Dietary inclusion of detoxified <Emphasis Type="Italic">Jatropha curcas</Emphasis> kernel meal: effects on growth performance and metabolic efficiency in common carp, <Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.

Jatropha curcas is a multipurpose and drought-resistant shrub or small tree widespread all over the tropics and subtropics. Its seeds are rich in oil, and the Jatropha kernel meal obtained after oil extraction is rich in protein. However, presence of toxic and antinutritional constituents restricts its use in fish feed. Jatropha kernel meal was detoxified. Common carp, Cyprinus carpio, fingerlings (15; av. body mass 10.9 ± 0.65 g) were randomly distributed in three groups with five replicates. A 6-week feeding experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilisation and energy budget. Fish were fed isonitrogenous diets (38% crude protein): control diet (C _ontrol group) containing fish meal (FM) protein based protein and two other diets replacing 75% FM protein with detoxified Jatropha kernel meal (DJKM, J _atropha group) and soybean meal (SBM, S _oybean group). At the end of the experiment, body mass gain, metabolic growth rate, protein efficiency ratio, protein productive value, energy retention, efficiency of metabolised energy for growth and efficiency of energy retention were determined. These parameters were high and statistically similar for C _ontrol and J _atropha groups and significantly lower (P < 0.05) for S _oybean group. Whereas a reverse trend was observed for energy expenditure per g protein retained in fish body. No significant differences were found in heat released, gross energy uptake, metabolised energy intake, metabolisability, energy expenditure, energy expenditure per g protein fed and apparently unmetabolised energy. Conclusively, common carp–fed plant protein (DJKM and SBM) and FM protein–based diets exhibited equal average metabolic rate.     

Comparative nutritional value of <Emphasis Type="Italic">Jatropha curcas</Emphasis> protein isolate and soy protein isolate in common carp

Jatropha seed cake (JSC) is an excellent source of protein but does contain some antinutritional factors (ANF) that can act as toxins and thus negatively affect the growth and health status of fish. While this can limit the use of JSC, detoxified Jatropha protein isolate (DJPI) may be a better option. An 8-week study was performed to evaluate dietary DJPI to common carp Cyprinus carpio. Five iso-nitrogenous diets (crude protein of 38%) were formulated that consisted of a C _ontrol (fish meal (FM) based protein), J ₅₀ or J ₇₅ (50 and 75% of FM protein replaced by DJPI), and S ₅₀ or S ₇₅ (50 and 75% of FM protein replaced by soy protein isolate, SPI) and fed to triplicate groups of 75 carp fingerlings (75; av. wt. ± SD; 11.4 ± 0.25 g). The growth, feeding efficiencies, digestibility, plasma biochemistry, and intestinal enzymes were measured. Results showed that growth performance of fish fed the S ₇₅- or DJPI-based diets were not significantly different from those fed the C _ontrol diet, while carp fed the S ₅₀ had significantly better growth than the J ₇₅ diet. Fish fed the J ₇₅ diet had significantly lower protein and lipid digestibility as well as significantly lower intestinal amylase and protease activities than all other groups. However, all plant protein-based diets led to significantly higher crude protein, crude lipid, and gross energy in the body of common carp compared to the control treatment. Plasma cholesterol and creatinine significantly decreased in the plant protein fed groups, although plasma triglyceride as well as the red blood cells count, hematocrit, albumin, globulin, total plasma protein, and lysozyme activity were higher in plant protein fed groups compared to FM fed group. White blood cells, hemoglobulin concentration, alkaline phosphatase and alanine transaminase activities, and glucose level in blood did not differ significantly among treatments. The results suggest that the DJPI is non-toxic to carp and can be used to replace FM in the diets of common carp up to 75%, but further research to potentially reduce some inherent ANF within this protein source, such as non-starch polysaccharides, may improve nutrient utilization.     

Nutritional,physiological and haematological responses in rainbow trout (Oncorhynchus mykiss) juveniles fed detoxified Jatropha curcas kernel meal

Jatropha curcas is a multipurpose and drought‐resistant tree, widespread throughout tropics and subtropics. Its seeds are rich in oil and protein. It is being promoted as a biofuel plant. Jatropha kernel meal obtained after oil extraction is an excellent source of protein [580–660 g kg^?1 crude protein (CP)]. However, the presence of toxic and antinutritional constituents restricts its use in fish feed. Jatropha kernel meal was detoxified. Using Oncorhynchus mykiss juveniles, a 12‐week experiment was conducted to evaluate the nutritional quality of detoxified Jatropha kernel meal (DJKM). Oncorhynchus mykiss juveniles (36, av. wt. 4.2 ± 0.4 g) were distributed into three groups with 12 replicates and fed isonitrogenous (CP 450 g kg^?1) diets: control [fish meal (FM)–based protein], J₅₀ and J_62.5 (50% and 62.5% of fishmeal protein replaced by DJKM). Growth performance, apparent lipid conversion, hepatosomatic index, nutrients and energy digestibilities; efficiency of digestible nutrients and energy; and glucose and creatinine levels in blood were statistically similar (P > 0.05) for control and J₅₀ but were higher (P < 0.05) than for J_62.5. Opposite trend was observed for phosphorus, sodium, albumin and total protein in blood. Feed conversion ratio, protein efficiency ratio, protein productive value, energy retention, gastro somatic index, muscle lipid peroxide; and red and white blood cells, haematocrit, haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration; alkaline phosphatase and alanine transaminases activity, globulin, total bilirubin, blood urea nitrogen, calcium and potassium in blood and lysozyme activity in serum did not differ significantly among the groups. Intestinal enzyme activities; and plasma and muscle cholesterol levels for control were higher (P < 0.05) than for DJKM groups, while opposite trend was observed for relative intestinal length (mm g^?1). Conclusively, performance of J₅₀ group was similar to control group and, thus, is recommended as the optimal diet for rainbow trout.     

Substitution of fish meal by Jatropha curcas kernel meal: Effects on growth performance and body composition of white leg shrimp (Litopenaeus vannamei)

Jatropha curcas (L.) is a multipurpose and drought‐resistant tree, widespread throughout the tropics and subtropics. Its seeds are rich in oil and protein (contains 600–660 g kg^?1 crude protein similar to fish meal). It is being promoted as a biofuel plant. Jatropha kernel meal obtained after oil extraction is an excellent source of protein. However, presence of toxic and antinutritional constituents restricts its use in fish and shrimp feed. An 8‐week experiment was conducted to evaluate the nutritional quality of the detoxified Jatropha kernel meal (DJKM) in white leg shrimp (Litopenaeus vannamei). Shrimp (60) with an initial average body weight of 4.46 ± 0.64 g were randomly distributed into three treatments with four replicates and fed isonitrogenous and isoenergetic diets (crude protein 350 g kg^?1, crude lipid 90 g kg^?1): Control (fish meal‐based protein), JC₂₅ and JC₅₀ (25% and 50% of fish meal protein replaced by DJKM). Higher (P < 0.05) body mass gain, specific growth rate and metabolic growth rate were observed in DJKM‐fed groups than in Control group. However, lower (P > 0.05) feed conversion ratio was observed in DJKM‐fed groups, while protein efficiency ratio exhibited an opposite trend. Protein, ash and gross energy content of the whole shrimp body were higher (P < 0.05) in DJKM‐fed groups compared to Control group. Moisture and lipid content of the whole shrimp body did not differ significantly among the three groups. Cholesterol level in plasma was highest (P < 0.05) in the Control group, followed by JC₂₅ and JC₅₀ groups; all being significantly different. In conclusion, DJKM is a promising fish meal replacer in shrimp diets.     

Detoxified Jatropha curcas kernel meal as a dietary protein source: growth performance,nutrient utilization and digestive enzymes in common carp (Cyprinus carpio L.) fingerlings

Jatropha curcas kernel meal is rich in protein; however, it is toxic. Two durations of detoxification process were investigated: 30 and 60 min; designated as J_a and J_b, respectively. Common carp fingerlings (252 fish; 3.2 ± 0.07 g) were fed diets: control containing fishmeal (FM); S₅₀, J_a50 and J_b50: 50% of FM protein replaced by soybean meal (SBM), detoxified Jatropha kernel meal (DJ_aKM and DJ_bKM); S₇₅, J_a75 and J_b75: 75% of FM protein replaced by SBM, DJ_aKM and DJ_bKM. Highest body mass gain, specific growth rate, metabolic growth rate (MGR) and energy production value were observed for the J_b50 group which were statistically similar to that for control group and significantly (P < 0.05) higher than for all other groups. Lowest feed gain ratio was observed in control group, which was statistically similar to than in J_b50 group. Lowest MGR, protein efficiency ratio, protein productive value and lipid production value were observed in J_a75 group. The dry matter and lipid digestibilities were statistically (P < 0.05) highest in control group and lowest in J_a50 group. Protein and energy digestibilities were statistically similar (P > 0.05) for control and J_b50 groups, and these values were highest among the groups. Highest crude protein efficiency was observed in J_b50 group, whereas lowest in J_b75 group. Relative intestinal length and hepatosomatic index were higher in plant protein–fed groups. Intestinal amylase, protease and lipase activities for control group were statistically higher (P < 0.05) than for plant protein–fed groups. Conclusively, performance of J_b50 group was similar to control group and better than other groups and, thus, is recommended as the most optimal diet for common carp fingerlings.     

Nutritional and biochemical studies on feeding of hydrolysed and unhydrolysed detoxified Jatropha curcas protein isolate in common carp fingerlings

Detoxified Jatropha protein isolate (DJPI), prepared from Jatropha seed cake was hydrolysed using Alcalase 2.4L FG. Both DJPI and hydrolysed DJPI (HDJPI) were evaluated as a fish meal (FM) replacement in common carp (Cyprinus carpio L.) diets. The peptide concentration in HDJPI was determined using matrix‐assisted laser desorption ionization‐time of flight mass spectrometer (MALDI‐TOF). Twenty‐two peptides with molecular mass ranging from m/z 906.455 to 1774.943 Da were identified. Fingerlings (45; av. wt. 10.1 ± 0.4 g) were randomly distributed in five groups with three replicates. An 8‐week feeding experiment was conducted to compare the nutritional quality of the HDJPI, DJPI and FM. Fish were fed on iso‐nitrogenous diets: control (FM based protein), J₅₀ (50% of FM protein replaced by DJPI), J₇₅ (75% of FM protein replaced by DJPI), JH₅₀ (50% of FM protein replaced by HDJPI) and JH₇₅ (75% of FM protein replaced by HDJPI). Growth performance was higher for FM fed group compared with the other groups, while nutrient utilization parameters were similar for control and J₅₀ groups and superior (P < 0.05) to J₇₅ and both the HDJPI fed groups. No variation (P > 0.05) was observed in blood albumin and hepatosomatic index among all different groups. Blood urea nitrogen, calcium, sodium and potassium ions in the blood were similar among all five groups.     

Dry whey meal as a protein source in practical diets for Nile tilapia,Oreochromis niloticus fingerlings

ABSTRACT

This study was conducted as a trial of using dry whey meal (DWM) as a substitute for fish meal (FM) in practical diets for Nile tilapia, Oreochromis niloticus. Triplicate fish groups were fed on five isonitrogenous (30.2%) and isolipidic (6.9%) diets. The control diet (D1) used FM as the sole protein source. In the other four diets (D2–D5), FM protein was substituted by 25, 50, 75, or 100% DWM. Fish (3.5 ± 0.1 g) were stocked at a rate of 20 fish per 100-L aquarium and fed one of the tested diets up to satiation twice daily for 12 weeks. Fish growth, feed utilization, protein efficiency ratio, apparent protein utilization, and energy utilization for fish fed DWM diets up to 75% FM (D2–D4) tended to be higher but were not statistically different than the control diet. No significant effect of diet was found in whole-body moisture, crude protein, and total ash contents. Whole-body lipid content in fish fed the 100% DWM (D5) diet was significantly higher than that for fish fed the control diet. The optimal replacement level of FM by DWM was estimated by second-order polynomial regression to be 62.5%.     

Substitution of fish meal with sunflower seed meal in diets for Nile tilapia (Oreochromis niloticus L.) reared in earthen ponds

This study investigated sunflower seed meal (SSM) as dietary protein replacement of fish meal (FM) for Nile tilapia (Oreochromis niloticus) juveniles (initial mean weight of 19.8 ± 6.3 g) reared in earthen ponds for 210 days. SSM replaced 25%, 50%, 75%, and 100% (i.e., D₂₅, D₅₀, D₇₅, and D₁₀₀, respectively) of FM in an isonitrogenous and isocaloric diet. The optimum FM replacement level of D₂₅ as predicted by the equation y = 177.5 + 26.5x – 7.9x² yielded an optimum weight of about 184 g within 100 days. Thus D₂₅ was the most effective SSM level for Nile tilapia growth in earthen ponds. Fish growth declined as SSM exceeded D₂₅. The length-weight relationship (r ≥ 90%) depicted an isometric fish growth. Nutrient utilization parameters were similar in all the diets except for D₁₀₀. The protein content of fish carcass was highest in the control and D₂₅, while fiber level was highest in D₁₀₀. Amino acids imbalance and high fiber content could have reduced the fish growth at D₅₀, D₇₅, and D₁₀₀.     

The use of fermented soybean meal and squid by-product blend as a substitute for fish meal in practical diets for climbing perch,Anabas testudienus (Bloch, 1792), pond culture: Growth performance and economics analysis

A feeding trial was conducted to evaluate the effects of different ratios of fish meal (FM) to a fermented blend (FB: fermented soybean meal and squid by-product blend) on growth and economic performance of climbing perch, Anabas testudineus (Bloch, 1792), in earthen ponds. Five diets were prepared where FB was substituted for 0 (D1), 25 (D2), 50 (D3), 75 (D4), or 100% FM protein (D5), while a commercial diet (D6) was used for comparison. Triplicate groups of fish (1.03 ± 0.07 g) were fed twice daily up to satiation for 70 days in earthen ponds. No significant (P > 0.05) differences were found in growth performance of fish fed D1, D2, D3, and D6 diets, while fish growth decreased significantly (P < 0.05) in D4 and D5 groups. Feed intake decreased (P < 0.05) with the increasing levels of FB with no significant difference in the feed conversion ratio, which ranged from 1.98 to 2.08. The fish survival decreased significantly in D5 alone. While considering the overall production, the total yield and economic return were found to be highest in D2 (64176.7 TK ha^?1) and lowest in D5 (14418.3 Tk. ha^?1). Based on the present experimental condition, it is concluded that FB can economically be included in aquafeed as a substitute for up to 50% of FM protein from the diets of climbing perch.     

Response of juvenile tench (Tinca tinca L.) fed practical diets with different protein contents and substitution levels of fish meal by soybean meal

A basal practical diet for juvenile tench (Tinca tinca) was formulated and elaborated to test several protein contents and substitution possibilities of fish meal (FM) by soybean meal (SBM) in a 90‐day trial with 5‐month‐old juveniles (30.54 mm TL, 0.30 g W). A factorial design included nine feeding treatments: three protein contents (50%, 40% or 30%) and three levels of replacement (0%, 25% or 45%) of FM protein by SBM protein. In addition, a commercial carp feed was used as reference. Final survival ranged from 98.2% to 99.4%. The 50% dietary protein with 0% or 25% replacement and 40% dietary protein with 25% replacement diets enabled higher growth (P < 0.05) and lower FCR (P < 0.05) than the rest of practical diets. Fish fed 50% dietary protein had similar growth than those fed carp feed (63.8% protein). Deformed fish averaged 1% for the practical diets and 87.6% for the carp feed. The basal practical diet has showed to be feasible and levels of 40–50% dietary protein with 25% replacement of FM protein by SBM protein can be recommended for juvenile tench aged 5–8 months.     

Effects of lysine and methionine supplementation on growth,body composition and digestive function of grass carp (Ctenopharyngodon idella) fed plant protein diets using high‐level canola meal

A 76‐day feeding trial was carried out to evaluate the effects of Lysine and Methionine supplementation on growth and digestive capacity of grass carp (Ctenopharyngodon idella) fed plant protein diets using high‐level canola meal (CM). Fish with initial average weight 103.9 ± 0.6 g were fed three extruded diets. Fish meal (FM) diet was formulated as the normal control with 40 g kg^?1 FM and 300 g kg^?1 CM; CM diet was prepared by replacing all FM with CM (total 340 g kg^?1) without Lys or Met supplementation; CM supplement (CMS) diet was similar to CM diet but was supplemented with essential amino acids (EAA) to ensure the levels of Lys and Met similar to those in the FM diet. Feed intake, feed efficiency and specific growth rate of the grass carp fed CMS and FM diets were similar (P > 0.05), but higher than those of the grass carp fed CM diet (P < 0.05). The hepatosomatic index, relative gut length, intestosomatic index and intestinal folds height were significantly improved in fish fed FM and CMS diets as compared to CM diet (P < 0.05). Lower activities of trypsin, lipase and amylase in hepatopancreas were observed in fish fed CM diet (P < 0.05). Three hundred and forty gram per kilogram CM without Lys or Met supplementation significantly decreased trypsin, lipase and amylase mRNA levels in hepatopancreas (P < 0.05). These results indicated that the high supply of CM (340 g kg^?1) in plant protein (200 g kg^?1 soybean meal and 100 g kg^?1 cottonseed meal) diets decreased digestive ability through decreasing digestive enzyme activities and enzyme gene's expressions of grass carp, and these side effects can be reversed by supplementing Lys and Met. Therefore, CM could be high level used in a plant protein blend‐based extruded diet for grass carp as long as EAA were supplemented.     

低鱼粉饲料中添加牛磺酸对青鱼幼鱼生长、肠道修复及抗急性拥挤胁迫的影响

为研究低鱼粉饲料中添加牛磺酸对青鱼幼鱼[初始质量(5.90±0.03)g]生长、肠道修复及抗急性拥挤胁迫的影响,实验以青鱼正常鱼粉组(20%)为对照组,10%鱼粉组为负对照组(I_0组),在低鱼粉饲料中分别添加0.05%(I_(0.05)组)、0.1%(I_(0.1)组)、0.2%(I_(0.2)组)、0.4%(I_(0.4)组)牛磺酸,配制6种等氮等脂饲料,饲养8周。饲养实验结束后,参考生长结果,选择对照组、I_0组、I_(0.1)组、I_(0.4)组进行急性拥挤胁迫实验。结果显示:①与对照组相比,I_0组增重率显著下降,随着低鱼粉饲料中牛磺酸水平的升高,青鱼幼鱼增重率呈先上升后下降趋势,当牛磺酸添加量为0.1%时与对照组差异不显著;②相对于对照组,I_0组的绒毛高度降低、隐窝深度增加,杯状细胞数降低,添加牛磺酸使绒毛高度升高、隐窝深度降低,杯状细胞数和淋巴细胞数增多;③急性拥挤胁迫使青鱼幼鱼血清史质醇、血糖、血清溶菌酶(LSZ)、补体C3、超氧物歧化酶(SOD)和谷胱甘肽(GSH)含量均呈先升高后下降的趋势,其最大值出现在胁迫2 h或者8 h。在整个胁迫期间,I_0组史质醇和血糖含量高于其他各饲料组,I_0组溶菌酶、补体C3、SOD和GSH均低于其他各饲料组。研究表明,在低鱼粉饲料中添加牛磺酸可提高青鱼生长性能、改善肠道结构、增强青鱼的抗急性拥挤胁迫的能力。     

Effect of replacement of dietary fish meal by meat and bone meal and poultry by-product meal on growth and feed utilization of gibel carp, Carassius auratus gibelio

Triplicate groups of gibel carp Carassius auratus gibelio (initial body weight: 5.25 ± 0.02 g) were fed for 8 weeks at 20–25 °C on five isonitrogenous (crude protein: 400 g kg^?1) and isoenergetic diets (gross energy: 17 kJ g^?1). Meat and bone meal (MBM) or poultry by‐product meal (PBM) were used to replace fish meal at different levels of protein. The control diet contained fish meal as the sole protein source. In the other four diets, 150 or 500 g kg^?1 of fish meal protein was substituted by MBM (MBM₁₅, MBM₅₀) or PBM (PBM₁₅, PBM₅₀). The results showed that feeding rate for the MBM₅₀ group was significantly higher than for other groups except the PBM₅₀ group (P < 0.05). Growth rate in the MBM₁₅ group was significantly higher than that in the control (P < 0.05), while there was no significant difference in growth between the control and other groups (P > 0.05). Feed efficiency and protein efficiency ratio in MBM₅₀ was significantly lower while that in MBM₁₅ was significantly higher (P < 0.05). Replacement of fish meal by MBM at 500 g kg^?1 protein significantly decreased apparent dry matter digestibility (ADC_D) and gross energy (ADC_E) while apparent protein digestibility (ADC_P) was significantly decreased by the replacement of MBM or PBM (P < 0.05). The results suggest that MBM and PBM could replace up to 500 g kg^?1 of fish meal protein in diets for gibel carp without negative effects on growth while 150 g kg^?1 replacement by MBM protein improved feed utilization.     

Substituting fish meal with poultry by-product meal in diets for black Sea turbot Psetta maeotica

A 60 days feeding experiment was carried out with Black Sea turbot Psetta maeotica to determine the amount of poultry by‐product meal (PBM) that could replace fish meal (FM) in formulated diets without reducing growth performance. Juvenile Black Sea turbot (initial average weight, 30 g) were fed five isoenergetic (gross energy, 20.5 ± 0.21 kJ g^?1 diet) and isonitrogenous diets (protein content, 550 ± 0.35 g kg^?1). The control diet used white FM as the sole protein source, the other four diets were prepared to replace FM protein at levels of 25%, 50%, 75% and 100% with PBM. The fish readily accepted all experimental diets and no mortality were recorded during the trial. There were no significant differences in growth performance of turbot (P < 0.05) fed the diets with 25% and 50% replacement levels compared with fish offered the control diet (100% FM), however, final body weight and specific growth rate values in the 50% replacement diet were about 8% lower than those of the control. Total nitrogen excretion in fish fed 50% replacement diet were about 10% higher than the control group, even though these parameters were not found to be statistically different. At the levels of 750 and 1000 g kg^?1 of the protein, PBM inclusion caused a severe decrease in growth performance, feed utilization, protein efficiency ratio and per cent nitrogen retention. The results in the present study indicate that up to 25% of FM protein can be replaced by PBM protein without causing reduction in growth performance, nutrient utilization and nitrogen retention.     

Phosphorus utilization in juvenile Clarias gariepinus fed phytase-supplemented diets based on soya bean (oil-extracted) and full-fat (roasted): A comparison

The effect of microbial phytase on phosphorus utilization in juvenile Clarias gariepinus (initial fish body weight 11.55 ± 0.2 g) was tested on two different diets based on oil-extracted soya bean (Experiment 1) and roasted soya bean meal (Experiment 2) using a 5 × 5 experimental design for 84 days. The basal isonitrogenous and isocaloric diets for oil-extracted and roasted soya bean were formulated to replace fish meal at 25% (S1E), 50% (S2E), 75% (S3E), 100% (S4E); and 25% (S1), 50% (S2), 75% (S3), 100% (S4), respectively. Each treatment was replicated four times. Microbial phytase was supplemented in each replicate at 250 FTU/g (P1), 500 FTU/g (P2), 750 FTU/g (P3), and 1,000 FTU/g (P4). Basal controls, which included a fish meal-based diet (S0), were not supplemented with phytase (P0). The result in Experiment 1 showed that there was a significant increase in whole-body protein and reduction in fat with phytase compared to a diet without phytase (P < 0.05). Serum total protein declined significantly with phytase supplementation (P < 0.05). Serum phosphorus and glucose were higher with phytase supplementation compared to control (P < 0.05). Bone minerals declined significantly with increasing level of soya bean compared to fish meal diet (P < 0.05). In Experiment 2, serum phosphorus was improved with phytase compared to control with no phytase (P > 0.05). A significant reduction in whole-body protein and increase in fat was observed for fish fed phytase diets compared to diets with no phytase, regardless of soya bean level (P < 0.05); however, ash content was improved with phytase (250 FTU/g) compared to control (P < 0.05). Phytase supplementation improved bone phosphorus (250 FTU/g), calcium (250 FTU/g), magnesium (250–500 FTU/g), and zinc (250–1,000 FTU/g) compared to control (P < 0.05). In conclusion, the research has demonstrated that improved bone phosphorus (P) and growth could be achieved with the supplementation of dietary phytase.     

Partial substitution of dietary fish meal with soybean meal for speckled shrimp,Metapenaeus monoceros (Fabricius, 1798) (Decapoda: Penaeidae) juvenile

A 63‐day feeding study was conducted to evaluate the effect of partial substitution (0%, 20%, 40% and 60%) of dietary fish meal (FM) with soybean meal (SBM) on the growth performance and feed utilization of speckled shrimp, Metapenaeus monoceros juveniles. A total of 180 M. monoceros juveniles with an average weight of 0.67 ± 0.18 g were equally distributed over 12 glass aquaria (30 L each, triplicate per treatment). All aquaria were filled with filtered sea water (30–35 ‰, salinity). Four isonitrogenous (400 g kg^?1 crude protein) and isocaloric (20.5 MJ GE kg^?1) test diets were formulated. The control diet contained FM (D₁) as the main protein source. In the other diets, FM was partially replaced with 20 (D₂), 40% (D₃) or 60% (D₄) SBM. The results indicate that the diet in which 40% of the FM is replaced by SBM yields similar growth and production, and is as cost effective, as the control diet.     

Dietary dehulled soybean meal as a replacement for fish meal in fingerling and growing olive flounder Paralichthys olivaceus (Temminck et Schlegel)

Two experiments were conducted to determine the optimum dietary inclusion level of dehulled soybean meal (DHSM) as a fish meal (FM) replacement in diets for olive flounder Paralichthys olivaceus. All the experimental diets were formulated to be isonitrogenous and isoenergetic to contain 50% crude protein (CP) and 16.7 kJ energy g^?1 diet. In the first experiment, eight diets were formulated to replace FM with DHSM at 0%, 10%, 20% without amino acid (AA) supplementation; 20%, 30%, 40% with AA supplementation and 30%, 40% with AA & attractant supplementation (DHSM₀, DHSM₁₀, DHSM₂₀, DHSM_20+AA, DHSM_30+AA, DHSM_30+AA+Att, DHSM_40+AA, DHSM_40+AA+Att respectively). Triplicate groups of 25 fish averaging 5.0±0.04 g (mean±SD) were fed one of eight experimental diets for 8 weeks. In the second experiment, six diets were formulated to replace FM with DHSM at 0%, 10%, 20%, 30% without attractant supplementation and 20%, 30% with attractant supplementation (DHSM₀, DHSM₁₀, DHSM₂₀, DHSM₃₀, DHSM_20+Att, DHSM_30+Att respectively). Triplicate groups of 15 fish averaging 45.5±0.08 g (mean±SD) were fed one of six experimental diets for 10 weeks. Based on growth performance, we concluded that DHSM could replace FM up to 20% without AAs (lysine and methionine) and attractant supplementation, and up to 30% with AAs and/or attractant supplementation in diets for fingerling and growing olive flounder.     

Substitution of fish meal by soybean meal in diets for juvenile marbled spinefoot,Siganus rivulatus

The present work was performed to assess whether soybean meal (SBM) could replace fish meal (FM) as a source of dietary protein in diets of the marine herbivore Siganus rivulatus. Five iso-nitrogenous (40% protein) and iso-energetic (14 MJ/Kg) diets were prepared with SBM replacing fish meal at 0%, 25%, 50%, 75%, and 100% dietary protein. A 60-day feeding trial was conducted with 240 juvenile S. rivulatus (initial body mass 1.74 ± 0.03 g). Survival, growth, feed, and protein efficiency and hematological parameters were assessed. Growth correlated negatively with increase in dietary SBM. All production parameters measured were negatively affected at all levels of SBM inclusion. There were no effects on total or differential blood counts, hemoglobin, or plasma protein, but hematocrit values were negatively correlated with SBM addition. Results suggest that total replacement of FM by SBM without adding other supplements is not recommended, even for an herbivorous marine fish such as S. rivulatus.     

Effect of replacement of dietary fish meal with silkworm pupae meal on growth performance,body composition,intestinal protease activity and health status in juvenile Jian carp (Cyprinus carpio var. Jian)

This study investigated the effect of replacement of graded dietary fish meal (FM) protein (0, 50%, 60%, 70% and 80%) with silkworm pupae meal (SP) in juvenile Jian carp. Triplicate groups comprising 18 fish (15.96 ± 0.66 g) were fed one of five isonitrogenous and isocaloric diets (designated SP0, SP50, SP60, SP70 or SP80) for 8 weeks. The final body weight and specific growth rate of fish in the SP60, SP70 and SP80 groups were significantly lower than those for fish in the SP0 group (P < 0.05). The muscle protein content in the SP50 group was significantly higher than in the SP80 group (P < 0.05). With increasing FM replacement levels, the hepatic superoxide dismutase (SOD) activity decreased and the malondialdehyde (MDA) content increased among the groups, with the significant difference appeared in SP80 group. The gene expression level of heat shock protein 70 in the SP70 group was significantly higher than in the SP0 group (P < 0.05), while that in the SP80 group was significantly less than in the SP70 group (P < 0.05). Significantly decreased intestinal protease activity, increased serum ALT and AST activities, irregular‐shaped hepatocytes and intestinal microvilli were found in the SP80 group. The study demonstrates that it is practical to replace 50% of the Jian carp dietary FM protein with SP, higher SP levels are not recommended and that oxidation status of the SP should be carefully assessed.     

The effect of replacing fish meal with fermented meal mixture of silkworm pupae,rapeseed and wheat on growth,body composition and health of mirror carp (Cyprinus carpio var. Specularis)

To investigate the effect of fermented meal mixture of silkworm pupae, rapeseed and wheat (FMM) on growth and health of juvenile mirror carp (Cyprinus carpio var. specularis), fish meal (FM) was replaced with FMM where FMM was increasingly added in the diets by 0, 40, 80, 120, 160 g kg^?1 and FM decreased accordingly to form five isonitrogenous (365 g kg^?1 crude protein) and isolipidic (60 g kg^?1 crude lipid) diets, being FM, T1, T2, T3 and T4 groups. 270 mirror carp (9.70 ± 1.02 g) were randomly divided into five groups (each group having three replicates) and fed for 58 days. Following termination of the experiment, the fish growth, body composition and health status were analysed. Growth, feed utilization and crude lipid content were negatively correlated with FMM levels in the diet. Increasing the FMM levels led to decreased serum TG, total cholesterol, LDL‐c, MDA and SOD, while GOT and GPT increased. Relative expression of TNF‐α1 and IL‐6 genes in hepatopancreas increased in the T3 and T4 groups and the spleen index showed significant differences in the T2 and T3 groups. In conclusion, 40 g kg^?1 FMM can be included into diets of juvenile mirror carp, while 80–160 g kg^?1 FMM inclusion adversely affects the growth and health status of the fish.