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 46 毫秒
1.
A 15‐wk study was conducted to evaluate the effect of supplemental menhaden fish oil levels and feeding duration on growth performance and tissue proximate and fatty acid (FA) compositions of juvenile channel catfish, Ictalurus punctatus. Dietary fish oil levels had no effect on final weight gain, feed efficiency, and survival of channel catfish. Tissue lipid contents were directly correlated to dietary lipid levels, while moisture contents were inversely related to dietary lipid levels. Fillet moisture contents progressively decreased, whereas fillet lipid increased with increasing feeding duration. Significant increase in saturated and total n‐3 FAs and decrease in monoenoic and total n‐6 FA in whole body and fillet were observed at each incremental level of dietary fish oil. Percentages of n‐3 and n‐3 highly unsaturated fatty acids in fillet of fish fed the control and 3% fish oil diets decreased with increasing feeding periods, whereas those of fish fed 6 or 9% added fish oil diets remained stable or increased. Ratios of n‐3/n‐6 were statistically comparable throughout the 15‐wk feeding. When expressed in terms of mg/g of fillet, the highest concentration of n‐3 was obtained in fillets of fish fed the 9% added fish oil diet for 15 wk.  相似文献   

2.
This study was undertaken to determine the suitability of using cold‐pressed flaxseed oil (FO) as a major source of lipid in place of anchovy oil (AO) in the diet of juvenile sablefish (Anoplopoma fimbria), a relatively new marine species to aquaculture. Sablefish were fed one of four diets twice daily to satiation for 15 weeks. The test diets were identical in composition, except for the source of supplemental lipid which was either 100% AO (100AO), or increasing replacement of AO with FO i.e., 75AO:25FO, 50AO:50 FO or 25AO:75FO. Sablefish growth parameters, whole body and fillet proximate constituent concentrations and apparent digestibility coefficients were uninfluenced by diet treatment. There were also no adverse effects of the diet treatments on fish health, as determined from analysis of various haematological and innate immunological parameters. Terminal fillet fatty acid compositions generally reflected the dietary fatty acid compositions, while flesh contaminant concentration decreased with increasing dietary flaxseed oil content. Results indicated that FO may comprise up to 75% of the supplemental lipid in a grower diet for sablefish, while still providing humans with a rich dietary source of highly unsaturated fatty acids.  相似文献   

3.
The effect of varying dietary lipid and n‐3 polyunsaturated fatty acids (PUFAs) on growth, feed efficiency, protein and energy utilization, carcass quality, and nonspecific immune functions was investigated in rainbow trout reared at two different water temperatures (7.5 and 15 C). Six diets were formulated to contain 47% digestible protein and 21 MJ/kg digestible energy. Three of the diets were formulated to contain increasing lipid levels (10, 16, and 18%) and three additional diets formulated to 18% lipid with different lipid sources. Varying dietary lipid and n‐3 PUFA levels had little effect on growth and on protein and energy utilization. Diet composition only had limited effect on susceptibility of the flesh to rancidity and on the nonspecific immunity of the fish. Increasing lipid levels did not affect fish carcass or fillet proximate composition. Replacing half of fish oil with beef tallow resulted in lower n‐3 PUFAs in fish fillet but did not affect nutrient digestibility or growth performance of fish even at 7.5 C. Increasing dietary n‐3 levels using a fish oil concentrate resulted in significant enrichment of n‐3 PUFAs and elevated n‐3 : n‐6 ratio of the whole body and carcass. Water temperature significantly affected apparent digestibility coefficient (ADC) of protein and energy but did not affect the ADC of lipid, nor did it affect nitrogen and energy retention efficiencies. The study suggests that highly saturated fats, such as beef tallow, can be used to partially replace fish oil without negative effect on digestibility and growth even at low water temperature. High dietary n‐3 PUFAs levels can be used to enrich n‐3 PUFAs of the flesh without negative effect on the immune response.  相似文献   

4.
Effect of different levels (0%, 0.15%, 0.25%, 0.35% and 0.50%) of Optimûn, a commercial nucleotide (NT) product, on the growth performance, body composition and fatty acid profile of juvenile Beluga sturgeon (Huso huso) (12.57 ± 0.5 g) was investigated over a 62‐day period. This experiment was done in fifteen 600 L tanks, each stocked with 30 fish. Fish fed nucleotide showed significantly better growth performance (P < 0.05). Incorporation of 0.25% and 0.35% NT resulted in whole body protein content elevation, but the other proximate composition indices were not influenced by dietary nucleotide treatments. There were significant differences in saturated fatty acids (SFA) and total unsaturated fatty acids (TUFA) levels among fish fed on different experimental diets, while monounsaturated fatty acids, polyunsaturated fatty acids (PUFA), n‐3 PUFA, n‐6 PUFA, n3/n6 and eicosapentaenoic acid + docosahexaenoic acid were not influenced by NT. The results showed that diet supplementation with 0.35% Optimûn (NT) enhance growth performance, also administration of 0.25% and 0.35% affected chemical composition, as well as decreased SFA/TUFA ratio of Beluga juvenile.  相似文献   

5.
This study was conducted to investigate the influence of dietary lipid source and n‐3 highly unsaturated fatty acids (n‐3 HUFA) level on growth, body composition and blood chemistry of juvenile fat cod. Triplicate groups of fish (13.2 ± 0.54 g) were fed the diets containing different n‐3 HUFA levels (0–30 g kg?1) adjusted by either lauric acid or different proportions of corn oil, linseed oil and squid liver oil at 100 g kg?1 of total lipid level. Survival was not affected by dietary fatty acids composition. Weight gain, feed efficiency and protein efficiency ratio (PER) of fish fed the diets containing squid liver oil were significantly (P < 0.05) higher than those fed the diets containing lauric acid, corn oil or linseed oil as the sole lipid source. Weight gain, feed efficiency and PER of fish increased with increasing dietary n‐3 HUFA level up to 12–16 g kg?1, but the values decreased in fish fed the diet containing 30 g kg?1 n‐3 HUFA. The result of second‐order polynomial regression showed that the maximum weight gain and feed efficiency could be attained at 17 g kg?1 n‐3 HUFA. Plasma protein, glucose and cholesterol contents were not affected by dietary fatty acids composition. However, plasma triglyceride content in fish fed the diet containing lauric acid as the sole lipid source was significantly (P < 0.05) lower than that of fish fed the other diets. Lipid content of fish fed the diets containing each of lauric acid or corn oil was lower than that of fish fed the diets containing linseed oil or squid liver oil only. Fatty acid composition of polar and neutral lipid fractions in the whole body of fat cod fed the diets containing various levels of n‐3 HUFA were reflected by dietary fatty acids compositions. The contents of n‐3 HUFA in polar and neutral lipids of fish increased with an increase in dietary n‐3 HUFA level. These results indicate that dietary n‐3 HUFA are essential and the diet containing 12–17 g kg?1 n‐3 HUFA is optimal for growth and efficient feed utilization of juvenile fat cod, however, excessive n‐3 HUFA supplement may impair the growth of fish.  相似文献   

6.
The objective of this study was to access the suitability of using poultry fat (PF) or blends of PF with flaxseed oil (FO) to replace 75% of the supplemental anchovy oil (AO) in the diet of juvenile sablefish (Anoplopoma fimbria), a relatively new marine species to aquaculture. Sablefish were fed one of four diets twice daily to satiation for 15 weeks. The test diets were identical in composition except for the source of supplemental lipid which was either 100% AO (100AO), or had 75% of the supplemental AO replaced with 50% FO:25% PF, 25% FO:50% PF or 75% PF. Sablefish growth parameters, whole body and fillet proximate constituent concentrations, and apparent digestibility coefficients were uninfluenced by diet treatment. There were also no adverse effects of the diet treatments on fish health, as determined from analysis of various haematological and innate immunological parameters. Terminal fillet fatty acid compositions generally reflected the dietary fatty acid compositions. Results indicated that PF or blends of PF and FO may comprise 75% of the supplemental lipid in a grower diet for sablefish and are an economic alternative to AO while still providing humans with a rich dietary source of highly unsaturated fatty acids.  相似文献   

7.
A 8‐week feeding trial was conducted to determine the effect of substituting fish oil with palm oil‐laden spent bleaching clay (SBC), a by‐product from crude palm oil (CPO) refining, on growth, feed utilization, fatty acid composition and heavy metal accumulation in the muscle of Nile tilapia, Oreochromis niloticus. Four isonitrogenous and isolipidic practical diets were formulated to contain 0, 100, 200 or 300 g kg?1 SBC. Growth performance of Nile tilapia was significantly better in fish fed the 100 g kg?1 SBC diet compared with fish fed the 0, 200 or 300 g kg?1 SBC diet. Growth and feed utilization efficiency of fish fed 200 or 300 g kg?1 SBC were similar to fish fed the control diet without added SBC. Whole‐body composition, body‐organ indices and haematocrit of tilapia were not affected by dietary treatments. Fatty acid compositions in the muscle lipid of Nile tilapia were strongly influenced by dietary treatments with progressively elevated levels of total saturates and n‐6 PUFA because of the dietary influence of these fatty acids from residual CPO adsorbed onto SBC. A gradual decrease in total n‐3 PUFA concentrations were also observed with the ratio of n‐3 to n‐6 fatty acids in muscle lipids decreasing from 4.75 to 4.41, 3.23 or 2.37 after 8 weeks on the 0, 100, 200 or 300 g kg?1 SBC diet, respectively. The arsenic, cadmium and lead concentrations in the experimental diets increased with increasing dietary levels of SBC but the concentrations of these heavy metals in the whole body and bone of Nile tilapia were not significantly different among fish fed the various diets. The present 8‐week study showed that in fishmeal‐based diets for Nile tilapia, palm oil‐laden SBC can totally replace added fish oil. The use of this presently discarded waste product from palm oil refining in tilapia diets will greatly contribute to reducing the impact of rising feed costs in the culture of tilapia in many tropical countries. Other potential benefits may include acting as a feed binder, removal of mycotoxins in fish feeds as well as adsorbing toxic substances present in the culture water.  相似文献   

8.
Five sources of dietary fatty acids (fish, linseed, sunflower, olive and coconut oils) were evaluated in juvenile Nile tilapia in two trials: at optimal (28°C) and suboptimal (22°C) temperatures lasting 9 and 12 weeks, respectively. At 28°C, there was no clear effect of dietary source on fish growth, but at 22°C, the highest daily weight gain occurred in fish fed sunflower, linseed and fish oil. Feed efficiency and apparent net protein utilization increased as the amount of unsaturated fatty acids, especially n‐3 polyunsaturated fatty acids (PUFA), in the diet increased. Coconut oil, which is rich in saturated fatty acids (SFA), led to the worst growth results, especially at 22°C, with the lowest weight gain, feed intake and feed utilization by tilapia. The body fatty acid profile, in % of total fatty acids, was dependent on diet composition. However, for all treatments, PUFA body content increased with the decrease in temperature, but SFA and monounsaturated fatty acids remained the primary contributors to the body profile. Either fish oil or vegetable oil may be used as sources of dietary fatty acids for Nile tilapia, but at suboptimal temperatures, a dietary source containing more PUFA and less SFA improves performance.  相似文献   

9.
The replacement of dietary marine fish oil with vegetable oils was examined in fingerling humpback grouper, Cromileptes altivelis, over the course of an 8‐week growth trial. Five isolipidic (10%) and isoproteic (50%) fish meal‐based practical diets were formulated to contain iso‐ingredients but with different sources of lipids [crude palm oil (CPO), refined, bleached and deodorized, palm olein (RBDPO), soybean oil (SBO) or canola oil (CNO)], and their performance was compared with the control diet, which contained cod liver oil (CLO) as the added lipid source. The experimental diets were fed close to apparent satiation twice a day to triplicate groups of fish (10.6 ± 2.2 g). The grouper fingerlings were randomly distributed into groups of 12 fish in cylindrical cages (61 cm depth and 43 cm diameter) that were placed in a 150 tonne polyethylene seawater tank. There were no significant differences (P>0.05) in terms of growth, survival, feed conversion ratio, protein efficiency ratio, net protein utilization, hepatosomatic index and condition factor among fish fed the various dietary treatments. Similarly, the dietary lipid source did not significantly affect the whole body proximate composition of the fish. Muscle and liver fatty acid composition of fish was influenced by the experimental diets. Replacement of dietary CLO with CPO, RBDPO, SBO or CNO produced fish with lower n‐3 highly unsaturated fatty acids and increased levels of 18:2n‐6 in the muscle and liver. The n‐3:n‐6 fatty acid ratio in the muscle of fish fed the CLO‐based diet was 3.0 compared with 0.5–0.8 in the muscle of fish fed the various vegetable oil‐based diets. The present study demonstrated that various vegetable oils can be used in fish meal‐based dietary formulations for humpback grouper without compromising growth or feed utilization efficiency.  相似文献   

10.
Five dietary lipid sources (fish oil, soybean oil, palm oil, rapeseed oil and linseed oil) were evaluated in juvenile red claw crayfish, Cherax quadricarinatus, based on the response of growth, antioxidant capacity, intestine histology, whole‐body composition, fatty acid nutrition and lipid metabolism. Crayfish were fed in quadruplicate net cages for 8 weeks. Crayfish fed diets with fish oil, soybean oil and linseed oil obtained significantly higher weight gain and specific growth rate than those fed the other two diets. Survival, condition factor and hepatosomatic index were not significantly affected by lipid sources. Lipid sources also do not affect the whole‐body composition of crayfish. Serum SOD, T‐AOC and GSH‐PX activities of crayfish fed the palm oil and rapeseed oil diets had a significantly lower value than those fed other diets. The minimum concentrations of MDA have been observed in crayfish fed the soybean oil diet. The activity of ACC in the hepatopancreas of crayfish fed the linseed oil diet showed the highest value, and the CPT‐1 activity was not significantly affected by different lipid sources. Crayfish fed the soybean oil diet showed significantly higher TC and TG contents in hepatopancreas than those fed other diets. Crayfish fed linseed oil diet had a significantly higher percentage of EPA, C18:3n?3 and Σn?3 PUFA in muscle than those fed other treatments. Most of the fatty acid compositions in the hepatopancreas had a close correlation to fatty acid compositions in diets. All findings in this study indicate that soybean oil is the advantageous lipid source for juvenile C. quadricarinatus which can reflect in satisfactory growth performance, antioxidant capacity and fatty acid nutrition of edible tissues.  相似文献   

11.
This study investigated the effects of varying dietary levels of decosahexaenoic acid (DHA) on growth performance, proximate composition and whole body fatty acid profiles of juvenile silver pomfret, Pampus argenteus. Triplicate groups of fish (30.55 ± 0.08 g) were fed diets containing 5.2%, 9.31% and 13.38% DHA (% of total fatty acids) or 0.85%, 1.52% and 2.18% DHA on dry diet weight for diets 1, 2 and 3 respectively. Survival was not affected by dietary DHA levels. The growth performance and feed utilization parameters of fish fed diets 2 and 3 were significantly (P < 0.05) higher than those fed diet 1, although these parameters in diets 2 and 3 did not differ significantly (P > 0.05). Whole body lipid and fatty acid profiles were influenced by dietary DHA levels. Significantly higher n‐3 fatty acids particularly DHA, DHA:EPA(eicosapentaenoic acid) ratios and n‐3:n‐6 ratios were observed in fish fed diets 2 and 3 compared to those fed diet 1. Better growth performance and higher whole body DHA:EPA (2.31, 2.29) ratios and n‐3:n‐6 ratios (2.17, 2.12) observed in fish fed diets 2 and 3, respectively, suggests that silver pomfret juveniles have a higher requirement for n‐3 fatty acids, notably DHA for optimum growth and survival.  相似文献   

12.
This study assessed the suitability and cost efficacy of an equal blend of canola oil (CO) and poultry fat (PF) as a supplemental dietary lipid source for juvenile Atlantic salmon. Quadruplicate groups of Atlantic salmon (～400 g) held in 4000 L outdoor fibreglass tanks supplied with running (35–40 L min?1), aerated (dissolved oxygen, 7.88–10.4 mg L?1), ambient temperature (8.6–10.9°C) sea water (salinity, 26–35 g L?1) were fed twice daily to satiation one of three extruded dry pelleted diets of equivalent protein (488–493 g kg?1 dry matter) and lipid (267–274 g kg?1 dry matter) content for 84 days. The diets were identical in composition except for the supplemental lipid (234.7 g kg?1) source viz., 100% anchovy oil (AO; diet COPF‐0), 70.2% AO and 29.8% CO and PF (diet COPF‐30), and 40.3% AO and 59.7% CO and PF (diet COPF‐60). Atlantic salmon growth rate, feed intake, feed efficiency, protein and gross energy utilization, percent survival and whole body and fillet proximate compositions were not affected by diet treatment. Cost per kilogram weight gain was about 10% less for fish fed diet COPF‐60 than for diet COPF‐0. Percentages of saturated fatty acids in dietary and fillet lipids varied narrowly. Moreover, percentages of 18:1n‐9, monounsaturated fatty acids, 18:2n‐6, n‐6 fatty acids, 18:3n‐3, and ratios of n‐6 to n‐3 fatty acids in the flesh lipids were directly related to the dietary level of CO and PF whereas 22:6n‐3, the total of 20:5n‐3 (eicosapentaenoic acid; EPA) and 22:6n‐3 (docosahexaenoic acid; DHA), and n‐3 fatty acids revealed the opposite trend. Percentages of 22:6n‐3, EPA and DHA, and n‐3 fatty acids were significantly depressed in fish fed diet COPF‐60 versus diet COPF‐0. We conclude that a 1:1 blend of CO and PF is an excellent cost‐effective dietary source of supplemental lipid for Atlantic salmon in sea water.  相似文献   

13.
A 56‐d feeding trial was conducted to evaluate the growth performance, feed utilization, biochemical composition, and antioxidant status of chu's croaker, Nibea coibor (12.6 ± 0.1 g) in net pens fed diets supplemented with various levels of crude palm oil: 0% fish oil (FO), 20% palm oil (2PO), 40% (4PO), 60% (6PO), 80% (8PO), and 100% (10PO). Weight gain and specific growth rate (SGR) were significantly lower in fish fed 8PO and 10PO diets. The increase of PO levels did not affect fish survival, feed intake, and feed conversion ratio. Feeding diet 10PO led to significantly higher lipid content in the liver, but not the whole body and dorsal muscle, than diets FO and 2PO. PO supplementation led to increased α‐tocopherol, but decreased thiobarbituric acid‐reactive substances, n‐3 highly unsaturated fatty acid (n‐3 HUFA), and n‐3/n‐6 fatty acid ratio, in both the liver and muscle. Hepatic superoxide dismutase and catalase were significantly higher in fish fed 10PO diet than FO diet. Polynomial regression analysis showed that the maximum SGR was obtained at 24.2% crude PO. Results of this study suggested that PO could replace up to 60% of FO without adverse effect on growth performance or nutritional quality of fish.  相似文献   

14.
This study investigated the effect of n‐3 to n‐6 fatty acid ratios in broodstock diets on reproduction performance, fatty acid composition of eggs and gonads of tongue sole Cynoglossus semilaevis. Broodstock were fed five isonitrogenous and isoenergetic diets for 60 days. The supplemented lipids were prepared by a combination of fish oil and soybean oil inclusion FO (fish oil); FSO1 (fish oil: soybean oil = 7:1); FSO2 (fish oil: soybean oil = 2.2:1); FSO3 (fish oil: soybean oil = 1:1); FSO4 (fish oil: soybean oil = 1:4.3) as lipid sources with different n‐3 to n‐6 fatty acid ratios 10.40, 5.21, 2.81, 1.71 and 0.87. Results showed that relative fecundity, fertilization rate and survival rate of larvae at 7 days posthatching were all higher in broodstock fed FSO1 and FSO2 diet and significantly (P < 0.05) decreased in groups fed FSO3 and FSO4 diets. The best result in starvation tolerance test was obtained in FSO2 diet. The present study suggests that n‐3 and n‐6 PUFA ratio in broodstock diet has a considerable effect on spawning performance, egg and larval quality for C. semilaevis.  相似文献   

15.
The aim of this study was to investigate the effects of different oils on growth performance and lipid metabolism of the grouper, Epinephelus coioides. Five experimental fish meal‐based isonitrogenous and isolipidic diets were formulated containing either 5.5%‐added fish oil (FO), soybean oil (SBO), corn oil (CO), sunflower oil (SFO) or peanut oil (PO). Each diet was fed to triplicate groups of 20 fish (initial body weight 13.2±0.02 g) grown in seawater at 28.0–30.5 °C for 8 weeks. Fish were fed twice a day to visual satiety. No significant differences in the survival, weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio or hepatosomatic index were found between fish fed the FO or vegetable oils (VO) diets. Dietary lipid sources did not affect whole‐body composition among grouper fed the various diets. Muscle of fish fed the FO diet had significantly higher levels of 14:0, 16:0, 16:1n‐7, 20:5n‐3[eicosapentaenoic acid (EPA)] and docosahexaenoic acid (DHA)+EPA (except for PO fed fish) compared with those of fish fed VO diets. However, the levels of 18:1n‐9, 18:2n‐6 and DHA/EPA ratios in the muscle of fish fed FO diet were significantly lower than those of fish fed the VO diets. The liver of fish fed the FO diet had significantly higher levels of 18:0, 20:5n‐3, 22:6n‐3, n‐3 highly unsaturated fatty acids and DHA+EPA than those of fish fed the VO diets, whereas increases in 18:1n‐9, 18:2n‐6 and mono‐unsaturated fatty acid levels were observed in the liver of fish fed the VO diets.  相似文献   

16.
The effective implementation of a finishing strategy (wash‐out) following a grow‐out phase on a vegetable oil‐based diet requires a period of several weeks. However, fish performance during this final stage has received little attention. As such, in the present study the growth performance during both, the initial grow‐out and the final wash‐out phases, were evaluated in Murray cod (Maccullochella peelii peelii). Prior to finishing on a fish oil‐based diet, fish were fed one of three diets that differed in the lipid source: fish oil, a low polyunsaturated fatty acid (PUFA) vegetable oil mix, and a high PUFA vegetable oil mix. At the end of the grow‐out period the fatty acid composition of Murray cod fillets were reflective of the respective diets; whilst, during the finishing period, those differences decreased in degree and occurrence. The restoration of original fatty acid make up was more rapid in fish previously fed with the low PUFA vegetable oil diet. During the final wash‐out period, fish previously fed the vegetable oil‐based diets grew significantly (P < 0.05) faster (1.45 ± 0.03 and 1.43 ± 0.05, specific growth rate, % day−1) than fish continuously fed with the fish oil‐based diet (1.24 ± 0.04). This study suggests that the depauperated levels of highly unsaturated fatty acids in fish previously fed vegetable oil‐based diets can positively stimulate lipid metabolism and general fish metabolism, consequently promoting a growth enhancement in fish when reverted to a fish oil‐based diet. This effect could be termed ‘lipo‐compensatory growth’.  相似文献   

17.
To aid in development of nutritionally complete diets, a 12‐week experiment was conducted to identify appropriate sources of dietary lipid for bull trout. The basal diet was top‐coated with marine fish oil (MFO) (pollock liver oil), canola oil (CO), linseed oil (LO) or a mixture of canola and linseed oils (CLO) to produce four treatments. Each diet was fed to triplicate groups of fish initially averaging 1.6 g per fish. Weight gain, feed efficiency, survival and carcass proximate composition were not significantly different among fish fed the dietary treatments. However, whole‐body fatty acid percentages varied significantly among fish fed the four diets. Whole bodies of fish fed diets with vegetable oil (VO) contained significantly higher 18:2n‐6, 18:3n‐3 and total n‐6 polyunsaturated fatty acid percentages and significantly lower 20:5n‐3, 22:6n‐3 and total saturated fatty acid percentages compared with fish fed the MFO diet. Whole‐body fatty acid percentages also varied among fish fed VO diets. Despite similar 18:2n‐6 and 20:4n‐6 percentages in the VO diets, fish fed diet CO contained significantly lower 18:2n‐6 proportions and significantly higher 20:4n‐6 proportions compared with fish fed other VO diets. Results of this study suggest dietary fish oil is not required for short‐term rearing of bull trout.  相似文献   

18.
A 12‐week feeding trial was conducted to investigate the interactive effects between water temperature and diets supplemented with different blends of fish oil, rapeseed oil and crude palm oil (CPO) on the apparent nutrient and fatty acid digestibility in Atlantic salmon. Two isolipidic extruded diets with added fish oil fixed at 50% and CPO supplemented at 10% or 25% of total added oil, at the expense of rapeseed oil, were formulated and fed to groups of Atlantic salmon (about 3.4 kg) maintained in floating cages. There were no significant effects (P>0.05) of diet on growth, feed utilization efficiency, muscle total lipid or pigment concentrations. Fatty acid compositions of muscle and liver lipids were mostly not significantly different in salmon fed the two experimental diets but showed elevated concentrations of 18:1n‐9 and 18:2n‐6 compared with initial values. Decreasing water temperatures (11–6°C) did not significantly affect protein, lipid or energy apparent digestibilities of the diets with different oil blends. However, dry matter digestibility decreased significantly in fish fed the diet with CPO at 25% of added oil. Increasing dietary CPO levels and decreasing water temperature significantly reduced the apparent digestibility (AD) of saturated fatty acids. The AD of the saturates decreased with increasing chain length within each temperature regimen irrespective of CPO level fed to the fish. The AD of monoenes and polyunsaturated fatty acids was not affected by dietary CPO levels or water temperature. No significant interaction between diet and water temperature effects was detected on the AD of all nutrients and fatty acids. The results of this study showed that the inclusion of CPO up to about 10% (wt/wt) in Atlantic salmon feeds resulted in negligible differences in nutrient and fatty acid digestibility that did not affect growth performance of fish at the range of water temperatures generally encountered in the grow‐out phase.  相似文献   

19.
Barramundi (Lates calcarifer), a catadromous teleost of commercial interest, perform well when fed a wide range of dietary oils. However, the range of alternative oils now being explored is typically rich in saturated and monounsaturated fatty acids (SFA and MUFA). In this study, the response of juvenile barramundi (47.0 g per fish initial weight) fed isolipidic and isoenergetic diets with 82 g kg?1 added oil was tested. The experimental test diets had a 2 : 1 or 1 : 2 ratio of SFA to MUFA (SFA‐D and MUFA‐D, respectively) compared to a control diet (CTRL‐D) fed for 8 weeks. The diets containing mostly olive oil (dietary MUFA‐D) and mostly refined palm oil (dietary SFA‐D) did not impact the growth performance or feed utilization parameters of the barramundi. The in vivo beta‐oxidation activity was consistent with the dietary fatty acid composition, with the most dominant FA being heavily beta‐oxidized. Together, the in vivo whole‐body mass balance of fatty acids showed that n‐3 long‐chain polyunsaturated fatty acids (LC‐PUFA) were most efficiently utilized in the SFA‐D‐ and MUFA‐D‐fed fish. This study provides evidence that additional dietary MUFA and SFA are suitable lipid classes for juvenile barramundi and they are both equally efficient at sparing LC‐PUFA from an oxidative fate.  相似文献   

20.
A feeding experiment was conducted to develop non‐fish meal and non‐fish oil diet for red seabream by using plant protein source and Schizochytrium meal which is rich in 22:6n‐3 (DHA). Three iso‐nitrogenous and iso‐lipidic experimental diets were prepared (CP 41.2% ± 0.4%, CL 16.4% ± 1%). Control diet contained both fish meal (40%) and fish oil (6%). In the second diet, fish meal was replaced by plant meals (soy protein concentrate, soybean meal, corn gluten meal) [FO]. In the third diet, fish meal and fish oil were replaced by algae meal (Schizochytrium sp. powder) and plant proteins [AO]. Duplicated groups of juvenile red seabream (8.8 g ± 1.5) were fed the experimental diets for 12 weeks to near satiation. There was no statistical difference among treatment in specific growth rate. Feed conversion ratio of AO diet group was higher than that of control. In wet basis, whole body protein level was significantly higher in AO diet than FO group while lipid content was lower than control group. In fatty acid profile, AO group had significantly lower 18:4n‐3, 20:4n‐3, 22:5n‐3 and 20:5n‐3 (EPA) level, but significantly higher 18:3n‐3 and DHA level than the other two diet fed fish. The results might suggest that further developments in microalgae diet offer a promising lipid source of n‐3 PUFA as essential fatty acid on marine fish. And it showed possibility to develop non‐fish meal and non‐fish oil feed for marine aquaculture fish by using microalgae.  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