首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 500 毫秒
1.
Simultaneous, 6-week feeding trials were conducted in which diets containing menhaden, corn, coconut and hydrogenated menhaden oil at 7.0%, plus a diet containing 14% menhaden oil, were fed to triplicate groups of juvenile red drum (Sciaenops ocellatus) at two different salinities (5 and 32%.). Weight gain was significantly (p < 0.05) affected by diet and salinity. Fish fed the diet containing 14% menhaden oil had the greatest weight gain; whereas, fish fed the diet containing coconut oil gained the least weight. Fish in brackish water had significantly greater weight gain than fish in full-strength seawater over the 6-week period, although fish fed coconut and saturated menhaden oil in brackish water had reduced survival. Dietary lipid also significantly affected muscle and liver total lipid, hepatosomatic index (HSI), and intraperitoneal fat (IPF) ratio, as fish fed the diets containing 14% menhaden oil had higher values for all of these body condition indices.After the feeding trial, fish were subjected to a chronic cold tolerance assay. In the chronic trial, where temperature was gradually reduced over a 3-week period, fish fed the diets containing menhaden oil had significantly lower median lethal temperatures (MLT) than those fish fed the diets containing coconut, corn and saturated menhaden oils. No significant effects of cold exposure were observed on muscle and liver total lipid. Cold exposure prompted a modification in lipid metabolism by lowering total saturated fatty acids and raising (n – 3) highly unsaturated fatty acids (HUFA) in the neutral lipid of liver. Fish with the lowest MLT in the chronic assay exhibited signs of conserving (n – 3) HUFA and depleting (n – 6) fatty acids [primarily 18:2 (n – 6)], resulting in higher (n – 3)/(n – 6) ratios in the polar lipid of liver. These data suggest that the lower lethal temperature of juvenile red drum can be reduced through dietary manipulation involving the inclusion of high levels of dietary lipid rich in (n – 3) HUFA.  相似文献   

2.
This study was performed to evaluate the effect of replacing fish meal with local by‐products on Clarias gariepinus growth performance, feed utilization and body composition. A control diet contained 50% of fish meal. In four other diets, fish meal was partially replaced by vegetable and animal protein blend composed of sunflower oil cake, soybean oil cake, groundnut oil cake, bean meal, chicken viscera and blood meal. The study was conducted in a recirculating water system at a mean temperature of 23.6°C. The five test diets were compared with a commercial diet developed for African catfish. All diets were balanced to be equal in gross energy (19 kJ g−1) and crude protein (40%). The experimental groups were fed in triplicate for 8 weeks, increasing fish weight from about 6.2 g at start to 52.3 g in the end. Best specific growth rate (SGR=3.4), feed efficiency (FE=1.3) and protein efficiency ratio (PER=3) were obtained with the control diet (diet 50% fish meal), although there were no significant differences between the group of fish fed the control diet and those fed diets based on groundnut oil cake or bean meal, whereas SGR (2.17), FE (0.85) and PER (1.95) were significantly (P<0.01) lower in fish fed diet containing sunflower oil cake. No significant differences (P<0.05) were found in fish fed commercial diet and diets containing bean meal or groundnut oil cake. Groundnut oil cake or bean meal can thus replace at least 50% of fish meal in the diet of Clarias fingerlings without amino acid supplementation. Because of its economic importance and its potential in animal nutrition sunflower oil cake is still an interesting feed ingredient, but its efficiency should be improved by various processing techniques. African catfish can utilize efficiently a diet with low percentage of animal protein without growth reduction.  相似文献   

3.
A 10‐week feeding trial was conducted to evaluate the effects of dietary lipid sources on the growth and immune responses of Chinese mitten crab Eriocheir sinensis. Six isonitrogenous and isoenergetic diets were formulated with fish oil (FO), linseed oil (LO), soybean oil (SO), rapeseed oil (RO), coconut oil (CO) and beef tallow (BT) as the sources of lipid with five replicates each. Thirty crabs (2.35 ± 0.14 g) were stocked into each tank and fed twice daily. Weight gain and specific growth rate of crab fed the FO diet were significantly lower than those fed other diets (P < 0.05), except for crabs fed LO diet (P < 0.05). Crab fed the SO diet weighed more than those fed FO diets (P < 0.05). Serum superoxide dismutase and malondialdehyde of crab fed the FO diet were significantly higher than in other groups (P < 0.05). Crab fed the FO diet had the highest activities of serum phenoloxidase, acid phosphatase, alkaline phosphatase and lysozyme (P < 0.05). The fatty acid composition in the liver of crab reflected the change in test diets. Our results indicate that the use of dietary vegetable or animal oils can achieve similar growth performance to the use of dietary FO in Chinese mitten crab, but non‐FOs may impair crab immunity. Soybean oil is recommended as a suitable replacer for FO in Chinese mitten crab diet.  相似文献   

4.
Two hundred and twenty rainbow trouts (IBW: 700 g) were randomly allotted to four tanks, with a male/female ratio of 0.56. Fish were fed for 168 d with four experimental diets containing herring oil, cod liver oil and coconut oil with the following inclusion rates: diet A: 12-1-0% respectively; diet B: 6-1-6%; diet C: 0-1-12%; diet D: 0-0-13%. Irrespective of the dietary treatment, weight gains of broodstocks were high (> 3 g/d) and FCR below 2. No significant difference was observed concerning the total amount of eggs spawn, egg average weight (82.5 mg/egg) and lipid content (5.4 mg/egg). However, the fatty acid profile of eggs was significantly affected by the dietary treatments. The content of unsaturated fatty acids, particularly the n-3 fatty acid series (EPA and DHA) significantly decreased with increasing levels of coconut oil in the diet.  相似文献   

5.
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   

6.
This study investigated the effects of coconut oil as a dietary supplement on the growth, lipid metabolism and related gene expressions of juvenile orange‐spotted grouper Epinephelus coioides. Coconut oil at concentrations of 0, 10, 30 and 50 g/kg was used to replace dietary lipids in a basal diet containing 150 g/kg lipids. The four experimental diets were, respectively, fed to triplicate groups of juvenile groupers (initial weight: 8.53 ± 0.13 g) in a recirculating system for 8 weeks. Fish fed the diet containing 50 g/kg coconut oil exhibited lower (p < .05) weight gain than did fish fed the diet containing 30 g/kg coconut oil; however, no significant differences in weight gain were observed between fish fed diets containing 0 and 10 g/kg coconut oil. Hepatic carnitine palmitoyltransferase‐1, fatty acid synthase, fatty acid elongase, fatty acid desaturase and peroxisome proliferator‐activated receptor gamma gene expressions were all the highest in fish fed the diet containing 10 g/kg coconut oil. Fish fed the coconut oil‐free basal diet demonstrated upregulated gene expression of neuropeptide Y. The results suggest that dietary supplementation with 10 g/kg coconut oil exerted beneficial effects on lipid metabolism by E. coioides.  相似文献   

7.
Arctic charr (Salvelinus alpinus L.) were fed either a commercial diet or six experimental test diets containing coconut oil and different polyunsaturated fatty acids (PUFA) at a level of 1% by dry weight. Best growth rates were observed with the commercial diet, worst with diet containing coconut oil with no PUFA. An increase in hepatic lipid, hepatic sterol esters and muscular moisture content, and a decrease in muscular lipid was generally found in fish fed the test diets compared to those maintained on the commercial diet.Phosphatidylcholine was the dominant polar lipid (PL) class in all tissues examined. Extensive modification of dietary saturated fatty acids into 18:1 (n-9) was observed in tissue triacylglycerols (TAG) of fish fed test diets. No changes occurred with the commercial diet.Dietary PUFA were essentially incorporated unchanged into tissue TAG of all fish in the present study. PUFA composition of hepatic phospholipids was significantly influenced by that contained in the diets. However both 18:2 (n-6) and 18:3 (n-3) in the test diets were extensively elongated and desaturated prior to incorporation into PL. The (n-9) PUFA content was always higher in liver of fish fed the test diets. When 18:2 (n-6) and 18:3 (n-3) were supplied together, the level of (n-3) PUFA exceeded those of (n-6) PUFA. Muscle PL were less influenced by diet than liver. In muscle (n-3) PUFA were always the predominant PUFA irrespective of diet. Only low amounts of (n-9) PUFA were found. It is suggested that (n-3) PUFA are the prime essential fatty acids for Arctic charr, and that they are used in preference to (n-6) PUFA for elongation, desaturation and incorporation into PL. The results suggest that the quantitative requirement of Arctic charr for EFA is may be higher than that of other salmonids.  相似文献   

8.
Rainbow trout were fed either a commercial diet or semi-purified diets containing 8% by weight of either cod liver oil, grape seed oil or hydrogenated coconut oil. Important changes in the fatty acid composition of erythrocyte membrane phospholipids were induced by these dietary fats. No changes were seen in the cholesterol/phospholipid ratio and in the cellular ATP level. Shape changes (crenation of cell margin and shrinkage) were only seen in trout fed hydrogenated coconut oil in connection with an accumulation of high amounts of (n-9) fatty acids including 20:3 (n-9) phospholipids. The compositional changes affect the stability of the erythrocyte membrane. An increased rate of osmotic hemolysis appeared to be associated with an increased unsaturated fatty acid content of the membranes.  相似文献   

9.
Abstract Goldfish Carassius auratus L., larvae were raised on a diet of yeast, rice flour, vitamins and a lipid source consisting of 10% of either canola oil (CAN) or cod liver oil (COD) or a mixture of 5% of each (MIX). Survival of larvae raised on CAN or MIX diets was comparable to that of larvae raised on COD diets. In longer-term experiments, growth was superior and development more rapid in larvae receiving the COD diet.  相似文献   

10.
The aim of the present study was to determine the combined effect of both stress and EFA deficiency on several biological and biochemical parameters. Fish were fed during 15 weeks two isocaloric and isoproteic diets: a control diet based on fish oil and formulated to meet the n-3 HUFA requirements for this species (1.5% of n-3 HUFA) and a deficient diet containing beef tallow and formulated to be deficient in n-3 HUFA. Each experimental diet was evaluated both at high and low stocking densities (10 and 3.2 kg m–3 of initial density, respectively).High stocking density produced a chronic stress situation with elevation of plasma cortisol levels. It also caused a reduction in hepatosomatic index and liver lipid contents, increasing the oleic acid/n-3 HUFA ratios in the polar lipids. Fish fed the EFA deficient diet at low stocking density showed common deficiency symptoms. High stocking density in fish fed the EFA deficient diet induced a higher degree of EFA deficiency symptoms leading to mortality, liver steatosis, liver lipid deposition, reduced muscle lipid and reduced n-3 HUFA contents, which particularly affected EPA, but not DHA, suggesting a preferential retention of the latter fatty acid, specially in the phosphoglycerides fraction.  相似文献   

11.
The present paper gives an overview on the use of plant protein and plant oils as replacers for fish meal and fish oil in diets for Atlantic cod Gadus morhua L. In focus are effects on growth, feed utilization, digestibility, gut health, muscle and liver uptake and retention of nutrients, and muscle quality. Plant oil can replace fish oil without affecting growth provided that the requirement of marine long chain (LC) n‐3 fatty acids is met, but the altered dietary fatty acid profile in diet will be reflected in both muscle and liver. This can reduce the value of cod liver as an oil source for cod liver oil production. For the fish itself, there are more challenges replacing fish meal than fish oil, due to the amount of fibre and antinutrients in plant protein meals. However, A. cod seems to tolerate a wide range of plant types and their inclusion levels provided that the amino acids requirements are met. It is our view that there is sufficient knowledge to be able to design an A. cod diet based on a mixture of plant and marine ingredients and be able to predict performance such as growth, feed utilization, digestibility, liver size and fish health in general.  相似文献   

12.
Australian red claw crayfish Cherax quadricarinatus is considered a popular crustacean species in several countries around the world because of its large size potential and resemblance to high‐priced American lobsters. However, little is currently known of the nutrient requirements and practical diet formulations for red claw. Lecithin has been shown to be required in the diets of several crustacean species, but there are no reports of dietary lecithin requirements for red claw. A 10‐week feeding trial was conducted in an effort to evaluate lecithin requirements for juvenile red claw. Juvenile red claw (mean individual weight of 1.6 ± 0.91 g) were individually stocked in a recirculating system at random into 80 plastic‐mesh culture units, each containing its own individual water line. There were 20 red claw per treatment (diet). Water was recirculated through biological and mechanical filters. Four semi‐purified diets were formulated to contain increasing percentages of commercial soya bean lecithin (0, 0.5, 1.0 and 2.0%). Diet ingredients included solvent‐extracted menhaden fish meal (FM), casein, dextrin, wheat flour, pellet binder, vitamin and mineral mix, cod liver oil, and corn oil. Semi‐purified diets were formulated to contain 40% protein using casein, menhaden FM, and wheat flour as protein sources. After 10 weeks, no significant differences (P > 0.05) were found in final weight, percentage weight gain and specific growth rate with average values of 13.0 g, 934%, and 3.14% day?1, respectively. Percentage survival was high during the 10‐week period (100, 95, 100 and 95%) as only two individuals died during the study; one of these, because of an escape from the culture unit. There was also no significant differences (P > 0.05) in percentage moisture, protein, fat and ash in whole‐body red claw carcasses (wet‐weight basis) among any treatment (diet) and averaged 77.1, 12.6, 1.3 and 6.2%, respectively. Based upon the present study, these results indicate that a diet containing 5% cod liver oil and 1% corn oil, and having no supplemental lecithin, may be sufficient for growth and survival of juvenile red claw crayfish.  相似文献   

13.
介绍了链，鲫细菌性败血症的病原，症状及在章丘市的流行情况，采取清塘排水，消毒鱼等措施可预防此病。全池泼洒鱼虾安，鱼虾宁，半呋喃唑酮拌在面糊中制成药饵，然后拌在麦麸，豆饼中投喂，收到较好治疗效果。  相似文献   

14.
Rainbow trout (Salmo gairneri) were given slow-release coconut oil implants which contained triiodo-L-thyronine (T3) and were subsequently administered ovine growth hormone (oGH) (either 0.24 or 2.5 g/g body weight) or saline every seventh day for four injections. The purpose of the study was to examine the interactions between oGH and T3 on several aspects of the metabolism in rainbow trout.Trout treated with T3 alone had higher carcass water content, lower liver glycogen, higher plasma T3 levels and lower plasma cholesterol, triglyceride and protein levels compared with the controls implanted with coconut oil implants alone. Trout treated with oGH alone had higher condition factors, lowered carcass total lipid content, elevated liver lipid and RNA content, and elevated plasma T3 and L-thyroxine (T4) levels compared with the coconut oil-implanted and saline-injected controls. Trout treated with T3 and oGH had lower liver glycogen content, higher plasma T3 and fatty acid levels and lower plasma T4, cholesterol and triglyceride levels compared with the controls given coconut oil implants and saline injections alone. There were no apparent effects of either hormone alone or in combination on liver: body mass ratios, liver DNA content, liver RNA:DNA ratios, liver RNA:protein ratios, liver protein:DNA ratios and liver protein content.The data suggest an interaction between oGH and T3 as regards the regulation of condition factor, carcass water content, carcass and liver total lipid content, liver RNA content, plasma fatty acid and plasma protein content.  相似文献   

15.
ADELIZI  ROSATI  WARNER  WU  MUENCH  WHITE  & BROWN 《Aquaculture Nutrition》1998,4(4):255-262
Eight experimental diets were formulated for rainbow trout using agricultural byproducts as major ingredients. Each experimental diet contained varying amounts of corn grain, corn gluten meal, corn gluten feed and one of the following: 200 g kg?1 peanut meal, 200 or 400 g kg?1 soybean meal (SBM), 390 g kg?1 low-allergen soy flour, 310 g kg?1 soy protein concentrate, 300 g kg?1 low-allergen soy protein concentrate or 200 g kg?1 SBM + 110 g kg?1 blood meal. One diet contained 200 g kg?1 SBM and canola oil as the main lipid source. The remaining diets contained 95 g kg?1 menhaden oil. Fish fed a commercial trout diet exhibited significantly greater weight gain (322%), and a lower feed conversion ratio (0.89) but significantly lower protein efficiency ratio (2.18) than fish fed the experimental diets. Within the experimental diets, fish fed the 400 g kg?1 soy flour diet and the 400 g kg?1 soybean meal diet had significantly higher weight gains (276% and 268%) and protein efficiency ratios (2.58 and 2.52), and lower feed conversion ratios (1.02 and 1.03) than fish fed other experimental diets. Fillet flavour varied between treatments. Most notable was the lower fishy flavour and higher chicken flavour of fish fed the diet that contained canola oil rather than menhaden oil. Microscopic evaluation of the liver and five sections of the gastrointestinal tract failed to demonstrate any differences between treatment groups. The ingredient costs of several experimental diets were lower than the estimated cost of a standard commercial trout diet. However, the superior feed conversion ratios of fish fed the control diet resulted in lower feed costs per unit of fish produced.  相似文献   

16.
Ten-week experiment was carried out on Japanese sea bass (5.87 ± 0.02 g) to study the effects of replacement of fish oil with six alternative lipid sources: pork lard, PL; beef tallow, BT; poultry fat, PF; soybean oil, SO; corn oil, CO; and a mixed-fat (MF: tallow, 60%; soy oil, 20%; fish oil, 20%) on growth performance and fatty acid (FA) composition in fillet and liver. Seven isoenergetic and isonitrogenous experimental diets were formulated, containing 10% of added lipid. Fish oil was used in control diet, which was substituted by 50% with the alternative lipid sources in the other six diets.

Weight gain (WG), specific growth rate (SGR), Feed conversion ratio (FCR) feed intake and hepatosomatic index (HSI) of fish fed the experimental diets were not significantly different (P > 0.05). Protein efficiency ratio (PER) in fish fed the PF diet were significantly lower than those of fish fed SO and CO diets. Significant differences in carcass moisture and lipid contents of carcass and liver were observed among fish fed the dietary treatments. Generally, the fatty acid composition of fish fillets and livers reflected the dietary FA composition.  相似文献   


17.
Six iso‐nitrogenous (30% crude protein) and iso‐energetic (15 kJ g−1) diets were prepared using different oil cake sources, viz. groundnut, soybean, sunflower, sesame, mustard and mixed oil cakes as major ingredients, and protein sources along with a minimum of 5% fish meal in each diet and were fed to silver barb Puntius gonionotus fingerlings (16.20±0.11 g) ad libitum four times a day close to an apparent satiation level for a period of 60 days to determine the effect of diets on growth, nutrient utilization, apparent digestibility coefficient (ADC) of the nutrients in the diets, gut enzyme activity, muscle nucleic acid content and whole‐body chemical composition of fish. Significantly higher (P<0.05) weight gain, specific growth rate, protein efficiency ratio, nutrient retention, ADC of nutrients in the diets, DNA:RNA ratio, protease and amylase activity with lower (P<0.05) feed:gain values were recorded in fish‐fed groundnut and soybean oil cake‐based diets than other diets tested. Among the dietary treatment groups, significantly higher (P<0.05) whole‐body protein, lipid and energy were also found in groundnut oil cake‐ and soybean oil cake‐based diets. The study suggests that the groundnut and soybean oil cake‐based diets, which led to significantly higher (P<0.05) growth and nutrient utilization than the other oil cake‐based diets in P. gonionotus fingerlings, may be used for pond culture of this species.  相似文献   

18.
In a 6-week feeding experiment, chum salmon, Oncorhynchus keta, swim-up fry, were fed fish meal diets supplemented with silkworm pupae powder (5%), dried beef liver (5%), krill meal (5%) or earthworm powder (5%) at the expense of fish meal, or substituting glucose (13%) for dextrin. Fish fed the diet with earthworm powder showed the best growth performance (675% weight gain in 6 weeks) and feed efficiency (117%). The growth rate and feed efficiency of the krill meal group were also significantly better than those of the control group (without supplement or substitution). Substitution of glucose and supplementation of silkworm pupae or beef liver failed to improve the growth rate, but significantly improved feed efficiency. Food consumption of fish fed the diet supplemented with earthworms was lowest, and none of the dietary treatments appreciably increased food intake of the fish over that of the control group. The dietary group receiving earthworm powder also showed significantly higher body fat content than the remaining dietary groups. No significant differences were noted in body protein and ash contents among all dietary treatments.  相似文献   

19.
The effect of using a finishing diet containing menhaden fish oil on the fatty acid composition of fingerling channel catfish, Ictalurus punctatus, was evaluated in a 12‐wk growth trial. Three isocaloric, isonitrogenous practical diets with three different sources of lipids (menhaden oil [MO], catfish oil [CO], or beef tallow [BT]) were formulated (35% crude protein). No differences in eicosapentaenoic acid, docosahexaenoic acid, or arachidonic acid were observed to occur in catfish fed MO or CO diets; however, these fatty acids were significantly lower in fish fed BT diet. No differences were observed for unsaturated fatty acid content in channel catfish fed a diet containing MO for 8 or 12 wk. In addition, no differences in production characteristics were observed to occur when catfish were fed diets containing CO, MO, or BT as the dietary lipid source, which indicates that BT, CO, and MO are equally effective as sources of energy. It is apparent from these results that CO may be successfully substituted for MO in formulated diets without adversely affecting n‐3 highly unsaturated fatty acid content in channel catfish.  相似文献   

20.
Rubber seed oil has a high potency to be used as a new lipid source within red tilapia diet. However, the rubber seed oil contains antinutritional factor such as hydrogen cyanide (HCN). HCN is classified into heat‐labile; therefore, heating effectively reduces the HCN content. Based on this fact, this research evaluated the use of rubber seed oil with and without heating as lipid source in red tilapia diet. Four isonitrogenous and isocaloric diets were prepared as experimental diet. Each test diet contains different lipid sources such as crude palm oil + corn oil (CTRL), crude palm oil + rubber seed oil with heating (CPO:PRSO), 100% rubber seed oil with heating (PRSO) and 100% RSO without heating (URSO). In average, there were no significant differences (Tukey: p < .05) among test diet except diet with 100% rubber seed oil without heating. It concluded that 100% rubber seed with heating within test diet has no effect on growth, feed performance, blood profile, cholesterol plasma, body and liver glycogen, malondialdehyde (MDA) and the activity of superoxide dismutase (SOD).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号