the lowest survival rate (P?<?0.05), whereas growth performance decreased in fish fed all EAA-deficient diets, although the reduction in body growth varied depending on the EAA considered. Pancreatic enzymes (trypsin, lipase, α-amylase, and carboxypeptidase A) activities significantly decreased in fish fed the EAA-deficient diets in comparison with fish fed the control diet (P?<?0.05). Fish fed with the arginine-deficient diet had the highest plasma and liver alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels (P?<?0.05). Plasma and liver lactate dehydrogenase and superoxide dismutase showed the highest and lowest values, respectively, in fish fed the arginine and lysine-deficient diets (P?<?0.05). Plasma metabolites were significantly affected by dietary EAA deficiencies (P?<?0.05). The results of this study suggesting dietary EAA deficiencies led to reduction in growth performance as well as pancreatic and liver malfunction. Furthermore, arginine and lysine are the most limited EAA for digestive enzyme activities and liver health in silvery-black porgy.     

Fish meal replacement with squilla (<Emphasis Type="Italic">Oratosquilla nepa</Emphasis>, Latreille) silage in a practical diet for the juvenile giant freshwater prawn, <Emphasis Type="Italic">Macrobrachium rosenbergii</Emphasis> de man, 1879

Replacement of fish meal with squilla silage in practical diet for the juvenile giant freshwater prawn, Macrobrachium rosenbergii, was evaluated. Five iso-nitrogenous and iso-caloric diets were prepared in which protein requirements were met with 100% fish meal (control, diet 1) and squilla silage replacing fish meal at 25, 50, 75 and 100% (diets 2, 3, 4 and 5, respectively). Water stability and water absorption of five feeds revealed significant differences (P?<?0.05). The weight gain varied between a maximum of 248.50?±?34.07% in diet 4 to lowest 132.45?±?14.34% in diet 1. The average daily gain in weight in grams varied from 0.091?±?0.01 (diet 5) to 0.154?±?0.04 (diet 3), whilst the specific growth rate and gross growth coefficient values were recorded highest in diet 4. Highest survival rates (86.66?±?5.77%) were recorded in both experimental diets 4 and 5. Low feed conversion ratio of 1.19?±?0.21 was recorded from diet 4, whilst the highest value of 2.16?±?0.09% was estimated from the diet 5. Proximate carcass composition showed highest crude protein content in post-larvae fed with diet 5 (47.24%) in contrast to lowest diet 1 (36.12%). Lipid values fluctuated significantly between 2.45 and 7.18% (P?<?0.05) between treatments. The ash content significantly increased from diet 1 (16.34%) to diet 5 (20.69%) (P?<?0.05). Highest feed efficiency (gain/feed) value was recorded in diet 4 (1.52?±?0.22), whilst the diet 5 showed lowest value (0.99?±?0.06). The results suggested that squilla silage can be utilised up to 75% of the protein in prawn diets for fish meal replacement.     

Replacement of fishmeal by soy protein concentrate with taurine supplementation in diets for golden pompano (Trachinotus ovatus)

Two 7‐week feeding trials were conducted to evaluate the capacity of golden pompano (Trachinotus ovatus) to use soy protein concentrate (SPC) as a dietary fish meal substitute. In trial I, fish were fed with a control diet (C) containing 400 g kg^?1 fish meal and other four diets in which the fish meal in diet C was replaced by SPC at 20 (R20), 40 (R40), 60 (R60) and 80% (R80). In trial II, a 3 × 2 design was used, and 40 and 80% of the fish meal in diet C were replaced by SPC, with or without 5 g kg^?1 taurine supplementation (six diets, C + T, R40 + T, R80 + T, C, R40 and R80, were formulated). In trial I, no significant difference was found in the feed intake between feeding treatments. The weight gain and nitrogen retention efficiency (NRE) decreased, whereas the feed conversion ratio (FCR) and phosphorus retention efficiency (PRE) increased, with decreasing dietary levels of fish meal. No significant differences were found in the weight gain, FCR and NRE between fish fed diets C and R20, whereas fish fed diets C and R20 had higher weight gain than those fed diets R40, R60 and R80. In trial II, no significant differences were found in the feed intake, weight gain, FCR, NRE and PRE between fish fed diets C + T and C. No significant differences were found in the feed intake, weight gain and NRE between fish fed diets R40 and R40 + T or between fish fed diets R80 and R80 + T. At the end of trial II, no significant differences were found in the condition factor, hepatosomatic index and body composition between fish fed diets C and C + T, or between fish diets R40 and R40 + T, or between fish fed diets R80 and R80 + T, except that fish fed diet R40 had lower body protein content than that of fish fed diet R40 + T. The present study reveals that taurine supplementation can elevate fish meal replacement level by SPC in the golden pompano diets. Fish meal can be reduced from 400 to 320 g kg^?1, if fish meal is substituted by SPC without taurine supplementation, and can be further reduced to 240 g kg^?1, if fish meal is substituted by SPC with 5 g kg^?1 taurine supplementation.     

Effect of feeding Spirulina platensis on the growth, proximate composition and organoleptic quality of common carp, Cyprinus carpio L.

The effect of feeding Spirulina platensis on the growth, carcass composition, organoleptic quality, digestive enzyme activity and digestibility of common carp, Cyprinus carpio L., was studied through a culture trial lasting 120 days. Four experimental diets were employed by replacing fish meal protein from the standard diet at 25%, 50%, 75% and 100% through the incorporation of Spirulina. Another diet with Spirulina as the sole source of protein was also used. The final weight gain, specific growth rate, food conversion ratio and protein efficiency ratio of common carp were not affected by Spirulina supplementation. However, the diet with Spirulina as the sole source of protein resulted in better net protein retention. The muscle RNA:DNA ratio of fish fed Spirulina diets was higher than that of fish fed control diet. There was no significant difference in carcass moisture and protein content in the fish fed Spirulina diets as compared to fish-meal-based control diet. The carcass ash and fat contents were positively and negatively correlated with dietary Spirulina level, respectively. Organoleptic evaluation revealed no effect of Spirulina feeding on the quality of both raw and cooked fish. The gut digestive enzyme activity did not show any definite trend with respect to Spirulina supplementation. Spirulina improved the protein digestibility of the diets.     

Optimizing dietary protein sources for Japanese sea bass (Lateolabrax japonicus) with an emphasis on using poultry by‐product meal to substitute fish meal

This study evaluated the potential of using poultry by‐product meal (PBM) to replace fish meal in diets for Japanese sea bass, Lateolabrax japonicus. Fish (initial body weight 8.5 g fish^?1) were fed six isoproteic and isoenergetic diets in which fish meal level was reduced from 400 g kg^?1 (diet C) to 320 (diet PM1), 240 (diet PM2), 160 (diet PM3), 80 (diet PM4) or 0 g kg^?1 (diet PM5), using PBM as the fish meal substitute. The weight gain (WG), specific growth rate, nitrogen retention efficiency, energy retention efficiency and retention efficiency of indispensable amino acids were higher in fish fed PM1, PM2, PM3 and PM4 diets than in fish fed diets C or PM5. The phosphorus retention efficiency was lower in fish fed PM3, PM4 and PM5 diets than in fish fed C, PM1 or PM2 diets. Fish fed diet PM5 had the highest feed conversion ratio, total nitrogen waste output (TNW) and total phosphorus waste output (TPW) among the treatments. No significant differences were found in the hepatosomatic index or body contents of moisture, lipid and ash among the treatments. Fish fed diet C had lower condition factor and viscerosomatic index than those of fish fed PM1, PM3, PM4 and PM5 diets. The results of this study indicate that using fish meal and PBM in combination as the dietary protein source produced more benefits in the growth and feed utilization of Japanese sea bass than did using fish meal or PBM alone as the dietary protein source. The dietary fish meal level for Japanese sea bass can be reduced to 80 g kg^?1 if PBM is used as a fish meal substitute.     

Effect of the use of the microalga Spirulina maxima as fish meal replacement in diets for tilapia, Oreochromis mossambicus (Peters), fry

The present study addresses the use of the microalga Spirulina maxima as a protein source in diets for tilapia, Oreochromis mossambicus (Peters), fry. Animal protein was replaced with algae protein at ratios of 20%, 40%, 60%, 80% and 100%, and the substitution effect was compared with a control diet in which fish meal was the sole protein. An additional 100% spirulina protein diet was supplemented with phosphorous to test for possible mineral deficiency in the plant-protein-based diet. The six treatments were tested in triplicate in a closed-recirculating system where the fish were fed by hand at 6% of their body weight. After a 9-week feeding period, the growth rate and protein utilization of fish fed the diet with 20% and 40%Spirulina were elevated and not significantly different (P>0.05) from those fed the control diet. Further increases in the alga protein content significantly decreased the growth and feeding performance. The addition of P to the 100%Spirulina diet slightly improved performance in comparison to the same diet without P. None of the treatments produced any clear adverse effects on carcass composition. It is observed that Spirulina can replace up to 40% of the fish meal protein in tilapia diets.     

The effects of less-expensive plant protein sources replaced with soybean meal in the juvenile diet of grass carp (Ctenopharyngodon idella): growth, nutrient utilization and body composition

In this study, the effects of less-expensive protein sources replaced with soybean meal on growth performance, nutrient utilization and body composition of juvenile grass carp were investigated. For this purpose, a control diet containing 42% soybean meal was prepared. Cotton seed meal (CSM), sunflower meal (SFM) and corn meal (CM) were added to the experimental diets by replacing 100% of the soybean meal protein used in the control diet. All diets were iso-nitrogenous (40% crude protein) and iso-caloric (19.5?MJ?kg^?1 gross energy). Each treatment had three replicates, and 20 juvenile grass carps (3.5?±?0.1?g, initial weight) were located in per replicate. The fish were fed to satiety three times in a day during 3?months at 26°C of water temperature in glass aquarium (45 l). The results of the study showed that the weight gain (308.6?C448.6%), specific growth rate (1.56?C1.89%/day), feed conversion rate (1.2?C1.9), protein efficiency ratio (1.32?C2.08), and apparent digestibility coefficients of protein (80.5?C89%) or sum of amino acids (80.5?C88.9%) were not significantly affected by the experimental diets, except diet CM. All of these values obtained for the diet CM were significantly lower than those of fish fed on the control, CSM and SFM diets. However, there were no significant differences between the lipid digestibility of the diets, and crude protein, lipid, and gross energy contents in the whole body of fish in experiments. In conclusion, CSM and SFM diets were highly utilized by juvenile grass carp, but not CM diet. These results combined with the remarkable acceptability of diets containing high levels of plant protein ingredients with identical growth performances of juvenile grass carp show clearly that dietary soybean meal level can be considerably reduced without any adverse consequence in terms of somatic growth and nitrogen utilization.     

Color intensity and growth performance of common clownfish (Amphiprion ocellaris) enhanced by dietary Spirulina (Arthrospira platensis)

In this study, the effect of dietary Spirulina (Arthrospira platensis) on color intensity, growth performance, total ammonia–nitrogen excretion (TAN), and profitability of common clownfish (Amphiprion ocellaris) was investigated. Three isoproteic (46%) and isolipidic (13%) diets were formulated as one control (C) and two different levels (15 and 30%) of Spirulina (SP15 and SP30) substituted for fish meal and cornmeal. Ten clownfish (initial body weight of 0.55?±?0.04 g) per aquarium were distributed to nine glass aquariums (60 L) with three replicates. Fish were hand-fed a day to the satiation thrice. Clownfish were weighed in bulk, and the photographs were taken biweekly during the 12-week experiment. The determined regions of the images were standardized with a raster graphics editor and recorded the color parameters by considering both CMYK (cyan magenta yellow key) and RGB (red green blue) models. After the feeding trial, fish were starved for 3 days, and the total ammonia–nitrogen (TAN) was analyzed with the ammonia salicylate method on the next day for 12 h. At the end of the trial, the final mean weights (FMW) and specific growth rates (SGR) of SP15 (FMW: 1.95?±?0.18 g, SGR: 1.75?±?0.04%/day) and SP30 (FMW: 2.05?±?0.14 g, SGR: 1.81?±?0.05%/day) were significantly higher than the C (FMW: 1.68?±?0.12 g, SGR: 1.58?±?0.06%/day) group (P?<?0.05). Both color models have proved the enhancement of the skin coloration (significant improvements were recorded in the colors, including red, green, magenta, and key, P?<?0.05). Also, it was determined that the TAN was decreased with the increase of the Spirulina level (29.8, 22.9, and 17.6 mg-N/100 g fish/12 h for C, SP15, and SP30, respectively) in the diet (P?<?0.05). However, a high level of Spirulina in the diet negatively affected profitability. Consequently, common clownfish’s growth, color, and TAN improved with the dietary Spirulina. Considering that Spirulina is an expensive raw material, adding it into the diet at medium levels (15%) is recommended.

     

Total fish meal replacement with rapeseed protein concentrate in diets fed to rainbow trout (Oncorhynchus mykiss Walbaum)

The potential of rapeseed protein concentrate as fish meal alternative in diets for rainbow trout (initial average weight 37.8?±?1.4?g) was evaluated. Nine experimental tanks of a freshwater flow-through system were stocked with 12 fish each. Triplicate groups of fish received isonitrogenous (47.9?±?0.5% CP) and isoenergetic (22.4?±?0.2?kJ?g^?1) experimental diets with 0, 66 and 100% of fish meal substituted with rapeseed protein concentrate (71.2% CP), thereby providing 0, 29 and 43% of dietary protein. As the amino acid profile of rapeseed protein concentrate was comparable to fish meal, there was no need to supplement experimental diets with synthetic amino acids. At the end of the 84?days of feeding period, fish growth performance, feed intake and feed efficiencies were not compromised, when 100% of fish meal in the control diet was replaced with rapeseed protein concentrate, revealing a SGR of 1.19 or 1.10, a FCR of 1.09 or 1.18 and a feed intake of 78.5 or 74.7?g in fish fed on the control diet or fed the diet devoid of fish meal, respectively. Intestinal morphology did not reveal any histological abnormalities in all dietary groups. Blood parameters including haematocrit and haemoglobin as well as glucose, triglycerides and total protein in the plasma were not different between treatment groups. Thus, the rapeseed protein concentrate tested here has great potential as an alternative to fish meal in rainbow trout diets.     

Evaluation of fish-meal free diets for rainbow trout, Oncorhynchus mykiss

Eight experimental diets were formulated for rainbow trout using agricultural byproducts as major ingredients. Each experimental diet contained varying amounts of corn grain, corn gluten meal, corn gluten feed and one of the following: 200 g kg^?1 peanut meal, 200 or 400 g kg^?1 soybean meal (SBM), 390 g kg^?1 low-allergen soy flour, 310 g kg^?1 soy protein concentrate, 300 g kg^?1 low-allergen soy protein concentrate or 200 g kg^?1 SBM + 110 g kg^?1 blood meal. One diet contained 200 g kg^?1 SBM and canola oil as the main lipid source. The remaining diets contained 95 g kg^?1 menhaden oil. Fish fed a commercial trout diet exhibited significantly greater weight gain (322%), and a lower feed conversion ratio (0.89) but significantly lower protein efficiency ratio (2.18) than fish fed the experimental diets. Within the experimental diets, fish fed the 400 g kg^?1 soy flour diet and the 400 g kg^?1 soybean meal diet had significantly higher weight gains (276% and 268%) and protein efficiency ratios (2.58 and 2.52), and lower feed conversion ratios (1.02 and 1.03) than fish fed other experimental diets. Fillet flavour varied between treatments. Most notable was the lower fishy flavour and higher chicken flavour of fish fed the diet that contained canola oil rather than menhaden oil. Microscopic evaluation of the liver and five sections of the gastrointestinal tract failed to demonstrate any differences between treatment groups. The ingredient costs of several experimental diets were lower than the estimated cost of a standard commercial trout diet. However, the superior feed conversion ratios of fish fed the control diet resulted in lower feed costs per unit of fish produced.     

Growth,hematological and biochemical indices of common carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis> fed diets containing corn gluten meal

The effects of replacing fish meal (FM) with corn gluten meal (CGM) on growth and physiological performance were evaluated in common carp (Cyprinus carpio). Six experimental diets were formulated by substituting 0 (control), 20, 40, 60, 80, and 100% CGM protein for FM protein. The concentrations of dietary protein in the experimental diets were 27.8–29% and the P:E ratios were 14.7–15.46 mg/kJ. Eighteen fish with an initial weight of 13.5?±?0.1 g were allocated to each of 18 circular tanks (450 L) to give triplicate groups for each dietary treatment. The fish were fed to satiation for 8 weeks. At the end of the feeding trial, growth indices, body proximate composition, and hematological and biochemical parameters were measured. Blood samples were taken from six fish in each tank. Final weight and total length were significantly higher in fish fed 100% CGM (27.8?±?1.2 g and 11.9?±?0.3 cm) than for those fed the control (22.7?±?1.4 g and 10.9?±?0.5 cm) or 20% CGM (22.3?±?1.2 g and 11?±?0.4 cm) diets. No effect of FM replacement by CGM was observed for condition factor or hepatosomatic index (P?>?0.05). The highest value of protein productive value (14.31?±?0.65) was observed in fish fed 20% CGM (P?<?0.05). There were no significant differences in percentage body moisture and fat, but percentages of protein and ash were significantly different among experimental groups; the highest values of protein (15.6?±?0.24%) and ash (3.01?±?0.26%) were recorded in fish fed 40% CGM. For hematological parameters, the highest number of white blood cells (4.1?±?0.1?×?10³ mm^?3) was observed in fish fed 100% CGM (P?<?0.05). In addition, the highest hematocrit (42.1?±?0.7%) and triglyceride (294.11?±?23.82 mg dl^?1) were seen in fish fed the diet containing 40% CGM, while 80% CGM gave the highest cholesterol level (204.44?±?9.0 mg dl^?1; P?<?0.05). Replacement of FM with CGM had no negative effects on growth and physiological parameters of common carp fingerlings in this short (8 weeks) trial, suggesting that it may be feasible to replace FM with CGM in diets formulated for juvenile common carp.     

Evaluation of two soybean meals fed to yellow perch (Perca flavescens)

Aquaculture of yellow perch (Perca flavescens) has been increasing, yet there have been few nutritional studies and no evaluations of alternative protein sources in diets. Solvent‐extracted, dehulled soybean meal (SBM) and expelled‐extruded soybean meal (exSBM) were fed to yellow perch to evaluate their effectiveness in replacing dietary fish meal (FM) in isonitrogenous practical feed formulations. Both soy ingredients were incorporated in graded amounts from 100 to 730 g kg⁻¹ of the diet. Feed consumption, weight gain, feed efficiency (FE) and survival were significantly affected by type of soy ingredient, concentration and the interaction of the two main effects. Consumption was significantly lower in fish fed diets containing 400, 600 and 730 g kg⁻¹ compared to fish fed diets containing lower concentrations. Weight gain was significantly lower in fish fed diets containing 600 g kg⁻¹ and FE significantly lower in fish fed diets containing 500 g kg⁻¹ compared to fish fed the control diet or lower concentrations of soy ingredients. Most fatty acid concentrations were affected by feeding exSBM compared to fish fed the control diet, but long chain fatty acids remained at relatively high concentrations. Based on feed consumption, weight gain and FE data, yellow perch are able to effectively utilize both soy ingredients in practical diets. A conservative recommendation of 300 g kg⁻¹ diet appears appropriate for growout diets.     

Evaluation of Yellow Lupin Lupinus luteus Meal as an Alternative Protein Resource in Diets for Sea-Cage Reared Rainbow Trout Oncorhynchus mykiss

The performance of sea-water reared rainbow trout Oncorhynchus mykiss fed three isonitrogenous and iso-energetic diets based on either fishmeal, solvent-extracted soybean meal or yellow lupin ( L luteus cv. Wodjil) kernel meal was evaluated. Over the course of a 10-wk study, the fastest growing fish were those fed the diet containing 50% yellow lupin kernel meal (YLM), which grew from 83.6 ± 0.7 g to 322.8 ± 3.2 g (mean ± SEM). This was not significantly faster than growth of fish fed the diet based on 50% solvent-extracted soybean meal (SBM), though it was significantly ( P < 0.05) faster than the growth of fish fed the fishmeal based diet (FSM). Growth of fish fed the experimental diets was comparable to growth of fish fed a range of commercial diets as a reference. Survival of fish fed the FSM diet was poorest of all the treatments (47.4%), though this was only significantly poorer than that of fish fed the YLM diet (88.9%). Feed intake was highest by fish fed the YLM diet (5.58 g/d) and lowest for fish fed the FSM diet (336 g/d). Reasons for these differences in feed intake were not clear, though they may be related to different levels of buoyancy and palatability among the diets. Feed conversion rate (FCR) was consistent between treatments at about 1.6:1, though given that this study was a sea-cage based experiment it is likely that considerable unaccounted feed losses occurred, thereby inflating the feed conversion value. Sensory evaluation of fish fed the three test treatments showed no overall difference in the acceptability of the fish, further supporting that solvent-extracted soybean meal and yellow lupin kernel meal both have considerable potential to replace fishmeal as a protein resource in diets for rainbow trout.     

Partial replacement of fish meal by soybean meal with or without methionine and phytase supplement in diets for juvenile Chinese sucker,Myxocyprinus asiaticus

This study was designed to evaluate the effects of using soybean meal supplemented with or without methionine (M) and graded levels of phytase (P) to replace high‐level (60%) fish meal in the diets for juvenile Chinese sucker. Seven experimental diets (about 430 g kg^?1 crude protein on dry matter basis) were formulated from practical ingredients. The control diet (FM) was formulated to contain 400 g kg^?1 white fish meal (FM), whereas in the other six diets (diets 2–7), soybean meal (SBM) was used to replace 60% fish meal with or without methionine (3 g kg ^?1) and 0,500, 1000, 1500 and 2000 U kg^?1 phytase (designated as SBM, SM, SMP500, SMP1000, SMP1500 and SMP2000, respectively). Results from the feeding trial indicated that SBM without any methionine or phytase supplement replacing about 60% FM significantly affected the growth of fish (P < 0.05). Weight gain of fish fed diet SM was significantly higher than the fish fed diet SBM, but still much lower than fish fed the control diet (P < 0.05). SBM with methionine and phytase supplement significantly improved the growth of fish and apparent digestibility coefficients of phosphorus compared with the groups which fed diet SBM and diet SM (P < 0.05). Weight gain of fish fed SMP1000, SMP1500 and SMP2000 had no significant difference than fish fed control diet. Furthermore, fish fed SMP1500 showed optimum weight gain and ADC of phosphorus between these three groups. This suggested that soybean meal with 3 g kg^?1 methionine and 1500 U kg^?1 phytase supplement could successfully replace 60% fish meal in the diet for juvenile Chinese sucker without affecting growth and enhanced the apparent digestibility coefficient of phosphorus.     

Evaluation of fisheries by-catch and by-product meals in diets for red drum Sciaenops ocellatus L.

This study evaluated various by‐catch and by‐product meals of marine origin with red drum (Sciaenops ocellatus L.). Four different kinds of by‐catch or by‐product meals [shrimp by‐catch meal from shrimp trawling, Pacific white shrimp (Litopenaeus vannamei (Boone)) processing waste meal, red salmon (Oncorhynchus nerka (Walbaum)) head meal, and Pacific whiting (Merluccius productus (Ayres)) meal] were substituted for Special Select? menhaden fish meal at 33% or 67% of crude protein in diets formulated to contain 40% crude protein, 12% lipid, and 14.6 kJ digestible energy g^?1. Each of these diets and three additional diets consisting of shrimp processing waste meal formulated on a digestible‐protein basis and two Pacific whiting diets containing reduced levels of ash were also evaluated in two 6‐week feeding trials with juvenile red drum (initial weight of 4–5 and 1–2 g fish^?1 in trials 1 and 2). Red drum fed by‐catch meal at either level of substitution performed as well as fish fed the control diet; whereas, fish fed shrimp processing waste meal diets had significantly (P≤0.05) reduced weight gain and feed efficiency ratio values compared with the controls, even when fed on a digestible‐protein basis. The diets containing Pacific whiting at either levels of substitution and regardless of ash level supported similar performance of red drum as those fed the control diet. Fish fed the red salmon head meal diet fared poorly, probably owing to an excessive amount of lipid in the diet that became rancid. Overall, by‐catch meal associated with shrimp trawling and Pacific whiting appear to be suitable protein feedstuffs for red drum.