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1.
A total of 1050 Jian carp, Cyprinus carpio var. Jian (23.39 ± 0.06 g) were randomly divided into seven groups of each three replicates, which were fed respectively with seven semi‐purified diets contained 1.25, 2.71, 4.22, 5.78, 7.23, 8.83 and 11.44 mg riboflavin kg?1 diet for 6 weeks. The results showed that riboflavin significantly improved percent weight gain, specific growth rate, feed efficiency and protein efficiency ratio at the level of 4.22 mg kg?1 diet. Gross protein retention efficiency and lipid production value improved with increasing dietary riboflavin levels from 1.25 to 5.78 mg kg?1. Activities of trypsin, lipase, α‐amylase, Na+,K+‐ATPase and alkaline phosphatase in the intestinal tract were significantly improved with increasing riboflavin levels. Weight and protein content of hepatopancreas, intestine protein and intestine length index were also significantly improved.  相似文献   

2.
A total of 1050 juvenile Jian carp (Cyprinus carpio var. Jian) (8.20 ± 0.02 g) were fed diets containing seven graded levels of thiamin (0.25, 0.48, 0.79, 1.06, 1.37, 1.63 and 2.65 mg kg?1) for 60 days to investigate the effects of thiamin on growth, body composition and digestive enzyme activities. Percent weight gain (PWG), feed intake and feed efficiency (FE) were the lowest in fish fed the basal diet (P < 0.05). Protein productive value and lipid productive value increased with increasing dietary thiamin levels up to 1.06 and 0.79 mg kg?1 diet, respectively (P < 0.05). Body protein and lipid increased with increasing dietary thiamin levels (P < 0.05), while moisture and ash of fish carcasses decreased with the increase in dietary thiamin supplementation (P < 0.05). Intestinal folds height had a similar trend to PWG (P < 0.05). Activities of α‐amylase, lipase, trypsin, Na+, K+‐ATPase, alkaline phosphatase and gamma‐glutamyl transpeptidase in intestine were all affected by the dietary thiamin (P < 0.05). In conclusion, thiamin could improve growth and intestinal enzyme activities of juvenile Jian carp. The dietary thiamin requirement of juvenile Jian carp (8.0–60.2 g) based on PWG was 1.02 mg kg?1 diet.  相似文献   

3.
The reaction of common carp (Cyprinus carpio L.) in an ice‐ and snow‐covered pond to depletion of dissolved oxygen (DO) in winter was recorded using radio telemetry. The carp moved from the deeper parts of the pond to the shallow areas near the tributary in search of better oxygenated water. Evidence was found that feeding occurred until December but ceased with the oxygen crisis. After the carp farmer started aeration to improve the oxygen supply, carp returned towards the deeper parts of the pond. The gross activity was significantly correlated with DO (P<0.001) and was not influenced by water temperature (P>0.05). The clear documentation of the carp's reaction to oxygen depletion suggests, that radio telemetry may be useful for investigating the effects of various stress factors on fish in pond aquaculture.  相似文献   

4.
A 9-week feeding trial was carried out with juvenile Jian carp to study the effect of dietary pantothenic acid (PA) on growth, body composition and intestinal enzyme activities. Semi-purified diets with seven levels (4.0, 15.5, 25.6, 36.1, 45.9, 56.1 and 65.9 mg PA kg−1) of supplemental calcium d -pantothenate were fed to Jian carp (13.0 ± 0.0 g). PA improved specific growth rate (SGR), protein productive value (PPV), protein efficiency ratio (PER) and lipid production value (LPV) ( P <  0.05). Fish fed the control diet had significantly lower feed efficiency (FE) than that in any other group ( P <  0.05). Body protein content increased with increasing PA levels ( P <  0.05), but moisture, lipid and ash of fish carcasses were negatively related to the graded PA levels ( P <  0.05). Intestine protein content (IPC), hepatopancreas protein content (HPC) and activity of α-amylase, lipase, trypsin, Na+,K+-ATPase, alkaline phosphatase (AKP) and gamma-glutamyl transpeptidase (γ-GT) were all positively affected by the dietary PA levels ( P <  0.05), while intestine index (ISI) and hepatopancreas index (HSI) decreased with the increment of supplemental levels of PA ( P <  0.05). These results suggested that PA could enhance fish growth and intestinal enzyme activities. The dietary PA requirement of juvenile Jian carp, Cyprinus carpio var . Jian (13.0–73.0 g), for optimal growth estimated by the broken-line analysis was 23.0 mg PA kg−1 diet.  相似文献   

5.
A 60‐day feeding trial was carried out to investigate the effect of iron on growth, body composition and digestive enzyme activities. Diets with seven levels of iron (53.9, 90.0, 115.6, 146.1, 176.0, 215.8 and 266.0 mg iron kg?1 diet) were fed to Jian carp (initial weight 11.4 ± 0.0 g). Per cent weight gain (PWG), feed efficiency (FE) and protein efficiency ratio were the lowest in fish fed the basal diet (P < 0.05). Body protein content was increased with the increasing iron levels (P < 0.05), but moisture, lipid and ash of fish were not significantly affected by dietary iron levels (P > 0.05). Activities of trypsin, lipase, α‐amylase, Na+, K+‐ATPase, alkaline phosphatase and gamma‐glutamyl transpeptidase were improved with increasing dietary iron levels. Serum iron were significantly enhanced with dietary iron levels up to 146.1 mg iron kg?1 diet, and plateaued. In conclusion, iron improved digestive enzyme activities of juvenile Jian carp and the dietary iron requirement for serum iron of juvenile Jian carp (11.4–64.0 g) was 147.4 mg iron kg?1 diet with ferrous fumarate as the iron source.  相似文献   

6.
A 9‐week feeding trial was carried out with juvenile Jian carp (Cyprinus carpio var. Jian) to study the effects of dietary phosphorus on growth, body composition, intestinal enzyme activities and microflora. Quadruple groups of juvenile Jian carp (7.17 ± 0.01 g) were fed practical diets containing available phosphorus 1.7 (unsupplemented control), 3.6, 5.5, 7.3, 9.2 and 11.0 g kg?1 diet to satiation. Feed intake, specific growth ratio and feed efficiency were the lowest in fish fed the basal diet (P < 0.05). Body moisture, protein, lipid content and ash were all significantly affected by dietary available phosphorus levels (P < 0.05). Activities of trypsin, amylase, Na+, K+‐ATPase, alkaline phosphatase and gamma‐glutamyl transpeptidase were improved with increasing dietary phosphorus levels. Intestinal Aeromonas and Escherichia coli decreased with increasing dietary phosphorus up to 3.6 and 5.5 g kg?1 diet respectively (P < 0.05), while Lactobacillus increased with the increasing dietary phosphorus up to 9.2 g kg?1 diet (P < 0.05). These results suggested that phosphorus could enhance intestinal enzyme activities of juvenile Jian carp and the minimum dietary available phosphorus requirement for SGR of juvenile Jian carp (7.2–63.8 g) was 5.2 g kg?1 diet.  相似文献   

7.
This study was aimed to develop captive breeding and nurture the young of stonesucker (Garra ceylonensis, Bleeker), a small threatened freshwater fish species endemic to Sri Lanka. Breeding of stonesucker was possible under indoor conditions without hormonal stimulation. They were single spawners having a fecundity of 562±176 eggs per fish (total length of 7.9±0.6 cm) with an egg size of 770–1877 μm. Duration of development stages were, egg to hatchling 36–48 h, hatchling to postlarva stage 3–4 days, postlarva to juvenile stage 5–64 days and adult stage in 300–365 days at 26–28°C. Juveniles exhibited bottom dwelling habit in 70–75 days. Postlarva fed with formulated feed exhibited the highest growth (P<0.05) compared with live diets, Artemia and microworm (Anguillula sp.). Although the juveniles revealed a significantly high growth performance (P<0.05) with swine liver diet up to day 45 compared with formulated feed and combination of detritus and plankton, formulated feed exhibited an increase in growth from day 50. Therefore, formulated feed could be used for rearing of postlarva and juvenile stages without any live feeds.  相似文献   

8.
A 6‐week trial was carried out with 900 juvenile Jian carp (Cyprinus carpio var. Jian) to investigate the effects of dietary zinc on growth, body composition and intestinal enzyme activities. Diets supplemented with increasing levels (15.3, 26.9, 40.8, 58.2, 68.9 and 92.5 mg Zn kg?1) of zinc lactate were fed to Jian carp (mean initial weight 15.7 ± 0.01 g). Results indicated that per cent weight gain (PWG), feed efficiency (FE), protein efficiency ratio (PER) and lipid productive value (LPV) enhanced with dietary zinc levels up to 40.8 mg kg?1 diet (P < 0.05), and plateaued thereafter (P > 0.05). Feed intake (FI) was similar to that observed for PWG. Intestosomatic index (ISI), relative gut length (RGL), hepatopancreas protein content (HPC), intestine protein content (IPC), trypsin, chymotrypsin, lipase, amylase, alkaline phosphatase (AKP), Na+, K+‐ATPase and γ‐glutamyl transpeptidase (γ‐GT) activities were all higher by dietary zinc supplementation than zinc un‐supplementation (P < 0.05). These results suggested that zinc could promote growth and increase nutrient deposition and intestinal enzyme activities. The dietary zinc requirements (use zinc lactate as zinc source) of juvenile Jian carp (15.7–42.2 g) based on PWG and serum zinc were 48.7 and 43.2 mg Zn kg?1 diet, respectively.  相似文献   

9.
A total of 1200 juvenile Jian carp (Cyprinus carpio var. Jian) (8.76 ± 0.02 g) were fed diets containing graded levels of histidine at 2.3 (unsupplemented control), 4.4, 6.3, 8.6, 10.8 and 12.7 g kg?1 diet for 60 days to investigate the effects of histidine levels on growth performance, body composition, intestinal enzymes activities and microflora. Specific growth rate (SGR), feed efficiency, protein efficiency ratio, protein productive value, body protein content and lipid content of fish were lowest in fish fed the basal diet (P < 0.05). Activities of glutamate‐pyruvate transaminase in muscle and hepatopancreas, trypsin, chymotrypsin, amylase, lipase activities in intestine and hepatopancreas, and Na+, K+‐ATPase, creatine kinase, alkaline phosphatase, γ‐glutamyl transpeptidase activities in three intestinal segments were improved by dietary histidine (P < 0.05), whereas glutamate‐oxaloacetate transaminase activities and plasma ammonia content followed an opposite trend. The amounts of Lactobacillus, Escherichia coli and Aeromonas were significantly affected by dietary histidine levels (P < 0.05). These results suggested that histidine could improve growth and enhance intestinal enzymes activities of juvenile Jian carp. The dietary histidine requirement of juvenile Jian carp (8.76–68.02 g) based on SGR was 7.8 g kg?1 diet or 2.38 g 100 g?1 protein by quadratic regression analysis.  相似文献   

10.
The aim of this study was to investigate the effect of natural zooplankton versus rotifers and the effect of prey size on the growth and survival of cod larvae. At 20 days post hatch (DPH) myotome height, standard length and dry mass were significantly higher in larvae fed zooplankton compared to those fed rotifers. The dry mass at age 25 DPH was 135 μg (±45), 331 μg (±114), 391 μg (±121) for larvae fed rotifers, small size and large size plankton, respectively. At 25 days post hatch, the survival rates were 41.8% (±10.5), 90.7% (±2.3) and 91.4% (±1.7) for larvae reared on rotifers, small size and large size plankton, respectively. The limited growth and survival of cod larvae reared on rotifers were not mainly caused by the small size of rotifers. Large differences in skin coloration between larvae in the rotifer group and the two zooplankton groups were observed, probably caused by the large difference in astaxanthin levels in rotifers and natural zooplankton. We suggest that the nutritional composition of rotifers is a limiting factor for cod larvae growth and survival.  相似文献   

11.
Biochemical and immunological characteristics of peroxidase activity of the skin epithelium of common carp (Cyprinus carpio) were investigated and compared with peroxidase activity of blood cells. Skin as well as blood-borne peroxidases eluted from the Superdex column as a 135 kDa protein and both probably are tetrameric molecules. Skin peroxidase activity was characterized by a Vmax of 51.5 ± 1.3 U mg-1 min-1 and a KM of 1.64 ± 0.18 mM ortho-phenylenediamine (OPD), whereas blood-borne peroxidase was characterized by a 1,000 fold higher specific activity (Vmax = 30.5 103 ± 2.5 103 U mg-1 min-1) and a higher affinity (KM = 0.875 ± 0.003 mM OPD). Polyclonal antibodies were raised against concanavalin-A purified skin peroxidase as well as blood-borne peroxidase. Immunocytochemical labelling showed that peroxidase is present in mucous cells and in mucus covering the skin and gill epithelia, as well as in erythrocytes and leucocytes. We conclude that the mucous cells of the skin produce a biochemically distinct peroxidase that is released in the mucus and may contribute to the antimicrobial properties of the mucous layer covering the skin. After exposure of the fish to cadmium the kinetic characteristics of the enzyme activity, as determined in skin homogenates, changed considerably. The Vmax increased significantly to 61.9 ± 1.1 U mg-1 min-1, and the affinity for OPD increased to the value demonstrated for blood-borne peroxidase (KM = 0.888 ± 0.045 mM OPD). Increased peroxidase levels after cadmium exposure were also demonstrated immunochemically in a dotblot assay. However, no significant changes were observed when the circulatory system of the fish was perfused prior to sampling, indicating that erythrocytes are a major contributor to the increased peroxidase activity in carp skin during cadmium exposure. This likely reflects the increased vascularization of the connective tissue layer underlying the skin epithelium, which takes place when the fish are exposed to chronic stressors including cadmium. In the cadmium-exposed fish this effect prevented the biochemical detection of stressor-related changes in epithelial peroxidase reported earlier with cytochemical methods.  相似文献   

12.
Experiments were conducted to enhance the growth of common carp (Cyprinus carpio), rohu (Labeo rohita) and Mozambique tilapia (Oreochromis mossambicus) through use of sugarcane bagasse as substrate. Bagasse was suspended in water with or without supplementation with fertilizers. Bagasse supplemented with cattle dung and urea favoured higher zooplankton production and significantly (p < 0.05) increased fish growth by over 50% compared to bagasse or fertilizers on their own. This higher production of fish is attributed to bacterial biofilm promoted on the substrate which, apart from forming food for zooplankton and fish, contributed to improved water quality by lowering ammonia.  相似文献   

13.
在室内循环水养殖系统中设置28℃、30℃和32℃三个高温处理组,研究高温对2种规格(规格Ⅰ:7.58~7.90 g/尾和规格Ⅱ:25.45~27.41g/尾)花鳗鲡(Anguilla marmorata)存活、摄食和生长的影响,实验周期30 d。结果显示:(1)水温28~32℃时,2种规格花鳗鲡存活率均高于95%;(2)高温对规格Ⅰ的实验鱼饲料转化率、摄食率以及生长性能影响不显著,对规格Ⅱ的实验鱼摄食率影响不显著,对饲料转化率、生长性能影响显著,且均与温度呈负相关的关系;(3)规格大小对花鳗鲡的饲料转化率和摄食率有显著影响,饲料转化率随规格的增大而升高,摄食率随规格的增大而下降。结果表明高温对小规格花鳗鲡幼鳗的摄食和生长影响不明显,对大规格幼鳗的摄食和生长有显著的抑制作用。  相似文献   

14.
The aim of the study was to determine the possibility of inclusion of cold‐pressed rapeseed cake (CPRC) in diets for common carp, Cyprinus carpio L. Four isonitrogenous (322 g kg?1 crude protein) and isoenergetic diets (17.5 MJ kg?1) with four levels of CPRC incorporation 0, 110, 220 and 330 g kg?1 (treatments RC0, RC11, RC22 and RC33, respectively) were evaluated in a 50‐day growth test with common carp of 500 g initial weight. Statistically significant higher final weights (1215–1243 g) were obtained in fish fed diets including CPRC. Fish growth rates were nearly identical in all treatments (specific growth rate of 1.7–1.8% day?1). Similar results were obtained in respect of feeding coefficients (FCR) that ranged from 1.6 to 1.8. Crude protein and ash concentration in fish bodies did not change. Statistically significant decreases in moisture content were found in carp in groups RC22 and RC33. Statistically significant increase of crude lipid in fish bodies were found in groups RC22 and RC33. The slaughter traits and meat quality analysis of carp did not show significant differences. We conclude that it is possible to include up to 330 g kg?1 of CPRC in diets of 2‐year‐old common carp without significant effects on growth and food utilization.  相似文献   

15.
Since virus isolation is seldom successful, KHV infection is commonly detected by PCR examination. A number of different PCR assays have been described in recent years. However, at present no commonly accepted PCR method is used amongst different laboratories. The aim of this study was to check if the examination of infected fish by different PCR methods yielded comparable results. We used tissue samples of three KHV‐infected koi, one KHV‐infected common carp, one KHV‐infected goldfish and one non‐infected common carp. DNA was extracted with DNAzol Reagent, High Pure PCR Template DNA Preparation Kit and QIAamp DNA Mini Kit. The DNA was tested by PCR with different combinations of published primer sets –KHV‐F and ‐R, KHV‐Gray‐2F and ‐2R and KHV‐TKf and ‐TKr – plus different DNA polymerases – a standard Taq DNA polymerase, a Platinum (hotstart) Taq DNA polymerase and a Platinum (hotstart) Pfx DNA polymerase with proofreading activity. The different extraction methods produced DNA solutions with different yields of DNA and different degrees of homogeneity. Also, the sensitivity of the PCR depended on the choice of the primer set and polymerase. Not all infected fish could be identified with all methods; there were large differences in the sensitivity between methods.  相似文献   

16.
This experiment was conducted to evaluate the effects of protein levels on the growth performance, digestive capacity and amino acid metabolism of juvenile Jian carp. Brown fish meal was used as the sole protein source in the present study. Six isoenergetic experimental diets containing 14.4 MJ kg?1 of digestible energy and 220–495 g crude protein kg?1 diets were fed to triplicate groups of 50 fish with a mean initial weight of 16.67 ± 0.01 g for 45 days. Per cent weight gain (PWG) and feed efficiency ratio (FER) improved with an increase in the dietary protein levels up to 330 g kg?1 diet. The condition factor, relative gut length, intestinal folds height, hepatopancreas and intestine protein content improved with an increase in the protein levels up to 330–385 g kg?1 diet. Trypsin, creatinkinase, Na+, K+‐ATPase and alkaline phosphatase activities generally followed the same tendency as that of growth parameters. Amylase and γ‐glutamyl transpeptidase (γ‐GT) activities were negatively correlated with increasing protein levels from 220 to 330 g kg?1 diet, and no differences were found thereafter. Lipase activity was unaffected by protein levels. Lactobacillus amount was increased with protein levels up to 275 g kg?1 diet, while Aeromonas amount followed the opposite pattern. Escherichia coli amount was not influenced by dietary protein levels. Glutamate–oxaloacetate transaminase (GOT) activities in the hepatopancreas and plasma ammonia concentration (PAC) were not influenced by protein levels between 220 and 275 g kg?1 diet, but significantly increased with increasing protein levels from 275 to 440 g kg?1 diet, and remained similar thereafter. Glutamate–pyruvate transaminase (GPT) activities significantly increased with protein levels >275 g kg?1 diet. Based on the broken‐line model, the dietary protein requirement for PWG of Jian carp (16.7–55.0 g) was estimated to be 341 g kg?1 diet with a digestible energy of 14.4 MJ kg?1 diet.  相似文献   

17.
The present study was designed to determine the positive effects of artificial illumination on the juvenile black seabream, Acanthopagrus schlegeli , by comparing stomach contents and growth between juveniles exposed to light and those maintained in the absence of light. The major prey items for juvenile black seabream reared in illuminated cages were amphipods (IRI%=50.5), copepods (IRI%=44.7) and polychaetes (IRI%=3.0), whereas those for the juveniles maintained in unilluminated cages were copepods (IRI%=96.0), amphipods (IRI%=3.4) and polychaetes (IRI%=0.6). The specific growth rates (SGR) of the juveniles reared in illuminated cages (0.99%) were significantly higher than those of the juveniles maintained in unilluminated cages (0.78%).  相似文献   

18.
养殖密度影响鱼类福利是鱼类生理生态学、福利学和种群生态学研究中的关键问题,已受到各国学者的关注。文章综述了养殖密度影响鱼类福利的主要研究进展,讨论了鱼类死亡率、生长、摄食以及应激反应等福利指标随养殖密度变化的规律及其描述方法;在此基础上,对鱼类福利指标随不同放养密度变化规律的研究以及应用前景进行了展望。  相似文献   

19.
We determined how varying stocking density and food ration can influence the growth, mortality and biomass return of abalone raised in slab tanks. The abalone used were 2- year-old hybrids of Haliotis laevigata and Haliotis rubra . The experimental design involved replicate tanks and three levels of each factor (normal practice and ±20% density or food ration). Although increasing density from that typically used in farm practices reduced the growth rate by roughly 6%, biomass return increased by 15.5%, over the 9-month period. Increasing feed ration by 20% boosted biomass by significantly increasing abalone growth during the first 3 months by 4%, but was less effective as the animals grew. Growth, mortality and food conversion ratios were optimized in tanks with a low density and a low feed ration, but economic gains were dominated by the increased biomass return from tanks with a higher stocking density. It is thought that reduced dissolved oxygen and differing access to food contributed to the patterns observed.  相似文献   

20.
We tested the effects of monochromatic light on the specific growth rate (SGR), feed intake and feed efficiency (FE) of juvenile pikeperch, Sander lucioperca (L.). Pikeperch were reared individually for 42 days in aquaria covered with blue, green, yellow or red gelatin filters or white paper (control; n =5). Linear regression analysis indicated a significant positive effect of longer wavelengths of light on the condition factor (CF), FE and SGR. The final weight, SGR and CF were significantly higher in fish reared under red than under white light, and FE was better under green, yellow and red light than under white light (Dunnett's post hoc test, P <0.05) while blue was comparable to white light in terms of the measured parameters. After the growth trial, the spectral sensitivity of photoreceptor cells in the retina was tested using microspectrophotometry, which revealed the presence of rods with λmax at ca. 530 nm and two cone classes, absorbing maximally at ca. 535 and 603 nm, all containing a porphyropsin-based pigment. These results suggest that the presence of mid and long wavelength-sensitive cones enhances visual sensitivity under mid-wavelength and long-wavelength environments, and thus supports the finding that longer wavelengths of incoming light can improve FE and SGR of the cultivated pikeperch.  相似文献   

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