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1.
Three experiments were conducted with rainbow trout to determine if Geotrichum candidum GC single cell protein could replace 100, 75 or 50% of fish meal in a pelleted diet. When the fish meal was completely replaced by GC the fish growth was retarded after 3 weeks of the experiment. With the larger fish (individual weight 47–54 g) in the short trial there were significant differences between fish fed the control diet (fish meal) and those fed the 75% substitution of GC diet. The most remarkable differences in fish growth appeared in a 42-day trial with small fish (5 g individual weight) when fish groups fed diets with 0.50 and 75% replacement gave significantly different results (P < 0.05), being 93,9, 46.6 and 34.2% gain, with feed coefficients of 1.49, 2.77 and 3.67, respectively. With large fish fed diets with 0,50 and 75% GC replacement, apparent digestibility of protein was 64.7, 68.2 and 37.5%, but fat digestibility was 79.5, 91.1 and 81.0%, respectively. No significant differences in amounts of free plasma amino acid (PAA) were found between rainbow trout fed diets with 0 or 50% substitution, but there was a marked decrease in PAA in the group fed the diet with 75% GC substitution. Analysis of chosen heavy metals was made on diets, fish and faeces, and Cu in particular was found not to be accumulated in the fish body.  相似文献   

2.
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.  相似文献   

3.
《水生生物资源》1998,11(4):239-246
High energy extruded diets were formulated to contain the same level of protein supplied either by soy protein concentrate (SPC) or fish meal. Three experiments were performed in order to measure voluntary feed intake and feed waste, faecal losses and soluble losses of nitrogen and phosphorus in rainbow trout (average body weight: 100 g). Voluntary feed intake and growth performance of fish fed with demand feeders were not different when diets contained 0, 50 or 75 % SPC instead of fish meal. Total replacement of fish meal by SPC led to a significant decrease in feed intake and resulted in poor growth. This was partly due to methionine deficiency in the SPC based diet. With the addition of crystalline DL-methionine in the diets, an improvement of feed intake and growth performance was apparent. Protein digestibility was high, regardless of the protein source. Excretion of ammonia and urea increased with the level of SPC in the diet. Nitrogen losses decreased when methionine was added to the diet containing only SPC as a protein source. Availability of phosphorus increased with the level of SPC in the diets. Daily soluble losses were not affected by the dietary treatments but the pattern of phosphorus excretion after feed intake was modified. The rise in soluble phosphorus in water occurred later when fish were fed diets with soy protein whatever the dietary level of soy protein concentrate.  相似文献   

4.
Six experimental diets were fed to rainbow trout to examine the effect of fish hydrolysate and ultra filtered fish hydrolysate on growth performance, feed utilization and growth regulation using diets low in dietary fish meal inclusion. One diet contained a high level of plant protein sources (90.6% of total dietary protein) and a low level of fish meal (9.4% of dietary protein). Two diets contained different levels of hydrolysate in exchange for the plant protein sources, reducing the plant protein level to 73.9% and 57.2%, respectively. Two further diets were identical in composition except that the hydrolysate was ultra filtered to remove low molecular weight compounds. A moderate level of fish meal was used in the sixth diet which had a dietary plant protein level of 57.0%. All diets were made equal in protein, lipid, energy and lysine. The feeding trial lasted for 90 days and for the fastest growing group, fed moderate level of fish meal, the fish increased in weight from 149 g at start to a final weight of 443 g. All groups showed significant differences in growth and feed utilizations. Specific growth rates were; 0.30% day− 1 for the plant protein diet, 0.98% day− 1 for the high hydrolysate diet, 0.72% day− 1 for the group containing the high level of ultra filtered hydrolysate, and 1.21% day− 1 for the moderate fish meal diet. Feed efficiencies (g fish weight gain per g feed intake) were found to be 0.57 for plant protein diet, 0.97 for high level of hydrolysate, 0.83 for ultra filtered hydrolysate and 1.03 for the moderate fish meal diet. Half dietary inclusions of hydrolysate and ultra filtered hydrolysate revealed values between the plant protein diets and high levels of these ingredients, respectively. Feed consumption in percentage of average fish weight per day, correlated with the feed efficiency for all groups. PER, PPV and BV correlated with the differences in growth. Protein digestibilities were equal for all groups, while the moderate fish meal diet showed higher lipid and energy digestibilities than the plant protein diets. Although some of the differences may be due to growth inhibitors in plant resources other explanations may be relevant. Plasma growth hormone (GH) levels were significantly higher in fish fed the plant protein diet than fish fed the fish meal or high hydrolysate diet, which is most likely a result of their poor feeding status. Plasma IGF-I levels were not affected by diet. Comparisons of groups with similar inclusion of plant ingredients, and thus equal level of growth inhibitors, show that in removing small molecular weight compounds from fish hydrolysate, the growth and feed efficiency were significantly reduced. Some of these small compounds in fish hydrolysate thus seem to be essential for biological performance. Further, as fish meal revealed the best performance, fish muscle protein is not the only nutrient that makes fish meal an essential ingredient in aqua feed for carnivorous fish. This information is important in the work to find replacement of fish meal in a sustainable growing global aquaculture industry.  相似文献   

5.
Replacement of fish meal with plant products in aquafeeds results in the elimination of dietary compounds which may be important for optimal growth and physiology. A study was conducted to determine if supplementation with macro‐minerals and/or inositol would improve performance of rainbow trout (Oncorhynchus mykiss) fed a plant‐based diet. Four iso‐caloric and iso‐nitrogenous diets (40 g kg?1 protein and 15 g kg?1 lipid) were formulated and consisted of a fish meal‐based control diet (control) and three plant‐based experimental diets. Plant‐based diets were supplemented with either macro‐minerals and inositol (+MM+I), no macro‐minerals with inositol (?MM+I), and no macro‐minerals and no inositol (?MM?I). Sodium chloride, potassium chloride and magnesium oxide were the sources used in the macro‐mineral premix. There was no effect of diet on survival, but there was an effect of diet on weight gain, FCR, feed intake, HSI and nutrient retentions. Significant liver pathology was observed in trout fed plant‐based diets without MM supplementation. Supplementation of MM and inositol significantly improved weight gain of trout fed a plant‐based diet. Supplementation of MM and/or inositol also improved PRE and ERE. This study demonstrates the importance of supplementing these nutrients to trout fed fish meal free diets.  相似文献   

6.
Abstract.— Taurine has been demonstrated to be conditionally indispensable for several carnivorous fish species. Current trends in trout production include decreasing levels of fish-meal content in feeds, along with faster growing strains of fish. Taurine may be a limiting nutrient in support of elevated planes of growth for rainbow trout. A 9-wk feeding trial was conducted using a factorial treatment design with protein source (fish meal or plant) and taurine supplementation (four levels) as the main effects. The fish-meal diet series included 23% herring meal and contained 1.76% total sulfur amino acids (TSAA). The plant diet series did not contain any animal proteins and substituted protein from soy protein concentrate in place of the herring-meal protein and contained 1.5% TSAA. Taurine was supplemented at 0, 5, 10, and 15 g/kg dry diet to each of the diets in the plant series and the fish-meal series of diets. All diets were formulated to contain 43.8% crude protein and 20% lipid with an estimated physiological fuel value of 4.2 kcal/g. Fifteen fish were stocked in each of 24 tanks with a mean initial weight of approximately 26.8 g per fish. The unsupplemented fish-meal diet contained 2 g/kg taurine, and the unsupplemented plant diet had taurine levels below the detection limit of 0.1 g/kg diet. Taurine supplementation improved growth, feed conversion ratios, protein retention efficiencies, and energy retention efficiencies of fish fed the plant protein diets. No effects of taurine supplementation were observed for these response factors in fish fed the fish-meal series diets. This study demonstrates that taurine supplementation may be necessary for rainbow trout fed plant-protein-based feeds.  相似文献   

7.
This study evaluated the potential of using poultry by‐product meal (PBM) to replace fish meal in diets for Japanese sea bass, Lateolabrax japonicus. Fish (initial body weight 8.5 g fish?1) were fed six isoproteic and isoenergetic diets in which fish meal level was reduced from 400 g kg?1 (diet C) to 320 (diet PM1), 240 (diet PM2), 160 (diet PM3), 80 (diet PM4) or 0 g kg?1 (diet PM5), using PBM as the fish meal substitute. The weight gain (WG), specific growth rate, nitrogen retention efficiency, energy retention efficiency and retention efficiency of indispensable amino acids were higher in fish fed PM1, PM2, PM3 and PM4 diets than in fish fed diets C or PM5. The phosphorus retention efficiency was lower in fish fed PM3, PM4 and PM5 diets than in fish fed C, PM1 or PM2 diets. Fish fed diet PM5 had the highest feed conversion ratio, total nitrogen waste output (TNW) and total phosphorus waste output (TPW) among the treatments. No significant differences were found in the hepatosomatic index or body contents of moisture, lipid and ash among the treatments. Fish fed diet C had lower condition factor and viscerosomatic index than those of fish fed PM1, PM3, PM4 and PM5 diets. The results of this study indicate that using fish meal and PBM in combination as the dietary protein source produced more benefits in the growth and feed utilization of Japanese sea bass than did using fish meal or PBM alone as the dietary protein source. The dietary fish meal level for Japanese sea bass can be reduced to 80 g kg?1 if PBM is used as a fish meal substitute.  相似文献   

8.
Abstract— Fisheries by-catch and by-product meals are portrayed as ingredients having a great potential as ingredients in aquaculture feeds. The present study was designed to evaluate the nutritional value of shrimp by-catch meal, shrimp processing waste meal, and two fish meals made from Pacific whiting (meal with and without solubles) for rainbow trout by determining apparent digestibilityof these ingredients and conducting a 12-wk feeding trial with juvenile fish (average initial weight 20 g/fish). Apparent digestibility coefficients (ADCs) for protein in diets containing by-catch and processing by-products were 76% for shrimp by-catch meal, 79% for shrimp processing waste meal, 88% for Pacific whiting meal without solubles, and 92% for Pacific whiting meal with solubles. ADCs for lipid were higher than 94% for all the diets. ADCs for energy were 57% for shrimp by-catch meal, 73% for shrimp processing waste meal, 70% for Pacific whiting meal without solubles, and 73% for Pacific whiting meal with solubles. Growth performance was significantly affected by dietary protein source. Fish fed the shrimp by-catch meal diet had weight gain and feed conversion ratios similar to that of fish fed the control diet with anchovy fish meal. Fish fed diets containing shrimp processing waste and Pacific whiting meal with solubles had significantly lower weight gain and higher feed conversion ratios than the control diet. Growth was significantly lower in fish fed the Pacific whiting meal diet compared to fish fed the anchovy fish meal. The lower growth of fish fed diets containing Pacific whiting meal appeared to be a result of lower feed intake, indicating perhaps a lower palatability of this ingredient. Additional research addressing processing methods, nutritional manipulations, and palatability enhancement is needed to improve potential of some fisheries byproduct meals as ingredients in the diets of rainbow trout.  相似文献   

9.
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.  相似文献   

10.
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.  相似文献   

11.
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.  相似文献   

12.
A 65-day study was undertaken to evaluate the utilization of lysine-supplemented wheat gluten meal as a protein source for rainbow trout, Oncorhynchus mykiss (Walbaum). The performance of the trout fed wheat gluten was compared to that of trout where protein was principally supplied using fish meal and full-fat soyabean meal. Six isonitrogenous diets (approximately 45% crude protein) were formulated. Thus, the reference diet (FS) was based on fish meal and full-fat soya bean meal while a further five diets were formulated with a mixture of wheat gluten and wheat middlings used to isonitrogenously replace approximately 75% and 57% of the full-fat soya and fish meal respectively. Crystalline l -lysine representing 0.00%, 0.29%, 0.58%, 0.87% and 1.16% of the complete diet was then added to the wheat-gluten-based diets. Optimal performance in terms of weight gain and apparent net protein utilization was achieved by the fish fed a wheat-gluten-based diet supplemented with lysine (0.58%) yielding a digestible lysine level of 1.9% of the complete feed. Within the range of supplements provided, lysine digestibility was high. However, at the highest levels of supplemental lysine the relationship between uptake and supplement level was not linear. Additionally, arginine digestibility was not affected by the level of lysine supplementation. However, amongst the wheat-gluten-based diets, optimal performance was associated with a lysine: arginine ratio of 1.1: 1. Despite a lysine: arginine ratio of approximately 1.1: 1, the overall performance of the fish fed the fish-meal-soya-based reference diet was poorer than expected. The results are discussed with respect to optimal patterns of gross and digestible amino acids, lysine-arginine antagonism and the possible relationship between antinutritional factors and the poor performance of the fish fed the fish-meal-soya-based reference diet.  相似文献   

13.
Animal and/or plant protein sources substituting fishmeal in the diets keep being developed due to its high price. The purpose of this study is to determine response of dietary substitution of fishmeal with silkworm pupae meal, promate meal?, meat and bone meal and/or their combination on the performance of juvenile olive flounder. A 60% fish meal was used as the main protein source, used as the control (Con) diet. The 10 and 20% fishmeal were substituted with silkworm pupae meal and meat and bone meal, referred to as the SPM10, SPM20, MBM10 and MBM20 diets, respectively. And the 10, 20 and 40% fishmeal were substituted with promate meal?, referred to as the PM10, PM20 and PM40 diets, respectively. Finally, the 10 and 20% fishmeal were substituted with combined silkworm pupae meal and promate meal?, refereed to as the SPM + PM10 and SPM + PM20 diets, respectively. Weight gain and specific growth rate of fish fed the MBM10 diet were higher than those of fish fed the Con, SPM20, PM20, PM40 and SPM + PM20 diets. Feed efficiency ratio of fish fed the SPM10, MBM10, MBM20, PM10 and SPM + PM10 diets was higher than that of fish fed the SPM + PM20 and PM40 diets. Protein efficiency ratio of fish fed the MBM10 and MBM20 diets was higher than that of fish fed the SPM20, PM20, PM40 and SPM + PM20 diets. In conclusion, dietary substitution of fishmeal with 10% SPM, 20% MBM, 10% PM and 10% SPM + PM could be made.  相似文献   

14.
To be able to study nutrient requirement and utilization in any species, a diet supporting normal feed intake and growth equally well as a traditional fish meal‐based diet is needed. Additionally the formulation of the diet should allow low levels of the nutrient under study. When studying the amino acid metabolism and requirements, one cannot rely on the fish meal‐based diets as fish meal are nicely balanced according to requirements. Therefore the current study aimed to develop a plant protein‐based diet (with low fish meal inclusion) to be used in the nutritional studies of Senegalese sole juveniles supporting feed intake and growth close to that obtained in a fish meal‐based control feed. Two experiments were conducted to evaluate whether Senegalese sole juveniles would accept and utilize diets containing high plant protein inclusion. For testing the acceptance of high plant protein inclusion, two diets were formulated: a reference diet that contained fish meal as the main protein source (450 g kg?1 dry matter) whereas in the test diet, fish meal was substituted by a mixture of plant ingredients (soybean meal, corn and wheat gluten) with l ‐lysine supplementation. In order to improve the palatability, 50 g kg?1 squid meal was added to both diets. The indispensable amino acids (IAA) profile of the test diet was made similar to the control diet by adding crystalline amino acids. Further, automatic feeders were used to improve the feed intake. Fish (24 g initial body weight) were fed the diets for a period of 4 weeks. As fish accepted both diets equally well, a second study was undertaken to test the growth performance. Fish (6 g initial BW) were fed the diets for a period of 12 weeks. The use of automatic feeders to deliver the feed and the addition of both squid and balancing the indispensable amino acids resulted in growth performance and accretion not differing from the fish meal fed control. It can be concluded that juvenile Senegalese sole are able to grow and utilize high plant‐protein diets when both diet composition and feeding regime are adequate for this species.  相似文献   

15.
A laboratory study was conducted to evaluate effects of dietary total protein and animal protein source and concentration on growth and feed efficiency of juvenile channel catfish Ictalurus punctutus and their response to Edwardsiellu ictuluri challenge. Eight diets evaluated were: three diets containing either 28, 32, or 36% crude protein with 6% menhaden fish meal and 6% meat and bonehlood meal and five diets containing 32% crude protein with either no animal protein, 68 or 12% menhaden fish meal, or 6% or 12% meat and bonehlood meal, respectively. Twenty channel catfish with an average weight of 6.6 g/fish were stocked into each of forty 110-L flow-through aquaria (five aquaridtreatment). Fish were fed to approximate satiation twice daily for 9 wk. Fish in each tank were then exposed to E. ictaluri . There were no differences in feed consumption, weight gain, feed efficiency, and survival before and after challenge among fish fed diets containing 28, 32, or 36% protein with 6% menhaden fish meal and 6% meat and bone/ blood meal. Fish fed a 32% all-plant protein diet had weight gain and feed efficiency similar to fish fed diets containing 12% menhaden fish meal, but had a higher weight gain than fish fed a 32% protein diet containing 6% meat and bonehlood meal. No significant differences were observed in survival after E. ictuluri challenge among fish fed diets containing the various levels of animal proteins. Results indicate that dietary protein levels varying from 28% to 36% do not appear to affect growth, feed efficiency. and E. icraluri resistance or susceptibility in fingerling channel cattish fed to satiation and raised from approximately 7 to 56 g under laboratory conditions. Data also demonstrate that a 32% all-plant protein diet can be fed to small fingerling channel catfish without adversely affecting growth, feed efficiency, or resistance to E. ictuluri .  相似文献   

16.
Abstract.— Fish meal is one of the predominant sources of crude protein used in practical feeds for most cultured species. However, with overfishing and increasing demand for protein feedstuffs, new competitively priced sources of dietary protein are needed. A coextruded soybean meal-red blood cell (SBM-RBC) ingredient was evaluated as a source of crude protein for rainbow trout Oncorhynchus mykiss . The SBM-RBC ingredient was incorporated at either 0, 21, 42 or 63% of the dietary protein, replacing an isoni-trogenous amount of fish meal. All diets were fed for 8 wk to triplicate groups of juvenile rainbow trout (average initial weight 49.5 g) stocked into a recirculating system consisting of 48, 114-L aquaria. There were no significant differences in weight gain, feed conversion ratio, protein efficiency ratio, apparent crude protein digestibility, apparent gross energy digestibility, dress-out percentage, or fillet protein and fat concentrations in fish fed any of the experimental diets. Based on these data, extruded SBM-RBC appears to be a suitable ingredient in diets fed to rainbow trout.  相似文献   

17.
Two experiments were conducted to evaluate the effect of lowering crude protein level and fish-meal inclusion rate by using commercially available synthetic amino acid supplements in practical diets on the growth performance of Litopenaeus vannamei. In experiment 1, three diets were formulated to assess whether 50% of fish meal could be replaced by soybean meal with synthetic amino acid supplementation. Diet 1 was formulated as the normal control with 20% fish meal and 36% crude protein; diet 2 was the negative control with 34% crude protein and half of the fish meal was replaced with soybean meal; and diet 3 was similar to diet 2 but was supplemented with amino acids to ensure the level of lysine, methionine plus cystine, and threonine similar to that in the diet 1. After a 70-day feeding trial, weight gain and specific growth rate of shrimps fed diet 2 were significantly lower than those fed diet 3, and numerically lower than those fed diet 1. Feed intake of shrimps fed diet 3 was significantly higher than those fed diets 1 and 2. There were no significant differences in feed conversion ratio among shrimps fed different diets. In experiment 2, four diets were prepared with diet 1 as the normal control with 41.26% crude protein, diets 2–4 were formulated to contain 39.81, 38.40, and 35.52% of crude protein with synthetic amino acids were added to simulate the amino acid levels of the diet 1. After a 70-day feeding trial, it was found that reducing dietary crude protein from 41.26 to 35.52% did not affect weight gain or feed conversion ratio. The survival of crude protein 35.52% treatment was significantly lower than other treatments. No difference was observed in body protein, lipid composition, and apparent digestibility coefficient among dietary treatments. Results of this study suggested that dietary crude protein could be reduced from 41.26 to 35.52% in the diets of L. vannamei as long as synthetic amino acids were supplemented.  相似文献   

18.
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.  相似文献   

19.
The potential of lupin meal as an alternative protein source to soybean meal in isonitrogenous practical diets for the juvenile black tiger shrimp Penaeus monodon was evaluated through the studies of growth, digestibility and pellet water stability. Five isonitrogenous diets were formulated to contain 40% protein. Protein from dehulled Lupinus albus seed meal replaced 0, 25, 50, 75 and 100% of the protein from defatted soybean in the diets. Juvenile P. monodon (4.35 × 0.31 g) were assigned randomly and fed each test diet at a daily feeding rate of 5 % body weight for 42 d in triplicate tanks equipped with a flow-through sea water system. No statistically significant differences were observed in weight gain, feed intake, feed conversion ratio (FCR), protein conversion efficiency and apparent protein utilization of shrimp fed diets with 0, 25, and 50% replacement. Shrimp fed the diet with total replacement of soybean meal by lupin meal had the poorest performance (P < 0.05) with regard to the above parameters. Survival was similar (87%) for all dietary treatments. The apparent dry matter digestibility and apparent protein digestibility were similar for all diets ranging between 70.5 and 72.8% and 89.7 and 90.8%, respectively. There was no significant difference in whole body composition (dry matter, lipid, protein and ash) of shrimp on the various diets. The poorest pellet water stability was displayed by the diet with 100% replacement while the diet containing a combination of soybean meal and lupin meal (50% replacement) was the most stable. The results have demonstrated that dehulled lupin seed L. albus meal has good potential as a substitute protein source for up to 50% of the protein from defatted soybean meal and could be included up to 17% inclusion level in juvenile P. monodon practical diets with no adverse effects on growth, feed intake, FCR, survival, feed utilization, body composition, and digestibility coefficients of dry matter and protein.  相似文献   

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

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