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.     

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.     

Effect of fishmeal replacement by poultry by‐product meal on growth performance,proximate composition,digestive enzyme activity,haematological parameters and gene expression of gilthead seabream (Sparus aurata)

Two feeding trials examined the replacement of fishmeal (FM) with poultry by‐product meal (PBM) in the diet of juvenile Sparus aurata. In Feeding trial I (100 days), three diets were formulated, where FM protein was replaced by 50% (PBM50) and 100% (PBM100) PBM, while in Feeding trial II (110 days), four diets were formulated using the same FM control diet, but FM was replaced at lower levels: 25% (PBM25), and 25% (PBM25 + ) and 50% (PBM50 + ) with the supplementation of lysine and methionine amino acids. PBM protein can successfully replace 50% of FM protein in the diet of S. aurata without adverse effects on survival, feed intake, growth performance and feed utilization, given that the diet is balanced with lysine and methionine. The proximate composition of body and muscle was unaffected by the diet, but the total FM replacement resulted in reduced lipid and energy contents in fish. A fifty per cent FM replacement by PBM did not affect haematological parameters indicating a good fish health. Similarities in trypsin and chymotrypsin activities with FM‐fed fish suggest a high digestibility of PBM. High dietary levels of PBM reduced the liver gene expression of GH/IGF axis and of cathepsin D suppressing fish growth and modulating the protein turnover.     

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.     

Fishmeal can be totally replaced by a mixture of rapeseed meal and Chlorella meal in diets for crucian carp (Carassius auratus gibelio)

This study was conducted to investigate the effects of dietary fishmeal (FM) replacement by a mixture of rapeseed meal and Chlorella meal (RCM) on growth performance, apparent digestibility coefficients (ADCs), digestive enzymatic activities and intestinal histology of crucian carp Carassius auratus gibelioi. Five isonitrogenous diets were formulated to replace 0% (RCM0), 25% (RCM25), 50% (RCM50), 75% (RCM75), and 100% (RCM100) of protein from fishmeal with RCM respectively. Each experimental diet was randomly assigned to triplicate groups with 25 juvenile fish (initial body weight: 1.77 ± 0.04 g) per fibreglass tank for 6 weeks. With increasing substitution levels, weight gain rate, specific growth rate, feed intake and protein efficiency ratio increased, but feed conversion rate decreased. Dietary RCM substitution improved lipid content of muscle, but had no significant effect on other proximate composition of muscle and liver. ADCs of dry matter, protein, lipid, energy and the majority of amino acids increased with increasing substitution level, and digestive enzyme activities (amylase, trypsin and lipase) in intestine showed the similar trend with ADCs. Dietary RCM substitution had no significant adverse effect on intestinal histology. This study indicated that FM protein could be completely replaced by mixed protein sources (RCM) in crucian carp diets.     

Effects of replacing fish meal with soybean meal and peanut meal on growth,feed utilization and haemolymph indexes for juvenile white shrimp Litopenaeus vannamei,Boone

An 8‐week feeding trial was conducted to evaluate the effects of replacing fish meal (FM) with soybean meal (SBM) and peanut meal (PM) on growth, feed utilization, body composition and haemolymph indexes of juvenile white shrimp Litopenaeus vannamei, Boone. Five diets were formulated: a control diet (FM30) containing 30% fish meal and four other diets (FM20, FM15, FM10 and FM5) in which protein from fish meal was substituted by protein from SBM and PM. The dietary amino acids of diets FM20, FM15, FM10 and FM5 were equal to those of the diet FM30 by adding crystalline amino acids (lysine and methionine). Each diet was randomly assigned to triplicate groups of 30 shrimps (initial weight = 0.48 g), each three times daily. The results indicated that shrimp fed the diets FM15, FM10 and FM5 had poor growth performance and feed utilization compared with shrimp fed the control diet. No difference was observed in feed intake, survival and body composition among dietary treatments. The plasma total cholesterol level of shrimp and the digestibility of dry matter, protein and energy contained in the diets decreased significantly with increasing PM and SBM inclusion levels. Results of this study suggested that fish meal can be reduced from 300 to 200 g kg^?1 when replaced by a mixture of SBM and PM.     

Effects of fish meal replacement with meat and bone meal using garlic (Allium sativum) powder on growth,feeding, digestive enzymes and apparent digestibility of nutrients and fatty acids in juvenile rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

Effects of graded dietary levels of fish meal (FM) replacement with meat and bone meal (MBM) with garlic powder (G) or without garlic powder (WG) garlic powder were investigated on growth, digestive enzymes, apparent digestibility, body composition and fatty acid profile of juvenile rainbow trout (Oncorynchus mykiss; 8.26 ± 1.10 g). A total of eight dietary treatments were evaluated: control with garlic powder (0 MBM+G), 250 MBM+G, 450 MBM+G, and 650 MBM+G (g MBM/kg diet; treatments with garlic powder; G treatments), control without garlic powder (0 MBM), 250 MBM, 450 MBM and 650 MBM (g MBM/kg diet; treatments without garlic powder; WG treatments). Our results demonstrated that increased dietary content of MBM impaired growth and production performance, body composition, digestive enzyme activity, tissue fatty acid profile and overall digestibility. Addition of garlic powder was able to correct fish performance, body composition, enzyme activity and digestibility to some extent. Dietary supply of garlic resulted in increased digestive enzyme activity improving fish performance. The current results indicated that fish fed 650 g MBM/kg feed exhibited impaired growth that could be attributed to reduce digestibility of protein, fat, energy and dry matter, PUFAs and n‐3 LC‐PUFAs in muscle. We suggest that 450 g FM per kilo feed can be successfully replaced with MBM supplemented with 30 g garlic powder per kilo feed without impairing fish performance and physiology, however distorting tissue fatty acid composition resulting in lesser levels of n‐3 LC‐PUFAs compared to the 0 MBM+G diet.     

Evaluation of rendered animal protein ingredients for replacement of fish meal in practical diets for gibel carp,Carassius auratus gibelio (Bloch)

A 12‐week feeding trial was carried out in fibreglass tanks to examine partial replacement of fish meal (FM) with poultry by‐product meal (PBM), meat and bone meal (MBM) and blood meal (BM) in practical diets for gibel carp Carassius auratus gibelio (Bloch). Triplicate groups of fish (initial body weight 15.3 g fish^?1) were fed eight isonitrogenous (crude protein: 37.5%) and isolipidic diets (crude lipid: 7%). The control diet is the commercial diet of gibel carp, which used 18% of FM as the sole animal protein source. In the other seven diets (Diet 2–Diet 8), 17–83% of FM protein was substituted by a blend of PBM and BM or a blend of PBM, MBM and BM. The final body weight and thermal‐unit growth coefficient of fish fed the feeds in Diet 8 in which 83% of FM protein was replaced by the blend of 3% BM, 10% PBM and 5% MBM is significantly lower than Diet 1 (the control). The feed efficiency ratio in Diet 8 group is significantly lower than Diet 1, 2, 4 and 7 groups. The results of the present study indicated that a combination of PBM, BM and MBM can replace most of the FM protein and the FM level can be reduced to about 6% with satisfactory growth and feed utilization in practical diets for gibel carp.     

A combination of rapeseed,cottonseed and peanut meal as a substitute of soybean meal in diets of Yellow River carp Cyprinus carpio var

A feeding trial was conducted to evaluate the results of replacing soybean meal (SBM) with other blend plant protein (BP) (rapeseed meal, cottonseed meal and peanut meal) sources on growth, fish body composition, biochemical parameters, non‐specific immune index and gene expression of growth hormone/insulin‐like growth factor‐1 in Yellow River carp Cyprinus carpio. The results showed that the 600 g/kg replacement with BP in diet did not affect the growth performance of Yellow River carp, but the 800 g/kg SBM replacement diet could depress the growth of fish (p < .05). The 800 g/kg SBM replacement diet significantly impacted the superoxide dismutase, malondialdehyde contents, lysozyme, alanine aminotransferase and aspartate aminotransferase activities (p < .05). Fish fed 800 g/kg SBM replacement diet showed lowest insulin‐like growth factor 1 and highest growth hormone level than that of other diets (p < .05). Both gene expression levels of GH and IGF‐I in hepatic showed significant difference among dietary treatments (p < .05), and the lowest GH and IGF‐I mRNA level in liver were found in fish fed 800 g/kg SBM replacement diet (p < .05). In conclusion, no more than 600 g/kg SBM could be replaced by BP in diet of Yellow River carp without adverse effects on the growth performance. However, 800 g/kg SBM replacement with BP in diet inhibited the growth performance, affected some blood parameters and immune response index, and down‐regulated GH and IGF‐1 gene expression of liver in Yellow River carp. Further, GH level in serum was negatively correlated with GH mRNA level in liver; meanwhile, serum concentrations of IGF‐I were positively correlated with hepatic IGF‐I mRNA expressions.     

Effect of totally or partially replacing fish meal by alternative protein sources on growth of African catfish Clarias gariepinus (Burchell, 1822) reared in concrete tanks

A 12‐week feeding trial was carried out in concrete tanks to examine complete and partial replacement (75%) of fish meal (FM) with poultry by‐product meal (PBM), meat and bone meal (MBM) and soybean meal (SBM) in practical feeds for African catfish Clarias gariepinus. Triplicate groups of fish (initial body weight ranged from 90.33 to 93.93 g fish⁻¹) were fed seven isonitrogenous and isocaloric diets of 20% digestible protein and 300 kcal 100 g⁻¹ of digestible energy. The control contained 25% herring meal, whereas in the other six diets, PBM, MBM and SBM replaced 75% or 100% of the FM. Final body weight (FBW) and specific growth rate (SGR) of the fish fed diets containing PBM (75% and 100%), SBM (75% and 100%) and MBM (75%) were all higher, but not significantly different than those for fish fed the control diet. Replacing 100% of the FM by MBM significantly lowered FBW and SGR. Concerning whole body composition, there were no significant differences in ash and gross energy content of whole‐body among fish; fish fed diets containing PBM‐100% recorded significantly lower protein content compared with the control diet, while fish fed diet SBM‐100% recorded significantly lower moisture content compared with the control diet. Also fish fed diets SBM‐100% and PBM‐75% recorded higher lipid and gross energy contents compared with the control diet. The study revealed that satisfactory growth and feed utilization responses could be achieved through the replacement of FM by PBM, SBM and MBM in the diet of African catfish.     

Partial replacement of fish meal by a mixture of soybean meal and rapeseed meal in practical diets for juvenile Chinese mitten crab Eriocheir sinensis: effects on growth performance and in vivo digestibility

An 8‐week experiment was conducted to examine the effect of partial replacement of fish meal (FM) by a mixture of soybean meal (SBM) and rapeseed meal (RM) in practical diets of juvenile Chinese mitten crab Eriocheir sinensis of initial body weight of 1.54±0.12 g (means±SD, n=90). Five isonitrogenous diets were formulated to contain 35% protein and 5% lipid. Soybean meal and RM mix (1:1 ratio) were included at five levels of 0 (control), 15%, 30%, 45% and 60%, replacing 0, 20%, 40%, 60% and 80% FM respectively. When FM was replaced by 15% of SBM and RM, crab showed the highest growth, feed utilization and moulting frequency (MF). Fish meal replaced by SBM and RM did not significantly influence crude protein, lipid and moisture contents of whole body crab, but ash content was the lowest for crab fed the diet with FM replaced by 15% of SBM and RM. Apparent digestibility coefficients (ADCs) of dry matter, crude protein and energy tended to decline with increasing inclusion levels of dietary SBM and RM. In general, ADCs of lipid were high (over 90%) and showed no significant differences among the treatments (P>0.05). Based on these observations above, these results indicated that about 40% of FM can be replaced with a mixture of SBM and RM (1:1 ratio) in the diet of E. sinensis without adverse growth performance, compared with the FM‐based diet. However, 20% of FM replaced by SBM and RM produced the best growth performance and feed utilization.     

Partial replacement of fish meal by cottonseed meal and soybean meal with iron and phytase supplementation for parrot fish Oplegnathus fasciatus

Two consecutive feeding trials were conducted to determine the optimum dietary level of the cottonseed and soybean meal (CS) for replacement of fish meal (FM) in diets for juvenile and ongrowing parrot fish with or without iron and phytase. In experiment I, juvenile parrot fish (BW: 3.17 g) were fed one of six experimental diets for 12 weeks which were formulated to replace FM protein by equal proportion (1:1, w:w) of CS at 0, 10, 20, 30, 40, or 50% (designated as CS0, CS10, CS20, CS30, CS40, or CS50, respectively). In experiment II, ongrowing parrot fish (BW: 55 g) were fed one of five experimental diets for 9 weeks. The experimental diets were formulated to replace FM protein by CS at 0, 20, or 30% (designated as CS0, CS20, or CS30, respectively) and to include ferrous sulfate (0.1 and 0.2%) and phytase into the CS20 and CS30 diets (CS20 + Fe&P and CS30 +Fe&P, respectively). Results from the two feeding trials indicated that the CS could replace up to 20% FM protein in diets for juvenile parrot fish (3–22 g) and up to 30% in ongrowing (55–120 g) parrot fish. The supplemental effect of iron and phytase was not significant on growth performance. Total or each gossypol enantiomer concentration in the liver increased as the level of dietary cottonseed meal increased. However, gossypol in the liver of fish fed diets supplemented with iron was not detected. The dietary supplementation of CS significantly reduced the levels of plasma triacyglycerols and total cholesterol. The present study indicates that plant protein sources are better utilized in larger fish, and that up to approximately 30% FM protein could be replaced by CS with iron and phytase in the presence of supplemental lysine and methionine.     

Evaluation of a fish meal analogue as a replacement for fish meal in practical diets for Pacific white shrimp Litopenaeus vannamei

Three six‐week growth trials and a digestibility trial were conducted to evaluate a fish meal analogue (FMA) as a replacement for fish meal (FM) in shrimp feeds. Trials 1 and 2 evaluated and confirmed the potential of FMA supplementation (0, 48.5, 97, 145.5 and 194 g/kg) as a replacement for FM up to 200 g/kg without balancing for phosphorus (P) in practical diets for juvenile Pacific white shrimp L. vannamei. At the end of trial 1, shrimp offered diets containing 48.5 g/kg FMA exhibited significantly higher weight gain (WG) than those fed with the diet containing 145.5 g/kg FMA. At the end of trial 2, dietary FMA inclusion at 48.5 and 97 g/kg significantly improved WG and protein retention (PR), while reducing FCR and protein content of shrimp body compared to the diet containing 194 g/kg FMA. To determine whether P deficiency is the cause of reduced growth, the third trial was conducted utilizing equivalent diet but balanced for P. At the end of trial 3, shrimp fed diet containing 48.5 g/kg FMA+P showed significantly higher WG and PR than those fed diet containing 145.5 g/kg FMA+P. No decreasing trend of growth was detected in the diets containing FMA compared to the FM‐based diet. Apparent digestibility coefficients of dry matter, energy, protein and amino acids of FMA were determined using chromic oxide as an inert maker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility of FMA were significantly lower than those of soybean meal and FM which were run at the same time. Results of this work indicate that FMA can replace up to 200 g/kg FM in shrimp diets with supplemental inorganic P. Given the good growth across the range of inclusion without any indication of a growth depression, the low nutrient digestibility of FMA may be due to an atypical response or the product simply does not work with the testing technique.     

Replacement of fish meal with processed carinata (Brassica carinata) seed meal in low animal protein diets of rainbow trout (Oncorhynchus mykiss)

A 56‐day growth trial was conducted to determine the amount of fish meal (FM) in rainbow trout (Oncorhynchus mykiss) diets containing 200 g/kg FM as the sole animal protein source; that could be replaced with carinata (Brassica carinata) meal (CM) processed by aerobic conversion (AC, by fungi ssp.) followed by a single wash (ACCM). ACCM replaced 50, 100 and 150 g of FM. Replacement of ≥100 g of FM with ACCM, resulted in reduced (p < 0.01) growth, due to reduced dietary lysine and diet consumption (p < 0.01). Fulton's condition factor K decreased (p < 0.01) with increased FM replacement. FCR (p < 0.01) had an inverse relationship with diet consumption. The trend in FCR was similar to the trend in PER (p < 0.01). Apparent net protein utilization was lower (p < 0.01) for the highest FM replacement diet. There was no effect of FM replacement by ACCM on whole‐body composition or viscera, spleen and liver weights. However, visceral fat increased (p < 0.01) with increased feed consumption. There was no apparent effect of ACCM on hematocrit, haemoglobin or mean corpuscular haemoglobin contents. Results of this study indicate that replacement of ≥100 g of FM by ACCM in low FM/animal (200 g/kg) RBT diets may have been achieved if feed consumption and dietary lysine were similar.     

Growth performance and the soft body composition of juvenile abalone,Haliotis discus,Reeve 1846, fed the extruded pellets substituting fish meal and macroalgae with tunic meal of sea squirt,Halocynthia roretzi

Growth performance and the soft body composition of juvenile abalone fed the extruded pellets (EPs) substituting fish meal (FM) and macroalgae (MA) with tunic meal of sea squirt (SS) was investigated. A total of 1,260 abalone were distributed into 18 containers. Six experimental diets were prepared in triplicate. Five diets were pelletized by an extruder pelleter. The 140 g/kg FM and 250 g/kg mixture of MA were included into the control (Con) diet. Five hundred and 1,000 g/kg of each FM and MA were substituted with an equal amount of tunic meal of SS, referred to as the FM50, FM0, MA50 and MA0 diets, respectively. Finally, dry Undaria pinnatifida was prepared. Weight gain and specific growth rate of abalone fed all EPs were greater than those fed U. pinnatifida. Weight gain of abalone fed MA50 and FM50 diets was greater than Con and FM0 diets, but not different from MA0 diet. Higher crude protein and lipid contents were observed in soft body of abalone fed all EPs compared to U. pinnatifida. In conclusion, FM and MA up to 500 and 1,000 g/kg, respectively, could be replaced with tunic meal of SS in EPs without retardation in growth of abalone.     

Evaluation of poultry by‐product meal as partial replacement of fish meal in practical diets for juvenile tench (Tinca tinca L.)

The aim of this study was to evaluate different replacement levels of fish meal (FM) by poultry by‐product meal (PBM) on survival, growth performance and body composition of juvenile tench (Tinca tinca). A 90‐day experiment was conducted with 5 month‐old juveniles (31.95 mm total length, 0.396 g weight). Eight practical diets (50% crude protein) differing in the level of replacement of FM protein by PMB protein were tested: 0% (control), 25%, 31%, 37%, 43%, 49%, 55% and 61% corresponding to 0, 184.8, 229.2, 273.5, 317.8, 362.1, 406.5 or 450.8 g PBM kg^?1 diet respectively. Significant differences were not found (P > 0.05) between 25% replacement of FM protein by PBM protein (184.8 g kg^?1 PBM in diet) and control diet. At higher replacement levels, fish had significantly lower growth, higher feed conversion ratio and lower protein productive value (P < 0.05). Fish with externally visible deformities ranged from 1.1% to 3.3%. The relation among amino acid profiles of the diets, body composition, growth performance of juveniles and amino acid requirements of other fish species is discussed. Up to 184.8 g PBM kg^?1 diet can be included in diets for juvenile tench without impairing growth performance.     

Fishmeal replacement by soybean,rapeseed and cottonseed meals in hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂

A 12‐week feeding trial was conducted to evaluate the effects of replacing fishmeal (FM) with soybean meal (SBM), rapeseed meal (RM) and cottonseed meal (CSM) on growth, feed utilization and body composition of juvenile hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂ (initial body weight, 8.63 ± 0.24 g). Five isonitrogenous and isoenergetic diets were formulated as follows: a control diet (FM60) containing 600 g/kg FM and four other diets (FM45, FM30, FM15 and FM0 containing 450, 300, 150 and 0 g/kg FM, respectively) where protein from FM was substituted by a mixture of SBM, RM and CSM. Fish fed FM0 and FM15 had poorer growth performance, feed utilization, apparent digestibility coefficients of dry matter, protein, lipid and gross energy, and fed FM0 had poorer hepatosomatic index and survival compared with the fish fed FM60. The whole body lipid in fish fed FM0 was significantly higher than that in fish fed FM60 and FM15. This study indicates that 300 g/kg of FM can be replaced with a mixture of SBM, RM and CSM in the diet of juvenile hybrid sturgeon without compromising growth performance, feed utilization and body composition.     

Incorporation of a mixture of meat and bone meal,poultry by‐product meal,blood meal and corn gluten meal as a replacement for fish meal in practical diets of Pacific white shrimp Litopenaeus vannamei at two dietary protein levels

A 6‐week feeding trial was carried out in glass tanks to determine the effects of partial replacement of fish meal (FM) with a combination of meat and bone meal (MBM), poultry by‐product meal (PBM), blood meal (BM) and corn gluten meal (CGM) in practical diets on the growth, nutrient digestibility and body composition of Pacific white shrimp. Six practical diets were formulated, containing two levels of crude protein (CP) (330 and 380 g kg^?1) and similar crude lipid (CL) levels. For the 330 g kg^?1 dietary protein level, 0, 357 and 714 g kg^?1 FM were replaced by the mixture in Diets 1–3, respectively; while 0, 514 and 784 g kg^?1 FM were replaced in Diets 4–6, respectively, for 380 g kg^?1 dietary protein level. White shrimp‐fed diets containing 330 g kg^?1 CP had significantly lower weight gain compared with white shrimp fed diets containing 380 g kg^?1 CP. Increasing the mixture and dietary protein level significantly raised the body ash content of white shrimp. White shrimp fed a low‐protein diet obtained better nutrient digestibility compared with those fed a high‐protein diet.     

Using a fermented mixture of soybean meal and earthworm meal to replace fish meal in the diet of white shrimp,Penaeus vannamei (Boone)

An experiment was conducted to evaluate the potential of a Bacillus subtilis E20‐fermented mixture (FSFEM) containing soybean meal (SBM) and Eisenia fetida earthworm meal (EM) at a ratio of 4:1 to increase the methionine level in order to satisfy the methionine requirement of white shrimp, Penaeus vannamei in a diet with fish meal (FM) completely replaced by mixtures. B. subtilis E20 fermentation improved the mixture's palatability and utilization based on better growth performance in comparison to shrimp fed FSEM (contains fermented SBM and EM at a ratio of 4:1) diets. FSFEM is a good substitute for FM. Maximal replacement levels of FM with FSFEM were 80% in a shrimp diet with 37% of crude protein and 7% of crude lipid based on weight gain and 100% based on feeding efficiency. In addition, shrimp fed experimental diets had no significant differences in survival after being challenged by Vibrio alginolyticus. It is suggested that B. subtilis E20‐FSFEM has the potential to replace FM in cultured shrimp diets.     

Using Bacillus subtilis E20‐fermented soybean meal as replacement for fish meal in the diet of orange‐spotted grouper (Epinephelus coioides,Hamilton)

The potential of Bacillus subtilis E20‐fermented soybean meal (FSBM) as a partial alternative component of fish meal (FM) in fed diets of orange‐spotted grouper (Epinephelus coioides) was evaluated in this study. An FM‐based diet and seven diets containing 10%, 20% and 30% and 10%, 20%, 30% and 40% of FM replaced by soybean meal (SBM) and FSBM, respectively, were fed to grouper for 84 days to evaluate possible substitution levels of FM by tracking growth performance, digestive enzyme activity and morphological changes in the liver and distal intestine. No significant differences in survival and muscle composition of grouper were found between controls and treatments. Growth performance and feed efficiency of fish fed diets with FM replaced by FSBM up to 30% were not significantly different from controls, whereas significantly decreased growth performance and feed efficiency occurred with diets containing >20% of SBM. Based on the feed efficiency, the maximum substituted levels of FM by SBM and FSBM in grouper diets were 18.36% and 29.32%, respectively, based on broken‐line analyses. Histopathological changes in the liver and distal intestine, and significantly lower activity levels of digestive enzymes, including pepsin in the stomach and trypsin, chymotrypsin, amylase and lipase in the distal intestine, were found in fish fed a diet containing 30% of FM replaced by SBM. However, these parameters were improved by the substitution of FSBM. It is therefore believed that FSBM has great potential to be used as a protein source in grouper diets in partial replacement of FM.