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1.
A feeding trial was conducted to determine effects of dietary inosine on growth, immune responses, oxidative stress resistance and intestinal morphology of juvenile red sea bream. A semi‐purified basal diet supplemented with 0 (D1, control), 2 g kg?1 (D2), 4 g kg?1 (D3), 6 g kg?1 (D4) and 8 g kg?1 (D5) dietary inosine, respectively, to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish (initial weight: 8 g). After 50 days of feeding trial, fish fed diets with 4 g kg?1 inosine had the highest (p < .05) final weight, weight gain and specific growth rate. Similarly, improved feed intake, feed conversion ratio and protein efficiency ratio were also found at 4 g kg?1 inosine supplemented group. Some non‐specific immune parameters such as total serum protein, lysozyme activity and bactericidal activity tended to be higher for fish fed diets supplemented with inosine. Peroxidase and catalase activity also influenced (p < .05) by dietary inosine supplementation. Fish fed 2 g kg?1 and 4 g kg?1 inosine supplemented diets showed the least oxidative stress condition. Inosine supplementation significantly increased (p < .05) anterior enterocyte height and posterior fold height, enterocyte height and microvillus height compared with control. We concluded that 4 g kg?1 dietary inosine supplementation effectively provokes growth and health performance of red sea bream by increasing growth, immune response, oxidative stress resistance and intestinal health condition.  相似文献   

2.
A 60‐day feeding trial was conducted to determine the effects of copper nanoparticles (Cu‐NPs) and vitamin C (VC) on red sea bream. Besides the control diet (D1), six diets were supplemented with Cu‐NPs and VC [0/800 (D2), 0/1,000 (D3), 0/1,200 (D4), 2/800 (D5), 2/1,000 (D6) and 2/1,200 (D7) mg Cu‐NPs/VC per kg]. Cu‐NP was a significant factor on final weight (FBW), weight gain (WG) and specific growth rate (SGR), feed intake (FI), feed (FER) and protein efficiency ratios (PER), protein gain (PG) and protein retention (PR), body protein and lipid contents, protease (PA) and bactericidal activities (BA) and tolerance against stress (LT50%) (p < .05). In addition, BA and LT50% were significantly affected by either Cu‐NPs or VC (p < .05). Fish fed Cu‐NPs or/and VC‐supplemented diets showed higher FBW, WG, SGR, PG, PR, FI, PA, LA and BA values when compared with the control group (p < .05). FER, PER and body lipid content were significantly enhanced in D4, D5, D6 and D7 groups; meanwhile, body protein and LT50% were significantly enhanced in D5, D6 and D7 groups when compared with D1 group (p < .05). In conclusion, dietary Cu‐NPs or/and VC improved growth and health of red sea bream.  相似文献   

3.
为了探讨饲料LNA/LA比对鲤幼鱼生长性能和LC-PUFA合成代谢的影响,本研究以鱼油和混合植物油(花生油和紫苏籽油)为脂肪源配制5组等氮等脂饲料。对照组(D1)以鱼油为唯一脂肪源,其他5组实验饲料以花生油和紫苏籽油为脂肪源,且LNA/LA比分别为0.02(D2)、0.46(D3)、1.09(D4)和1.53(D5)。8周养殖实验后,分析各处理组鱼体的生长性能指标、肝脏脂肪酸组成,肝脏Δ6 fad-a/b和elovl5-a/b基因表达水平。结果显示,与对照组相比,植物油饲料对鱼体增重率(WGR)、特定生长率(SGR)和饲料系数(FCR)无显著影响,但显著影响了鱼体肝脏LC-PUFA水平,提高了肝脏Δ6 fad-a和elovl5-a mRNA表达水平。在各植物油组之间,饲料LNA/LA比显著影响了鱼体WGR和SGR指标,其中D2和D4组鱼体生长表现较好;随着饲料中LNA/LA比的升高,鱼体肝脏LC-PUFA水平,以及Δ6 fad-a和elovl5-a mRNA表达水平也随之增加,其中D4组鱼体肝脏Δ6 fad-a和elovl5-a mRNA表达量最高,且其LC-PUFA含量显著高于D2和D3组。由此可见,植物油饲料尽管不影响鲤正常生长,但影响了鱼体肝组织LC-PUFA含量。然而,饲料中添加适宜的LNA/LA比(1.09∶1)可促进鲤肝脏Δ6 fad-a和elovl5-a mRNA的表达,最大限度地提高鱼体内源LC-PUFA合成量,从而有效地降低植物油饲料对鱼体组织LC-PUFA含量的负面影响。  相似文献   

4.
Essential fatty acids should be included in the diet to ensure adequate fish growth. Despite the great number of studies on fatty acid nutrition of fish, there are still several unknowns. The aim of the present study was to investigate fatty acid nutrition of jundiá, a Latin American freshwater catfish. Four diets were formulated containing (i) coconut oil (?C, negative control), (ii) coconut oil + high‐docosahexaenoic‐acid‐fish oil (+C, positive control) and coconut + sunflower + linseed oils at different ratios, producing either (iii) a diet rich in linoleic acid (LA) (HighLA) or 4) a diet low in LA (LowLA). All diets contained significant amounts of saturated fatty acids (at least 57.5% total fatty acids in HighLA) and monounsaturated fatty acids (at least 19.1% total fatty acids in ?C). Diets were fed to jundiá fingerlings (1.5 g) for 70 days; growth, body composition and liver histology were evaluated. The ?C diet, without essential fatty acids, promoted significantly lower fish growth, body fat accumulation and hepatic lipidosis. Fish fed HighLA and LowLA diets presented similar growth as fish fed +C diet. These findings suggest that diet formulations for jundiá catfish fingerlings can include only plant oils without negative effect on growth, survival, body composition, fish health or parameters of feed utilization (ingestion rate and protein utilization).  相似文献   

5.
The effects of dietary linoleic (LA) and linolenic acids (LN) on growth and immunity of all‐male hybrid tilapia, Oreochromis niloticus × Oreochromis aureus, were evaluated for 10 wk. Fish fed 0.12% LA + 0% LN had the lowest weight gain (WG) but was not significantly different from diets containing 0.5% LA or 0.40% LA + 1.0% LN. Fish fed 1% LA had the highest WG but did not differ from diets with 0.5% LA, 2.0% LA, 0.26% LA + 0.5% LN, 0.69% LA + 2.0% LN, or diets containing both LA and LN at 0.25, 0.5, and 1.0%. Feed intake, feed efficiency, and survival did not differ among treatments. Total body n‐6 fatty acids (FAs) increased with increasing dietary levels of n‐6. Total body n‐3 FAs also appeared to increase with increasing dietary n‐3 levels but peaked at 1% of diet. Dietary treatment had no effect on hematology, immune function, or survival to Streptococcus iniae. This study indicates that both LA and LN are dietary essential for growth of hybrid tilapia. Dietary LA alone can meet the essential FA requirement, and a level of 1.14% of diet is required for optimum growth.  相似文献   

6.
Six isonitrogenous and isoenergetic purified diets were formulated to feed Songpu mirror carp for 60 days. The control diet (CD) was only supplemented with soybean oil. The other five experimental diets contained soybean oil, linseed oil and lard oil blended at various inclusion levels to attain different linoleic acid (LA)/α‐linolenic acid (LNA) ratios (0.53, 1.04, 2.09, 3.95, 6.82) with a constant total C18 polyunsaturated fatty acids (PUFA; LA+LNA, 2% dry weight) content. The fatty acid (FA) profiles of hepatopancreas, dorsal muscle, intestine, intraperitoneal fat (IPF), spleen and kidney reflected those of the diets, but with some differences. The spleen showed the lowest correlation with diet compared with other tissues, followed by the hepatopancreas (P < 0.05). The intestine and IPF showed relatively higher correlation. On the other hand, the control group had the lowest tissue‐diet correlation, followed by the LA/LNA0.53 group (P < 0.05), whereas the LA/LNA2.09 showed the highest. The LA/LNA ratios in the tissues were up‐regulated in the LA/LNA0.53, 1.04 groups and down‐regulated in the LA/LNA3.95, 6.82 groups. This was due to when LA (or LNA) was highly added in diet, the decrease in this FA was huge in tissue. The contents of saturated fatty acids and monounsaturated fatty acids increased in the control group, but seemed not influenced by dietary LA/LNA ratios. These results demonstrated that the FA deposition was tissue‐specific, and also influenced by the dietary FA composition in the experimental fish. Finally, we suggest that 2.09 is the optimal LA/LNA ratio (2% C18 PUFA) of Songpu mirror carp for fillet FA composition.  相似文献   

7.
The wide use of lipid as a non‐protein energy substitute has led to lipid metabolic problems in cultured tilapia. Therefore, studies that reduce the effects of high‐fat diets in genetically improved farmed tilapia (GIFT) are required. This study evaluated the optimum level and effects of dietary α‐lipoic acid (α‐LA) on growth performance, body composition, antioxidant capacity and lipid metabolism of GIFT tilapia. The basal diet (120 g/kg lipid) was supplemented with six concentrations of α‐LA at 0 (control), L300, L600, L900, L1200 and L2400 mg/kg diet to make the experimental diets, which were fed to GIFT tilapia juveniles (initial body weight: 0.48 ± 0.01 g) for 8 weeks. The weight gain of fish improved significantly in the L300 than other dietary treatments. The intraperitoneal fat index and lipid content of fish fed on the L2400 diet decreased significantly than those fed on the control diet. The activities of superoxide dismutase and glutathione peroxidase (GSH‐Px) in serum and liver were significantly higher in fish fed on the L300 diet than the control. The reduced GSH content of fish fed on the L300 in serum and liver was significantly higher than those fed on control diet. The malondialdehyde content in serum and liver was significantly lower in L300 than in the control. The adipose triglyceride lipase gene was significantly up‐regulated in fish fed on the L2400, but the diacylglycerol acyltransferase 2 gene was down‐regulated in adipose. The liver‐type fatty acid‐binding protein gene in the liver was significantly up‐regulated in fish fed on the L300 and L600 diets. Moreover, the acyl‐coenzyme A oxidase gene in liver was significantly up‐regulated in fish fed on the L300, L600, L900 and L1200 diets. Polynomial regression analysis indicated that 439–528 mg/kg α‐LA is an appropriate dosage in high‐fat diet to improve growth performance and relieve lipid oxidative damage by accelerating lipid catabolism and reducing lipid synthesis in GIFT tilapia.  相似文献   

8.
Replacement of fish meal with plant products in aquafeeds results in the elimination of dietary compounds which may be important for optimal growth and physiology. A study was conducted to determine if supplementation with macro‐minerals and/or inositol would improve performance of rainbow trout (Oncorhynchus mykiss) fed a plant‐based diet. Four iso‐caloric and iso‐nitrogenous diets (40 g kg?1 protein and 15 g kg?1 lipid) were formulated and consisted of a fish meal‐based control diet (control) and three plant‐based experimental diets. Plant‐based diets were supplemented with either macro‐minerals and inositol (+MM+I), no macro‐minerals with inositol (?MM+I), and no macro‐minerals and no inositol (?MM?I). Sodium chloride, potassium chloride and magnesium oxide were the sources used in the macro‐mineral premix. There was no effect of diet on survival, but there was an effect of diet on weight gain, FCR, feed intake, HSI and nutrient retentions. Significant liver pathology was observed in trout fed plant‐based diets without MM supplementation. Supplementation of MM and inositol significantly improved weight gain of trout fed a plant‐based diet. Supplementation of MM and/or inositol also improved PRE and ERE. This study demonstrates the importance of supplementing these nutrients to trout fed fish meal free diets.  相似文献   

9.
A growth trial was conducted to evaluate the effects and safety of nucleotides in low fish meal diets on the growth performance, antioxidative capacity and intestinal morphology of turbot (Scophthalmus maximus). High fish meal control diet was formulated with 500 g kg?1 fish meal. Seven levels (0.075, 0.15, 0.225, 0.300, 1.5 and 3.0 g kg?1, respectively) of nucleotides were added to a low fish meal basal diet, which was formulated with 400 g kg?1 fish meal. The eight experimental diets were fed to groups of juvenile turbot (initial weight: 6.0 ± 0.03 g) for 60 days. Results showed that compared with high fish meal control diet, low fish meal basal diet treatment had lower total antioxidative capacity (T‐AOC), glutathione peroxidase activity, fold height of proximal and distal intestine, enterocyte height of all evaluated enteric section and microvillus height of mid‐intestine and distal intestine (P < 0.05). However, supplemented nucleotides in diets could significantly improve growth (specific growth rate, SGR), feed utilization, antioxidative capacity and intestinal morphology of turbot (P < 0.05). Broken‐line regression analysis of SGR and T‐AOC showed that the optimal supplemental levels of dietary nucleotide for juvenile turbot were 0.366 and 0.188 g kg?1, respectively. In summary, 0.300 g kg?1 of dietary nucleotides was helpful in improving growth, feed utilization, antioxidative capacity and intestinal morphology of turbot fed with low fish meal diet. Excessive dietary nucleotides (3.0 g kg?1) might cause oxidative stress and morphological damage in intestine and then reduce the growth of turbot.  相似文献   

10.
An 8‐week feeding trial was conducted to evaluate the effects of dietary nucleotide (NT)‐rich yeast supplementation on growth, innate immunity and intestinal morphology in Pacific white shrimp (Litopenaeus vannamei). Four isonitrogenous and isolipidic practical diets were formulated to contain 0 (control), 10, 30 and 50 g/kg of NT‐rich yeast, respectively. A total of 480 shrimp with an average initial body weight of 1.86 ± 0.02 g were randomly allocated into four groups, with four replicates per group and 30 shrimp each replicate. The results indicated that shrimp fed the diet containing 50 g/kg NT‐rich yeast had significantly higher weight gain (WG), specific growth rate (SGR) and protein efficiency ratio (PER) than those fed the control diet, and the lowest feed conversion ratio (FCR) was observed in the shrimp fed the 50 g/kg NT‐rich yeast supplemental diet. However, there was no significant difference in survival among all treatments. The crude protein of whole shrimp in the 50 g/kg NT‐rich yeast group was higher than that in the control group. Total protein, triglyceride concentrations, the activities of aspartate aminotransferase and alanine aminotransferase in serum were significantly influenced by the dietary NT‐rich yeast supplementation. The activities of serum phenoloxidase (PO) and lysozyme (LZM) of shrimp fed the diet containing 50 g/kg NT‐rich yeast were higher than those in shrimp fed the other diets. Relative expressions of alp and lzm significantly upregulated in the 30 g/kg NT‐rich yeast group compared to the control group. The intestinal fold height and fold width in the 30 g/kg NT‐rich yeast group were significantly higher than those fed the control diet; and the highest microvillus height occurred in the shrimp fed the 50 g/kg NT‐rich yeast diet. In summary, dietary 30–50 g/kg NT‐rich yeast supplementation promotes growth performance, enhances innate immunity and improves intestinal morphology of Litopenaeus vannamei.  相似文献   

11.
Abstract— A pair of experiments were performed to assess amino acid supplementation of pet food grade poultry by‐product meal for utilization as the sole protein source for hybrid striped bass Morone chrysops×M. saxatilis. The first experiment determined the available amino acids from menhaden fishmeal and poultry by‐product meal for hybrid striped bass. The second experiment determined the efficacy of supplementing poultry by‐product meal with amino acids based on an ideal amino acid profile of hybrid striped bass muscle. The positive control diet contained 40% digestible protein solely from menhaden fishmeal and the negative control diet contained 40% digestible protein solely from pet food grade poultry by‐product meal. The negative control diet was additively supplemented with lysine, methionine, threonine, and leucine at 1.16,0.57,0.31 and 0.47% of the diet, respectively. Lysine supplementation alone did not improve fish performance based on any measured response. Moreover, the negative control diet and the lysine supplemented diet had lower weight gain and feed efficiency than the positive control diet. Supplementation of the diet containing pet food grade poultry by‐product with lysine and methionine; lysine, methionine, and threonine; or lysine, methionine, threonine, and leucine improved weight gain and feed efficiency above that of the negative control diet. The diet containing poultry by‐product supplemented with lysine, methionine, and threonine produced weight gains statistically indistinguishable from those of the positive control diet. Protein and energy retention efficiencies also improved with supplementation of at least lysine and methionine and were statistically indistinguishable from those observed in fish fed the positive control diet. Supplementation with lysine and methionine reduced the hepatosomatic index to levels similar to those found in fish fed the menhaden fishmeal diet. Intraperitoneal fat levels were similar among treatments (6.1‐6.6%) with the exception that fish fed the diet supplemented with lysine, methionine, and threonine exhibited lower (5.5%) fat levels. Supplementing the poultry by‐product meal diet with only lysine and methionine increased muscle ratio to levels equivalent to those found in fish fed the positive control (fishmeal) diet. In conclusion, amino acid supplementation of pet food grade poultry by‐product meal can be used to replace fishmeal in diets for hybrid striped bass without a reduction in fish performance.  相似文献   

12.
The present study examines the effect of four semi‐purified diets (casein–gelatin based) where the source of fatty acids was free (esterified) oleic acid and linoleic acid (LA) (LOA diet), linseed and olive oil (predominantly LA and linolenic acid) (LO diet), cod liver oil (rich in highly unsaturated fatty acids) (CLO diet), and soybean lecithin (phospholipids; mostly LA) (LE diet) on the growth of juvenile South American catfish (surubim, Pseudoplatystoma fasciatum, Pimelodidae) (0.98 ± 0.04 g individual weight). Fish were fed at a restricted–readjusted feeding rate for 8 wk. At the end of the experiment, LE‐diet‐fed fish grew significantly larger than those of the other three groups (P < 0.05). Considerable cannibalism was observed in all the treatments. It is suggested that the quantitative growth performance may possibly change under other conditions, with less or no cannibalism. Survival did not differ significantly among the fish fed four different diets. Muscle and liver lipid contents did not vary among dietary treatments (P > 0.05), but whole‐body lipid concentrations were affected by dietary treatments. Fish fed LE diet contained significantly lower lipid level than those fed three other diets (P < 0.05). Muscle and liver fatty acid profiles reflected dietary fatty acid composition. Arachidonic acid level was significantly higher in muscle and liver of fish fed LOA and LE diets than in those fed LO and CLO diets. The results suggest that the efficiency of elongation and desaturation of 18C fatty acids depends on the dietary lipid source, and South American catfish has considerable capacity to transform linoleate to arachidonate.  相似文献   

13.
To evaluate the effects of dietary linoleic (LA) and linolenic acids (LN) on growth, enzyme activities to lipid addition and antioxidant capacity of the Russian sturgeon, Acipenser gueldenstaedti, 10 diets with different sources of lipid were formulated. Coconut oil in the basal diet was replaced by sunflower oil to make three diets (LA0.5 + LN0, LA1.0 + LN0 and LA2.0 + LN0) with dietary LA at 0.5%, 1.0% and 2%, by perilla oil to obtain three diets (LA0 + LN0.5, LA0 + LN1.0 and LA0 + LN2.0) with dietary LN at 0.5%, 1.0% and 2%, and by the combination of sunflower oil and perilla oil to provide three diets (LA0.25 +LN0.25, LA0.5 + LN0.5 and LA1.0 + LN1.0) containing LA and LN at 0.25, 0.50 and 1.00%. Coconut oil was used as the control diet at 10%, but without LA and LN (LA0 + LN0). After feeding for 56 days, the fish whole body, the serum and the liver of sturgeon were sampled. Fish fed LA0 +  LN0 and LA0 + LN2.0 gained lowest weight but was not significantly different from the fish fed LA0 +  LN1.0. Fish fed LA1.0 + LN1.0 gained highest weight among all groups. Feed conversion ratio was the best in fish fed LA1.0 +  LN1.0. Survival, condition factor and viscerosomatic index did not differ among treatments. Total body n‐6 fatty acids increased with the levels of n‐6. Total body n‐3 fatty acids also increased with dietary n‐3, and fish fed 2.0% LN had the highest content of total body n‐3 fatty acids among all groups. Triglyceride and cholesterol in the serum of fish fed LA1.0 +  LN1.0 were lowest. Fish fed LA1.0 +  LN1.0 showed the highest lipoprotein lipase and lipase activities, but the lowest malate dehydrogenase activity. Fish fed LA1.0 +  LN1.0 showed higher catalase, superoxide dismutase activity and total antioxidant capacity than fish fed other diets. This study indicates that diets containing both LA and LN are best for the growth of Russian sturgeon. The level of LA1.0 + LN1.0 in the diet is most beneficial for growth performance and antioxidant capacity in juvenile Russian sturgeon.  相似文献   

14.
This study evaluated the effects of increasing levels of methionine (Met) supplementation on the success of almost total replacement of fish meal (FM) with soybean meal (SBM) in diets for hybrid tilapia (Oreochromis niloticus × Oreochromis mossambicus). Fish were fed for 70 days a FM‐based diet (Diet1‐positive control) or SBM‐based diets supplemented with graded levels of DL‐methionine (Diet2 to Diet7). Contrast in dietary Met, concentration was created by supplementing Diet2‐negative control with 1.2 (Diet3), 2.4 (Diet4), 3.6 (Diet5), 4.8 (Diet6) or 6.0 g kg?1 (Diet7) of DL‐Met. Specific growth rate (SGR), feed conversion ratio (FCR), and protein gain and retention efficiency (PER) improved significantly with increasing levels of dietary DL‐Met supplementation. Moreover, nonlinear regression analysis of the effects of supplementing SBM‐based diet with graded levels of DL‐Met indicated that a dietary Met + Cys level of 15.7 and 12.5 g kg?1 diet (as fed) was required to reach 95% of maximum weight and protein gain, respectively. Supplementation of SBM‐based diet with graded levels of DL‐Met proved an effective strategy in reducing FM content in practical diets for hybrid tilapia. Data also indicate that adjustment of dietary formulas according to currently recommended Met or Met + Cys dietary concentrations is probably limiting maximum growth potential of hybrid tilapia.  相似文献   

15.
Supplementation of crystalline amino acids (CAA) in shrimp diets is unsuccessful in most cases. In the present study, various pre‐coated CAA were developed to minimize the leaching losses from diets in water and assessed using kuruma shrimp Marsupenaeus japonicus juveniles. Experimental diets were supplemented with coated CAA or non‐coated CAA to simulate the dietary amino acid profile to that found in the whole body protein of shrimp. The four diets contained CAA coated with either carboxymethyl cellulose (CMC) (diet 1), zein (diet 2), k‐carrageenan (diet 3) or agar (diet 4), respectively. Another four diets contained CMC‐coated CAA with the addition of either zein (diet 5), casein‐gelatin (diet 6), zein and k‐carrageenan (diet 7), or casein‐gelatin and k‐carrageenan (diet 8), respectively. The 8 weeks feeding trial demonstrated that the diets containing coated CAA gave significantly higher weight gains than diets containing non‐coated CAA, with the highest value for the diet 6. The diets containing coated CAA also yielded higher feed conversion efficiency, protein efficiency ratio, and specific growth rate than diets containing non‐coated CAA. Leaching trials suggested that shrimp growth performance was improved partly due to the retardation or reduction of CAA leaching by coating them with specific binders.  相似文献   

16.
The main objectives of this study were to evaluate the effect of partial and total replacement of fish meal (FM) protein by cow pea seed meal (CPSM) protein in practical diets on growth performance, feed utilization, and body composition of Nile tilapia, Oreochromis niloticus (L.). Fish of an average initial weight of 4.6 ± 0.2 g were stocked in 15 glass aquariums (80 L each) at a rate of 15 fish per aquarium. FM protein (30% of the diet) was used as the sole source of animal protein in the control diet. Percent replacement of FM by CPSM on the basis of crude protein were as follows: 0% (control diet A), 25% (diet B), 50% (diet C), 75% (diet D), and 100% (diet E). Diets were fed to fish at a rate of 4% of the total fish biomass daily, for a period of 16 wk. The results of this study revealed that the fish fed control diet A (100% FM) had the best average final body weight, specific growth rate (SGR %/d), weight gain (g/fish), weight gain %, while the poorest results for all parameters were obtained with fish fed diet E (100% CPSM). The same parameters of fish fed diets B (25% CPSM) and C (50% CPSM) were not significantly different (P > 0.05) from those of fish fed the control diet A. Feed utilization parameters of fish fed diets A, B, C, and D were better than for diet E. Proximate composition of whole‐body moisture and ash contents were not significantly different (P > 0.05) among all experimental diets and control diet. Whole‐body protein contents for fish fed diets B and C were superior to the control diet A. Incorporation of CPSM in the diets significantly increased whole‐body fat content. Incorporation of CPSM in the diets significantly decreased apparent digestibility coefficient of crude protein crude fat and energy. Diets B and C were not significantly different from control diet A. Therefore, these findings suggest that up to 50% of FM protein can be replaced by CPSM protein in Nile tilapia diets without any adverse effects on growth performance, feed utilization, body composition, and digestibility.  相似文献   

17.
A 10‐week feeding experiment was conducted to evaluate the effects of replacing fish meal with soybean meal (SBM), with or without dietary arginine (Arg), on growth performance, immune indices and intestinal morphology of grouper, Epinephelus malabaricus. Nine experimental diets were formulated to contain 20%, 30% and 40% fish meal protein (FMP) replaced using SBM and 0, 0.5% and 1% dietary Arg supplementation. The results showed that weight gain (WG) of fish was significantly affected by the interaction of substitution level and Arg supplemental level. The maximum WG occurred at the 30% FMP substitution level and the 0.5% Arg supplemental level. The immune assay showed that the interaction between the two levels significantly influenced the production of serum nitric oxide but did not affect serum IgG concentration and alkaline phosphatase activity or the liver IGF‐1 gene expression. Significant interaction effects between the two levels were observed in muscle layer thickness (tML) and fold height (hF) in the proximal and mid‐intestine. High SBM level in diets reduced the tML and hF in the entire intestine. The results suggested that the interaction of 30% FMP substitution level and Arg supplemental level of 0.5% most benefitted growth performance, immune indices and intestinal structure of grouper.  相似文献   

18.
ABSTRACT

The immunostimulatory and disease-resistance properties of Achyranthes aspera were evaluated in rohu (Labeo rohita) challenged with Aeromonas hydrophila. Experimental diets were enriched with leaves at 0.25% (D1) and 0.5% (D2) and seeds at 0.5% (D3); the control diet (D4) was without any enrichment. Rohu (2.02 ± 0.23 g) were cultured for 75 days and then challenged with bacteria. The highest average weight was observed in the D3 diet-fed fish. The cumulative mortality rates were 70%, 60%, 40%, and 30% in the D4, D1, D2, and D3 diets fed to rohu respectively. Enriched diets significantly increased myeloperoxidase, nitric oxide synthase, and serum lysozyme levels and decreased malondialdehyde and carbonyl protein content. Expressions of lysozyme C and lysozyme G were significantly (P < .05) higher in the D3 diet-fed fish. In the kidney, IL-1β and TLR 4 were up-regulated in enriched-diet-fed fish. Supplementation of seeds and leaves at 0.5% showed a positive impact in fish.  相似文献   

19.
ABSTRACT:   An experiment was conducted to investigate the effect of various organic acid (OA) supplementation on phosphorus (P) and nitrogen (N) retention by rainbow trout fed low fishmeal-based diets. Six experimental diets were formulated, and diet 0.5P was arranged as a positive control diet with 0.5% calcium phosphate and 0P as a negative control without additional P. Diets CA and LA were supplemented with 1% citric (CA), and lactic (LA) acids, respectively, and diets MHA and LTE were supplemented with 1% methionine hydroxy analog (MHA) and 1% liquid trace elements (LTE), respectively. Fish fed CA and LTE showed similar growth to that of the positive control diet. P retention was lowest in the 0.5P group and was elevated with CA and LTE diets. Therefore, in this study it is suggested that it might not be necessary to supplement the low fishmeal-based diet of rainbow trout with P if certain organic acids such as CA are added.  相似文献   

20.
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   

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