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1.
A 12‐wk feeding trial was conducted to evaluate the effects of the dietary fishmeal analogue (FMA) adding 2% shrimp soluble extract (SSE) on growing rainbow trout, Oncorhynchus mykiss. Fish averaging 146 ± 3.8 g (mean ± SD) were randomly distributed into 500‐L aquaria as groups of 20 fish per tank. Fish were fed the experimental diets in triplicate groups to apparent satiation twice a day on a dry matter basis. Each group was fed one of the four experimental diets: control (FM100% + FMA0%), FMA0 (FM100% + FMA0% + SSE2%), FMA12 (FM88% + FMA12% + SSE2%), and FMA24 (FM76% + FMA24% + SSE2%). After the feeding trial, weight gain and specific growth rate of fish fed the FMA0 and FMA12 diets were significantly higher than those of fish fed the FMA24 diet (P < 0.05). Feed efficiency and protein efficiency ratio values of fish fed the control, FMA0, and FMA12 diets were significantly higher than those of fish fed the FMA24 diet (P < 0.05). The values of superoxide dismutase activity showed significantly higher amounts for the FMA0, FMA12, and FMA24 groups than the control group (P < 0.05). Lysozyme activity in the FMA12 group was significantly higher than in the control group (P < 0.05). Therefore, according to our results, FMA with additive SSE can be used up to 12% as a substitute of fishmeal for growing rainbow trout.  相似文献   

2.
The effect of dietary phytase on phosphorus (P) digestibility, growth, bone mineralization and plasma P of common carp (Cyprinus carpio) was investigated. Five diets, D0, DP, PHYT1, PHYT2 and PHYT4, were used. D0 contained no supplement. DP was supplemented with 2.6 g P (Na2HPO4× 2H2O) kg−1. PHYT1, PHYT2 and PHYT4 comprised 1000, 2000 and 4000 U phytase [Ronozyme P (CT)] kg−1. D0, PHYT1, PHYT2, PHYT4 had average of 7.95 g P kg−1; DP contained 10.3 g P kg−1. After 126 days of feeding, fish grew from 115 to 347 g (D0), 583.7 g (DP), 352.6 g (PHYT1), 393.3 g (PHYT2) and 406.4 g (PHYT4). Addition of phytase significantly increased daily feed intake, but only led to a marginal improvement in the weight gain, SGR and FCR of fish fed PHYT2 and PHYT4 compared with fish fed D0. Fish fed DP showed the best (P<0.05) growth performances. Fish fed DP and PHYT4 significantly digested dietary P more than the fish fed D0. Fish fed D0, PHYT1, PHYT2 and PHYT4 retained higher (P<0.05) Zn in their bones than fish fed DP. However, there was no further effect on bone mineralization. Plasma P scarcely improved by between 14% and 26% in fish fed PHYT2 and PHYT4 relative to fish fed D0. P concentration of the faeces was reduced by about 9–22% in fish fed PHYT1 and PHYT4 compared with fish fed D0.  相似文献   

3.
An 8‐week feeding trial was implemented to evaluate the effects of replacing fish meal (FM) with mussel (Cristaria plicata) meat (MM) on growth, digestive ability, antioxidant capacity and hepatic insulin‐like growth factor I (IGF‐I) gene expression of juvenile Ussuri catfish (Pseudobagrus ussuriensis). Three isonitrogenous and isolipidic diets were formulated to include 0, 177.5 and 355.1 g/kg of MM, accordingly, replacing 0% (M0, control), 50% (M1) and 100% (M2) of FM protein, respectively. The results showed that the final body weight, weight gain, specific growth rate and feed intake were gradually decreased with dietary MM protein levels increased, but there were no significant difference between M0 and M1 groups (p > 0.05). The protein efficiency ratio was increased significantly with dietary MM inclusion (p < 0.05). The apparent digestibility coefficient of dry matter, crude lipid and gross energy gradually increased with increasing dietary MM protein levels, but the apparent digestibility coefficient of crude protein was not significantly affected by MM protein supplementation (p > 0.05). Fish fed diet, M0 and M1 remained unaffected significantly on activities of alpha‐amylase and pepsin (p > 0.05), but fish fed diet M2 had the highest activities of alpha‐amylase and pepsin. Fish fed diet M1 or M2 had significantly lower hepatic total antioxidant capacity, superoxide dismutase and the higher malondialdehyde level compared to fish fed diet M0. In addition, no significant difference was observed in hepatic IGF‐I gene expression level for fish fed diet M0 and diet M1, and fish fed diet M2 showed significantly lower hepatic IGF‐I gene expression level. Therefore, we can conclude that MM protein can successfully substitute 50% of FM protein without significantly negative effect on growth, nutrient utilization, and hepatic IGF‐I gene expression for juvenile Ussuri catfish, but the antioxidant capacity was negatively affected in the present study, what is more, the total replacement of FM by MM in diet may result in the inhibition of the growth and antioxidant capacity of fish.  相似文献   

4.
The present study was conducted to evaluate the efficacy of organic acid blends as dietary antibiotic replacer in marine fish olive flounder, Paralichthys olivaceus. Fish averaging 3.5 ± 0.05 g (mean ± SD) were fed one of the four experimental diets: (1) without antibiotic or organic acid (Control/CON); (2) with antibiotic—50 mg oxytetracycline per kg body weight per day (OTC); (3) with organic acid blend A—4 g/kg diet (OAA); and (4) with organic acid blend B—4 g/kg diet (OAB), for 10 weeks. At the end of the experiment, total intestinal bacterial counts in fish‐fed OAA, OAB and OTC were significantly lower than that of fish‐fed CON diet (p < 0.05). Further, the group of fish‐fed organic acid blends (OAA, OAB) or antibiotic (OTC)‐supplemented diets exhibited lower intestinal Vibrio sp. counts compared with fish‐fed CON diet. Disease challenge test with bacteria Edwardsiella tarda showed significantly lower cumulative mortality rates for the group of fish‐fed OAA, OAB or OTC than that of fish‐fed CON diet (p < 0.05). There were no negative effects on the growth, serological characteristics and proximate composition among the group of fish‐fed different experimental diets. Therefore, the present experiment demonstrates that blends of organic acid could be a promising alternative to dietary antibiotics for the preventive and/or curative health management in marine fish olive flounder aquaculture.  相似文献   

5.
The research was aimed to assess the effect of dietary carvacrol (0.025% and 0.05%) on sea bass (Dicentrarchus labrax) growth, immune response and resistance to Listonella anguillarum. Fish (69.2 ± 0.22 g) were fed the experimental diets for 9 weeks. Dietary carvacrol did not negatively affect fish survival, growth performance, feed intake and feed conversion ratio (P > 0.05) nor carcass yield and viscerosomatic, hepatosomatic and mesenteric fat index (P > 0.05). Serum and head kidney leucocytes were collected after 1, 4 and 8 weeks of feeding. Carvacrol significantly reduced serum proteins, immunoglobulins and lysozyme activity (P < 0.01) and moderately increased phagocytosis and pinocytosis of head kidney macrophages. The release of reactive oxygen species by leucocytes was reduced in carvacrol‐fed fish, even if significantly (P < 0.05) only in those fed 0.05% carvacrol for 1 week. Dietary carvacrol did not significantly affect the aspecific immune response, although a potential antioxidant activity might be speculated. Moreover, feeding carvacrol provided an appreciable resistance to a challenge with L. anguillarum, when a bacterial dose lower than the Lethal Dose50 was used. Cumulative mortality in fish fed 0.025% carvacrol was significantly lower than that of untreated controls (75% Relative Per cent Survival).  相似文献   

6.
A 45‐day feeding trial was conducted to study the effect of replacing dietary fish meal (FM) with a tuna by‐product meal (TBM) on the growth, feed efficiency, carcass composition and stress oxidative status of juvenile Nile tilapia, Oreochromis niloticus L.). Triplicate groups of fish (2.21 ± 0.01 g) were fed on four iso‐nitrogenous and iso‐energetic diets. The control diet (A0) used FM as the sole source of animal protein. In the other three diets (A10–A30), 33%–100% of FM was substituted by TBM at 10% increments. There were no significant differences (P>0.05) in growth performance among fish fed on diets A0, A10 and A20. Fish fed these experimental diets (i.e., A0, A10 and A20) showed significantly (P<0.05) better daily mass gain, specific growth rate and protein efficiency ratio than those fed on diet A30. Feed conversion ratio increased with increasing TBM content, but only the value found in fish fed on diet A30 differed significantly (P<0.05) from the other treatments. The fish accumulated increasing quantities of lipids and decreasing levels of ash in their carcasses with increasing levels of dietary TBM. At the end of the experimental period, a significant increase (P<0.001) in catalase and glutathione S‐transferase activities was seen only in groups fed on diet A30. Similarly, a significant enhancement in glutathione peroxidase and superoxide dismutase activities was observed in groups fed on diets A20 and A30 compared with the other groups. The results show that this product can be included up to 20% in practical Nile tilapia diets without any detrimental effects.  相似文献   

7.
The present trial was performed to evaluate the effect of dietary incorporation of dried Spirulina, Chlorella and their mixture on the immune status of Nile tilapia (Oreochromis niloticus) before and after artificial infection with pathogenic bacterium Aeromonas hydrophila (A. hydrophila). Two hundred and forty fish were divided into four groups: (a) a control group fed on a basal diet only, (b) a second group fed on a diet containing Spirulina 15%, (c) a third group fed on a diet containing Chlorella 15%, and (d) a fourth group fed on a diet containing a mixture of both Spirulina 15% and Chlorella 15%. At the end of the experiment (9 weeks), the four groups were experimentally infected with A. hydrophila for 7 days. Antioxidant enzymes, lysozyme and bactericidal activities and histopathological changes were determined just before the challenge test and 7 days post‐challenge. Significant (p ≤ 0.05) increases in fish body protein% before the challenge test and increases in serum antioxidant enzymes, lysozyme and bactericidal activity in the Chlorella and algal mixture groups before and after the challenge test were observed. Spirulina, Chlorella and their mixture groups significantly decreased serum malondialdehyde compared to the control group before and after the challenge test. Using Spirulina, Chlorella and their mixture mitigated the necrotic and degenerative changes induced by A. hydrophila and revealed well‐developed and multiple melanomacrophage centres. Thus, dietary Spirulina, Chlorella and their mixture inclusion in Nile tilapia fish proved to have a protective effect against A. hydrophila infection.  相似文献   

8.
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   

9.
The present study was conducted to investigate the changes in mineralization and morphology in response to graded levels of dietary phosphorus in Indian major carp, Catla (Catla catla) fingerlings (av. wt. 4.23 ± 0.87 g). The experimental system constituted of 24 150-L capacity plastic tanks (eight treatments, three replicates) stocked with 20 fingerlings each. Eight isonitrogenous and isocaloric semi-purified diets (crude protein 35%, crude lipid 8.5%) were formulated with graded levels of phosphorus (0%-control; 0.1; 0.3; 0.5; 0.7; 0.9; 1.1; 1.3; 1.5%) using KH2PO4. The fish were fed twice daily with the respective feeds for a period of 120 days. The percentage of ash content in whole body, vertebrae and opercular bones was found to be significantly (P < 0.05) lower in fish fed low levels of dietary phosphorus (T1, T2) in comparison with other treatments. The concentration of phosphorus and calcium was found to be significantly (P < 0.05) lower in whole body, vertebrae and opercula of fish fed low phosphorus diets (T1, T2) relative to treatments with higher levels of dietary phosphorus supplementation. The concentration of magnesium in opercular and vertebral tissues of T1 group was significantly (P < 0.05) lower than all other groups. The X-ray radiographs did not reveal any skeletal deformities in any of the treatments. Truss analysis showed absence of significant morphological variations between fish of different treatments. The deficiency of dietary phosphorus in catla led to significantly lower mineralization of whole body and bone tissues, but the deficiency was not severe enough to cause skeletal deformities and morphological changes in the fish.  相似文献   

10.
Rainbow trout Oncorhynchus mykiss grew from 44 to 326 g in 96days when held at 12 °C. Fish were fed to satiation twice dailywith either high (L1: 30.8%, L2:31.4%) or lower-lipid feeds (C1: 18.8%,C2: 21.8%). Four feeding treatments were studied.Group C1C2 received feed C1 for 43 days(days 0–43) and C2 thereafter (days 44–96).Groups L1L2, L1C2 andC1L2 were subjected to dietary changes asindicated by the feed designations. After a short period of feedadaptation, fish ingested similar amounts of feed energy i.e., they ateless by weight of the lipid-rich (L) feeds. Feed lipid content did notaffect growth but fish fed L-feed had reduced feed conversion ratio(FCR) compared to fish fed C-feed (0.731 vs. 0.773) during days0–43 (P < 0.01). After 96 days,L1L2-fish were lower in body protein(15.8%) than the C1C2-fish (16.8%)(P < 0.01). L-feeds also tended to increase percentage lipidand reduce percentage whole body moisture and ash. A higher net proteinutilisation (NPU) was recorded in fish fed L-feeds (43.6%)compared to fish fed C-feeds (38.8%) in days 0–43(P < 0.05). This seemed to be the result of a lower proteinintake rather than a protein-sparing effect of feed lipid. Above athreshold value of approximately 6.5 mg protein eaten·g bodywtminus 1·day–1, NPU decreased.  相似文献   

11.
A feeding trial with striped catfish, Pangasianodon hypophthalmus was performed to determine the effect of Yucca schidigera in practical diet on the growth, feed utilization, body composition, total ammonia–nitrogen (TAN) excretion and haematological parameters. A diet with fish meal as the main protein source without yucca extract was used as the control diet (Diet 1). Four diets were formulated with 0.075 (Diet 2), 0.1 (Diet 3) and 0.15 (Diet 4)% of yucca extract respectively. Fifteen fish per tank (initial mean weight 1.78 ± 0.05 g) were randomly allocated to 15 fibreglass tanks (80‐L) connected to a freshwater closed recirculation system (temperature 29.7 ± 1.0°C). The experimental diets were tested in triplicates for 12 weeks. The specific growth rate of fish fed Diet 4 was significantly higher when compared with fish fed Diet 1. The growth of fish fed diets Diet 2 and Diet 3 were not significantly different compared with fish fed the Diet 1. Striped catfish fed Diet 4 had significantly lower feed conversion ratio compared with fish fed Diet 1 and Diet 2 (P < 0.05).The incorporation of high level Yucca schidigera extract in the diets reduced TAN compared with Diet 1. Dietary inclusion of Yucca extract levels did not significantly affect the biometric parameters or whole body proximate composition of the striped catfish (P > 0.05). The PCV (%) in fish significantly increased with high levels of Yucca inclusion (Diet 4) compared with control diet. Fish fed Diet 4 showed significantly higher haemoglobin levels than Diet 1 (P < 0.05). The results indicate that dietary inclusion of Yucca schidigera extract is promising as a feed additive that could improve growth performance and some haematological parameters and the best Yucca schidigera level was 0.15%.  相似文献   

12.
Abstract

Two trials evaluated winter feeding strategies for small golden shiners, Notemigonus crysoleucas destined for the crappie, Po-moxis spp. market. Fish were stocked at 615 g/pool (approximately 127 or 158 fish/m2, trials 1 and 2, respectively) in aerated, 5.9-m2 pools for 100 and 104 days, respectively. In the first trial, fish were fed a commercially available 32% crude protein crumbled, extruded pellet once daily at feeding rates of 0% (fertilizer only), 1%, or 2% of body weight/day (bw/d) on days when the afternoon air temperature was >7°C. Unfed fish lost weight, and their condition declined. Fish fed at 1% maintained both weight and condition, while fish fed at 2% gained weight. Fish in the second trial were fed once daily at 1% bw/d on those days when the air temperature was either >7°C or >10°C, with either a commercially available crumbled, extruded pellet or a sinking pellet (compressed). Fish fed crumbles were in significantly better condition at harvest than fish fed a sinking pellet, regardless of trigger feeding temperature, although average weight was not significantly different. Feeding on days with air temperatures >7°C provided 13% more feeding days than a trigger temperature >10 °C, and fish grew more over the winter. Two condition indices, relative weight (Wr) and Fulton's condition factor (K), proved useful in evaluating the condition of golden shiners cultured using different feeding strategies.  相似文献   

13.
Two experiments were conducted to investigate the effects of varying dietary protein (35–45%) and energy levels (17.34–19.44 kJ g−1) on the growth performance of milkfish (Chanos chanos) maintained under laboratory (experiment 1) and field conditions (Experiment 2) in inland saline groundwater. The results of experiment 1 (initial weight of fish: 0.25 g) revealed that, irrespective of the protein source (fish meal or processed full fat soybean), fish fed a diet containing 40% protein showed significantly (p<0.05) higher growth in terms of live weight gain and specific growth rate, low feed conversion ratio [1.71 (fish meal) and 1.58 (soybean)], high nutrient retention (gross protein retention: 28.59 and 31.05%; gross energy retention: 24.23 and 26.04%), apparent protein digestibility (81.74 and 85.91%) and digestive enzyme activity (specific protease and amylase). An observation on the postprandial excretion of metabolites (N–NH4 and o–PO4) indicated significantly (p<0.05) low levels of these metabolites in aquaria where the fish were fed 40% dietary protein irrespective of the protein source. The results of experiment 2 also indicate (initial weight of fish: 4.43 g) a significantly (p<0.05) higher growth performance (weight gain, biomass, specific growth rate, growth day−1 and fish production) in ponds where the fish were fed 40% dietary protein. Irrespective of the experimental conditions (laboratory/field), feeding the fish higher dietary protein levels (beyond 40%) not only repressed growth performance but also affected proximate composition by lowering protein accumulation and energy assimilation. An investigation on the effects of feeds on water quality parameters revealed that values for total alkalinity, NH4–N, NO3–N, turbidity, total dissolved solids and parameters indicative of productivity (chlorophyll a, net primary productivity and plankton population) increased significantly (p<0.05) from treatments 1–3 (35–40% protein) and declined thereafter, in treatment 4 (42% dietary protein), indicating that water quality characteristics correlated well with fish growth. The results suggest that in order to obtain a high-yield in milkfish culture system the fish should be fed supplementary diets containing appropriate (40%) protein levels, especially when the stocking rates are high.  相似文献   

14.
A 6‐week feeding trial was conducted to examine the effect of feeding frequency on growth, feed utilization efficiency, body composition and waste output of juvenile golden pompano Trachinotus ovatus reared in net pens. Fish (10.3 ± 0.5 g) were either fed a formulated diet containing 48.4% crude protein and 5.7% crude lipid at 0.5, 1, 2, 3 or 4 meals per day or fed a raw fish feed at two meals per day as a control. The weight gain (WG) increased with increasing feeding frequency from 0.5 to 3 meals per day (P < 0.05), but did not significantly change with the further increase in feeding frequency from 3 to 4 meals per day (P > 0.05). The feed intake (FI) was lower in fish fed at 0.5 or 1 meal per day than in fish fed at 2, 3 or 4 meals per day (P < 0.05). No significant differences were found in the feed conversion ratio (FCR), nitrogen retention efficiency (NRE), condition factor (CF), nitrogen waste output (NWO) and phosphorus waste output (PWO) between fish fed at 1, 2, 3 or 4 meals per day (P > 0.05), whereas no significant difference was found in the phosphorus retention efficiency (PRE) among the feeding treatments (P > 0.05). The body lipid content increased, whereas the contents of moisture and ash decreased, with the increase in feeding frequency (P < 0.05). At the same feeding frequency, fish fed the formulated diet exhibited lower FI, FCR, HSI, body moisture content, NWO and PWO, but higher NRE, PRE, body lipid content and body phosphorus content than those of fish fed the raw fish feed (P < 0.05). These results suggest that the formulated diet can satisfy nutrient requirements of juvenile golden pompano reared in net pens, and the suitable feeding frequency is 3 meals per day.  相似文献   

15.
A 10‐week feeding trial was carried out to evaluate the optimum dietary protein level for the maximum growth of juvenile beluga, Huso huso. Fish averaging 1.34 ± 0.07 g (mean ± SD) was randomly distributed into 18 circular fibreglass tanks of 500 L capacity (20 fish per tank). Six iso‐caloric diets were formulated to contain 30 (CP30), 35 (CP35), 40 (CP40), 45 (CP45), 50 (CP50) and 55% (CP55) crude protein (CP). Fish were fed each of the six experimental diets in triplicate groups. At the end of feeding trial, weight gain (WG) and specific growth rate (SGR) in fish fed CP40 and CP45 diets were significantly higher than those of fish fed CP30, CP35, CP50 and CP55 diets (P < 0.05). Lipid retention increased significantly from 24.7% to 31.6%, but protein retention decreased from 54.6% to 35.6% with increasing protein levels from 30% to 50%. Muscle total essential and non‐essential amino acid (EAA & NEAA) concentrations increased with the dietary protein level up to CP45 diets. Muscle total EAA concentrations (%) of fish fed CP45 were significantly higher than those of fish fed CP30, CP35, CP50 and CP55, but there was no significantly different between those of fish fed CP40 and CP45. Muscle total NEAA concentration (%) of fish fed CP45 were significantly higher than those of fish fed CP30 and CP35 diets. Broken‐line analysis of WG suggested that the optimum dietary protein level could be 38.9% for maximum growth performance in juvenile beluga (1.3–77 g).  相似文献   

16.
ABSTRACT

This experiment was conducted to determine the effect of dietary lipid sources on growth performance, body proximate composition, hematology, immune response and resistance of Nile tilapia, Oreochromis niloticus, to Streptococcus iniae infection. Six isocaloric (3.2 kcal/g) and isonitrogenous (34% crude protein) semi-purified diets were supplemented with 7% of various sources of lipid, namely, corn oil (CO), beef tallow (BT), menhaden fish oil (FO), linseed oil (LO), and equal combinations of FO+CO+BT or LO+CO+BT. Diets were fed to tilapia in quadruplicate aquaria to apparent satiation, twice daily for 12 weeks. Fish fed the BT-diet exhibited significantly lowest weight gain, diet intake, feed and protein efficiency ratios, apparent protein utilization, and survival. Whole-body protein and ash were significantly (P < 0.05) lowest and highest, respectively, for fish fed the beef tallow-diet, but the values of these parameters did not differ among fish fed other diets. No significant differences (P > 0.05) were found among hematological values, except for fish fed the FO-diet which had abnormally high red and white blood cell counts. Serum protein concentration, lysozyme activity, and natural hemolytic complement activity were significantly (P < 0.05) reduced in fish fed the BT-diet. The values of these parameters did not differ among fish fed other diets. Post-challenge antibody titer was not influenced by dietary lipid sources. Cumulative mortality 15 days post-challenge with S. iniae was significantly lower (P < 0.05) for fish fed the BT diet compared with those fed FO or FO+CO+BT diets. No significant differences were observed in fish fed other dietary lipid sources.  相似文献   

17.
This experiment was conducted to study the effects of different dietary levels of vitamin C, L‐ascorbyl‐2‐polyphosphate (ASPP), on growth and tissue vitamin C concentrations in juvenile olive flounder, Paralichthys olivaceus (Temminck et Schlegel). Fish were fed one of six semi‐purified diets containing an equivalent of 0, 25, 50, 75, 150, or 1500 mg ascorbic acid (AA) kg?1 diet (C0, C25, C50, C75, C150 or C1500) in the form of ASPP for 12 weeks. Weight gain (WG) and protein efficiency ratio (PER) of fish fed the C0 diet were significantly lower than those of fish fed the other diets (P < 0.05), and WG and PER of fish fed the C25, C50 and C75 diets were significantly lower than those of fish fed the C1500 diet (P < 0.05). Fish fed the C0 diet exhibited vitamin C deficiency symptoms such as anorexia, scoliosis, cataract, exophthalmia and fin hemorrhage at the end of the 12‐week test. After 12 weeks of the feeding trial, AA concentrations from gill, kidney, and liver of fish fed the C0, C25, C50 and C75 diets were significantly lower than those of fish fed the C150 and C1500 diets (P < 0.05). Based on broken line analyses for WG and PER, the optimum dietary levels of vitamin C were 91 and 93 mg AA kg?1 diet respectively. These findings suggest that the dietary vitamin C requirement could be 93 mg AA kg?1 diet to support reasonable growth, and greater than 150 mg AA kg?1 diet may be required for AA saturation of major tissues for juvenile olive flounder under experimental conditions.  相似文献   

18.
A feeding trial of 120 days was conducted to study the effect of graded levels of dietary phosphorus on haematology, serum protein concentrations and HSP70 expression in fingerlings of the Indian major carp, Catla (Catla catla). Eight isonitrogenous and isoenergetic purified diets were formulated to contain graded levels of dietary phosphorus (dP), i.e., T1, 0.1%; T2, 0.3%; T3, 0.5%; T4, 0.7%; T5, 0.9%; T6, 1.1%; T7, 1.3%; or T8, 1.5%. Four hundred and eighty fish (average weight 4.23 ± 0.016 g) were equally distributed into 24 tanks forming eight treatments with three replicates each. The fish were fed daily at the rate of 3.5% body weight in two instalments. At the end of feeding trial fish were sampled to study total RBC and WBC count, haemoglobin, serum lysozyme activity, serum total protein, albumin (A), globulin (G) concentration and HSP70 expression. Total RBC count, haemoglobin concentration and serum lysozyme activity did not vary significantly in response to different dietary phosphorus concentrations. Total WBC count was found to be significantly (P < 0.05) higher in T1 relative to all other treatments. Serum albumin and A/G ratio was found to be significantly lower in fish of T1 and T2 in relation to T7 group (P < 0.05). Serum globulin and total protein levels remained unaffected by variations in dietary phosphorus. HSP70 expression was observed in T1 group (0.1% dP) in gills and brain tissue, but not in liver and muscle tissues. No HSP70 expression was observed in fish of T4 (0.7% dP) and T8 (1.5% dP) treatments. These prima facie results suggest that dietary phosphorus had only minor influence on the haemato-biochemical parameters studied; however dietary phosphorus deficiency caused organ specific induction of HSP70 in catla fingerlings.  相似文献   

19.
Lipopolysaccharide (LPS), a component of Gram negative bacteria, was reported as important immunostimulant for fish. In this study, striped catfish were fed diets containing different Escherichia coli LPS concentrations (0%, 0.01% and 0.05%) for 2 weeks and then fed control feed (0% LPS) for 4 weeks. Plasma cortisol and glucose were rather low and did not differ significantly among treatments (P > 0.05). The respiratory burst activity, lysozyme, complement, total of antibody as well as mortality in fish challenged with Edwardsiella ictaluri were recorded every 2 weeks (W2, W4 and W6). The lysozyme activity significantly increased in fish treated with LPS (P < 0.05) in W2, W4 and W6. The highest values of respiratory burst activity were observed at week 4 in fish fed 0.01% LPS. There were significant differences in total of antibody between fish fed LPS (0.01%) and control in W2, W4. The challenge test with Edwardsiella ictaluri showed that fish fed 0.01% LPS had lower cumulative mortality (40%, 33% and 42%) compared with the fish fed 0.05% LPS (50%, 40% and 47%) and control fish (40%, 57% and 53%) in the three difference sampling times respectively. These results suggest that feed supplemented with 0.01% LPS could enhance immunity of striped catfish after 2 weeks of oral administration and fish could be protected against bacterial infection during the following 4 weeks.  相似文献   

20.
This study evaluated the effects of dietary fermented tuna by‐product meal (FTBM) in juvenile olive flounder, Paralichthys olivaceus. Five diets were formulated to replace fishmeal (FM) with FTBM at 0% (FTBM0), 12.5% (FTBM12.5), 25.0% (FTBM25), 37.5% (FTBM37.5), or 50% (FTBM50). After 8 wk, weight gain, specific growth rate, and feed efficiency of fish fed FTBM0 and FTBM12.5 diets were significantly higher than fish fed the other diets (P < 0.05). Also, mean cumulative survival rates (%) of fish fed the FTBM0 and FTBM12.5 diets were significantly higher than those fed FTBM50 diet at Day 9 postchallenge with Edwardsiella tarda (P < 0.05). Protein efficiency ratio of fish fed FTBM0 and FTBM12.5 diets was significantly higher (P < 0.05) than fish fed diets FTBM37.5 and FTBM50. Broken‐line regression analysis of weight gain showed an optimal FM replacement level of 10.65% with FTBM. Therefore, the optimal dietary inclusion of FTBM in juvenile olive flounder diets could be greater than 10.65% but less than 12.5% without any adverse physiological effects on fish health.  相似文献   

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