共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Mohebbi A. Nematollahi A. Gholamhoseini A. Tahmasebi‐Kohyani S. Keyvanshokooh 《Aquaculture Nutrition》2013,19(4):506-514
An 8‐week feeding experiment was conducted to evaluate the effects of dietary nucleotides (0, 0.5, 1, 1.5 and 2 g kg?1) on serum antioxidative biomarkers and lipid contents of rainbow trout fingerlings. The serum triglycerides and low‐density lipoprotein (LDL)‐C levels were significantly decreased in fish fed diets containing 1.5 and 2 g kg?1, whereas serum high‐density lipoprotein (HDL)‐C was higher in trout receiving diets with those levels of nucleotides. A significant decrease in thiobarbituric acid reactive substances concentration was observed in groups receiving 1.5 or 2 g kg?1 of dietary nucleotides in comparison with control group (?32% and ?27%, respectively). A significant decrease was observed in catalase and serum glutathione peroxidase activity in trout fed 1.5 and 2 g kg?1 dietary nucleotides compare with other groups. There were no significant changes in serum superoxide dismutase activity among the experimental groups. In conclusion, these results suggest that dietary nucleotides may reduce lipid peroxidation by increasing the levels of antioxidant lipoprotein, HDL‐C, and decreasing the LDL‐C, the main substrate of lipid peroxidation. 相似文献
2.
The effect of chromium (chromium picolinate, CrPic) supplementation at various levels (0, 400, 800 or 1600 μg Cr/kg diet) on serum concentrations of glucose and cholesterol and on serum and liver concentrations of Cr, Zn, Cu and Fe of rainbow trout (Oncorhynchus mykiss) was evaluated. One-year-old rainbow trout (n=120) were randomly assigned to four treatment groups, each with two replicates of 15 fish. The fish were fed either a control diet or the control diet supplemented with either 400, 800 or 1600 μg Cr/kg diet. Serum glucose and cholesterol concentrations decreased (p=0.001) with higher dietary chromium supplementation. Increasing dietary chromium supplementation linearly increased serum chromium and zinc concentrations (p=0.001). Serum copper and iron concentrations did not change (p>0.10) as dietary chromium supplementation increased. Liver chromium and zinc concentrations linearly increased (p=0.001). Also, liver Cu and Fe concentrations did not change (p>0.10) as dietary chromium supplementation increased. The results of present study conclude that supplemental chromium to the diet of rainbow trout influences serum and liver Cr and Zn concentrations, thus most probably functions of the organs as well as the welfare of raibow trout. 相似文献
3.
Effects of Haematococcus pluvialis supplementation on antioxidant system and metabolism in rainbow trout (Oncorhynchus mykiss) 总被引:1,自引:0,他引:1
Sheikhzadeh N Tayefi-Nasrabadi H Oushani AK Enferadi MH 《Fish physiology and biochemistry》2012,38(2):413-419
Effects of commercial source for astaxanthin (Haematococcus pluvialis) (H.p) on antioxidant power, specific marker enzymes, and some metabolites were examined in rainbow trout (Oncorhynchus mykiss). Fish were fed on diets containing 1, 3, and 10 g microalga kg−1 feed for 30 days. Serum total antioxidant activity and lipid peroxidation product, indicated by malondialdehyde (MDA), significantly
enhanced with different doses of administration, indicating the elevated antioxidant status in all treatment groups. In group
fed with high dose of alga, significantly elevated aspartate aminotransferase activity (AST) was noted, indicating damage
of normal liver function in this group. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were not affected in
all groups. Although serum total protein remained unaffected, serum glucose level was decreased significantly in lower doses
of administration. Furthermore, triglyceride and cholesterol levels showed significant decrease in 3 g kg−1 microalga group by modulation of lipid metabolism in this group. On the other hand, in highest dose, significant increase
in lipids was observed, indicating the slight dysfunction in lipid metabolism in this treatment group. The present study suggests
that Haematococcus pluvialis especially in dose of 3 g kg−1 feed administration may effectively enhance the antioxidant system and some biochemical parameters in rainbow trout. 相似文献
4.
Jun‐Ming Deng Xin‐Dang Zhang Jian‐Wei Zhang Bao‐Liang Bi Heng‐Zhi Wang Lu Zhang Hai‐Feng Mi 《Aquaculture Nutrition》2019,25(6):1345-1353
An 80‐day feeding trial was conducted to evaluate the effects of dietary ascorbic acid (AA) supplementation at different levels (0, 0.2 and 0.4 g/kg l ‐ascorbate‐2‐polyphosphate; 7.6, 77.2 and 146.7 mg/kg AA, respectively) on cholesterol metabolism in rainbow trout (Oncorhynchus mykiss). Dietary AA supplementation regardless of inclusion level increased the serum total cholesterol and low‐density lipoprotein (LDL) cholesterol levels and LDL cholesterol/high‐density lipoprotein cholesterol ratio. No significant differences were observed in the serum triiodothyronine and thyroxine levels, faecal cholesterol content, hepatic activity and mRNA expression of acyl‐coenzyme A:cholesterol acyltransferase among the dietary treatments. Dietary AA inclusion increased the faecal bile acid content, hepatic activity and mRNA expression of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase and hepatic cholesterol 7α‐hydroxylase mRNA expression, but decreased the hepatic LDL receptor content. High level of AA supplementation (0.4 g/kg) depressed the serum cortisol levels. These results suggest that dietary supplementation with 0.2?0.4 g/kg l ‐ascorbate‐2‐polyphosphate may increase the serum total cholesterol level in rainbow trout. The cholesterol‐raising effect of AA may be due to the increased hepatic cholesterol production and the depressed cholesterol clearance from serum. In addition, dietary AA inclusion also facilitates the hepatic conversion of cholesterol to bile acids. 相似文献
5.
The aim of this study was to clarify further the relationship between dietary keto-carotenoids (canthaxanthin and astaxanthin) and reproductive performance in female rainbow trout. Three experiments were undertaken in three successive breeding seasons. In addition to a control diet, fish were fed a canthaxanthin-supplemented diet (200 mg canthaxanthin kg−1 feed, designated as 6mC200) for 6 months prior to spawning (experiment A); the same diet as in A but for either 3 months (3mC200) or 6 months (6mC200) before spawning (experiment B); diets with one of two levels of astaxanthin supplementation, 50 mg (6mA50) or 100 mg (6mA100) kg−1 feed, or a diet with 100 mg canthaxanthin kg−1 feed (6mC100) fed for 6 months (experiment C).
There was no significant influence of carotenoid supplementation on either the frequency of maturing females or the date of maturation. The number of ova per kg of female body weight averaged 2700 and did not vary significantly among fish fed the different diets. Across experiments A, B and C there was no significant difference in egg and larval survival among fish fed carotenoid-supplemented and control diets. In experiment A, 6mC200 females produced smaller eggs than controls but this result was not confirmed in experiments B and C. In general, eyed egg yield appeared partly dependent upon egg size. Alevin weight was also correlated with egg weight. The growth test conducted on fingerlings from experiment B failed to provide any evidence of an effect of feeding carotenoid supplemented diets to the female parent. Pigment analyses conducted on alevins revealed that canthaxanthin fed to the female parent was transferred into the eggs and therefore to the larvae, although canthaxanthin was metabolized within a few weeks after hatching. 相似文献
There was no significant influence of carotenoid supplementation on either the frequency of maturing females or the date of maturation. The number of ova per kg of female body weight averaged 2700 and did not vary significantly among fish fed the different diets. Across experiments A, B and C there was no significant difference in egg and larval survival among fish fed carotenoid-supplemented and control diets. In experiment A, 6mC200 females produced smaller eggs than controls but this result was not confirmed in experiments B and C. In general, eyed egg yield appeared partly dependent upon egg size. Alevin weight was also correlated with egg weight. The growth test conducted on fingerlings from experiment B failed to provide any evidence of an effect of feeding carotenoid supplemented diets to the female parent. Pigment analyses conducted on alevins revealed that canthaxanthin fed to the female parent was transferred into the eggs and therefore to the larvae, although canthaxanthin was metabolized within a few weeks after hatching. 相似文献
6.
This study compared the effects of dietary l ‐carnitine and ploidy on growth performances and fatty acid content in rainbow trout (Oncorhynchus mykiss). Fish [initial body weight (BW) = 30 g] reared under high density (50 kg biomass m?3) were hand‐fed in triplicate (3 tanks treatment?1, 34 fish tank?1) twice a day, with three nutritionally identical diets containing 15, 200 or 530 mg l ‐carnitine kg?1 of diet. No significant growth differences were observed over a 56‐day grow‐out period, during which BWs increased threefold. Growth performances and survival were not significantly affected by either ploidy or dietary l ‐carnitine content, although daily growth index showed an increasing trend (2.52–2.65% day?1) with increasing dietary l ‐carnitine. Body l ‐carnitine content increased significantly with dietary l ‐carnitine content. Diploid fish had higher plasma ammonia (716–725 μmol L?1) and osmolality (297–303 mOsm) levels than triploid trout (523–649 μmol L?1 and 285–291 mOsm, respectively). l ‐carnitine, ploidy and their interaction showed to affect significantly the concentration of several fatty acids. Palmitoleic (16:1), oleic (18:1) and erucic (22:1) acids showed lower concentrations, while the eicosadienoic (20:2n‐6) and arachidonic (20:4n‐6) acids were elevated in liver of triploid fish. Eicosapentaenoic acid (22:5n‐3) was significantly higher in fish fed 200 mg than in fish fed 15 mg l ‐carnitine. 相似文献
7.
Edgar C Amar Viswanath Kiron Shuichi Satoh Nobuaki Okamoto and Takeshi Watanabe 《Fisheries Science》2000,66(6):1068-1075
SUMMARY: We attempt to assess the impact of different levels of dietary β-carotene on immune function in rainbow trout. Semi-purified diets containing 0, 40, 200, and 400 mg β-carotene/kg dry diet were fed for 12 weeks to fish with average weight of 45 g. In addition to the humoral and cellular immune parameters, growth and feed utilization were examined. There were no marked differences in growth and feed utilization showing that β-carotene was not particularly efficient in enhancing growth of rainbow trout. Of the immune parameters measured, total immunoglobulin was significantly highest for the 200 mg β-carotene fed group. Serum complement activity (alternate pathway) at 200 and 400 mg β-carotene supplementation was significantly higher than that of the unsupplemented group. An increasing trend in lysozyme activity was observed, however, the differences among the groups were not significant. Phagocytic activity was similar among diet groups except at the highest level of supplementation where it was the maximum. Oxygen radical production by peripheral blood leukocytes appeared to be lower at higher levels of carotenoid supplementation. Overall, dietary β-carotene clearly enhanced immune response parameters in rainbow trout such as serum complement activity and total plasma immunoglobulin but did not show a definite influence for the other factors examined in the present study. 相似文献
8.
9.
F.Z. KÜÇÜKBAY H. YAZLAK N. SAHIN F. AKDEMIR C. ORHAN V. JUTURU & K. SAHIN 《Aquaculture Nutrition》2008,14(3):257-262
Arginine silicate inositol complex (ASI; arginine 49.47 g kg?1, silicon 8.2 g kg?1, inositol 25 g kg?1), a novel composition that is a bioavailable source of silicon and arginine, has potential benefits for vascular and bone health. We have previously reported that bone mineral content increased and the amount of Ca, P, Mg and Mn in the excreta decreased in poultry with ASI supplementation. In the present study, the effect of ASI supplementation at various levels (0, 500, 1000 mg kg–1 ASI) on growth, feed intake, feed conversion ratio (FCR) and concentrations of body elements, operculum bone ash and activity of serum alkaline phosphatase (ALP) in rainbow trout was evaluated. Ninety 0+ year‐old rainbow trout with initial average weight of 50 ± 3 g were randomly assigned to three treatment groups, three replicates of 10 fish each. The fish were fed either a basal diet or the basal diet supplemented with either 500 or 1000 mg of ASI. Body weight gain (P = 0.25), feed intake (P = 0.36) and feed efficiency (P = 0.42) were not signifcantly influenced by the dietary ASI supplementation. Per cent operculum bone ash (634 g kg?1 versus 558 g kg?1, P = 0.001) and ALP activity (112 UL–1 versus 92 UL–1, P = 0.001) linearly increased as dietary ASI supplementation increased. Increasing dietary ASI supplementation linearly increased serum and whole body Ca (P = 0.01), P (P = 0.01), Mg (P = 0.05; P = 0.001) Mn (P = 0.05; P = 0.01) and Zn (P = 0.01; P = 0.02) concentrations respectively. In conclusion, ASI supplementation to the basal diet significantly improved operculum bone ash and whole body mineral content in rainbow trout and did not impact feed consumption, weight gain or FCR. 相似文献
10.
Effects of dietary Camelina sativa products on digestible nutrient compositions for rainbow trout (Oncorhynchus mykiss)
下载免费PDF全文
![点击此处可从《Aquaculture Nutrition》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J.M. Fraser S.A. Collins Z. Chen S.M. Tibbetts S.P. Lall D.M. Anderson 《Aquaculture Nutrition》2017,23(5):973-982
Two trials were conducted to determine the effect of dietary inclusion of camelina (Camelina sativa) products on their digestible nutrient compositions in rainbow trout. In the first experiment, the following camelina products: full‐fat seed, oil, high‐oil residue meal (HORM), pre‐press solvent‐extracted meal (SECM) and toasted SECM were evaluated. In the second trial, the utilization of SECM, SECM soaked in water (WS), SECM treated with a multicarbohydrase, Superzyme?‐OM, SECM treated with Bio‐Phytase and SECM treated with Superzyme?‐OM and Bio‐Phytase (MIX) was determined. The experimental diets consisted of a basal diet and test ingredient with a ratio of 70:30, except for camelina oil where the ratio was 80:20. In Experiment 1, SECM had the highest level of digestible crude protein (352 g kg?1), whereas the oil was the best source of digestible energy (8,063 kcal kg?1) and digestible crude fat (908 g kg?1). In Experiment 2, there were no significant differences in nutrient digestibility of SECM and HORM; however, WS and MIX had significantly more digestible dry matter and digestible crude fat than SECM and HORM. Camelina by‐products have the potential to replace fishery by‐products in rainbow trout feeds. 相似文献
11.
Effects of dietary astaxanthins on pigmentation of flesh and tissue antioxidation of rainbow trout (Oncorhynchus mykiss) 总被引:1,自引:0,他引:1
Juanjuan Zhang Xiaoqin Li Xiangjun Leng Chenglong Zhang Zhiying Han Feige Zhang 《Aquaculture International》2013,21(3):579-589
The present study was conducted to evaluate the effects of three commercial astaxanthin preparations (100 mg kg?1 diet) with different solubilities in water, from DSM (Dutch State Mines), BASF (Badische Anilin and Soda Fabrik) and Wisdom Company on pigmentation of flesh and antioxidation of flesh, serum and liver in rainbow trout with an initial weight of 52.07 g. After 60 days of feeding, there were no significant differences in growth or flesh proximate composition of rainbow trout among groups (P > 0.05); the Salmo Fan score, redness and astaxanthin content of flesh in rainbow trout fed diets supplemented with astaxanthins were higher than those of the control group (P < 0.05). At 0, 12, 24, 48 and 72 h after thawing, the flesh malondialdehyde (MDA) content of the three astaxanthin groups was lower than that of the control group (P < 0.05). The total antioxidation capacity (T-AOC) of liver in the three astaxanthin groups was significantly higher, but serum catalase (CAT) activities were lower, than that of the control group (P < 0.05). The results indicate that addition of 100 mg kg?1 astaxanthin from DSM, BASF or Wisdom to the diet could improve flesh redness and liver T-AOC, reduce serum CAT, SOD and flesh MDA and extend the shelf life of flesh, in spite of the different solubilities of the three sources in water. 相似文献
12.
Effects of low‐level dietary microalgae supplementation on the distal intestinal microbiome of farmed rainbow trout Oncorhynchus mykiss (Walbaum)
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Philip P Lyons James F Turnbull Karl A Dawson Margaret Crumlish 《Aquaculture Research》2017,48(5):2438-2452
In this study, high throughput 16S rRNA sequencing was used to investigate the effect of a novel whole‐cell dietary microalgae meal (Schizochytrium limacinum), on the distal intestinal microbiome of farmed rainbow trout, Oncorhynchus mykiss. Heterotrophic microalgae are rich in omega 3 polyunsaturated fatty acids, can be produced sustainably and have been shown to have beneficial effects on host health. After a 15‐week trial period, microbial community profiles were compared between the distal intestinal contents of fish fed either a control diet or a treatment diet that partially replaced fish oil with microalgae meal, at a substitution level of 5%. The results of this research showed that the microbial communities of both fish populations were composed of similar microbial taxa, however, the treatment group fed the microalgae supplement possessed a greater level of microbial diversity than those in the control group. A limited number of bacterial taxa were discriminatory between diets and were significantly elevated in the treatment group, notably operational taxonomic units (OTUs) assigned to the genera Streptococcus, Leuconostoc, Lactobacillus, Lactococcus and Weissella. However, the overall structure of the intestinal microbiome between control and treatment groups was not found to be significantly different. The treatment group displayed a heavier mean weight and condition factor at the end of the trial period. The results of this study suggest that the tested microalgae meal can be used as a replacement for a proportion of fish oil in aquafeeds, with minor changes to the intestinal microbiome of farmed rainbow trout, and positive effects on growth. 相似文献
13.
Mohammad Asgari Abdolmohammad Abedian Kenari Mohammad Esmaeili Artur Rombenso 《Aquaculture Nutrition》2020,26(5):1505-1519
The effects of dietary hydroalcoholic extract of honeybee pollen (HBPE) on growth performance, flesh quality, immunity and stress response were investigated. Two hundred fifty‐five rainbow trout (11.14 ± 1.06 g) were fed five diets containing increasing levels of HBPE: control, 0.25HBPE (0.25 g HBPE/kg), 0.5HBPE (0.5 g HBPE/kg), 1HBPE (1 g HBPE/kg) and 1.5HBPE (1.5 g HBPE/kg). After 56 days, rainbow trout fed the 0.5HBPE and 1HBPE diets displayed significantly higher weight gain (49.58 and 53.25 g) and protein efficiency (2.88 and 2.83) compared to those fed the control diet (4.89 and 2.05), respectively (p < .05). For flesh quality, higher protein content in the whole body of fish fed the 1HBPE (633.3 g/kg) and 1.5HBPE (640.9 g/kg) diets was observed when compared to other groups (p < .05). There were no significant differences in the saturated and monounsaturated fatty acid content. Individuals fed the 1HBPE (234.5 g/kg) and 1.5HBPE (234.7 g/kg) diets exhibited higher levels of n‐3 long‐chain polyunsaturated fatty acids in the muscle than the other groups (p < .05). In terms of the immune system, the serum lysozyme and alternative complement pathway haemolytic activity levels in the 0.5HBPE (47.66 and 148.00 U/ml) and 1HBPE (46.00 and 146.33 U/ml) treatments were higher than the other treatments (p < .05). When Aeromonas hydrophila was exposed to different dosages of HBPE, a higher inhibitory zone resulted from 1,000 and 1,500 mg/ml dosage. The lower levels of plasma cortisol were observed in the 1HBPE and 1.5HBPE groups after the complement stress test. Collectively, the present findings suggest that the 1HBPE diet supported superior growth, flesh quality, immunity and stress response of rainbow trout. 相似文献
14.
15.
Edwardsiella tarda was isolated from naturally infected rainbow trout (Oncorhynchus mykiss) in raceway culture on a commercial fish farm where the fish were kept at a density of 110 kg m?3 and at a water temperature of 14°C and with a photoperiod of 13 h light:11 h dark. The clinical signs of diseased fish (150 ± 20 mm standard length) were anorexia and lethargy. The most striking lesions in the fish were in the liver. There were hyperaemia and haemorrhages; on histopathological examination, the liver displayed inflammatory infiltrate in portal area, focal necrosis, dilatation of blood sinus and activation of sinusoidal cells. Infection experiments, performed 2 years after isolation of the original culture of E. tarda, were carried out under laboratory conditions at water temperatures of 15, 18 or 24°C. All experimental fish (common carp, Prussian carp, tench), intraperitoneally injected with 8 × 106 cells, demonstrated a total resistance to E. tarda. 相似文献
16.
During the reproductive season, rainbow trout spermatozoa are stored in the sperm ducts for several months. There is no sperm production at this time since spermatogenesis is completed before spawning. To leam more about characteristics of semen during such a long storage, we analyzed changes in protein concentrations, anti-proteinase activity in seminal plasma and sperm aspartate aminotransferase activity during an extended reproductive period during which fish were fed diets supplemented with various ascorbic acid concentrations. Seminal plasma protein concentration and anti-proteinase activity declined toward the end of the reproductive season. These phenomena may be related to oncoming proteolytic events leading to degradation of the sperm. Protein concentrations and anti-proteinase activities were strongly correlated within groups of different ascorbic acid supplementations and several sampling dates (r=0.6–0.9 in most cases, p<0.05). Ascorbic acid deficiency resulted in a decrease in both parameter levels as compared to levels in groups with vitamin C supplement (p<0.08). Deficiency also resulted in lower stimulation of aspartate aminotransferase by an exogenous pyridoxal 5-phosphate in comparison to fish fed vitamin C-supplemented diets (p<0.05). These results support earlier studies suggesting a protective role of ascorbic acid toward maintaining sperm quality. 相似文献
17.
This study was conducted to evaluate the effect of dietary lysozyme supplementation on growth performance and plasma biochemical parameters of rainbow trout (Oncorhynchus mykiss). Graded levels of lysozyme [0 (control), 150, 300, 450 and 600 mg kg?1 diet] were fed to fish (initial average weight 7.76 g) for 10 weeks. Dietary lysozyme supplementation regardless of inclusion level generally improved the growth, feed utilization and nutrient retention, but significant differences were mainly observed between the 450 or 600 mg kg?1 lysozyme group and the control group. Lysozyme supplementation generally decreased the plasma aspartate aminotransferase and alanine aminotransferase (ALT) activities, but significant difference was only observed in the ALT activity between the 450 mg kg?1 lysozyme group and the control group. In contrast, lysozyme supplementation generally increased the plasma alkaline phosphatase and lysozyme activities, but significant difference was only observed in the lysozyme activity between the 600 mg kg?1 lysozyme group and the control group. Lysozyme supplementation generally increased the plasma antioxidant activities of enzymes (including superoxide dismutase, glutathione peroxidase and catalase) and total antioxidant capacity, but decreased the plasma malondialdehyde level. These results suggest that dietary 450–600 mg kg?1 lysozyme inclusion may improve the growth and non‐specific immune response of rainbow trout. 相似文献
18.
Junming Deng Xi Zhang Xiaowen Long Linli Tao Zhen Wang Guoyi Niu Bin Kang 《Fish physiology and biochemistry》2014,40(6):1827-1838
This study was conducted to evaluate the effects of cholesterol on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal (CSM) or rapeseed meal (RSM). Four experimental diets were formulated to contain 550 g kg?1 CSM or 450 g kg?1 RSM with or without 9 g kg?1 supplemental cholesterol. Growth rate and feed utilization efficiency of fish fed diets with 450 g kg?1 RSM were inferior to fish fed diets with 550 g kg?1 CSM regardless of cholesterol level. Dietary cholesterol supplementation increased the growth rate of fish fed diets with RSM, and growth rate and feed utilization efficiency of fish fed diets with CSM. Similarly, dietary cholesterol supplementation increased the plasma total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triiodothyronine levels, but decreased the plasma triglycerides and cortisol levels of fish fed diets with RSM or CSM. In addition, supplemental cholesterol increased the free cholesterol and TC levels in intestinal contents, but decreased the hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase activity of fish fed diets with RSM or CSM. These results indicate that 9 g kg?1 cholesterol supplementation seems to improve the growth of rainbow trout fed diets with CSM or RSM, and the growth-promoting action may be related to the alleviation of the negative effects caused by antinutritional factors and/or make up for the deficiency of endogenous cholesterol in rainbow trout. 相似文献
19.
Sayed Mohammad Ali Jalali Haji‐abadi Nasrollah Mahboobi Soofiani Ali Asghar Sadeghi Mohammad Chamani Gholam Hossein Riazi 《Aquaculture Research》2010,41(11):1582-1591
This study was carried out to investigate a possible protein‐sparing action of l ‐carnitine and ractopamine in rainbow trout, Oncorhynchus mykiss. An 8‐week feeding trial was carried out to evaluate the effects of supplementation of three levels of l ‐carnitine (0, 1 and 2 g kg?1) and two levels of ractopamine (0 and 10 mg kg?1) on growth performance, fillet fatty acid compositions and blood biochemical parameters in a 3 × 2 factorial experimental design. Ractopamine and 1 g kg?1 carnitine improved the specific growth rate (1.03% and 1.05% day?1), feed conversion ratio (FCR, 1.3 and 1.29), protein efficiency ratio (PER, 1.88 and 1.85) of fish and crude protein (73.5 and 73.8) content of fish fillet. l ‐carnitine and ractopamine increased the levels of albumin, total protein and globulin in the serum of fish. Apart from eicosapentaenoic acid and docosahexaenoic acid, other fatty acids of fish fillet were increased by ractopamine, while total saturated fatty acids were almost intact. However, the total n‐3 poly unsaturated fatty acids were reduced by l ‐carnitine supplementation (P<0.05). The present study showed that 1 g kg?1l ‐carnitine and 10 mg kg?1 ractopamine each can improve the performance of rainbow trout and their combination in diet could enhance the protein level and change the fatty acids profile in fillet muscle. 相似文献