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1.
A feeding trial was conducted to study the effect of partial replacement of dietary monocalcium phosphate (MCP) with neutral phytase on growth performance and phosphorus digestibility in gibel carp, Carassius auratus gibelio (Bloch). Control diet was prepared with 2% MCP but without phytase (P0). Other three experimental diets were prepared by replacement of MCP by 25%, 50% and 75% respectively in comparison with control with supplementation of neutral phytase at 500 U kg?1 diet in each and designated as P25, P50 and P75 respectively. Gibel carp (initial body weight of 30.22 ± 1.98 g) were reared in twelve 300‐L cylindrical fibreglass tanks provided with filtered flow‐through tap water at 26–28°C. After 8‐week experiment, gibel carp fed with P50 had no obvious differences from the control group on weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency rate (PER) and survival rate. Phytase supplementation did not affect body compositions or muscle compositions. Crude protein and phosphorus (P) contents in the faeces of fish fed with the phytase‐supplemented diets were significantly lower than those of the control group. The apparent digestibility coefficients (ADCs) of crude protein and P in gibel carp were increased when fish fed with the diets in which MCP was replaced by neutral phytase. This study suggested that partial replacement of dietary MCP at 50% with neutral phytase was considered as a recommended dietary supplemental level and increased dietary P and protein availability.  相似文献   

2.
An 8‐wk feeding trial was conducted to compare the effect of dietary pH on the utilization of crystalline amino acid (CAA, 0.2% dl ‐methionine and 0.4% l ‐lysine·HCl) by juvenile common carp, Cyprinus carpio. A basal diet (diet C) with protein derived mostly from fish meal and soybean meal was supplemented with CAA without pH adjustment (diet CAA, pH 6.2) and with pH adjusted to 7.0 and 8.0 (diets CAA pH 7.0, CAA pH 8.0, respectively). Supplementation of CAA, regardless of dietary pH adjustment, significantly increased the feed intake and weight gain, and the latter was significantly higher in fish fed diets CAA pH 7.0 or CAA pH 8.0 compared to fish fed diet CAA. The intestinal protease activity was significantly higher in fish fed diets CAA pH 7.0 or CAA pH 8.0 compared to fish fed diet CAA. Apparent digestibility of dry matter and crude protein in diets CAA pH 7.0 and CAA pH 8.0 were significantly higher than those in diet C. Dietary supplementation of CAA generally decreased the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, but markedly increased the hepatic AST and ALT activities. Compared to fish fed diet CAA, fish fed diets CAA pH 7.0 or CAA pH 8.0 showed higher hepatic AST activity but slightly lower plasma ammonia level. These results indicate that adjusting the pH of CAA‐supplemented diets to neutral or slightly alkaline resulted in improving the CAA utilization by common carp.  相似文献   

3.
Isolation and enumeration of phytase‐producing bacterial flora in the foregut and hindgut regions of the gastrointestinal tracts of 10 culturable freshwater teleosts of different feeding habits, namely rohu (Labeo rohita), catla (Catla catla), mrigal (Cirrhinus mrigala), bata (Labeo bata), kalbasu (Labeo calbasu), Nile tilapia (Oreochromis niloticus), climbing perch (Anabas testudineus), common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix) and grass carp (Ctenopharyngodon idella), have been carried out. Microbial culture of the gut mucosa on selected nutrient media following the enrichment culture technique was performed for bacterial isolation. The bacterial isolates were screened on the basis of their enzyme‐producing ability. The bacterial population on the tryptone soya agar (TSA) plate was maximum in the hindgut region of bata, followed by mrigal and minimum in the foregut region of Nile tilapia. In modified phytase screening medium (MPSM), phytase‐producing strains were recorded at higher densities in the foregut region of mrigal and grass carp and minimum in the foregut region of bata. In case of the hindgut, maximum phytase‐producing strains were present in grass carp and mrigal and minimum in rohu. In general, in MPSM, the bacterial population was lower in the hindgut region of all the 10 species of fish examined. The phytase‐producing ability of the selected 31 strains (16 from the foregut and 15 from the hindgut region) was determined by clearing zones on phytate‐containing plates. Among these isolates, 22 strains (12 from the foregut and 10 from the hindgut region) were selected as potent phytase producers according to a quantitative enzyme assay. The highest phytase activity was observed in the bacterial strains LF1 and LH1 isolated from the fore and the hindgut regions of rohu respectively. Both the strains were identified as Bacillus licheniformis on the basis of phenotypic characteristics as well as 16S rDNA sequence analysis.  相似文献   

4.

以鱼粉、豆粕、菜粕等为蛋白原料设计配方, 磷酸二氢钙的添加量分别为1.5%、1.0%、0.5%和0(对应的饲料组为P1.5、PP1.0、PP0.5和PP0组), 其中PP1.0、PP0.5和PP0组中均添加200 mg/kg的中性植酸酶, 开展为期8周的黑鲷(Acanthopagrus schlegelii)养殖实验, 以探讨中性植酸酶替代磷酸二氢钙对黑鲷生长和磷利用的影响。结果显示, 黑鲷摄食实验饲料8周后, 各组间成活率无显著差异(P>0.05); 摄食饲料PP1.0、PP0.5和对照组(P1.5组)实验鱼的增重率无显著差异(P>0.05), 但均显著高于PP0处理组, 饲料系数则显著低于PP0处理组(P<0.05)。摄食不同饲料的黑鲷全鱼中蛋白质、脂肪、灰分及钙磷含量在不同组间均无显著差异(P>0.05)。添加植酸酶的各组鱼磷的表观消化率均显著高于对照组(P<0.05)。随着磷酸二氢钙添加量的降低, 黑鲷对干物质和蛋白质的表观消化率呈升高的趋势, 当饲料中磷酸二氢钙的添加量降到0时, 黑鲷对干物质和蛋白质的表观消化率显著高于对照组(P<0.05)。以上结果说明, 在本研究配方下, 黑鲷正常生长对饲料有效磷的需求量≥0.51%; 磷酸二氢钙可部分被植酸酶替代, 当黑鲷饲料中含有20%鱼粉、32%豆粕和12%菜粕, 且植酸酶添加量为200 mg/kg时, 与饲料中添加1%的磷酸二氢钙相当; 在不影响黑鲷生长的前提下, 植酸酶部分替代磷酸二氢钙不仅可降低无机磷的添加, 同时可提高饲料中磷的利用率, 降低磷排放。

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5.
A 100‐day growth trial was executed to determine the dietary selenium (Se) requirement of juvenile gibel carp (Carassius auratus gibelio). Selenomethionine was supplemented to casein‐gelatin diets at 0, 0.1, 0.25, 0.5, 1.0, 2.5 and 5 mg Se kg?1, respectively. Each of these seven semi‐purified diets containing 0.34, 0.47, 0.66, 0.82, 1.23, 2.77 and 5.13 mg Se kg?1 was fed to triplicate groups of gibel carp (2.74 ± 0.02 g) in a flow‐through system. No behaviour abnormalities and no mortality were found in fish exposed to dietary Se concentrations. With the increasing dietary Se supplemented concentrations, weight gain of fish remarkably increased at the levels of ≤1 mg Se kg?1 diet and then showed no significant difference above 1 mg Se kg?1 levels. Although growth performances (weight gain, hepatosomatic index, condition factor and survival) were not impaired in gibel carp fed at above the levels of 2.5 mg Se kg?1, indicators of oxidative stress were changed significantly. Serum superoxide dismutase (SOD) activities significantly declined, hepatic glutathione peroxidase (GPx) activities significantly increased and the tissue Se concentrations significantly raised at the highest supplemented level of 5 mg Se kg?1. A clear linear relationship between Se‐depended GPx activities and hepatic Se concentrations was observed. The present results indicated that the dietary Se requirement for gibel carp is 1.18 mg Se kg?1 diet based on weight gain, GPx activities and tissue accumulation.  相似文献   

6.
本试验旨在研究不同蛋白源饲料中添加α-酮戊二酸(AKG)对松浦镜鲤肠道形态与功能的影响。在水温23℃下,将初始体质量为(217.93±0.78)g的松浦镜鲤Cyprinus carpio Songpu 400尾,随机分成4组,每组5个重复,每个重复20尾鱼,饲养在控温循环水系统中,投喂4种在不同蛋白源的等氮等脂饲料中添加不同剂量的α-酮戊二酸(AKG)的饲料10周,即饲料1(44%豆粕+0%AKG)、饲料2(44%豆粕+1.5%AKG)、饲料3(30%豆粕+10%鱼粉+0%AKG)、饲料4(30%豆粕+10%鱼粉+1.5%AKG),饲料中蛋白质和脂肪水平分别为28%和5.1%。结果表明:不同蛋白源饲料中添加AKG能显著提高松浦镜鲤后肠皱襞高度、前肠肌层厚度和前肠Na+,K+-ATP酶活性(P0.05);蛋白源和AKG对肠道形态指标和Na+,K+-ATP酶活性无显著交互作用(P0.05);饲料中蛋白源添加AKG能显著提高松浦镜鲤前肠和中肠蛋白酶、脂肪酶活性(P0.05),蛋白源和AKG对后肠蛋白酶活性具有显著交互作用(P0.05)。综上所述,饲料中添加1.5%AKG可以促进松浦镜鲤肠道发育,增强肠道消化酶活性。  相似文献   

7.
The present study aimed to investigate effects of dietary 1,8‐cineole (cineole) on common carp (Cyprinus carpio) health under ammonia toxicity. The fish were fed with four diets supplemented by 0 (control), 0.1 (0.1C), 0.5 (0.5C), and 1 (1C) percent cineole for 2 weeks, before a 24‐hr ammonia exposure. Blood samples were taken before and after ammonia exposure. The results showed that ammonia exposure significantly (p < 0.05) increased serum urea levels, and decreased serum alternative complement (ACH50) activity and serum total immunoglobulin (Ig) levels. Cineole significantly (p < 0.05) increased serum ACH50 activity (0.1% and 0.5% levels) and total Ig levels (0.5% levels). There was no significant difference (p > 0.05) in serum total protein, albumin and globulin levels among the treatments. Before ammonia exposure, there was no significant difference (p > 0.05) in serum alkaline phosphatase (ALP), alanine transaminase (ALT), and lysozyme activities among the cineole treatments. The treatment 0.5C had the lowest lactate dehydrogenase (LDH) and aspartate transaminase (AST) activities before ammonia exposure. After ammonia exposure, serum LDH and ALT activities increased in all treatments, but the treatment 0.5C had the lowest activities. Serum ALP activities increased after the ammonia exposure in the control and 1C groups. Serum AST and lysozyme activities increased after the challenge in all groups except for the 0.5C group. Overall, the results suggest that ammonia exposure causes increase in serum LDH, ALP, AST, and ALT activities and decreased immune responses, which are indicator of tissue damage and immunosuppression. 0.5% cineole is capable to suppress adverse effects of ammonia intoxication in carp.  相似文献   

8.
A 60‐day trial was conducted in a recirculation system to determine the responses of herbivorous grass carp (Ctenopharyngodon idellus) (0.43 g), omnivorous gibel carp (Carassius auratus gibelio CAS III) (0.46 g) and carnivorous black carp (Mylopharyngodon piceus) (0.46 g) when fed with fishmeal (FM)‐ or soybean meal (SBM)‐based diets. Two isonitrogenous (380 g kg?1 DM), isolipid (80 g kg?1 DM), isocaloric (17.75 kJ g?1) diets were formulated using FM and SBM as main protein sources. The results showed that weight gain (WG), feed efficiency (FE) and protein retention efficiency (PRE) in FM group were significantly higher than those in SBM group. Grass carp showed better utilization on SBM than other two species and presented higher WG, FE and PRE. When fed with SBM diet, intestinal chymotrypsin (CHY), lipase and trypsin (TRY) activities of gibel carp and black carp decreased while higher α‐amylase (α‐AMY) activity of grass carp increased. An enteritis‐like effect was observed in black carp and grass carp fed SBM diet. Intestine bacteria mainly belonged to Firmicutes in gibel carp and Proteobacteria in black carp. The dominant genera identified in three species were Cellulomonas, belonging to Actinobacteria. In conclusion, SBM decreased the growth of three carps. Grass carp was more adapted to plant protein.  相似文献   

9.
To evaluate the effects of dietary nano‐selenium (Nano‐Se) on antioxidant capacity and hypoxia tolerance of grass carp fed with high‐fat diet, experimental fishes were fed Nano‐Se supplemented diets at doses of 0 (Control), 0.3, 0.6, 0.9 and 1.2 mg/kg for 10 weeks. After feeding trial, a part of the fishes were exposed to hypoxia stress. Results showed that the survival ratio of grass carp significantly increased in 0.6 and 0.9 mg/kg Nano‐Se group, and the content of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) significantly decreased in 0.6–1.2 mg/kg Nano‐Se groups compared with the control group. In addition, dietary Nano‐Se significantly enhanced glutathione peroxidase (GPX) activity and reduced the malondialdehyde (MDA) content in fishes fed diets with 0.3 and 0.6 mg/kg Nano‐Se. Dietary Nano‐Se significantly elevated mRNA expression of GPX1 and catalase (CAT) by promoting the mRNA expression of NF‐E2‐related nuclear factor 2 (Nrf2) in the hepatopancreas. After hypoxia stress, the GPX and superoxide dismutase (SOD) activities were significantly enhanced, and the MDA content and mortality rate consequently decreased in fishes fed diets with 0.3 and 0.6 mg/kg Nano‐Se. In summary, these results suggested that optimal Nano‐Se in diet enhanced the antioxidant capacity and hypoxia tolerance of grass carp.  相似文献   

10.
The aim of this study was to investigate effects of dietary geniposide (GP) on growth performance, flesh quality, and lipid metabolism of grass carp, Ctenopharyngodon idella (95.2 ± 0.6 g), fed seven different diets, including a control diet; Eucommia ulmoides (EU)–supplemented diet (20 g/kg); and GP‐supplemented diets containing 100, 200, 400, 600, and 800 mg/kg GP, respectively. Weight gain rate was significantly improved (P < 0.05) and feed conversation ratio was significantly decreased (P < 0.05) by supplementation of EU. Grass carp fed 100–800 mg/kg GP‐supplemented diets showed significantly higher total collagen and alkaline‐insoluble collagen content in muscle than control (P < 0.05). Contents of total collagen and the alkaline‐insoluble collagen content in the skin of grass carp were significantly increased by dietary 600–800 mg/kg GP and EU (P < 0.05). Fish fed diets containing 600–800 mg/kg GP showed significantly lower muscle crude lipid content than the EU, control, and 100–400 mg/kg GP groups (P < 0.05). Fish fed 400–800 mg/kg GP diets had significantly higher muscle fiber density and lower muscle fiber diameter and serum triglyceride level than the control (P < 0.05). In conclusion, supplementation of GP could improve flesh quality, but not growth of grass carp. The supplemental level of GP for improving flesh quality was estimated to be a 400–600 mg/kg diet.  相似文献   

11.
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12.
The nutritional function of monosaccharides, disaccharides and polysaccharides for omnivorous gibel carp and carnivorous Chinese longsnout catfish were investigated and the ability of these two species to utilize carbohydrates was compared. For each species, triplicate groups of fish were assigned to each of five groups of isoenergetic and isonitrogenous experimental diets with different carbohydrate sources: glucose, sucrose, dextrin, soluble starch (acid‐modified starch) and α‐cellulose. The carbohydrates were included at 60 g kg?1 in Chinese longsnout catfish diets and at 200 g kg?1 in gibel carp diets. A growth trial was carried out in a recirculation system at 27.8 ± 1.9 °C for 8 weeks. The results showed that fish with different food habits showed difference in the utilization of carbohydrate sources. For gibel carp, better specific growth rate (SGR) and feed efficiency (FE) were observed in fish fed diets containing soluble starch and cellulose, but for Chinese longsnout catfish, better SGR and FE were observed in fish fed diets containing dextrin and sucrose. Apparent digestibility coefficient of dry matter (ADCd) and apparent digestibility coefficient of energy (ADCe) were significantly affected by dietary carbohydrate sources in gibel carp. ADCd and ADCe significantly decreased as dietary carbohydrate complexity increased in Chinese longsnout catfish except that glucose diet had medium ADCd and ADCe. In both species, no significant difference of apparent digestibility coefficient of protein was observed between different carbohydrate sources. Dietary carbohydrate sources significantly affected body composition, and liver phosphoenolpyruvate carboxykinase (PEPCK), pyruvate kinase (PK), glucose 6‐phosphate dehydrogenase (G6PD) and malic enzyme (ME) activities also varied according to dietary carbohydrate complexity. Fish with different food habits showed different abilities to synthesize liver glycogen, and the liver glycogen content in gibel carp was significantly higher than in Chinese longsnout catfish. The influence of carbohydrate source on gluconeogenesis and lipogenesis was also different in the two fish species.  相似文献   

13.
Gelatin and carboxymethyl cellulose (CMC) were often used as binders due to their binding ability. To investigate the effects of gelatin and CMC supplementation on feed quality, intestinal ultrastructure and growth performance of gibel carp, six pelleted feed were formulated: control; supplemented with gelatin (10 g/kg, 30 g/kg and 50 g/kg); and supplemented with CMC (10 g/kg and 30 g/kg). Increased gelatin supplementation levels reduced feed solubility and pellet softening (p < .05) and decreased chemical oxygen demand in the surrounding water after pellets were immersed (p < .05). Increased levels of gelatin supplementation enhanced digesta viscosity and reduced intestinal microvilli length and digestive enzymes activities (chymotrypsin and amylase; p < .05) of fish. Fish‐fed diets supplemented with 30 g/kg gelatin had higher levels of plasma total free amino acids and glucose (p < .05) than fish fed 10 g/kg and 50 g/kg gelatin. Feed supplemented with 10 g/kg CMC were softer than those supplemented with 30 g/kg CMC (p < .05); fish‐fed diets supplemented with 10 g/kg CMC had longer intestinal microvilli (p < .05) than fish fed 30 g/kg CMC. Thus, our results indicated that either gelatin or CMC is applicable to supplement in the feed for improving feed quality and without negative effect on growth performance of gibel carp.  相似文献   

14.
We studied the effects of Bacillus coagulans on growth, nonspecific immune parameters, and disease resistance in juvenile gibel carp. The fish were randomly divided into five groups: a control group fed a basic diet and four treated groups fed the basic diet supplemented with 125, 250, 500, and 1000 mg/kg B. coagulans, respectively, for 8 wk. Growth; plasma lysozyme activity; respiratory burst activity of phagocytes (RBAP); and the activity of tumor necrosis factor‐α (TNF‐α), interleukin‐1β (IL‐1β), and antioxidant enzymes were determined. The group that received 250 mg/kg B. coagulans showed an improved protein efficiency ratio, plasma lysozyme activity, superoxide dismutase, and superoxide anion radical scavenging activity and heat shock protein (HSP70) gene expression compared with the control group. Moreover, the 250 mg/kg B. coagulans group had a reduced feeding rate, feed conversion ratio, and plasma malondialdehyde content compared with the control group. The weight gain rate, protein efficiency ratio, plasma lysozyme, RBAP, TNF‐α, and superoxide anion radical scavenging activity and HSP70 gene expression were significantly increased, whereas the feed conversion ratio was significantly reduced, in the group supplemented with 500 mg/kg B. coagulans compared with the control. Artificial infection with Aeromonas hydrophila revealed a cumulative mortality in the control group that was higher than that in the 250, 500, and 1000 mg/kg B. coagulans groups. The results suggest that feed supplementation with 250–500 mg/kg B. coagulans has the potential to stimulate immunity, increase resistance against pathogenic infection, and promote growth in gibel carp.  相似文献   

15.
AlaSerCys Transporter 2 (ASCT2), a glutamine/amino acid transporter, plays an important role in the absorption of neutral amino acids. In this study, we cloned the full‐length cDNA of ASCT2 from grass carp, Ctenopharyngodon idella, which encodes a 541‐amino‐acid protein. Phylogenetic analysis revealed that the ASCT2 sequence of grass carp clustered with the ASCT2 from Danio rerio. ASCT2 mRNA was differentially expressed in different tissues, with a gradient expression from high to low in tissues of the liver, gill, muscle, midgut, hypophysis, hindgut, kidney, heart, foregut, brain, spleen, and gonad. Meanwhile, the quantitative real‐time polymerase chain reaction results showed that 22% crude protein diets could significantly stimulate ASCT2 gene expression. In addition, ASCT2 was expressed in higher quantities in the soybean meal group than in the fishmeal group. Furthermore, 7.5 g/kg glutamine and 2.5 g/kg glutamine dipeptide remarkably improved the expression of ASCT2. These results suggested that ASCT2 expression is regulated by the dietary protein levels and sources, as well as appropriate concentration of glutamine and glutamine dipeptide additives.  相似文献   

16.
Gibel carp (Carassius auratus gibelio) of mean initial weight 3.1 g were fed one of seven casein‐dextrin‐based diets containing graded levels of magnesium (Mg) (39, 120, 220, 380, 700, 1600 and 2900 mg kg?1) for 3 months with the waterborne Mg concentration of 10.6–12.7 mg L?1. Magnesium sulphate was used as the supplementation Mg source in the diets. The experiment was carried out in a flow‐through system. Growth, survival rate, Na+/K+‐ATPase, Mg2+‐ATPase and tissue mineral contents were measured to investigate the effect of dietary magnesium in gibel carp. At the end of the experiment, the hepatopancreas of fish were collected for enzyme determination. The hepatopancreas, vertebrae and whole body were collected for tissue magnesium content analysis. After 3 months, dietary magnesium supplementation did not improve the growth performance, including feed intake, weight gain and feed conversion efficiency of juvenile gibel carp. On the contrary, negative impacts on survival, reduced growth performance and dramatically decreased Na+/K+‐ATPase, Mg2+‐ATPase and superoxide dismutase activities were observed in gibel carp fed a high Mg diet of 2900 mg kg?1. Although serum and hepatopancreas Mg and Ca contents were not affected by dietary Mg supplementation, vertebrae and whole‐body Mg contents increased significantly with the increasing dietary Mg concentrations. Based on the relationship between whole‐body Mg retention and dietary Mg concentration, a suitable dietary Mg level of 745 mg kg?1 could be estimated for gibel carp. It could be concluded that dietary Mg supplementation did not improve the growth performance, but could increase vertebrae Mg contents of gibel carp. Considering the adverse effects, a dietary Mg concentration of above 2900 mg kg?1 is not recommended and it should be careful to supplement magnesium in practical diets for gibel carp as most feed ingredients contain high magnesium concentrations.  相似文献   

17.
ABSTRACT

This study was conducted to evaluate the effects of marshmallow extract (Althaea officinalis L.) administration on blood cells and biochemical parameters of carp liver. A total of 150 carps (Cyprinus carpio, initial body mass of 37.7 ± 4.4 g) were fed diets containing 0.0 (control diet), 2.5, 5, and 10 g marshmallow extract for 60 days. On days 30 and 60 of the experiment blood samples were collected and hematological parameters and liver enzyme activities—aspartate aminotransferase (AST), alanine amino transferase (ALT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP)—were measured. No significant difference was found (p > .05) in red blood cells (RBC); hemoglobin concentration (Hb); hematocrit (Htc); mean corpuscular volume (MCV); mean corpuscular hemoglobin concentration (MCH); or the percentage of neutrophils, basophils, and eosinophils in fish fed with different concentrations of marshmallow extract on days 30 and 60. However, the white blood cell (WBC) count was increased significantly in the fish fed for 60 days with feed supplemented with 5 g marshmallow extract (p < .05). The MCHC was increased signi?cantly in ?sh fed with diets supplemented with 2.5 g marshmallow extract for 60 days (p < .05). Administration of marshmallow extract (5 g) significantly increased (p < 0.05) lymphocytes on days 30 and 60. However, dietary intake of 10 g marshmallow extract had significantly decreased the monocyte percentage after 60 days. A significant increase was observed in AST, ALT, ALP, and LDH levels in livers of fish fed with extract 10 g, which may be attributed to cytotoxicity. However, marshmallow extract 2.5 and 5 g did not have adverse effects on liver enzymes. These results indicate that preclinical dietary supplementations of 2.5 and 5 g marshmallow extract per kg diet have no side effects on common carp.  相似文献   

18.
A 60‐day growth experiment was conducted to investigate the effect of dietary replacement of fishmeal by Spirulina platensis on growth performance, digestion and physiological parameters in juvenile gibel carp (5.0 ± 1.0 g). Four diets were formulated to replace 0 (SP0), 50% (SP50), 75% (SP75) and 100% (SP100) of dietary fishmeal protein by S. platensis respectively. Other two diets based on SP100 were supplemented with 2% dicalcium phosphate (SP100 + P) or 0.28% coated lysine (SP100 + Lys). The results showed that no significant differences of specific growth rate (SGR), feed efficiency (FE), feeding rate (FR) and protein efficiency ratio (PER) were observed between SP0 group and the replacement groups (SP50, SP75 and SP100). FE and PER of fish‐fed SP100 + Lys diet were significantly higher than the fish‐fed SP100 diet (p < .05). Apparent digestibility coefficients (ADCs) of dry matter, protein, energy and phosphorus increased significantly with the increasing S. platensis inclusion. Meanwhile, fish from SP100 + P or SP100 + Lys group had higher ADCs of nutrients compared to the SP100 group (p < .05). Compared with SP0 diet, fish‐fed S. platensis diets had higher activities of plasma superoxide dismutase, hepatopancreas total antioxidant capacity, plasma alkaline phosphatase and plasma lysozyme, as well as the lower content of plasma malondialdehyde. The present results indicated that dietary fishmeal could be fully replaced by S. platensis without any negative effects on growth performance of gibel carp. Supplementation of lysine in the S. platensis replacement diet could further improve the feed utilization of gibel carp.  相似文献   

19.
A feeding trial was conducted for 8 weeks to evaluate the effects of graded levels of neutral phytase supplementation using pretreatment or spraying method on growth performance, body composition, bone mineral content and serum biochemical parameter in grass carp, Ctenopharyngodon idellus. A control diet without phytase was added and six additional diets were arranged as a 2 × 3 factorial with two methods (pretreatment or spraying) and three levels of phytase (500, 1000 or 1500 U kg?1). The results showed that supplemental phytase at different levels in the diet and with different application methods all improved weight gain, specific growth rate and protein efficiency ratio of grass carp (P < 0.05). The feed conversion ratio in phytase‐supplemented groups was lower than the control. Dietary phytase addition reduced the lipid content in the whole body of grass carp. Phytase supplementation with different method increased ash and mineral (P, Ca, Mg and Zn) contents in whole‐body and vertebra (P < 0.05). The increase in these mineral contents was also observed in the serum. Based on the results, we may conclude that: 1) supplemental dietary phytase, regardless of the application methodology, improved the growth performance and nutrient utilization in grass carp; 2) the pretreatment mode of phytase application was more effective than spraying at the same phytase level.  相似文献   

20.
An 11‐week growth trial was conducted to determine dietary myo‐inositol (MI) requirement for juvenile gibel carp (Carassius auratus gibelio). Myo‐inositol was supplemented to the basal diet to formulate six purified diets containing 1, 56, 107, 146, 194 and 247 mg MI kg?1 diet, respectively. Each diet was fed to triplicate groups of juvenile gibel carp (initial body weight 3.38 ± 0.27 g, mean ± SD) in a flow‐through system. The diets were randomly assigned to different fish tanks. Fish fed ≥ 107 mg MI kg?1 diet had significantly higher weight gain (WG), feed efficiency (FE) and protein efficiency ratio than those fed 1 mg MI kg?1 diet. Fish fed ≥ 56 mg MI kg?1 diet had higher feeding rate and survival compared with fish fed 1 mg MI kg?1 diet. Dietary supplemental inositol did not affect fish liver inositol concentration. Fish fed ≥ 56 mg MI kg?1 diet had higher body dry matter, crude protein and gross energy and lower hepatosomatic index than fish fed 1 mg MI kg?1 diet. Dietary inositol supplementation decreased fish body ash. Quadratic regression of weight gain indicated that the myo‐inositol requirement to maximum growth for juvenile gibel carp was 165.3 mg MI kg?1 diet.  相似文献   

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