A comparison of the growth performance of rainbow trout (Oncorhynchus mykiss) when fed soybean,narrow‐leaf or yellow lupin meals in extruded diets

This study compared the effect of increasing dietary inclusion of soybean, narrow‐leaf lupin or yellow lupin kernel meals when fed to rainbow trout. Each meal was formulated into a test diet to create a series of inclusion levels of 0, 100, 200, 300 and 400 g kg^?1. Each diet was formulated to the same digestible protein and energy specifications. The diets were fed to apparent satiety to 30.0 ± 0.71 g rainbow trout for 28 days. After this period, fish in the reference (0 g kg^?1) treatment attained a weight of 93.2 g. Growth of the fish among the treatments was observed to be improved by the addition of either variety of lupin meal. In contrast, growth of fish fed the soybean meal was equivalent to that of the 0 g kg^?1 fish meal reference, but was poorer at the 400 g kg^?1 inclusion level. Feed intake with the lupin meals was marginally improved with lupin inclusion, but at the higher soybean meal inclusions, feed intake was reduced relative to the fish meal reference diet. The inclusion of the different grains also had significant effects on the physical properties of the pellets.     

Incorporation of Whole Lupin,Lupinus albus,Seed Meal in Commercial Extruded Diets for Rainbow Trout,Oncorhynchus mykiss: Effect on Growth Performance,Nutrient Digestibility,and Muscle Fatty Acid Composition

Whole lupin seed meal was evaluated as partial replacement for fishmeal in extruded diets for rainbow trout, with particular emphasis on the effect on growth performance and apparent digestibility coefficient (ADC) of protein, lipids, carbohydrates, and energy. Effect on muscle fatty acid composition was also evaluated. All diets were formulated to be isonitrogenous and isoenergetic and to contain approximately 45% crude protein and 5.5 kcal energy g/diet. Diets were formulated to include whole lupin seed meal at 0, 10, 15, and 20%. Triplicate groups of fish weighing 65.9 ± 15.1 g on average were fed twice a day until apparent satiation during 12 wk. Growth, feed intake, hepatosomatic index, hepatic histology, proximate composition of whole body, and muscular fatty acid profile were determined. Growth and feed utilization were similar in all treatments and whole‐body composition did not vary among treatments. Polyunsaturated fatty acids of the n‐6 and n‐3 series remained constant in muscle as the amount of lupin in diets increased. Furthermore, the ADCs were similar among all diets. These results suggest that inclusion of whole lupin seed meal up to 20% in extruded diets for rainbow trout do not have any negative effect on growth, feed performance, or flesh quality.     

Assessing the implications of variability in the digestible protein and energy value of lupin kernel meals when fed to rainbow trout, Oncorhynchus mykiss

A series of studies were designed to examine the degree of variability in the digestibility of protein and energy from lupin (Lupinus angustifolius) kernel meals when fed to rainbow trout (Oncorhynchus mykiss) and the potential implications of this variability. The digestibility of protein and energy from 10 different varieties of lupin kernel meal was assessed where the test ingredient comprised 30% of each test diet. Digesta was collected using faecal stripping techniques. Digestible protein value ranged from 331 to 508 g/kg DM and digestible energy values ranged from 10.6 to 13.3 MJ/kg DM. To examine the implications of variability in digestible protein and energy value, two lupin kernel meals from the extremes of the protein digestibility range (Lupin-1: AD_N ~ 70% and Lupin-2: AD_N ~ 100%) were chosen for assessment in two growth studies. Soybean meal and a reference diet with fishmeal as the only protein source were also included in the study. In the first growth experiment the test ingredients were included at equal concentrations (40%) in protein-limiting diets (350 g protein/kg DM) and fed at either of two ration levels (restricted and satiety). Diets were formulated on a crude basis so as to place the test variable on the variability in digestible protein value of the diets. In the restricted-fed treatments growth of fish fed the reference diet was highest, but not significantly better than lupin-H. Growth of fish fed the lupin-L diet was significantly poorer than both the reference and lupin-H diets, but not poorer than the soybean diet. The growth responses observed from this experiment clearly showed that the differences in feed intake and/or digestible protein value could be demonstrated in terms of significant differences in growth outcomes. In a second growth study high-nutrient dense extruded diets (400 g protein/kg and 23.5 MJ/kg) were prepared with a more practical level of 25% inclusion of the same test materials. Again the diets were formulated on crude basis so as to place the test variable on the variability in digestible protein and energy value of the diets. Growth of fish restrictively fed the lupin-H diet was highest, but not significantly better than the soybean, reference or lupin-L treatments restrictively fed. Growth of fish satietal fed the soybean diet was significantly poorer than the reference and lupin-H diets, but not compared to the lupin-L diet. The growth responses observed from this experiment showed that the differences in digestible protein and energy value could not be demonstrated in terms of significant differences in growth outcomes, and that feed intake variability and excess nutrient supply masked the effect of this variability; particularly at the satietal feed intake levels.     

Replacement of Fishmeal with a Blend of Poultry Byproduct Meal and Soybean Meal in Diets for Largemouth Bass,Micropterus salmoides

A feeding trial was conducted to evaluate the potential of replacing fishmeal with poultry byproduct meal (PBM) and soybean meal in diets for largemouth bass, Micropterus salmoides. A reference diet (C) contained 400 g/kg fishmeal, and 40 or 60% of the fishmeal was replaced with a blend of pet‐food‐grade PBM and soybean meal (diets PP1 and PP2) or a blend of feed‐grade PBM and soybean meal (diets PF1 and PF2). No significant differences were found in weight gain, nitrogen retention efficiency (NRE), condition factor, and body composition among fish fed diets PP1, PP2, PF1, and PF2. Feed intake and feed conversion ratio (FCR) were higher in fish fed diet PF1 than in fish fed diet PP1. No significant differences were found in weight gain, NRE, condition factor, and body composition between fish fed diet C and diets PP1, PP2, PF1, and PF2. The feed intake and FCR were lower in fish fed diet C than in fish fed diets PP2, PF1, and PF2. This study reveals that dietary fishmeal level for largemouth bass could be reduced to 160 g/kg by inclusion of PBM and soybean meal in combination.     

Salmon testes meal as a functional feed additive in fish meal and plant protein‐based diets for rainbow trout (Oncorhynchus mykiss Walbaum) and Nile tilapia (Oreochromis niloticus L.) fry

Fishery processing by‐products are a large resource from which to produce fishmeal and other products for a variety of uses. In this study, testes meal (TM) produced from pink salmon processing by‐product was evaluated as a functional ingredient in aquafeeds. Nile tilapia and rainbow trout fry were fed five isonitrogenous and isoenergetic experimental diets for 4 and 9 weeks respectively. Two diets were fishmeal‐based (FM) and three were plant protein‐based (PP). Salmon TM was added to the FM and PP diets at 7% to replace 20% of fishmeal protein (FMTM and PPTM respectively). An additional control diet was prepared in which fishmeal was added to the PP diet to supply an equivalent amount of protein as supplied by TM (PPFM). Inclusion of TM in both the FM‐ and PP‐based diets resulted in higher final body weights, although differences were only significant between rainbow trout fed FM or FMTM diets. Similar differences were calculated for other indices of fish performance, e.g. specific growth rate, feed conversion ratio, protein efficiency ratio and protein retention efficiency. Feed intake was significantly higher for fish fed FMTM compared with FM in rainbow trout. For tilapia, final weights were numerically higher, but not significantly different for fish fed diets containing TM compared with non‐TM diets (FM vs. FMTM; PP vs. PPTM). Performance of trout or tilapia fed the PPFM diet did not increase compared with the PP diet. The results indicate that TM addition to both FM and PP diets increased feed intake and also increased metabolic efficiency, demonstrating that TM can be a functional ingredient in aquafeeds.     

The Effects of Substituting Selected Oilseed Protein Concentrates for Fish Meal in Rainbow Trout Oncorhynchus mykiss Diets

Three oilseed protein concentrates (soybean, canola, and sunflower) were evaluated to determine their potential, when supplemented with deficient essential amino acids, to partially or completely replace fish meal in diets fed to rainbow trout Oncorhynchus mykiss . Triplicate aquaria of juvenile trout (average weight of 12 g) were fed the experimental diets for 10 wk, at which time the average weight of the fish was approximately sixfold higher than the initial weight. Average fish weight gains on diets in which the protein component was 100% fish meal; 75% fish meal, 25% soybean protein concentrate; 50% fish meal, 50% soybean protein concentrate; and 75% fish meal, 25% sunflowerseed protein concentrate were not significantly different ( P < 0.05). The average weight of fish fed a commercial feed was significantly lower than that of fish fed the 100% fish meal diet, but not significantly different from fish fed the three other formulations mentioned above. Fish fed diets containing 50% fish meal, 50% canola protein concentrate; and 25% fish meal, 75% sunflowerseed protein concentrate had significantly lower average final weights than those of fish fed the other diets. Feed conversion ratio patterns among the dietary treatment groups reflected those of weight gain. Fish survival exceeded 95% on all diets. Apparent protein digestibility coefficients ranged from 79.5% (75% soybean protein concentrate, 25% canola protein concentrate) to 90.6% (100% soybean protein concentrate). The results of this study demonstrated that certain oilseed protein concentrates have good potential as protein sources in rainbow trout feeds when properly supplemented with essential amino acids.     

A comparison of the digestibility of lupin (Lupinus sp.) kernel meals as dietary protein resources when fed to either, rainbow trout, Oncorhynchus mykiss or red seabream, Pagrus auratus

The nutritional value of the kernel meals of three species of lupin (Lupinus albus, L. angustifolius and L. luteus) was compared against each other and solvent extracted soya bean meal and wheat gluten, when fed to either rainbow trout or red seabream. The digestible nutrient and energy values were determined for each ingredient, based on the diet substitution digestibility method. Each test ingredient was included in test diets at 300 g kg^?1. As different faecal collection methods were used on each species, only ingredient comparisons within each fish species study are valid. Protein digestibility for all lupin kernel meals was significantly better than for soya bean meal when fed to red seabream, although only numerically so when fed to rainbow trout. The highest protein digestibility in both fish species was that from the wheat gluten (100.0% for both rainbow trout and red seabream). Energy digestibility for each of the lupin kernel meals (range 62.4%–64.9% in rainbow trout and 60.9%–69.5% in red seabream) was less than that obtained from soya bean meal (75.1% and 81.0% for rainbow trout and red seabream, respectively). However, the higher gross energy content of the lupin kernel meals still resulted in both L. albus and L. luteus providing equivalent levels of digestible energy as that of soya bean meal. Organic matter digestibility was generally poorer for each of the lupin kernel meals relative to that for the soya bean meal and particularly compared with the wheat gluten. Phosphorus digestibility was significantly better in all lupin kernel meals than that from both the soya bean meal and wheat gluten. Highest phosphorus digestibility was that obtained from L. albus kernel meal (100.0% for both rainbow trout and red seabream) although notably the phosphorus digestibility of all lupin kernel meals when fed to rainbow trout was determined at 100%. Similarly the digestibility of phosphorus from lupin kernel meals fed to red seabream was also very high. This study supported the good nutritional value to both rainbow trout and red seabream of kernel meals of all three species of lupin, although the digestible nutrient attributes of kernel meal from L. luteus were particularly favourable.     

Utilization of combined extruded soybean and corn gluten meals as feed ingredients for juvenile rainbow trout,Oncorhynchus mykiss diet

In this study, feeding experiment and subsequent digestibility trial were performed to investigate the utilization of extruded soybean meal (SBM) and corn gluten meal (CGM) as feed ingredients for juvenile rainbow trout. Plant ingredients have undergone extrusion at low temperature (100°C, LT) or high temperature (150°C, HT) for 30 s. Four isonitrogenous (44%, crude protein) and isolipidic (14%, crude lipid) diets were formulated. Control diet is fishmeal based while a combined (1:1) non‐extruded SBM and CGM for NE diet, LT SBM and LT CGM for LT diet and HT SBM and HT CGM for HT diet. Two hundred forty rainbow trout juveniles (7.8 g average body weight) were randomly divided into 12 rectangular 60 L glass aquaria and offered four different diets in triplicate. Fish were fed at satiation twice a day, six days a week for 12 weeks. Phosphorus in phytic acid level of extruded ingredients decreased through extrusion cooking. Final weight, weight gain, SGR and PER of fish fed HT diet were significantly (p < .05) higher than those fed with NE diet. Apparent digestibility coefficient for protein of LT and HT diets is significantly higher than of NE diet. The results of this study demonstrated that HT extruded SBM and CGM are suitable feed ingredients for rainbow trout diet without compromising fish growth, feed utilization and fish body composition.     

Evaluation of Three Soybean Products in Diets Fed to Juvenile Hybrid Striped Bass Morone saxatilis×M. chrysops

Juvenile hybrid striped bass Morone saxatilis×M. chrysops were fed practical diets containing graded levels of either solvent-extracted soybean meal, roasted soybeans, or raw, unprocessed soybeans. Two separate 10-wk studies were conducted; within each study, there were two separate evaluations of soy products. In the first study, weight gain and feed efficiency of fish fed 45% or higher levels of soybean meal were significantly lower than fish fed the positive control diet, while weight gain and feed efficiency of fish fed 30% soybean meal were not significantly different than fish fed the control diet. Fish fed the lowest level of unprocessed soybean (20%) exhibited significantly depressed weight gain and feed efficiency compared to fish fed the control diet. In the second study, weight gain and feed efficiency of fish fed 40% roasted soybeans were significantly lower than fish fed the control diet, but weight gain and feed efficiency of fish fed 20% roasted soybeans were not significantly lower than fish fed the control diet. In both studies, whole body proximate composition values were significantly different among treatments. Whole-body lipid concentrations were significantly higher in fish fed certain levels of soy products, but only at levels above those eliciting depressions in weight gain and feed efficiency. A further evaluation of solvent-extracted soybean meal was conducted with incorporation levels of 20–40% of the dry diet in gradations of 5% with a nutritionally complete mineral premix. Weight gain and feed efficiency of fish fed any level of soybean meal in that study were not significantly different from fish fed a positive control diet. Whole body proximate components were not significantly different between treatments. Unprocessed soybeans apparently have little potential as an ingredient in diets fed to juvenile hybrid striped bass; roasting, or heat treatment, improves their use. Solvent extracted soybean has the potential of supplying the majority of crude protein in diets fed to juvenile hybrid striped bass. Incorporation of complete mineral premixes seems beneficial with higher levels of solvent-extracted soybean meal.     

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.     

Supplemental effect of bile salts to soybean meal-based diet on growth and feed utilization of rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

A feeding experiment was conducted to evaluate the supplemental effect of bile salts to a defatted soybean meal-based non-fish meal diet for rainbow trout Oncorhynchus mykiss. A fish meal-based diet (FM) and two non-fish meal diets with and without bovine bile salts (SC+B and SC, respectively) were fed to fish (13 g initial weight) for 10 weeks. Fish fed diet SC showed inferior growth and feed efficiency, while bile salt supplementation improved the parameters to the same levels as fish fed diet FM. Crude fat and starch digestibility of diet SC-fed fish decreased after the 10-week feeding trial compared to the data obtained with fish that had no experience of the diet. Total biliary bile salt content and intestinal maltase activity of fish fed diet SC were the lowest among treatments, while these parameters were improved by bile salt supplementation. Morphological changes occurred in the distal intestine and liver of the diet SC group, although the histological features of fish fed diet SC+B were similar to those of fish fed diet FM. These results suggest that bile salt supplementation to a soybean meal-based diet improves the nutrient utilization by normalizing digestive processes in rainbow trout.     

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.     

The use of locally produced fish meal and other dietary manipulations in practical diets for rainbow trout Oncorhynchus mykiss (Walbaum)

The aim of this trial was to compare the performance of rainbow trout fed diets including local or imported fish meal as the main protein sources, and to test the effect of reducing the fish meal content or including a fish protein hydrolysate in the diets. Two experimental diets were formulated to include 35% (diet 2) or 20% (diet 3) of a local processed whole fish meal; two other diets were formulated similar to diets 2 and 3 but with 5% fish protein hydrolysate replacing the same amount of fish meal (diets 4 and 5 respectively); a diet similar to diet 2, but including Norwegian fish meal, was used as a control (diet 1). The growth trial lasted 14 weeks and was carried out in floating net cages (325‐L capacity), with duplicate groups of 20 rainbow trout of an initial average weight of 58 g. The apparent digestibility coefficients (ADC) of the diets were evaluated in a separate laboratory trial. At the end of the growth trial, there were no significant differences in growth rate and protein efficiency ratio among groups. Feed conversion ratios were significantly better in groups fed diets 3, 4 and 5 than in the other groups. Nitrogen retention (% of N intake) was significantly higher in fish fed diets 4 and 5 than in those fed diet 2. There were no significant differences in energy retention (% of energy intake) among groups. At the end of the trial, there were no significant differences among groups in proximate composition of whole fish. The ADC of protein, energy and phosphorus of diets 1 and 2 were significantly lower than those of diets 3 and 5. It was concluded that, under the experimental conditions tested, performance of rainbow trout fed practical diets including good quality local processed fish meal is similar to that of fish fed diets including Norwegian fish meal. A reduction in the fish meal from 35% to 20% of the diet or the inclusion of a fish protein hydrolysate had no negative effects on growth performance and improved feed utilization.     

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.     

The nutritional properties of co-dried fish silage in rainbow trout (Salmo gairdneri) dry diets

Feed ingredients containing fish silage and liquefied fish made from ground, whole Pacific whiting and co-dried in a vacuum dryer with mixtures of soybean meal and feather meal to facilitate drying were prepared. An additional batch of fish silage was co-dried with the other dry ingredients in the diet formulation that was used, Abernathy diet S8-1. Fish meal, made by vacuum drying Pacific whiting, was used in the control diet. Co-dried fish meal was made by co-drying Pacific whiting with a soybean meal-feather meal mixture. Fish meal was entirely replaced by the co-dried products in the experimental diets, which were fed to rainbow trout (Salmo gairdneri) for 32 weeks. The best growth and food conversion values were obtained by feeding the fish meal control diet or the diet in which the fish meal was replaced with co-dried liquefied fish. No significant differences in final weights were found between trout fed diets containing co-dried fish meal or co-dried fish silage (fish products were 25% of the diet), but these fish were significantly smaller than fish fed the fish meal control or the co-dried liquefied fish diets. Reducing the fish silage to 12.5% or increasing it to 50% further reduced weight gains in the trout. Food conversion values, protein efficiency ratios, and net protein utilization values generally followed the same trends between diets as did the final weight values. Apparent digestibility coefficients for the co-dried products were lower than for the fish meal, possibly because they contained soybean meal-feather meal mixtures. Organoleptic properties of the fish were not affected by diet.     

Replacement of fishmeal with commercial soybean meal and EnzoMeal in juvenile barramundi Lates calcarifer

This study investigates the impact of fishmeal replacement by soybean meal (SM) and improved SM known as EnzoMeal (EZ) on fish growth performance. The SM and EZ were used in five experimental diets: fishmeal (600 g/kg) as the control diet, 50% fishmeal replaced with soybean meal (SM50), 50% fishmeal replaced with EnzoMeal (EZ50), 100% fishmeal replaced with soybean meal (SM100) and 100% fishmeal replaced with EnzoMeal (EZ100). Fish in the control group gained the most weight, followed by those under the SM50 and EZ50 diets, while the least weight gain was observed in fish fed the SM100 and EZ100 diets. The specific growth rate (SGR) was higher in the control, but was not different between fish fed SM50 and EZ50, or between SM100 and EZ100. The highest feed intake occurred in the control but decreased sequentially from fish fed SM50 to fish fed EZ50, EZ100 and SM100. Protein digestibility was best in SM50, poorest in EZ100, but no difference between the control, EZ50 and SM100 diets. This study indicates that EnzoMeal, containing high crude protein (56%), is a potential source of plant meal to replace fishmeal in the barramundi diet, but low feed intake is a challenge when EnzoMeal is >300 g/kg.     

Effects of partial substitution of dietary fish meal by fermented soybean meal on growth performance,amino acid and biochemical parameters of juvenile black sea bream Acanthopagrus schlegeli

A feeding trial was conducted to evaluate the effect of replacing fish meal protein with fermented soybean meal (FSM) on the growth performance, feed utilization, amino acid profile, body composition, morphological parameters, activity of antioxidant and digestive enzymes of black sea bream (Acanthopagrus schlegeli) juvenile. Five isonitrogenic and isolipidic diets were prepared with levels of 0 (control), 80, 160, 240 and 320 g kg^?1 FSM. Triplicate groups (40 fish per tank) of juvenile black sea bream with initial weight of 1.17 ± 0.04 g were hand‐fed to visual satiation at three meals per day for 8 weeks. The fish fed diets containing different levels of FSM had no significant differences regarding survival and specific growth rate compared with control group. Feed and protein efficiency ratios of fish fed diet containing 320 g kg^?1 FSM were significantly lower than those of control group. Daily feed intake and daily protein intake of fish fed diet containing 240–320 g kg^?1 were significantly higher than those of control group. Hepatosomatic index and condition factor of fish were not affected by different dietary FSM level. Fish fed diets containing 240–320 g kg^?1 FSM had significantly higher visceral somatic index than control group. Whole body proximate and amino acid compositions of fish were not affected by dietary FSM level. The activity of digestive enzymes in the intestine was not affected by dietary FSM level. The activity of glutathione peroxidase in liver was significantly higher for fish fed the diet containing 160 g kg^?1 FSM compared with control group. This study showed that up to 40% fish meal in the diets of juvenile black sea bream could be replaced by fermented soybean meal with supplementation of methionine, lysine and taurine.     

Replacement of fish meal with two fermented soybean meals in diets for rainbow trout (Oncorhynchus mykiss)

The present study investigated the effect of fish meal (FM) replacement with fermented soybean meal (FSM) on growth and feed utilization of rainbow trout. Two FSM products, FSM1 (more fermentation with more small peptide and acid than FSM2) and FSM2 were used to replace 20%, 40% and 60% of FM in control diet (250 g/kg FM), respectively (FSM1‐20, FSM1‐40, FSM1‐60, FSM2‐20, FSM2‐40 and FSM2‐60). Then the seven diets were fed to rainbow trout (18.1 g) for 8 weeks. Weight gain (WG), feed conversion ratio (FCR) and digestibility of crude protein and dry matter showed no significant difference among the groups of FSM1‐20, FSM1‐40, FSM2‐20, FSM2‐40 and the control, but WG significantly decreased and FCR increased when 60% FM was replaced by both FSMs (p < .05). The replacement of 40%, 60% FM resulted in lower villus height than the control (p < .05), and intestinal protease activity was lower in FSM2‐40, FSM2‐60 and FSM1‐60 groups than the control group (p < .05). In addition, the activity of alkaline phosphatase and superoxide dismutase increased with increasing levels of FSM (p < .05). In conclusion, dietary fish meal could be replaced by 40% with both FSMs without adverse effects on growth and feed utilization of rainbow trout based on an eight weeks feeding trial.     

Effect of an alcohol extract from a defatted soybean meal supplemented with a casein-based semi-purified diet on the biliary bile status and intestinal conditions in rainbow trout Oncorhynchus mykiss (Walbaum)

A feeding experiment was conducted to examine the effect of a supplemental ethanol extract from a defatted soybean meal on the biliary bile status and intestinal conditions of rainbow trout Oncorhynchus mykiss . A semi-purified control diet based on casein (Cont) and three diets supplemented with the extract (ES), bovine bile salts (BS) and their combination (ESBS) were fed to trout (10 g) for 6 weeks. The growth, feed efficiency ratio, fat digestibility and gallbladder- and hepato-somatic indices of fish fed diet ES decreased. Compared with this group, these parameters were improved in fish fed diet ESBS. The total biliary bile salt content was the lowest in fish fed diet ES and this group had a high proportion of chenodeoxycholyltaurine. The inclusion of the bile salts to diet ES (diet ESBS) increased the total biliary bile salt content. A similar trend was observed in the bile salt concentration of intestinal digesta. Although morphological changes occurred in epithelial cells of the distal intestine of fish fed diet ES, the histological features of fish fed diet ESBS were similar to those of fish fed diet Cont. These results indicate that alcohol-soluble substances of soybean meal cause physiological changes in the biliary bile and intestine of rainbow trout.     

Partial or total replacement of fishmeal by solvent-extracted cottonseed meal in diets for juvenile rainbow trout (Oncorhynchus mykiss)

The effect of solvent‐extracted cottonseed meal (SCSM) as a partial or total replacement of fishmeal was studied in juvenile rainbow trout (Oncorhynchus mykiss). Six experimental diets SCSM0, SCSM25, SCSM50, SCSM75, SCSM75A and SCSMT, containing a gradient of SCSM 0, 152, 305, 465, 460 and 610 g kg^?1 to replace 0, 112.5, 225, 337.5, 337.5 and 450 g kg^?1 fishmeal protein were fed to triplicate groups (initial body weight of 39.2 ± 0.1 g) for 8 weeks. The diet SCSM75A was supplemented with lysine and methionine, to be similar to SCSM0 for juvenile rainbow trout. Faeces were colleted after 4 weeks of normal feeding for apparent digestibility coefficients (ADC) of dry matter, crude protein and gross energy determination. Total replacement of fishmeal adversely affected growth performance. Fish fed with diet SCSMT had significantly (P < 0.05) lower weight gain, specific growth ratio, feed conversion efficiency (FCE) and protein efficiency ratio than fish fed with other diets. The FCE of SCSM75 and SCSM75A were significantly lower (P < 0.05) than those of fish fed with SCSM0 diets. The ADC of the dry matter of SCSM75 and SCSMT were significantly lower than the SCSM0 diet, and the ADC of crude protein and the energy of SCSMT were the lowest (P < 0.05). The ADC of threonine, proline, alanine, valine, isoleucine, leucine, lysine and methionine of fish fed with diet SCSMT were lower. Lysine and methionine supplement positively affected the ADC of SCS75A diet. There were no significant differences in the fish body composition. It is shown that SCSM can be utilized in the juvenile rainbow trout diet up to 305 g kg^?1, to replace about 50% of fishmeal protein in this experiment.