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1.
This study evaluated effects of fishmeal replacement by cottonseed meal protein hydrolysate (CPH) on growth, antioxidant and immunity of Megalobrama amblycephala and its resistance to Aeromonas hydrophila. Fish (average weight: 38.66 ± 0.08 g) were divided into five groups and fed with five isonitrogenous (320 g/kg crude protein), isolipidic (70 g/kg crude fat) and isocaloric (17.8 MJ/kg gross energy) diets replacing fishmeal with 0%, 1%, 3%, 5% and 7% CPH, respectively. The control diet contained 60 g/kg fishmeal. Final weight and weight gain of fish fed 5% and 7% CPH were significantly lower than that of fish fed control diet (p < 0.05). 3% CPH significantly increased total protein, globulin, acid phosphatase, C3 and C4 contents of plasma and total‐superoxide dismutase and catalase activities of liver (p < 0.05), as well as upregulated the antimicrobial peptides 1 and 2 (Leap‐1 and Leap‐2) expression levels in liver and spleen (p < 0.05). After challenge, the lowest mortality was observed in fish fed 3% CPH, and it was significantly lower than that in fish fed the 7% CPH (p < 0.05). In conclusion, dietary fishmeal replacement by 3% CPH could increase antioxidative capacity, as well as enhance immunity of fish.  相似文献   

2.
For successful prawn aquaculture, feeds should be based on readily consumed ingredients that promote survival and optimal growth performance. This pilot study investigates the rearing of juvenile Baltic prawn Palaemon adspersus. Two feeding trials were carried out for 60 days; both incorporated insect meals, the first one in fishmeal‐based diets, whereas the second one in plant meal ones. Insect meals derived from larvae of Tenebrio molitor (TM), Hermetia illucens (HI) and Musca domestica (MD) were tested as feed ingredients. This study indicated that the inclusion of HI in fishmeal diets resulted in significantly higher growth performance and survival of the prawns, whereas the MD diet led to similarly high growth performance reducing significantly their survival. Growth performance was not affected by the insect inclusion in the plant‐based diets, but survival was higher in the TM and HI inclusion diets. The inclusion of TM and HI resulted in higher protein and energy content of the prawns’ muscle when incorporated in fishmeal and plant meal diets respectively. No significant differences were observed in the activities of hepatopancreas’ amino acid‐catabolizing enzymes. Concluding, the combinations fishmeal–HI and plant meal–TM can be used for the successful rearing of Baltic prawn.  相似文献   

3.
Two trials were conducted to compare the growth and survival of western rock lobster Panulirus cygnus post-pueruli and year 1 juveniles fed different diets. Trial 1 compared lobsters fed a formulated pelletised feed developed for Panulirus ornatus supplemented with fresh mussels (Mytilus edulis) two days per week, with lobsters fed a daily diet of pellets. Trial 2 compared lobsters fed the pellet-mussel supplement diet with those fed a daily diet of fresh mussels.In the first trial, diet treatment did not significantly affect survival, although it was higher in tanks supplemented with mussels. Growth of post-pueruli and year 1 juveniles fed the pellet diet (0.03 g/day; 0.14 g/day, respectively) was significantly lower than growth of post-pueruli and year 1 juveniles fed pellet-mussel supplement diets (0.07 g/day; 0.2 g/day, respectively). Year 1 lobsters fed the pellet-mussel supplement diet consumed considerably less pellet (0.27 vs 0.40 g pellet dry matter/day (DM/day)) than those fed pellets indicating that they will preferentially favour mussel over pellet diets. Feed conversion ratio (FCR) was significantly better for lobsters fed the pellet-mussel supplement diet as a result of the poor growth of pellet-fed lobsters.In the second trial, survival was significantly higher for lobsters fed mussels only. Growth of post-pueruli fed a mussel diet (0.14 g/day) was significantly higher than those fed pellet-mussel diets (0.11 g/day), but there was no significant difference in growth for year 1 juveniles (0.33 g/day). Feed intake of mussel on a dry matter basis was higher than pellet intake for both size classes, with mussel intake being more than double pellet intake for post-pueruli (0.20 vs 0.49 g DM/day).Poor growth of P. cygnus on a pellet only diet indicates that the current formulation for P. ornatus may be inadequate for P. cygnus. However, as pellet intake declined dramatically for year 1 lobsters offered a mussel supplement, and pellet consumption was significantly lower than mussel consumption, it is more likely that poor growth may be attributed to inadequate palatability and intake. The similarly good survival of lobsters fed pellet and pellet-mussel diets indicates that the pellet diet is an acceptable maintenance diet for P. cygnus, but is not suitable for maximising growth for this species. Further research is needed to improve palatability, intake and potentially nutritional composition of this pellet diet before its suitability for P. cygnus is assured.  相似文献   

4.
Soybean meal (SBM) inclusion in salmonid diets can lower feed cost, but dramatically reduces growth and feed utilization, and increases mortality in juvenile chinook salmon Oncorhynchus tshawytscha, due to diminished diet palatability and/or other adverse physiological effects exerted by antinutritional factors in SBM. The objective of this study was to investigate whether commercial Antarctic krill meal Euphausia superba or hydrolysates enzymatically produced from Pacific hake Merluccius productus could reverse the negative palatability effects of SBM inclusion in juvenile chinook salmon diets. Diets without SBM or with SBM and no added feed attractant were used as positive and negative control diets respectively. Incorporation of 2% krill meal or Alcalase®‐produced hydrolysates into SBM‐containing diets (20% of dry matter by isonitrogenous replacement of fishmeal) significantly (P < 0.05) increased feed intake, feed utilization, fish weight gain and thermal growth coefficient during a 5‐week trial. Nevertheless, the negative effects on fish performance incurred by dietary inclusion of 20% SBM could not be fully reversed, indicating that most of those effects were likely unrelated to palatability. This study demonstrates the potential for using Pacific hake hydrolysates as a dietary feed attractant for salmonid diets, and supports the need for further research to optimize its application for ideal fish performance.  相似文献   

5.
Fishmeal diets are shown to be unfavourable for successful weaning of ballan wrasse (Labrus bergylta) larvae. Variable fishmeal quality, and/or a possible negative effect of ethoxyquin (EQ) and/or palatability could be the reason for the reduced growth and increased mortality observed. This study weaned wrasse larvae on either a control diet of freeze–dried shrimp and cod fillet, or fishmeal‐based diets with 0, 11 or 44 ppm EQ, for 1 month. Lower final body weight and higher mortality were related to increased inclusion of EQ. Furthermore, fishmeal diets had increased lipid oxidation values with decreased EQ content, whereas the control diet had the lowest lipid oxidation levels. A combined negative effect of oxidation and EQ supplementation could have lowered the palatability of the feeds and be the reason for the unsuccessful larval weaning. Use of EQ is inevitable in large‐scale production of feed ingredients; however, the use of high‐quality ingredients with low EQ inclusion, or its replacement with other antioxidants, may be necessary for successful intensive culture of some marine fishes.  相似文献   

6.
One of the current challenges of global fish farming is developing plant‐based proteins as a feasible substitute for fishmeal in the formulation of aquafeeds. Substitution levels of fishmeal with hydrolyzed soybean meal (HSM) in diets for silver catfish (Rhamdia quelen) were evaluated for growth, protein metabolism and antioxidant activity. The experiment was carried out in a recirculation system of 20 tanks of 250 L. A total of 300 silver catfish juveniles were used to compose five treatments and four replicates per treatment. Levels of soybean hydrolysate (0%, 5%, 10%, 15% and 20%) were tested in diets (39% protein and 3,500 Kcal) for 60 days. Silver catfish growth was higher at all inclusion levels of HSM when compared to the control diet. No change was shown for body protein deposition. The production of nitrogenous compounds in the liver and muscle was also unaffected by any of the diets. The diet containing 20% HSM promoted an increase in the amounts of non‐protein thiols in the gills and brain. The HSM substitution levels of up to 20% of fishmeal in the diet increases growth and contributes to silver catfish antioxidant activity.  相似文献   

7.
Commercial de‐fatted groundnut oil cake (GNC) fermented with the fungus Aspergillus niger was evaluated as a fishmeal alternative in the diet of Penaeus vannamei. A 45‐day growth trail was performed using nine iso‐nitrogenous and iso‐lipidic diets. Untreated/fermented GNC was included at the rate of 0 (control), 25, 50, 75 and 100 g/kg by replacing fishmeal (w/w). Each diet was randomly assigned to triplicate group of 20 shrimps (initial weight of 3.09 ± 0.03 g). Results revealed that shrimp fed with diets having untreated GNC up to 50 g/kg has no significant difference in growth, whereas the inclusion level was enhanced to 100 g/kg with fermented GNC with no deleterious effect. The negative linear trend was found for SGR with increasing the inclusion of both untreated and fermented GNC. The feed and protein efficiency measures, viz. feed conversion ratio, protein efficiency ratio and apparent protein utilization, were better in shrimps fed with diets having fermented GNC than those fed the respective level of untreated GNC. The broken‐line analysis indicated that the inclusion of 72.5 g/kg fermented GNC showed the best FCR. No significant difference was observed in survival (86.67%–96.67%) between the dietary treatments. There was a significant difference in ether extract of shrimp between the treatments, whereas other parameters were not affected. Haemolymph indices showed a significant difference in total protein, glucose, cholesterol and triglycerides between control and test diets. The results conclude fermented GNC, which can be better than untreated one in the diet of shrimp.  相似文献   

8.
Nutritional qualities of fish processing by‐products can further be improved through enzymatic hydrolysis. The objective of this study was to elucidate the efficacy of hydrolysed milkfish offal at different inclusion levels when fed to juvenile grouper, Epinephelus fuscoguttatus, with an initial body weight of 2.88 ± 0.06 g. The animals were fed for 56 days with seven diets supplemented with 0 (control), 5%, 15% and 25% of milkfish offal (MO) and milkfish offal hydrolysate (MOH). The diets were formulated to be isonitrogenous (45%) and isolipidic (11%). The diets were assigned to 21 tanks (15 fish per tank) with each diet having three replicates. Results from the experimental trials indicated that feed conversion efficiency, feed intake and weight gain of fish significantly (P < 0.05) improved when fed diets with MOH. No significant differences within the rest of the dietary treatments were observed. Survival rate (>90%) did not differ in all the dietary treatments. Proximate composition (crude protein, crude fat and ash) indicated no significant difference among fish fed from all the dietary treatments. Apparent digestibility of MOH indicated a 95% and 66% digestibility for protein and dry matter respectively. Plasma stress parameters (cortisol and glucose) were not influenced by the dietary treatment when fish were subjected to an acute stressor (5‐min chasing). Liver morphology indicated normal hepatocyte shape and the presence of lipid droplets in fish fed from all the dietary treatments. The results indicated that milkfish offal processed as hydrolysate can be utilized in grouper diets and can promote growth and feed efficiency when supplied at 10–15%.  相似文献   

9.
A feeding trial with Macrobrachium rosenbergii was carried out to test the effectiveness of sunflower cake (SFC) as a replacement for conventional protein sources. Four isonitrogenous (~30% crude protein) and isocaloric (388–402 kcal) diets were formulated. Diet‐1 was a control made with conventional ingredients including fish meal, soya bean meal and mustard oil cake. Diet‐2, Diet‐3 and Diet‐4 were made with 30%, 40% and 50% SFC, respectively, replacing the usual protein sources used in Diet‐1. After 100 days, diets with SFC inclusion showed favourable growth and economic performance trends compared to control diet‐1, but without significant differences (p > .05). Better production (572.89 ± 62.99 kg/ha) was observed with Diet‐4 followed by Diet‐2, Diet‐3 and Diet‐1. Diet‐4 revealed the best feed conversion ratio (2.56 ± 0.24), specific growth rate (1.18 ± 0.05) and protein efficiency ratio (1.14 ± 0.10) among these diets. Whole carcass composition analysis revealed highest crude protein (18.19%) and lipid (4.43%) content in prawns fed Diet‐3 followed by Diet‐4. Highest total income, gross margin and benefit cost ratio (BCR) per hectare from prawns were US$5,759, US$2,623 and 1.84, respectively, found in Diet‐4. This study demonstrates that 30%–50% inclusion of SFC has favourable impacts on productivity and profitability compared with controls, with 50% SFC inclusion as the most cost‐effective diet for prawns without apparent compromise in growth, flesh quality or economics. The performances of the diets suggest that SFC may be a suitable substitute for fishmeal, soya bean meal and mustard oil cake in prawn feed. The effectiveness of higher SFC concentrations should also be investigated.  相似文献   

10.
A 60‐day growth experiment was conducted to investigate the effect of dietary replacement of fishmeal by Spirulina platensis on growth performance, digestion and physiological parameters in juvenile gibel carp (5.0 ± 1.0 g). Four diets were formulated to replace 0 (SP0), 50% (SP50), 75% (SP75) and 100% (SP100) of dietary fishmeal protein by S. platensis respectively. Other two diets based on SP100 were supplemented with 2% dicalcium phosphate (SP100 + P) or 0.28% coated lysine (SP100 + Lys). The results showed that no significant differences of specific growth rate (SGR), feed efficiency (FE), feeding rate (FR) and protein efficiency ratio (PER) were observed between SP0 group and the replacement groups (SP50, SP75 and SP100). FE and PER of fish‐fed SP100 + Lys diet were significantly higher than the fish‐fed SP100 diet (p < .05). Apparent digestibility coefficients (ADCs) of dry matter, protein, energy and phosphorus increased significantly with the increasing S. platensis inclusion. Meanwhile, fish from SP100 + P or SP100 + Lys group had higher ADCs of nutrients compared to the SP100 group (p < .05). Compared with SP0 diet, fish‐fed S. platensis diets had higher activities of plasma superoxide dismutase, hepatopancreas total antioxidant capacity, plasma alkaline phosphatase and plasma lysozyme, as well as the lower content of plasma malondialdehyde. The present results indicated that dietary fishmeal could be fully replaced by S. platensis without any negative effects on growth performance of gibel carp. Supplementation of lysine in the S. platensis replacement diet could further improve the feed utilization of gibel carp.  相似文献   

11.
A 45‐day feeding trial was conducted to evaluate the utilization of fermented plant protein mix (FPPM) as a fishmeal substitute in the diet of Penaeus vannamei. Six isonitrogenous and isolipidic diets were formulated by substituting fishmeal at 0% (control), 50%, 60%, 70%, 80% and 90% (FR‐0, FR‐50, FR‐60, FR‐70, FR‐80 and FR‐90, respectively) using FPPM. Shrimps fed with diets FR‐50, FR‐60 and FR‐70 had no significant difference in weight gain (173.22%–178.07%) with the control group (179.50%). However, the broken‐line regression indicated that 70.8% fishmeal could be substituted by FPPM. The trend of digestibility was reflected in growth performance. Survival had no significant difference among the treatments. Fishmeal substitution had significant (p < .05) variations in protease and amylase activity, but not in lipase. Except lipid, other body composition was not affected due to dietary change. A decrease (p < .05) in haemolymph total protein, cholesterol and triglycerides was observed to increase in fishmeal substitution. A higher fishmeal substitution (FR‐90) had significantly (p < .05) lower total haemocyte count and the reverse was true for phenoloxidase. Results conclude that a combination of fermented ingredients would be more effective rather using alone in shrimp feed, with a great potential in reducing the pressure on fishmeal.  相似文献   

12.
This study compared the nutritional profiles of menhaden fishmeal and pink salmon (Oncorhynchus gorbuscha) testes meal and investigated the nutritional values of the testes meal based on its effect on palatability, digestibility and growth performance of Pacific white shrimp (Litopenaeus vannamei). The testes meal replaced 0–91% of fishmeal protein in a control diet containing 150 g kg−1 fishmeal. Replacement of 69% of the fishmeal protein in the control diet significantly increased feed intake of shrimp from 0.61% to 1.10%. The apparent digestibility coefficient of dietary protein increased significantly when 91% of the fishmeal protein was replaced by the testes meal. Replacement of dietary fishmeal protein with up to 46% testes meal protein did not cause adverse effects on growth rate or nutritional composition of tail muscle. However, growth rate was significantly decreased in shrimp fed diets in which 69% or 91% of fishmeal protein was replaced by the testes meal. Results of this study indicate that the testes meal can be used as a feed additive to enhance the palatability and protein digestibility of low fishmeal diets for shrimp. It can replace up to 46% of fishmeal protein without any adverse effect on the growth performance of shrimp.  相似文献   

13.
The main objective of this study was to evaluate the effect of methionine supplementation when reducing fishmeal levels in diets for white shrimp (Litopenaeus vannamei). Tested diets consisted of a positive control with 260 g/kg fishmeal (D1), two negative controls with 100 g/kg fishmeal and no amino acid (AA) supplementation (D2) or supplemented with lysine but not methionine (D3), and four additional diets with 100g/kg fishmeal supplemented with increasing levels of DL‐Met (1.0, 2.0 or 3.0 g/kg) (D4, D5, D6) or Met‐Met (1.0 g/kg) (D7). Each diet was fed to four groups of 30 shrimp for 8 weeks at a daily rate of 70 g/kg body weight. Reduction in fishmeal from 260 g/kg down to 100 g/kg did not significantly affect survival rate, feed conversion ratio (FCR), protein efficiency ratio (PER) or protein retention efficiency (PR%) of white shrimp. However, growth performance (final body weight, FBW; weight gain, WG; specific growth rate, SGR) was reduced when dietary fishmeal level was reduced from 260 g/kg (D1) to 100 g/kg without methionine supplementation (D2). The growth performance (FBW, WG and SGR) of shrimp was significantly increased by supplementation of the 100 g/kg fishmeal diet with increasing levels of DL‐Met (p < .05). Same performance as positive control (D1) was achieved with diets containing 100 g/kg fishmeal and supplemented with 3.0 g/kg DL‐Met or 1.0 g/kg Met‐Met. The highest values of growth performance (FBW, WG and SGR) were found in shrimp fed D6 and D7 diets, which were significantly higher than those of shrimp fed D2 and D3 diets (p < .05) but without statistical differences with shrimp fed D1, D4 and D5 diets (p > .05). The highest values of whole‐body and muscle protein contents were found in shrimp fed D1 diet, which were significantly higher than those of shrimp fed all other diets (p < .05). The highest value of intestinal tract proteolytic enzyme activity was found in shrimp fed Met‐Met‐supplemented diet (D7) and followed by the positive control diet (D1) and 3 g/kg DL‐Met‐supplemented diet (D6) (p < .05). The highest values of apparent digestibility coefficients (ADCs) of dry matter and crude protein were found in Met‐Met‐supplemented diet (D7) and followed by the positive control diet (D1) (p < .05). Shrimp fed the D1 diet showed the highest value of total essential amino acid (EAA) and was significantly higher than shrimp fed D2–D3 (p < .05) but without significant difference with shrimp fed D4–D7 (p > .05). In conclusion, results showed that same performance can be achieved with diets containing 260 or 100 g/kg fishmeal supplemented with 3.0 g/kg DL‐Met or 1.0 g/kg Met‐Met. Moreover, supplementation of limiting methionine in low‐fishmeal diets seems to improve the digestive proteolytic activity, improving digestibility of dry matter and protein, and eventually to promote growth of juvenile white shrimp in fishmeal reduction diets.  相似文献   

14.
The development of cost-effective and digestible formulated diets is essential for the commercialisation of spiny lobster aquaculture. Large juvenile spiny lobsters, Jasus edwardsii (115 g), were used to measure the apparent digestibility of formulated diets with six different carbohydrate sources, three levels of gelatinised starch, three types of binder, and two ranges of particle size of fishmeal. Carbohydrate source, inclusion level and binder type all had a significant effect on the dry matter digestibility (ranging 61–79%) of formulated diets for J. edwardsii. The digestibility of the carbohydrates included at 35% by dry weight were: dextrin (99%), carboxymethyl cellulose (CMC; ~ 94%), native wheat starch (91%), gelatinised maize starch (84%), native potato (60%) and maize (59%) starches. Gelatinised maize starch inclusion level (ranging from 15% to 55% by dry weight) was negatively correlated with starch digestibility (ranging from 92% to 79% respectively). Dry matter digestibility of the diets was improved by using gelatine (73%) instead of alginate (68%) and agar (61%) as a binder. Nitrogen digestibility (ranging 82–89%) did not differ significantly among diets. Reducing the particle size distribution of the fishmeal from < 500 µm to < 106 µm did not improve digestibility. The results indicate that using digestible carbohydrate sources (dextrin, CMC, and native wheat starch) for energy, reducing the inclusion level of gelatinised starch, and using CMC or gelatine as binders improve the apparent digestibility of formulated diets. Furthermore, the results also indicate that the use of more soluble and pre-hydrolysed protein sources in diets for J. edwardsii may greatly improve digestibility which is critical in these spiny lobsters where overall food intake is limited.  相似文献   

15.
The purpose of this study was to evaluate the effect of two dry extruded diets on growth and nutritional composition of digestive gland (DG) and muscle of Octopus vulgaris. Both artificial diets (FMK and 3FMK) were composed of gelatin, maltodextrin, yolk, fish and krill meal. The 3FMK diet contained more fishmeal (3×) than the FMK diet. These diets were compared with a control frozen diet consisting of golden grey mullet (Liza aurata) and crab (Liocarcinus depurator). The 3FMK diet promoted higher intakes and feed efficiency than FMK diet, resulting in larger growths (296 respect to 158 g in 42 days; 0.81% vs. 0.78% body weight/day). There was significantly lower moisture, protein and ash content in digestive glands of animals fed pellets (P < 0.05). No significant differences were observed on nutritional composition of muscle among the three groups. Even though the results were still below those of the control group (increase of 1258 g), the good performance in terms of acceptance and growth showed that this extruded diet can be the starting point to develop a commercial feed for this species.  相似文献   

16.
The aim of this study was to evaluate the effects of dietary lipids on protein‐sparing and lipoprotein lipase (LPL) mRNA expression in culture using 360 juvenile soft‐shelled turtles (Pelodiscussinensis) (initial weight 4.26 ± 0.14 g). The turtles were allotted to six diets with three duplicates for 60 days. A control diet with 46% protein and 55% fishmeal (CD) and five isonitrogenous diets with 41.3% protein and 45% fishmeal (F, S, L1, L2 and L3) were used, containing the following three lipid types: fish oil, soybean oil and mixed oils (soybean oil: fish oil = 1:1). The results showed that the survival rate was not affected by dietary lipids (P > 0.05). The highest weight gain and lowest feed coefficient ratio were seen in the L3 diets (P < 0.05). Turtles fed with L2 and L3 diets had lower superoxide dismutase activities, higher alanine aminotransferase activities and higher cholesterol concentrations than those exposed to other diets (P < 0.05). Hepatic LPL activity and LPL mRNA expression were higher in the L3 diets than in the other diets (P < 0.05). Overall, there were obvious protein‐sparing effects of dietary lipids and LPL mRNA expression was stimulated by high dietary lipids in soft‐shelled turtles in this study.  相似文献   

17.
This study investigated in rainbow trout (Oncorhynchus mykiss) if diet composition and feeding level affect faecal bile acid loss, and whether this reflects on the apparent digestibility coefficient (ADC) of fat. Six diets were formulated with either fishmeal or plant protein as main protein source. This created a contrast in the supply of bile acids, the bile acid precursor cholesterol, taurine and the taurine precursors (methionine + cysteine) involved in bile acid conjugation. For both protein sources, three diets were formulated with increasing inclusion of a non‐starch polysaccharide (NSP)‐rich ingredient mixture (0.0, 82.0 and 164.2 g/kg diet). This aimed at enhancing faecal bile acid loss. Fish were fed both restrictively (1.2% BW/day) and to satiation. A similar fat ADC was found when substituting fishmeal with a plant protein mixture, suggesting that the lower content of bile acids, cholesterol, taurine, methionine and cysteine in the plant‐based diets did not limit fat digestion. Faecal bile acid loss increased alongside dietary NSP level, however, only during satiation feeding and most strongly for fish fed the fishmeal‐based diets. Enhanced faecal bile acid loss was not caused by NSP‐bile acid binding/entrapment, but by an increase in faeces production. During satiation feeding, fat ADC negatively correlated with faecal bile acid loss. From this it is concluded that bile acid availability/synthesis can become limiting for fat digestion in rainbow trout under conditions that enhance faecal bile acid loss (i.e. dietary NSP level and feeding level).  相似文献   

18.
The ability of frogs to digest dietary nutrients changes with growth, with the animals becoming more or less demanding. The objective of this study was to determine the apparent digestibility coefficients of protein, energy and ether extract of 14 ingredients used in bullfrog diets (spray‐dried blood meal, hydrolysed feather meal, poultry by‐product meal, red blood cell concentrate, tilapia by‐product meal, sardine fishmeal, salmon fishmeal, meat and bone meal, corn gluten meal, soybean meal, corn, wheat bran, soy protein concentrate and soybean oil). A total of 2,325 bullfrogs (Lithobates catesbeianus) in different phases of development were used: early phase (mean weight of 30–50 g), growth phase (80–110 g) and finishing phase (150–200 g). Faeces were collected using the method of dissection. Marked differences in digestibility of the ingredients were observed between the different phases of frog development. Among the ingredients studied, salmon fishmeal and corn gluten meal showed good utilization of the protein (78.9% and 86.7%, respectively) and energy fraction (89.4% and 83.3%, respectively). The salmon fishmeal, poultry by‐product meal, sardine fishmeal, soy protein concentrate, wheat bran and soybean oil exhibited good ether extract utilization (81.2%–92.8%), recommending their use in bullfrog diets.  相似文献   

19.
A study was carried out to examine and optimize the inclusion levels of shrimp hydrolysate (SH) or tilapia hydrolysate (TH) in low fishmeal diets for olive flounder (Paralichthys olivaceus). A fishmeal (FM)‐based diet was considered as a high FM (HFM) diet, and a diet containing soy protein concentrate (SPC) as a FM replacer at 50% substitution level was regarded as a low FM (LFM) diet. Six other experimental diets were prepared by dietary supplementation of SH or TH to LFM diet at different inclusion levels of 15 g/kg, 30 or 45 g/kg in the expense of FM (designated as SH‐1.5, SH‐3.0, SH‐4.5, TH‐1.5, TH‐3.0 and TH‐4.5, respectively). After 10 weeks of a feeding trial, growth performance and feed utilization efficiency of fish were significantly higher in fish fed HFM, SH‐3.0, SH‐4.5, TH‐1.5 and TH‐3.0 diets compared to those of fish fed LFM diet. Intestine diameter, villus height and goblet cell counts of fish were significantly increased by dietary inclusion of SH or TH into LFM diet. Dry matter and protein digestibility of diets were significantly improved by SH or TH incorporation. Innate immunity of fish was significantly enhanced by dietary SH or TH supplementation into LFM diet. Disease resistance of fish was significantly increased against Edwardsiella tarda by dietary inclusion of SH and TH at the highest inclusion level (45 g/kg). The optimum inclusion level of SH or TH in a SPC‐based LFM diet could be ~30 g/kg and 15–30 g/kg, for olive flounder.  相似文献   

20.
A 50‐day growth trial was conducted to evaluate the efficacy of Chlorella vulgaris (Beijerinck) as an ingredient in the diets of giant freshwater prawn Macrobrachium rosenbergii (De Man) postlarvae (PL30). Immune response (total haemocyte count and prophenoloxidase activity) was also assessed by subjecting postlarvae to a challenge test against Aeromonas hydrophila (Chester) for 14 days. Iso‐nitrogenous and iso‐lipidic test diets were prepared using a fishmeal‐based‐positive control diet (D0) and four basal diets with inclusion levels of 2% (D2), 4% (D4), 6% (D6) and 8% (D8) C. vulgaris. Postlarvae of M. rosenbergii were randomly stocked (mean initial body weight of 0.19 ± 0.02 g) in 30‐L tanks in three replicates per dietary treatment for evaluation of growth performance. Another set of postlarvae (mean initial body weight of 1.25 ± 0.02 g) was randomly distributed in 95‐L tanks in three replicates per dietary treatment for the assessment of immune response. Results showed that specific growth rate was significantly higher (P < 0.05) in postlarvae fed D4 and D6. Variations in values for carcass protein, lipid, moisture and ash were also evident. Postlarvae fed diets with Chlorella showed increased prophenol oxidase activity and total haemocyte counts. Moreover, survival rate after challenge with A. hydrophila was significantly increased (P < 0.05). Inclusion of C. vulgaris in diets enhanced immune response and resistance of M. rosenbergii postlarvae against A. hydrophila infection.  相似文献   

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