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1.
In this study, the effects of dietary tryptophan (a precursor of 5-hydroxytryptamine, 5-HT, serotonin) on the agonistic behavior, growth, and survival of freshwater crayfish were investigated. For this aim, a control diet (D1) and three experimental diets (D2, D3, and D4) were prepared. D1 contained no additional tryptophan (TRP), but D2, D3, and D4 diets were supplemented with TRP at 0.50, 0.75, and 1.00 % in dry diet, respectively. The control contained 0.33 % TRP. Results revealed that higher supplemental dietary TRP levels caused a significant decrease in the aggressive behavior (P < 0.05), but an increase in the calmness of crayfish. In addition, the results showed that 5-HT levels in the hemolymph before the fight (after 15 days of feeding; resting) were significantly different (P < 0.05) between D1 and D4. There was a significant difference (P < 0.05) in the 5-HT level of hemolymph between the crayfish fed control and D4 after 15 days of feeding. However, after the fight, 5-HT concentration was significantly higher (P < 0.05) in TRP-supplemented A. leptodactylus as compared with the control. The findings of this study showed that supplemental dietary TRP caused a significant increase (P < 0.05) in the growth and survival rate of A. leptodactylus. The crayfish fed D4 had the best survival rate at the end of the experiment (91.60 % in August). The findings of this study also showed that difference in survival rate between the crayfish fed control and D2 in June, July, and August was not significant (P > 0.05). In addition to these, supplemental dietary TRP gave rise to significantly higher specific growth rate (SGR) values in June and July (P < 0.05). For example, in June, it was 0.38 for the crayfish fed D4, 0.28 for the crayfish fed D3, 0.18 for the crayfish fed D2, and 0.13 for the crayfish fed control. However, in August, the highest SGR (0.56) was obtained from the crayfish fed control. The results also showed that the SGRs of females were lower than the males in June, July, and August (P < 0.05). In conclusion, this research shows that the aggressive behavior of A. leptodactylus can be suppressed, and rearing efficiency (i.e., increased growth and high survival rate) of this species can be improved by increasing TRP levels to 1.00 % in its diet.  相似文献   

2.
We evaluated the effect of dietary protein and lipid on growth and body composition in juvenile red swamp crayfish (Procambarus clarkii). Nine groups of crayfish were fed nine experimental diets containing three levels of protein (24, 27, and 30 %) and three levels of lipid (4, 7, and 10 %) for 8 weeks. We used a 3 × 3 factorial model with four replicates and 12 crayfish (initial average weight, 2.52 ± 0.04 g) per replicate. We measured weight gain ratio (WG), specific growth rate (SGR), and body composition. WG and SGR were significantly (P < 0.05) affected by dietary lipid but not significantly (P < 0.05) affected by dietary protein. When grouped by lipid levels, the WG of crayfish fed diets containing 7 % lipid was higher than that of crayfish fed diets containing 4 or 10 % lipid. The diet containing 30 % protein and 7 % lipid promoted the most efficient growth (WG: 483.38 %, SGR: 3.14 % day?1). Dietary protein and lipid had no effect on condition factor or the viscous content (VC). Dietary protein, but not lipid, had a significant (P = 0.038) effect on the muscle content (MC). Crayfish fed a diet containing 27 % protein and 4 % lipid had the highest (P < 0.05) MC (16.16 %). Dietary protein levels also had a significant (P = 0.04) effect on the shell content (SC). SC was higher in crayfish fed a 30 % protein diet than in those fed 24 or 27 % protein. Proximate analysis suggested that crayfish fed a diet containing 27 % protein had a significantly higher nutritive composition than fish fed 24 or 30 % protein. Dietary protein also affected both whole body and muscle dry matter (DM) content. Similarly, both dietary protein and lipid affected whole-body crude lipid. Hepatopancreas DM, lipid content, and protein content were affected by dietary lipid. In conclusion, a diet containing 4–7 % lipid and 27 % protein with a protein to digestible energy ratio of 17–21 g protein·MJ?1 appeared optimal.  相似文献   

3.
This review focuses on the present distribution of populations of the crayfish Astacus leptodactylus that are harvested in Turkey. It also examines the history of this harvest and the impact that crayfish plague has had on them. Crayfish plague, caused by the fungus-like organism, Aphanomyces astaci Schikora, 1906, is a severe parasite of freshwater crayfish and has caused a lot of damage to A. leptodactylus populations in Turkey since 1984. Turkey was the largest provider of A. leptodactylus to Western Europe from 1970 (or possibly earlier) until 1986. For example, the peak production was reached in the early 1980s, with over 5,000 tonnes being exported in 1984. On the other hand, as a result of the crayfish plague the harvest of A. leptodactylus was reduced severely in most populations in Turkey after 1985. The harvest was only 320 tonnes in 1991. After the occurrence of crayfish plague in Turkey, in order to increase crayfish production uncontrolled A. leptodactylus stockings have been carried out in many waterbodies throughout Turkey. These introductions have caused an increase in the number of A. leptodactylus populations, but exploitation of A. leptodactylus is still under the pressure of the plague, although there has been a steady increase in crayfish production in recent years. The harvest increased to 2,317 tonnes in 2004. Fortunately, among those populations affected by crayfish plague, large amounts of A. leptodactylus can still be harvested from three lakes, ?znik (Bursa), E?irdir (Isparta) and Çivril (Denizli). Thus, it seems that A. leptodactylus has a degree of resistance to crayfish plague. It is therefore interesting to investigate the resistance of A. leptodactylus caught from these populations to crayfish plague.  相似文献   

4.
Portunus trituberculatus broodstock were stocked in plastic tanks to evaluate the effects of starvation and feeding on gonadal development, blood chemistry, fatty acid composition, and expression of vitellogenin (Vtg) and fatty acid-binding protein genes (FABP) in females. Two treatments (starved and fed) were randomly assigned to triplicate groups of 90 swimming crab broodstock (approximately 230 ± 45 g). In the starved treatment, crabs were starved for 30 days, whereas in the fed treatment crabs were fed once a day with clams. The gonadosomatic index decreased significantly in starved crabs (P < 0.05), as did the serum glucose and cholesterol concentrations; conversely, the total protein concentration in serum significantly increased (P < 0.05). In the ovary, there was a significant relative decline of 18:0, 16:1n-7 and 20:1n-9 fatty acids and relative increases of 20:4n-6, 22:6n-3, 18:1n-9 and 20:5n-3 in starved crabs compared to fed crabs (P < 0.05). Relative expression of Vtg in the ovary decreased significantly in starved crabs (P < 0.05), while there was no significant difference in hepatopancreas Vtg expression between starved and fed crabs (P > 0.05). Starvation suppressed gonadal development in female swimming crab broodstock.  相似文献   

5.
This study investigated the effects of different soya oil products on growth, nutrient digestibility, and fatty acid composition of muscle in rainbow trout. The products’ ingredients were soap stock, fat powder, crude oil, and refined soya oil as a control. Four experimental diets were formulated by addition of 12 % of each of the four ingredients to a basal diet. Replacement of refined soya oil by the soya oil products did not influence growth performance until 8 weeks (P > 0.05). This replacement, however, reduced fat digestibility in rainbow trout (83.7 vs. 73.3–79.8 %; P < 0.05). Dietary inclusions of fat powder and crude oil led to larger values of protein digestibility than those of refined soya oil and soap stock (P < 0.05). The compositions of saturated and monounsaturated fatty acids of the muscle were similar, but linoleic acid concentration (LA, 18: 2n-6) increased in fish muscle fed refined soya oil compared to the other diets (37 vs. 30–31 %; P < 0.05). Arachidonic acid (ArA, 20: 4n-6) concentration was higher (P < 0.05) in fish fed both fat powder and soap stock than those fed the other diets. In conclusion, refined soya oil can be replaced by soya oil products in rainbow trout diet with no negative impacts on the growth. However, fish fed on diet containing refined soya oil had higher concentration of LA and lower density of ArA. It appears that rainbow trout is capable of digesting soya oil products though the digestibility rate reduced slightly with an increase in saturated fatty acid content.  相似文献   

6.
Camelina (Camelina sativa) oil was tested as a replacement for fish oil in diets for farmed Atlantic cod (Gadus morhua). Camelina differs from other plant oilseeds previously used in aquaculture with high lipid (40 %), α-linolenic acid (40 %), antioxidants and low proportions of saturated fats. Dietary treatments were fed to cod (19 g fish?1 initial weight) for 9 weeks and included a fish oil control (FO), 40 % (CO40) and 80 % (CO80) replacement of fish oil with camelina oil. There was no effect of replacing fish oil with camelina oil included at levels up to 80 % on the growth performance. Cod fed CO80 stored more lipid in the liver (p < 0.01), including more neutral lipid (p < 0.05) and triacylglycerol (p < 0.05). Cod fed CO80 decreased in total polyunsaturated fatty acids (PUFAs) in muscle compared to CO40 and FO (p < 0.05), increased in monounsaturated fatty acids (p < 0.01), decreased in total ω3 fatty acids (FO > CO40 > CO80; p < 0.01) and increased in total ω6 fatty acids (FO < CO40 < CO80; p < 0.01). In the liver, long-chain (LC) PUFA such as 20:4ω6, 20:5ω3, 22:5ω3 and 22:6ω3 decreased when fish oil was removed from the diet (p < 0.05), and increased in 18-carbon fatty acids (p < 0.01). Camelina oil can reduce the amount of fish oil needed to meet lipid requirements, although replacing 80 % of fish oil reduced LC PUFAs in both tissues. A comparison of BF3 and H2SO4 as catalysts to transmethylate cod liver and muscle lipids revealed small but significant differences in some fatty acid proportions.  相似文献   

7.
New and viable species for aquaponics and integrated multi‐trophic aquaculture (IMTA) in freshwater systems can improve yields and sustainability of aquaculture. Freshwater crayfish species such as Astacus astacus and Pontastacus leptodactylus are omnivorous feeders and considered candidates for feeding on faecal matters in existing aquaculture systems. Feeding trials were conducted to determine growth response and RNA/DNA ratio in freshwater crayfish fed fish waste. Carapace length and wet weight were measured to determine the growth response. Juvenile A. astacus was fed faeces of hybrid striped bass (Morone chrysops × Morone saxatilis) and rainbow trout (Oncorhynchus mykiss), while adult P. leptodactylus was fed with two commercial pellet diets and pikeperch (Sander lucioperca) faeces. The nutritional composition of hybrid striped bass faeces was close to optimal diet composition of A. astacus, and crayfish showed significantly higher carapace growth, weight gain and weight gain per moult as the group fed rainbow trout faeces. The growth of P. leptodactylus was significantly lower in terms of weight gain and weight gain percentage per moult for crayfish fed on pikeperch faeces. Thus, this study can recommend a co‐cultivation of hybrid striped bass and A. astacus within one system, but cannot recommend co‐cultivation of P. leptodactylus with pikeperch. Additionally, this study showed controversial results of RNA/DNA ratio and weight gain of both crayfish species. Thus, RNA/DNA ratio cannot be approved for investigations on crayfish physiological status in controlled feeding experiments if animals are fed with an inadequate diet.  相似文献   

8.
The influence of dietary lipid level was evaluated on growth, survival, and molting of yearling narrow clawed crayfish, Astacus leptodactylus. Yearling crayfish were fed five isonitrogenous diets (35% protein), formulated to contain 4%, 7%, 10%, 13%, or 16% lipid. Crayfish (10.1 ± 1.6 g) were reared for 56 days in 60-L fiberglass tanks at 23 ± 1.7 °C, with flow-through water and continuous aeration. At the end of the trial, crayfish fed 13% lipid had the highest weight gain and specific growth rate, significantly different from crayfish fed 4% and 7% lipid (p < 0.05). Crayfish fed 13% lipid had a significantly higher survival rate (86.7%) than the animals fed 4% lipid (71%) (p < 0.05). Molting was not affected by lipid level (p > 0.05). We recommend 13% dietary lipid level for optimum growth and survival of Astacus leptodactylus in intensive cultivation.  相似文献   

9.
The objective of this study was to evaluate the effects of the supplementation of vitamin D3 on the growth, vitamin D metabolites, and osteocalcin secretion in juvenile Siberian sturgeon (Acipenser baerii). A 90-day growth trial was conducted with juvenile Siberian sturgeon (initial body weight 3.47 ± 0.14 g) fed seven isonitrogenous and isoenergetic practical diets (45% CP and 13% lipid) containing 60 (basal diet), 240, 450, 880, 1670, 3300, or 1.0 × 105 IU/kg feed (D60~D 1.0 × 105) vitamin D3. The results showed that weight gain and specific growth rate increased as the dietary vitamin D3 levels increased from 450 to 3300 IU/kg (P < 0.05). The fish fed with D1670 and D3300 diets had higher crude lipid and ash levels than the fish fed the D60 diet (P < 0.05). The fish fed D880, D1670, or D3300 diets had higher 25-OH-D3 and 1,25-(OH)2-D3 levels than the fish fed the D60 diet (P < 0.05). The fish fed D880, D1670, D3300, or D1.0 × 105 diets had higher osteocalcin levels than the fish fed the D60 diet (P < 0.05). Based on the broken line method analysis of weight gain and osteocalcin, the dietary vitamin D3 requirement of juvenile Siberian sturgeon was estimated to be 1683.30 and 1403.27 IU/kg per diet, respectively.  相似文献   

10.
To examine the influence of the dietary ratio of (n-3) to (n-6) polyunsaturated fatty acids (PUFAs) on the immune system of Atlantic salmon, Salmo salar L., two dietary trials were carried out in which parr were maintained on diets containing either fish oil [(n-3)/(n-6) PUFA = 5.2] or sunflower oil [(n-3)/(n-6) PUFA = 0.3] and assessed for differences in immunological parameters. There were no significant differences in blood cell counts, differential leucocyte counts or haematocrit values between dietary groups, and while no apparent differences were observed in the non-specific immune parameters measured, there was a significantly higher number of B cells responding to Aeromonas salmonicida, in the kidney and spleen of vaccinated fish maintained on high (n-3)/(n-6) PUFAs diets. There was also a significant difference (P≤ 0.01) between the dietary groups in trial 1 and trial 2 when non-vaccinated fish were challenged with Aeromonas salmonicida and Vibrio anguillarum, respectively, with the (n-6) group succumbing to the bacterium before the (n-3) group. The results suggest that Atlantic salmon fed diets with a low ratio of (n-3)/(n-6) PUFA may be less resistant to infection than those fed diets containing lipid with a high (n-3)/(n-6) PUFA ratio.  相似文献   

11.
研究分析了饲料组成对银鲳(Pampus argenteus)幼鱼特定生长率(SGR)及肌肉氨基酸与脂肪酸组成的影响。实验共设4组不同的饲料组成,依次为饲料A(鱼肉糜)、饲料B(鱼肉糜+配合饲料)、饲料C(鱼肉糜+配合饲料+蛏子肉糜)和饲料D(鱼肉糜+配合饲料+蛏子肉糜+桡足类)。实验用银鲳幼鱼的平均体重为4.80±0.11 g,每组饲料设3重复,实验周期为9周。研究结果显示,不同饲料组成可显著影响银鲳的特定生长率,饲料A组的特定生长率最低,并显著低于其它各饲料组;饲料D组的特定生长率最高,且显著高于饲料B、C组的特定生长率(P<0.05);但饲料B、C组间银鲳特定生长率无显著性差异(P>0.05)。银鲳肌肉氨基酸与脂肪酸的分析结果显示,4组饲料组成对银鲳肌肉氨基酸的组成及含量并无显著性影响(P>0.05),但可显著影响肌肉脂肪酸的组成及含量(P<0.05)。饲料D组的多不饱和脂肪酸(PUFA)、高度不饱和脂肪酸(HUFA)及n-3HUFA含量均分别显著高于饲料A、B和C组(P<0.05),饲料B和C组的PUFA、HUFA及n-3HUFA均分别显著高于饲料A组(P<0.05),但饲料B、C组间并无显著性差异(P>0.05)。综合分析得出,丰富的饲料组成以及饲料中较高的HUFA含量均有利于银鲳幼鱼的生长。  相似文献   

12.
The effects of dietary calcium chloride (CaCl2) concentration on the growth, survival, moulting and body composition of Astacus leptodactylus were studied. Diets were prepared using supplementation of 0 (control), 30, 60 and 120 g kg?1 calcium chloride commercial trout larvae diet containing 50% protein and 12% lipid. Astacus leptodactylus larvae with an average total length of 22.0 ± 0.05 mm (TL) and weight of 0.53 ± 0.01 g obtained from eighteen ovigerous females collected from Seydisehir Sugla Dam lake in Konya, Turkey, were stocked in 0.2‐m2 aquariums at a rate of 50 crayfish m?2 and reared for 90 days. The experiments included four treatments (diets) with three replicates each. Calcium chloride exerted positive effects on growth, moulting frequency, feed efficiency and survival of narrow‐clawed crayfish. Crayfish fed with 60 g calcium kg?1 calcium chloride‐supplemented diet exhibited the highest weight gain and specific growth rate (SGR) but the lowest survival rate (63.3%) (P < 0.05). There were no significant differences (P > 0.05) in mean moisture (803.5 g kg?1) and protein content (177.0 g kg?1) in crayfish tail meat. However, lipid values were between 3.8 and 11.6 g kg?1 and significantly different among the diets (P < 0.05). Diet with 60 g kg?1 calcium chloride is recommended for the best growth of freshwater crayfish.  相似文献   

13.
This paper reports on inclusion of Spirulina platensis (SP) in rainbow trout (Oncorhynchus mykiss) fish diet and its effect on the fish tissue fatty acids (FAs) composition. Fish in triplicate groups with average initial body weight of 75 ± 0.23 g and age of about 7 months were fed a control diet with no supplements and with three experimental diets supplemented with 2.5, 5 and 7.5 weight percent (wt%) of SP for 12 weeks. At the end of experiment, the fillet FA compositions were evaluated. It was found that the composition of FAs in fish fillet was significantly (P < 0.05) affected by inclusion of SP in diets. As compared to the control sample, feeding the fish supplemented particularly with low levels of SP improved the quality of FAs by decreasing undesirable saturated FAs (SFAs) content from 20.03 to 17.93 % and increasing the level of some beneficial long-chain highly unsaturated FAs namely eicosapentaenoic acid (C20:5 n-3) from 6.47 to 7.27 %, docosapentaenoic acid (C22:5 n-3) from 1.42 to 1.56 % and docosahexaenoic acid (C22:6 n-3) from 1.26 to 1.35 %. Further increase in the SP inclusion level generally did not lead to desirable results. The SP inclusion in the fish diet had no significant impact on overall contents of n-3 and n-6 polyunsaturated FAs in fish fillet. However, the total highly unsaturated FAs (HUFAs) and n-3 HUFAs levels, UFAs/SFAs ratio and n-3/n-6 index were increased from 11.25, 10.65, 3.98 and 0.57 to 12.13, 11.56, 4.40 and 0.62 %, respectively, as a result of 5 wt% SP loading. In general, it can be concluded that SP inclusion up to 5 wt% of loading in rainbow trout culture can be beneficial in terms of FAs compositions of the fish fillet.  相似文献   

14.
A feeding trial was conducted to investigate the effects of the dietary incorporation of autoclaved and raw (non-autoclaved) Ulva meal on juvenile rainbow trout (Oncorhynchus mykiss) growth, nutrient utilization, body composition, diet digestibility and fatty acid composition. An algae-free control diet and four experimental diets with either 5 or 10 % inclusion levels of raw Ulva meal (5 % = RU5; 10 % = RU10) or autoclaved Ulva meal (5 % = AU5; 10 % = AU10) were formulated. Fish were fed three times daily to apparent satiation for 12 weeks. The growth of fish fed RU10 (final weight = 76.7 ± 3.31 g; SGR = 2.8 ± 0.05 %) diet was significantly higher than that in fish fed the AU10 diet (67.5 ± 1.61 g; SGR = 2.6 ± 0.03 %). The feed conversion ratio (FCR) was significantly better in fish fed the RU10 diet (0.9 ± 0.06) compared with control diet (1.0 ± 0.06). Condition factor, viscerosomatic index and dress-out remained unaffected by dietary treatment. The hepatosomatic index (HSI) was significantly lower (P < 0.05) in fish fed the AU10 diet (1.2 ± 0.19) than fish fed the other diets (≥1.6). The level of eicosapentaenoic acid (20:5n-3—EPA) in muscle from fish fed the RU10, AU5 and AU10 diets was significantly higher than in fish fed control diet (P < 0.05). Dietary inclusion of Ulva meals resulted in a significant increase in muscle docosapentaenoic acid (22:5n-3—DPA) levels at the end of the feeding period. The results indicate that the dietary inclusion of raw Ulva meal at levels of up to 10 % can be used without significant negative effects on the growth performance, nutrient utilization, dietary digestibility and muscle fatty acid composition. In fact, the inclusion of dietary raw and autoclaved Ulva meal elevated n-3 fatty acids levels of rainbow trout muscle.  相似文献   

15.
The effects of salinity on survival, growth, special activity of digestive enzymes, nonspecific immune response, and muscle fatty acid composition were evaluated in the American shad (Alosa sapidissima). Juveniles of 35 days after hatching were reared at 0 (control), 7, 14, 21, and 28 ppt for 60 days. At the end of the experiment, juvenile American shad presented higher survival and specific growth rate (SGR) in salinity group (7, 14, and 21 ppt) than control group (P < 0.05). The special activity of trypsin and chymotrypsin was highest in fish reared at 21 ppt, while the highest lipase special activity was obtained in control group (P < 0.05). The special activity of alkaline phosphatase (ALP), lysozyme (LZM), superoxide dismutase (SOD), and catalase (CAT) showed significant increases in salinity group (14 and 21 ppt) compared to control group (P < 0.05). Lower muscle ash contents were detected in salinity group (14, 21, and 28 ppt) than control group (P < 0.05), while the contents of crude lipid and crude protein were significantly higher than control group (P < 0.05). The level of monounsaturated fatty acids (MUFA) exhibited a decreasing trend, while an increased level of polyunsaturated fatty acids (PUFA) was detected with the increase of salinity. Among the PUFA, the content of n-3 fatty acids in muscle tissue was found to be increasing with the increasing salinity, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Results indicate that appropriate increase in salinity was reasonable and beneficial for juvenile American shad culture after a comprehensive consideration, especially salinity range from 14 to 21 ppt.  相似文献   

16.
The aim of this study is to evaluate the effects of total replacement of fish oil (FO) with pork lard (PL), soybean oil (SO), or tea seed oil (TO) on growth and fatty acid compositions of hybrid tilapia (Oreochromis niloticus × O. aureus). Four diets were formulated to contain 4.5 % of each of the different lipid sources. Each diet was assigned to triplicate groups of 15 hybrid tilapia with the same initial body weight (4.6 ± 0.5 g). After a 10-week feeding, the FO, SO, and TO groups had similar final body weight. The mean hepatosomatic index in the FO group was significantly lower than the other groups (2.5 vs 2.9–3.0; P < 0.05). Whole-body lipid levels were highest in the TO group (5.2 ± 0.4 %) and lowest in the FO group (4.3 ± 0.5 %). Total n-3 polyunsaturated fatty acids (PUFA) concentrations were greater in the SO and FO groups (5.5 ± 0.1 and 7.1 ± 0.2, respectively) than in the PL and TO groups (1.7 ± 0.1 and 1.4 ± 0.1, respectively). The FO group had a 2- to 4-fold reduction in the n-6/n-3 PUFA ratio relative to the other groups. The concentrations of both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were significantly (P < 0.05) higher in the FO group than in the other groups. Our data demonstrate that total replacement of dietary FO with SO or TO has little effects on growth of hybrid tilapia but reduces the contents of health-benefiting DHA and EPA in fish body.  相似文献   

17.
N-3 highly unsaturated fatty acids (n-3 HUFA) have been shown to inhibit body fat accumulation in animals. To clarify the mechanism of this fat-lowering effect of n-3 HUFA in grass carp (Ctenopharyngodon idellus), two experiments were conducted. In experiment 1, isolated grass carp mature adipocytes were incubated with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) at different concentrations for 6 h. The release of glycerol to the medium was detected, and the expression of the lipolysis-related genes was analyzed. In experiment 2, a 95-day feeding trial was conducted with two diets formulated with either lard oil (as control) or fish oil (supplying n-3 HUFA as treatment) as the main lipid source. The glycerol and free fatty acid (FFA) released from the isolated adipocytes of both groups were detected after the feeding period. The expression of select lipolysis-related genes in adipose tissue was also analyzed. The results from experiment 1 showed that the release of glycerol was significantly increased by DHA and EPA (P < 0.05). Moreover, the expression of lipolysis-related genes, such as adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), tumor necrosis factor α (TNFα) and leptin, was also significantly elevated in the treatment group (P < 0.05). Experiment 2 demonstrated that glycerol and FFA release from the isolated adipocytes were significantly higher in the treatment group compared to the control group (P < 0.05). The expression level of ATGL, HSL, TNFα and leptin in the treatment group was significantly higher than in the control group (P < 0.05). The present results provide novel evidence that n-3 HUFAs could regulate grass carp adipocyte lipolysis in vitro or in vivo, and the effect might be in part associated with their influence on the expression of lipolysis-related genes and lipolysis-related adipokines genes.  相似文献   

18.
为探讨饲料中不同n-3/n-6长链多不饱和脂肪酸(LC-PUFA)对大菱鲆(Scophthalmus maximus)幼鱼生长性能及饲料利用、体组成和消化酶的影响,配制了6种不同n-3/n-6 LC-PUFA比值(29.54,D1组;23.04,D2组;18.97,D3组;9.06,D4组;6.86,D5组;3.87,D6组)的实验饲料。以大菱鲆幼鱼[(12.18?0.01)g]为研究对象,在循环水养殖系统中开展了为期56 d的养殖实验。结果显示,n-3/n-6 LC-PUFA对大菱鲆幼鱼的成活率(SR)无显著影响(P0.05);增重率(WGR)随着n-3/n-6 LC-PUFA的降低呈先上升后下降趋势,D6组显著低于其他各组(P0.05);脂肪沉积率随着饲料中n-3/n-6 LC-PUFA的降低呈下降趋势,且D6组达到最小值,为14.80,显著低于其他各组(P0.05)。随着饲料中的变化,胰蛋白酶的活性呈先增强后减弱的趋势,且在D4组时达到最大值;脂肪酶活性呈上升趋势。随着饲料中n-3/n-6 LC-PUFA的变化,脂肪酸合成酶活性呈先上升后下降的趋势,最高值为D4组,显著高于其他各组(P0.05);葡萄糖-6-磷酸脱氢酶的酶活呈先上升后下降的趋势,D3组为最大值,显著高于其他各组(P0.05)。随着饲料中n-3/n-6 LC-PUFA的降低,谷草转氨酶呈先上升后下降的趋势;总蛋白、白蛋白和高密度脂蛋白胆固醇均随着饲料n-3/n-6LC-PUFA的变化呈先上升后下降的趋势,均在D5组时达到最大值。研究表明,饲料中n-3/n-6LC-PUFA的比例降低会导致大菱鲆幼鱼的脂肪沉积率降低。  相似文献   

19.
The effects of dietary mannan oligosaccharides (MOS) on the survival and growth of Astacus leptodactylus juveniles were evaluated. Experimental diets were prepared by using supplementation of 0 (Control), 1.5, 3.0, and 4.5 g MOS kg−1 commercial trout larvae diet containing 43 g kg−1 protein and 15.74 g kg−1 lipid. A. leptodactylus juvenile with an average total length of 3.6 ± 0.46 cm (TL) and average weight of 1.25 ± 0.43 g was stocked in 0.2-m2 aquariums at a rate of 50 crayfish/m2 and reared for 60 days at 22.8°C. The experiment consisted of four treatments with three replicates each. Each aquarium contained ten crayfish. Crayfish juvenile fed with 0, 1.5, 3.0, and 4.5 MOS attained 6.15 ± 0.49, 5.94 ± 0.29, 7.34 ± 0.39, and 5.94 ± 0.27 cm final total length and 50, 56.67, 46.67, and 50% survival rates, respectively. Moreover, molting frequencies in 0, 1.5, 3.0, and 4.5 g kg−1 MOS groups were detected as 44.44, 61.11, 83.33, and 38.88%, respectively. At the end of the experiment, a general enhanced growth performance (P < 0.05) and feed conversion ratio were observed in crayfish fed on the diet containing 3.0 g kg−1. Crayfish juveniles fed with 3.0 g kg−1 MOS had the highest final length (7.34 ± 0.39 cm), although their survival was the lowest (46.67%) compared to other treatments but not significant. Specific growth rates were significantly different (P < 0.05) among the treatment groups at the end of the 60-day experiment. There were no significant differences (P > 0.05) in percentage moisture, protein, and ash (wet-weight basis) in the tail meat of A. leptodactylus juvenile among treatments (diet) that averaged 82.3, 16.1, and 1.2%, respectively. However, lipid value was significantly different among the diets P < 0.05), with values between 0.13 and 0.32. From the current results, it could be advised to use MOS at the rate of 3.0 g kg−1 in A. leptodactylus juvenile diets.  相似文献   

20.
The objective of this study was to determine the effects of fish oil replacement with dietary vegetable oils on growth performance, chemical composition and fatty acids profiles in fillets of farmed Caspian great sturgeon juveniles Huso huso (26.97 ± 0.49 g). Five isonitrogenous and isolipidic diets were formulated, containing 10 % of added oil. The diet with 100 % kilka fish oil (Caspian tyulka, Clupeonella caspia) was the control. Fish oil was substituted by 50 % of vegetable oils consisting of an equal share of sunflower and soybean oils (diet A), sunflower and canola oils (diet B) and soybean and canola oils (diet C). In diet D, 100 % of fish oil was replaced with vegetable oil (1:1:1 ratio of sunflower oil, soybean oil and canola oil). Significant differences (P > 0.05) were not detected during 60 days feeding trial in final body weight, weight gain, condition factor, specific growth rate, feed conversion rate, protein efficiency ratio and the chemical composition of fillet (crude protein, crude lipid, moisture and ash). Generally, the fatty acids composition of fish fillets was reflective of the dietary lipid sources. These results indicate the feasibility of substituting fish oils with the mixture of vegetable oils in diets of juvenile H. huso without negative influence on growth providing optimum ratios of n-3/n-6 and n-3/18:1n-9 is met in the diet.  相似文献   

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