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1.
Dried distiller's grain (DDG) is considered as an alternative ingredient of dietary feed due to its high contents of protein, fibre and fat. In this study, 60 g kg‐1 of DDG was used to feed grass carp (Ctenopharyngodon idella), bluntnose black bream (Megalobrama amblycephala), gibel carp (Carassius gibelio) and black carp (Mylopharyngodon piceus) for 8 weeks, and its effect on fish production and gut allochthonous microbiota was investigated for the development of a suitable fish feed high in nutrients and low in cost for polyculture freshwater fish. DDG supplementation resulted in the less weight gain and higher feed conversion ratio of black carp (P < 0.05), but had no significant effects on other fish or parameters. PCR–denaturing gradient gel electrophoresis (DGGE) analysis indicated that all four fish species had some common and unique bacteria in their digestive tracts, and the gut microbiota of bluntnose black and gibel carp fed the control diet and DDG diets were very similar (Cs > 91%); of them, the total counts of intestinal bacteria studied by qPCR increased in grass carp (P < 0.05) and depressed in black carp (P < 0.05) when fed dietary DDG. Thus, we assumed that dietary DDG modulated production and gut microbiota of fish in a host‐specific way.  相似文献   

2.
Diets containing deoxynivalenol (DON) were fed to rainbow trout Oncorhynchus mykiss (Walbaum) for 4 weeks followed by experimental infection (intraperitoneal) with Flavobacterium psychrophilum (4.1 × 106 colony‐forming units [CFU] mL−1). Mortality of rainbow trout fed either 6.4 mg kg−1 DON or trout pair‐fed the control diet was significantly reduced (P < 0.05) in comparison with trout fed the control diet to apparent satiation (<0.1 mg kg−1 DON). In a second experiment, trout were fed one of three experimental diets; a control diet, a diet produced with corn naturally contaminated with DON (3.3 mg kg−1 DON) or a diet containing purified DON (3.8 mg kg−1); however, these fish were not experimentally infected. The presence of DON resulted in significant reduction (P < 0.0001) in feed intake as well as weight gain after 4 weeks. Respiratory burst of head‐kidney leucocytes isolated from rainbow trout fed diets containing purified DON (3.8 mg kg−1) was significantly higher (P < 0.05) at 35 day post‐exposure compared with controls. The antimicrobial activity of DON was examined by subjecting F. psychrophilum in vitro to serial dilutions of the chemical. Complete inhibition occurred at a concentration of 75 mg L−1 DON, but no effect was observed below this concentration (0–30 mg L−1).  相似文献   

3.
Pacific white shrimp Litopenaeus vannamei (1050 individuals with initial weight of 1.01 ± 0.001 g) were fed either control diet or one of six dietary astaxanthin (AX) concentration (25, 50, 75, 100, 125 and 150 mg kg−1) diets for 56 days in 35 tanks (30 shrimp per tank). After 56 days of culture, shrimp‐fed AX125 and AX150 diets had higher (P < 0.05) weight gain, specific growth rate, total antioxidant status and lower (P < 0.05) superoxide dismutase (SOD), catalase (CAT) than shrimp fed control diet. After low dissolved oxygen stress for 1 h, survival rate of shrimp fed AX75, AX100, AX125 and AX150 diets was higher (P < 0.05) than that of shrimp fed control diet. Hypoxia inducible factor‐1α (HIF‐1α), cytosolic manganese superoxide dismutase (cMnSOD) and CAT mRNA expression levels of shrimp fed seven diets were significantly down‐regulated under hypoxia than under normoxia, but their expression levels were higher under hypoxia in shrimp fed AX‐supplemented diets than in shrimp fed control diet. About 70‐kDa heat‐shock protein (Hsp70) mRNA expression level of shrimp fed seven diets was significantly up‐regulated under hypoxia than under normoxia, but its expression level was lower under hypoxia in shrimp fed AX‐supplemented diets than in shrimp fed control diet.  相似文献   

4.
Two, 8‐week feeding trials were conducted to compare protein‐sparing capability of dietary lipid in herbivorous grass carp (Ctenopharyngodon idella) and omnivorous tilapia (Oreochomis niloticus × O. aureus). Utilizing a 2 × 3 factorial design, experimental diets containing two levels of crude protein (380 and 250 g kg−1) and three levels of lipid (0, 40 and 100 g kg−1) were formulated for use in both feeding trials. Growth performances showed better response of both fish fed 380 g kg−1 protein diet than those fed 250 g kg−1 protein diet. Despite the dietary protein level, weight gain (WG), specific growth ratio (SGR), feed conversion ratio (FCR) and protein efficiency ratio were much higher (P < 0.05) for grass carp fed 40 g kg−1 lipid diet than those fed 100 g kg−1 lipid diet; however, there were no significant differences in tilapia fed the two diets. The feed intake of grass carp fed lipid‐free diet was the lowest, but it tended to decrease with increase in dietary lipids in tilapia. Lipid retention (LR) was negatively correlated with dietary lipid concentration of both fish. Viscerosomatic index (VSI), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF) and whole‐body and liver lipid content positively correlated with dietary lipid concentration of both fish. Plasma parameters and liver enzymes activities were also positively correlated with dietary lipid concentration of both fish. Liver lipid contents were higher and enzymes activities were lower in grass carp when compared with tilapia. These data suggested that there was no evidence of a protein‐sparing effect of dietary lipids in grass carp. Tilapia has relatively higher capacity to endure high dietary lipid level compared to grass carp.  相似文献   

5.
An experiment was conducted to investigate the effect of dietary chromium picolinate supplement on growth and haematology parameters of grass carp, Ctenopharyngodon idellus. Six diets with increasing dietary chromium picolinate levels 0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg kg−1 were fed to triplicate groups of 20 fish (initial weight of 12.78 ± 1.16 g, mean ± SD) in a flow water system for 10 weeks. Fish fed the diet supplemented with 0.8 mg Cr kg−1 had significantly improved weight gain (WG), feed efficiency ratio (FER), protein efficiency ratio (PER) and protein retention (PR). Fish fed high-chromium diets exhibited lower whole-body crude lipid contents than fish fed low-chromium diets. Liver glycogen concentrations for fish fed the diet with 0.2 mg Cr kg−1 was the highest (77.67 mg g−1). Fish fed the diet supplemented with 1.6 and 3.2 mg Cr kg−1 had significantly lower liver glycogen concentrations than other groups (P < 0.05). The highest serum insulin concentrations were observed in fish fed the diet supplemented with 0.8 mg Cr kg−1, but serum insulin concentrations decreased (P < 0.05) when dietary supplementation of chromium was higher than 0.8 mg Cr kg−1. Cholesterol concentrations decreased in direct proportion to dietary chromium level and achieved the lowest level when the fish were fed the 0.8 mg Cr kg−1 diet, but increased when the fish were fed the diet with more than 0.8 mg Cr kg−1 (P < 0.05). Fish fed the diet supplemented with 0.8 mg Cr kg−1 had higher triglyceride and high-density lipoprotein cholesterol (HDL-C) concentrations compared to other treatments. The results of the present study suggested that chromium picolinate could modify serum carbohydrate and lipid metabolism profile, and that the optimal dietary chromium level was 0.8 mg kg−1 for grass carp according to growth.  相似文献   

6.
This study investigated the effects of dietary mono‐ and multiprobiotic strains of Enterococcus faecalis, Lactobacillus fermentum and Leuconostoc mesenteroides on growth performance, intestinal bacteria and body composition of Javanese carp (Puntius gonionotus). Moreover, the effect of storage temperature on lactic acid bacteria (LAB) viability in the feed was studied. Compared to the control group, significant (P < 0.05) effect on weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio of probiotic fed Javanese carp was observed. Inclusion of individual LAB strains in the diet resulted in significantly improved growth performances of Javanese carps compared to fish fed a diet supplemented LAB mixture. The inclusion level of E. faecalis at 107 colony‐forming unit (cfu) g−1 in the diet revealed higher growth performance compared to other treatments. The population levels of LAB in the fish intestine were significantly increased while the levels of Gram‐negative bacteria were significantly decreased compared to the control. No significant variations were observed in the chemical composition of the carcass by probiotics. The viability of LAB in feed was higher when stored at 4 °C compared to 25 °C. It is suggested that E. faecalis has a greater potential for use in improving Javanese carp culture outcomes.  相似文献   

7.
A 63‐day growth trial was undertaken to estimate the effects of supplemented lysine and methionine with different dietary protein levels on growth performance and feed utilization in Grass Carp (Ctenopharyngodon idella). Six plant‐based practical diets were prepared, and 32CP, 30CP and 28CP diets were formulated to contain 320 g kg?1, 300 g kg?1 and 280 g kg?1 crude protein without lysine and methionine supplementation. In the supplementary group, lysine and methionine were added to formulate 32AA, 30AA and 28AA diets with 320 g kg?1, 300 g kg?1 and 280 g kg?1 dietary crude protein, respectively, according to the whole body amino acid composition of Grass Carp. In the groups without lysine and methionine supplementation, weight gain (WG, %) and specific growth rate (SGR, % day?1) of the fish fed 32CP diet were significantly higher than that of fish fed 30CP and 28CP diets, but no significant differences were found between 30CP‐ and 28CP‐diet treatments. WG and SGR of the fish fed 32AA and 30AA diets were significantly higher than that of fish fed 28AA diets, and the performance of grass carp was also significantly improved when fed diets with lysine and methionine supplementation (P < 0.05), and the interaction between dietary protein level and amino acid supplementation was noted between WG and SGR (P < 0.05). Feed intake (FI) was significantly increased with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05), but feed conversion ratio (FCR) showed a significant decreasing trend (P < 0.05). Two days after total ammonia nitrogen (TAN) concentration test, the values of TAN discharged by the fish 8 h after feeding were 207.1, 187.5, 170.6, 157.3, 141.3 and 128.9 mg kg?1 body weight for fish fed 32CP, 32AA, 30CP, 30AA, 28CP and 28AA diets, respectively. TAN excretion by grass carp was reduced in plant‐based practical diets with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05). The results indicated that lysine and methionine supplementation to the plant protein sources‐based practical diets can improve growth performance and feed utilization of grass carp, and the dietary crude protein can be reduced from 320 g kg?1 to 300 g kg?1 through balancing amino acids profile. The positive effect was not observed at 280 g kg?1 crude protein level.  相似文献   

8.
In this study, Bacillus natto NT was evaluated for use as a probiotic supplement in the feeds on the growth performance and the growth‐related genes' and microRNAs' (miRNAs) expression in the skeletal muscle of grass carp (Ctenopharyngodon idella). Grass carps (ave. wt. 43.96 ± 0.27 g) were fed diets supplemented with 1.87 × 109 (Bn1), 3.73 × 109 (Bn2), 5.60 × 109 (Bn3), 7.47 × 109 (Bn4) and 9.33 × 109 (Bn5) B. natto NT cells per 100 g feed for 56 days. The control group (BnC) was not supplemented with the B. natto NT. The fish of Bn3, Bn4 and Bn5 groups displayed better growth performance and lower feed conversion ratio (FCR) than the other groups (P < 0.05). Compared with the fish of BnC group, miR‐1a, miR‐181a, miR‐23a and miR‐206 expressions increased (P < 0.05), and the myostatin and myocyte enhancer factor C (MEF2C) mRNAs were down‐regulated (P < 0.05) in the fish of Bn4 and Bn5 groups. The specific growth rate analysis and apparent expressional regulation of the growth‐related miRNAs and genes stimulated by B. natto suggest the potential application of B. natto in improving the growth performance on the grass carps.  相似文献   

9.
A feeding trial was performed to determine the effect of a commercial source of Yucca schidigera and Quillaja saponaria extracts (Nutrafito Plus®), in practical diets, on striped catfish Pangasianodon hypophthalmus growth, feed utilization, body composition, total ammonia‐nitrogen (TAN) excretion and haematological parameters. Four experimental diets were supplemented with Nutrafito Plus® at 0%, 0.01%, 0.02% and 0.03% (diets: control, N01, N02 and N03 respectively). Three replicate groups of striped catfish, with initial mean weight of 1.78 ± 0.05 g, were fed one of the four diets for 12 weeks. The specific growth rate (SGR) and final weight of fish fed diet N03 was significantly higher (P < 0.05) than fish fed the other dietary treatments. The growth performance of fish fed diets N01 and N02 were not significantly different compared to fish fed the control diet. Striped catfish fed diet N03 had improved feed conversion ratio (FCR), net protein utilization (NPU) and protein efficiency ratio (PER) than the control (P < 0.05). The inclusion of the high dietary level of Yucca schidigera and Quillaja saponaria, diet N03, reduced TAN compared to all groups. Dietary inclusion of Yucca schidigera and Quillaja saponaria at all levels investigated did not affect the whole body proximate composition of the striped catfish (P > 0.05). The packed cell volume (PCV) and haemoglobin level in fish fed diet N03 was significantly higher than in the fish fed the control diet. The present study demonstrates that dietary inclusion of Yucca schidigera and Quillaja saponaria induced positive effects on growth performance and haematological parameters and decreased TAN excretion in striped catfish.  相似文献   

10.
To determine dietary magnesium (Mg) requirements of juvenile grass carp, Ctenopharyngodon idella, magnesium sulphate was added to the basal diet at 0, 150, 300, 600, 1200, 2400 mg Mg kg−1 diet. Each diet was fed to three replicate groups of juvenile grass carp (initial weight: 7.69 ± 0.13 g) in a closed, recirculating rearing system for 76 days. No mortality or nutritional deficiency signs were observed except the growth depression in fish fed the Mg‐deficient diet. Growth performance and activities of serum superoxide dismutase (SOD), glutathione peroxidase (GPx) and lysozyme (LSZ) were highest (P <0.05) in fish fed the diet supplemented with 600 mg Mg kg−1. The serum malondialdehyde (MDA) content was higher (P <0.05) in fish fed the diets supplemented with 0 and 150 mg Mg kg−1 than that in fish fed the diets with ≥300 mg Mg kg−1. Mg concentrations both in whole‐body and vertebrae increased with the increase in dietary Mg level up to 300 mg kg−1, whereupon the response reached a plateau. Analysis by second‐order polynomial regression of weight gain, by broken‐line regression of vertebrae Mg concentration and by linear regression of whole‐body Mg retention of fish indicated that the adequate dietary Mg concentration for juvenile grass carp was 713.5, 627.7 and 469.8 mg kg−1 diet, respectively.  相似文献   

11.
A 6‐week growth trial was conducted to investigate the effect of dietary supplementation with maggot meal (MGM) and soybean meal (SBM) on the growth performance and antioxidant responses of gibel carp (GC) and darkbarbel catfish (DC). The basal diet was formulated to contain 114 g kg−1 fish meal (FM) and 200 g kg−1 SBM. The basal diet was supplemented with either 280 g kg−1 FM (Control), 390 g kg−1 MGM or 450 g kg−1 SBM to obtain three isonitrogenous (crude protein: 380 g kg−1) and isocaloric (gross energy: 16 kJ g−1) diets. For GC, a significant decrease in specific growth rate (SGR) was only observed in fish fed the SBM diet compared with the control (P < 0.05). Principal components analysis (PCA) of GC showed a higher similarity in antioxidant response to dietary supplementation with MGM and SBM proteins between liver and intestine, but the DC did not. The present results suggest that supplementing 390 g kg−1 MGM protein to basal diet cause an enhancement of the antioxidant capacity in GC, but supplementing 390 g kg−1 MGM and 450 g kg−1 SBM proteins to basal diets resulted in a significant attenuation of the antioxidant capacity in DC.  相似文献   

12.
The effect conjugated linoleic acid (CLA) accumulation in fish fillet on sensory and texture attributes has been evaluated. Fish were fed diets with graded levels of CLA, which were administered for different durations prior to harvest. Fish were sampled for fillet proximate composition and fatty acid profile for sensory and texture parameters at the end of the trial. Growth performance, feed conversion ratio and muscle proximate composition were not affected by dietary treatments. Muscle fatty acid profile was not affected by dietary treatments despite the increase in saturated fatty acids in fish fed diet with 10 g kg−1 of CLA for 16 weeks before harvest. Besides, the deposition levels of CLA isomers increased gradually depending on the CLA treatment, reaching its maximum level in fish fed 10 g kg−1 CLA diet for 20 weeks before harvest. Fish fed 10 g kg−1 were juicier (P < 0.05) compared with control group, whereas fish fed 5 g kg−1 CLA diet were less (P < 0.05) chewy than fish fed control diet regarding sensory attributes. Texture parameters were not significantly affected by dietary CLA. These results suggest that market size European sea bass could successfully incorporate CLA isomers with some minor positive effects on sensory analyses.  相似文献   

13.
An 8‐week feeding trial was conducted to quantify the dietary l ‐lysine requirement of juvenile Chinese sucker with an initial weight of 1.81 ± 0.04 g reared in indoor flow‐through and aerated tanks. Six isonitrogenous and isoenergetic practical diets were formulated to contain graded levels of lysine (1.23%, 1.80%, 2.39%, 2.98%, 3.56% and 4.18% dry matter) at 0.6% increments from dietary ingredients and crystalline l ‐lysine. Each diet was randomly assigned to triplicate groups of 30 fish each and was fed to apparent satiation by hand three times a day (09:00, 13:00 and 17:00 hours) for 8 weeks. There were significant differences in growth performance and feed utilization among the treatments. Weight gain (WG), specific growth rate and protein efficiency ratio (PER) significantly increased with increasing lysine levels up to 2.39% of diet (P < 0.05) and remained nearly the same thereafter (P > 0.05). Feed efficiency was the poorest for fish fed the lowest lysine diet (P < 0.05) and showed no significant differences when dietary lysine level increased from 2.39% to 4.18%. The N retention (% N intake) significantly increased with dietary lysine level but did not attain a plateau (P < 0.05). Survival could not be related to dietary treatments. Whole body protein increased (P < 0.05) and whole body lipid decreased (P < 0.05) with increasing dietary lysine level. The condition factor and hepatosomatic index were significantly affected by dietary lysine levels, however, viscersomatic index, whole body moisture and ash did not differ significantly among dietary treatments. Broken‐line analysis on the basis of WG and PER showed that dietary lysine requirements of juvenile Chinese sucker were 2.43% and 2.40% dry diet (5.52% and 5.45% dietary protein) respectively. Based on the ideal protein approach and the A/E ratios determined from muscle amino acid profile an estimation of the EAA requirements of Chinese sucker juveniles were calculated.  相似文献   

14.
Litopenaeus schmitti juveniles (total length 15 ± 0.4 cm) were exposed to different concentrations of nitrite using the static renewal method at different salinity levels (5‰, 20‰ and 35‰) at pH 8.0 and 20 °C. The 24, 48, 72 and 96 h LC50 values of nitrite in L. schmitti juveniles were 40.72, 32.63, 24.63, and 19.12 mg L−1 at 5‰; 53.52, 38.60, 27.76, 25.55 mg L−1 at 20‰; 54.32, 47.87, 41.67 and 38.88 mg L−1 at 35‰ salinity. As the salinity decreased from 35‰ to 5‰, susceptibility to nitrite increased by 33.4%, 46.7%, 69.2% and 103.3%, after 24, 48, 72 and 96 h of exposure respectively. Furthermore, we found that exposure of shrimp to nitrite caused an increase in oxygen consumption by 137.3%, 99.2% and 81.4% and an increase in the ammonia excretion level by 112.5%, 87% and 64.3% with respect to the control with decreasing salinity levels.  相似文献   

15.
This study investigated the effects of phenylalanine on growth, digestive and absorptive ability and antioxidant status of young grass carp (Ctenopharyngodon idella). Young grass carp were fed diets containing 3.4 (basal diet), 6.1, 9.1, 11.5, 14.0 and 16.8 g phenylalanine kg?1 diet with a fixed of 10.7 g tyrosine kg?1 diet for 8 weeks. Percent weight gain (PWG), feed efficiency and feed intake of fish were the lowest in fish fed the basal diet (P < 0.05). Trypsin, lipase and amylase activities in the hepatopancreas, and antioxidants including glutathione contents and glutathione reducase activities in the hepatopancreas and intestine were all the highest in fish fed 11.5 g phenylalanine kg?1 diet (P < 0.05). Trypsin, chymotrypsin and amylase activities in whole intestine, and creatine kinase, Na+, K+‐ATPase and alkaline phosphatase activities in the proximal intestine, and superoxide dismutase activities in the hepatopancreas and intestine were all the highest when phenylalanine at level of 9.1 g kg?1 diet (P < 0.05). In conclusion, phenylalanine improved growth, digestive and absorptive ability, and antioxidant capacity of young grass carp. The phenylalanine requirement of young grass carp (256–629 g) based on PWG was 10.4 g kg?1 diet or 3.44 g 100 g?1 protein.  相似文献   

16.
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   

17.
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   

18.
The effect of six different binding agents (agar, sodium alginate, cassava starch, gelatin, wheat gluten and kelp meal) in two concentrations (30 g kg−1 and 50 g kg−1) were evaluated with respect to physical quality of Litopenaeus vannamei broodstock pelleted feed, after 15, 30, 60, 90, 120, 150 and 180 min of water immersion. The best treatments in terms of water stability, water absorption and protein leaching were obtained with sodium alginate and wheat gluten at 50 g kg−1. In a second experiment, the feed ingestion and diet digestibility with these two binders and their combination (1 : 1) were compared against a control diet containing 50 g kg−1 wheat flour. There were no significant differences (P > 0.05) in the daily feed ingestion rate 2.39–3.33% of the biomass. The most representative values of apparent digestibility of protein (ADP) and apparent dry matter digestibility (ADMD) were achieved with diets containing wheat gluten and alginate + gluten mixture as binder. Based on these results, combinations with 50 g kg−1 wheat gluten is recommended as binder in pelleted feed for broodstock L. vannamei.  相似文献   

19.
Different levels of dietary chitosan on growth performance, survival and stress tolerance to air exposure was studied in tiger shrimp, Penaeus monodon. Shrimp (mean initial wet weight about 1.16 g) were fed with six different diets (C0, C0.05, C0.1, C0.2, C0.3 and C0.4) containing six level of chitosan (0%, 0.05%, 0.1%, 0.2%, 0.3% and 0.4% respectively) in triplicate for 60 days. Growth performance [final body wet weight (FBW); weight gain (WG); biomass gain (BG)] of shrimp fed chitosan‐containing diets were higher (P < 0.05) than that of shrimp fed the basal diet, shrimp fed C0.1 diet showed the highest value of growth performance. Survival of shrimp in C0.1 and C0.2 diet groups were higher (P < 0.05) than that of shrimp in C0, C0.05 and C0.4 diet groups but without statistical difference (P > 0.05) in shrimp fed C0.3 diet group. Whole body and muscle lipid contents decreased with increasing dietary chitosan levels. Plasma total cholesterol and triglyceride contents of shrimp fed C0 diet was significantly higher (P < 0.05) than that of shrimp fed chitosan‐containing diets. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities of shrimp fed C0 diet were higher than those of shrimp fed chitosan‐containing diets. Digestive gland malondialdehyde (MDA) and carbonyl protein contents of shrimp fed chitosan‐containing diets were lower (P < 0.05) than that of shrimp fed C0 diet. Total haemocyte count of shrimp fed C0 diet was lower (P < 0.05) than that of shrimp fed chitosan‐containing diets. On the contrary, the haemolymph clotting time of shrimp fed C0 diet was higher (P < 0.05) than that of shrimp fed chitosan‐containing diets. In conclusion, all results suggested that dietary intake containing 0.1% and 0.2% chitosan enhanced the growth of shrimp, whereas a higher level than 0.3% and 0.4% decreased growth of shrimp. Second‐degree polynomial regression analysis of WG and BG indicated that the optimum supplement of dietary chitosan level should be 0.19–0.21%.  相似文献   

20.
A 6‐week study was conducted to determine the effects of different lipid sources in pelleted diets on juvenile mud crab Scylla paramamosain. Five isonitrogenous and isolipidic diets containing 8% level of fish oil (FO), lard (LD), safflower oil (SO), perilla seed oil (PO) or mixture oil (MO; VFO:VSO:VPO = 1:1:1), and a live food of marine bivalve Potamocorbula rubromuscula as the control diet (CF), were fed to groups of 25 juvenile crabs (average initial weight 7.4 g, carapace width 3.5 cm) in triplicate. The results showed that crabs fed MO had the highest survival (P < 0.05). The moisture content was significantly higher in crabs fed LD, SO and PO (P < 0.05). Crabs fed SO exhibited the lowest crude protein and lipid (P < 0.05). Ash contents were obviously lower in LD group (P < 0.05). Highest total lipid in the hepatopancreas and muscle was in LD and FO group respectively. Glucose, total cholesterol and low‐density lipoprotein were higher while high‐density lipoprotein was lower (P < 0.05) in LD group. Tissue fatty acid compositions were consistent with those in diets. FO and MO diets had the same depression effect like CF on fatty acid synthase activity and mRNA expression in the hepatopancreas. The results of this study indicated that FO and mixed oil are suitable for preparation of pelleted diets with better effects for juvenile S. paramamosain compared with live food, and the ratio of n‐6/n‐3 fatty acids in pelleted diets must be <1.  相似文献   

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