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1.
袁野  黄晓玲  陆游  马红娜  周歧存 《水产学报》2016,40(9):1349-1358
为研究饲料中不同泛酸水平对凡纳滨对虾生长性能、饲料利用及血清指标的影响,实验配制6种等氮等脂(41%粗蛋白质和8%粗脂肪)的实验饲料,泛酸添加水平分别为0(对照组)、50、100、150、300和600 mg/kg,饲料中实测泛酸水平分别为20.9、69.3、99.0、150.2、304.4和513.6 mg/kg。选用初始体质量为(0.73±0.12)g的凡纳滨对虾720尾,随机分为6组(每组3个重复,每个重复40尾),进行为期8周的养殖实验。结果显示,饲料中不同泛酸水平对凡纳滨对虾增重率和特定生长率的影响不显著;对照组凡纳滨对虾成活率显著低于泛酸添加组,然而各泛酸添加组的成活率组间差异不显著。随着泛酸水平从20.9 m.g/kg增加到99.0 mg/kg时,饲料效率和蛋白质效率显著提高,而随着泛酸水平的进一步增加,饲料效率和蛋白质效率显著降低。饲料中泛酸水平对凡纳滨对虾全虾和肌肉主要成分无显著性影响。对照组对虾血清葡萄糖含量显著低于泛酸各添加组,然而泛酸各添加组之间无显著差异;投喂150.2 mg/kg泛酸组血清甘油三酯含量显著低于对照组和513.6 mg/kg;而血清总蛋白和胆固醇含量不受饲料中泛酸水平的影响。随着饲料中泛酸水平由20.9 mg/kg增至150.2 mg/kg,血清超氧化物歧化酶活力显著提高,而随着饲料中泛酸水平的进一步增加,血清超氧化物歧化酶活力显著降低;饲料中泛酸水平为99.0mg/kg组凡纳滨对虾血清总氧化能力显著高于其他各组;投喂对照组和泛酸水平为69.3mg/kg组的凡纳滨对虾血清丙二醛含量最高,投喂泛酸水平为150.2 mg/kg组血清的丙二醛含量显著低于其他各组。以凡纳滨对虾的饲料效率和蛋白质沉积率为评价指标,通过折线模型分析得到凡纳滨对虾泛酸最适需要量分别为113.40和119.87mg/kg。  相似文献   

2.
A feeding trial was conducted to determine the dietary vitamin C requirement of juvenile hybrid striped bass Morone chrysops × M. saxatilis . Fish were fed a semi-purified basal diet with 40% crude protein and an energy to protein ratio of 8 kcal/g for a conditioning period of 2 wk. This diet which was not supplemented with vitamin C contained approximately 6-mg vitamin C/kg. Following conditioning, fish (approximately 0.55 g initial weight) were stocked as groups of 20 in 38-L aquaria and fed the basal diet and experimental diets supplemented with 10, 20, 30, 45, 60, 75, or 150-mg vitamin C/kg as ascorbate polyphosphate for a period of 10 wk. Fish fed the basal diet and the diet supplemented with 10-mg vitamin C/kg exhibited signs of vitamin C deficiency including suppressed weight gain, reduced plasma and liver ascorbic acid levels, and abnormalities in isthmus cartilage formation. Plasma and liver ascorbic acid levels generally reflected dietary supplementation with the lowest levels occurring in fish fed the basal diet and higher levels in fish fed the supplemented diets. The minimum dietary requirement (±SE) based on non-linear least squares regression analysis of weight gain was 22 (±6) mg vitamin C/kg diet.  相似文献   

3.
中草药对斑节对虾生长、饲料利用和肌肉营养成分的影响   总被引：4，自引：1，他引：4  
研究了中草药对斑节对虾Penaeusmonodon(初始体重0.30g.尾-1)生长性能、饲料利用以及肌肉营养成分和氨基酸的影响。6种实验饲料(按顺序分别为1,2,3,4,5和6)中中草药的添加量分别为0,0.5,1.0,2.0,4.0和8.0g·kg-1饲料。除了饲料2之外,斑节对虾的成活率、饲料系数和蛋白质效率都显著(P<0.05)优于对照组(饲料1)。投喂饲料3的斑节对虾增重率与对照组相比,虽然统计学上不存在显著差异,但有较大幅度的提高。投喂添加中草药的饲料对斑节对虾肌肉的水分和蛋白质含量无显著影响,但脂肪含量明显下降。结果表明,斑节对虾饲料中添加适量的中草药能够促进生长、显著提高成活率和降低饲料系数,并改变斑节对虾肌肉中脂肪含量和氨基酸组成。  相似文献   

4.
A 12-wk feeding trial was conducted in a flow-through system to determine whether juvenile golden shiner Notemigonus crysoleucas have a dietary requirement for ascorbic acid. Triplicate groups of 30 fish each weighing 0.44 g initially were fed semi-purified (casein) diets supplemented with 0 or 250 mg ascorbic acid/kg, or practical (fish meal) diets supplemented with 0 or 250 mg ascorbic acid/kg. The form of ascorbic acid used was L-ascorbyl-2-polyphosphate. Survival was higher in fish fed the semi-purified diet with 250 mg ascorbic acid/kg than in those fed the unsupplemented semi-purified diet, while weight gain did not differ between treatments. Weight gain was higher in fish fed the practical (fish meal) diet supplemented with 250 mg ascorbic acid/kg than in those fed the unsupplemented practical diet, while survival did not differ between treatments. No other signs of ascorbic acid deficiency were observed, but fish fed the casein diets had skin and fin erosion indicative of a possible bacterial infection. Whole-body concentrations of ascorbic acid (total, reduced, and percent of reduced ascorbic acid) were higher in fish fed semi-purified or practical diets supplemented with 250 mg ascorbic acid/kg than in fish fed unsupplemented diets. Golden shiners appear to require a dietary source of ascorbic acid for growth or survival, depending on experimental conditions. The two main differences in the study were in diet composition (semi-purified versus practical diets) and apparent health status of fish fed the different diet types. Additional studies are needed to define requirements further.  相似文献   

5.
Evaluation of the Dietary Iron Requirement of Penaeus vannamei   总被引：2，自引：0，他引：2  
Two experiments were conducted to evaluate the dietary iron requirement of juvenile Penaeus vunnamei . Prior to initiation of 28 day (Experiment I) and 35 day (Experiment II) feeding trials, 17–20day-old postlarvae were fed the basal diet lacking iron supplementation but containing 12 mg Fe/kg for seven days. After conditioning, juvenile shrimp (mean weight: 0.038 g Experiment I, 0.047 g Experiment II) were fed one of four diets supplemented with 0, 20, 40 or 80 mg Fe/kg from ferrous sulfate heptahydrate. Final weight gain of shrimp ranged from 1.03 to 1.28 g in Experiment I and 1.62 to 1.94 g in Experiment II. Although percent weight gain was in excess of 2700% in Experiment I and 3400% in Experiment II, there were no significant differences in growth or survival of shrimp fed the different levels of iron. Iron levels of the hepatopancreas and carapace increased linearly with dietary iron; however, there were no significant differences in the iron content of muscle tissue. Based on these results, the iron content of the basal diet appeared to satisfy physiological needs of the shrimp. Therefore, practical diets containing protein sources of animal origin which are rich in iron should not require iron supplementation.  相似文献   

6.
The effect of dietary astaxanthin on growth, survival, and stress tolerance was determined in postlarval Litopenaeus vannamei. An experiment was performed with postlarval shrimp (mean initial wet weight 1.2 mg) fed four isoenergic and isonitrogenous diets containing four supplemented levels of astaxanthin (0, 100, 200, and 400 mg/kg diet, respectively). Shrimp fed diets containing 100, 200, and 400 mg astaxanthin/kg diet for 30 d showed higher weight gain (WG, %) and survival compared to the control (without supplementation of astaxanthin). Specific growth rate (SGR, %/day) and final body wet weight (FBW, mg) showed the same pattern as WG. There were no significant differences in growth performance (FBW, WG, and SGR) among the groups fed the diets with astaxanthin supplementation at the termination of feeding trial. Survival of shrimp in the control and 100 mg/kg diet treatments was significantly lower than that of shrimp in the treatments with 200 and 400 mg/kg diet. After 9 d of a stress tolerance test, survival of shrimp in the 200 and 400 mg astaxanthin/kg treatments was significantly higher than that of shrimp in the 0 and 100 mg astaxanthin/kg treatments (P < 0.05). We concluded from this experiment that astaxanthin was a necessary ingredient for the development of larval L. vannamei. Considering the effect of astaxanthin on both, growth performance and survival of postlarval L. vannamei, the level of astaxanthin supplemented in the diet should be between 100 mg and 200 mg/kg of diet.  相似文献   

7.
硒源对凡纳滨对虾生长、体组成和抗氧化能力的影响   总被引：1，自引：0，他引：1  
水温(29.0±1.3)℃,将初始体质量(0.41±0.01)g的凡纳滨对虾随机分为4组,每组3个重复,饲养在室内循环水养殖系统中,投喂基础饲料(对照组)及在此饲料中分别添加硒含量相等(0.30mg/kg)的亚硒酸钠、酵母硒和蛋氨酸硒的4种饲料,养殖56d,比较了不同硒源对凡纳滨对虾生长、体组成和抗氧化能力的影响。试验结果表明,蛋氨酸硒组对虾的生长性能显著高于对照组和亚硒酸钠组(P0.05)。外源硒可显著影响对虾体蛋白和脂肪含量(P0.05),蛋氨酸硒组对虾机体营养成分显著优于其他组(P0.05)。添加外源硒组对虾的血清总抗氧化能力和谷胱甘肽过氧化物酶活性显著高于对照组(P0.05)。蛋氨酸硒组对虾血清丙二醛含量显著低于其他组(P0.05)。由此得出,饲料添加0.3mg/kg的硒能在一定程度上提高凡纳滨对虾的生长和抗氧化能力,蛋氨酸硒优于酵母硒和亚硒酸钠。  相似文献   

8.
The main objective of this study was to evaluate the effect of methionine supplementation when reducing fishmeal levels in diets for white shrimp (Litopenaeus vannamei). Tested diets consisted of a positive control with 260 g/kg fishmeal (D1), two negative controls with 100 g/kg fishmeal and no amino acid (AA) supplementation (D2) or supplemented with lysine but not methionine (D3), and four additional diets with 100g/kg fishmeal supplemented with increasing levels of DL‐Met (1.0, 2.0 or 3.0 g/kg) (D4, D5, D6) or Met‐Met (1.0 g/kg) (D7). Each diet was fed to four groups of 30 shrimp for 8 weeks at a daily rate of 70 g/kg body weight. Reduction in fishmeal from 260 g/kg down to 100 g/kg did not significantly affect survival rate, feed conversion ratio (FCR), protein efficiency ratio (PER) or protein retention efficiency (PR%) of white shrimp. However, growth performance (final body weight, FBW; weight gain, WG; specific growth rate, SGR) was reduced when dietary fishmeal level was reduced from 260 g/kg (D1) to 100 g/kg without methionine supplementation (D2). The growth performance (FBW, WG and SGR) of shrimp was significantly increased by supplementation of the 100 g/kg fishmeal diet with increasing levels of DL‐Met (p < .05). Same performance as positive control (D1) was achieved with diets containing 100 g/kg fishmeal and supplemented with 3.0 g/kg DL‐Met or 1.0 g/kg Met‐Met. The highest values of growth performance (FBW, WG and SGR) were found in shrimp fed D6 and D7 diets, which were significantly higher than those of shrimp fed D2 and D3 diets (p < .05) but without statistical differences with shrimp fed D1, D4 and D5 diets (p > .05). The highest values of whole‐body and muscle protein contents were found in shrimp fed D1 diet, which were significantly higher than those of shrimp fed all other diets (p < .05). The highest value of intestinal tract proteolytic enzyme activity was found in shrimp fed Met‐Met‐supplemented diet (D7) and followed by the positive control diet (D1) and 3 g/kg DL‐Met‐supplemented diet (D6) (p < .05). The highest values of apparent digestibility coefficients (ADCs) of dry matter and crude protein were found in Met‐Met‐supplemented diet (D7) and followed by the positive control diet (D1) (p < .05). Shrimp fed the D1 diet showed the highest value of total essential amino acid (EAA) and was significantly higher than shrimp fed D2–D3 (p < .05) but without significant difference with shrimp fed D4–D7 (p > .05). In conclusion, results showed that same performance can be achieved with diets containing 260 or 100 g/kg fishmeal supplemented with 3.0 g/kg DL‐Met or 1.0 g/kg Met‐Met. Moreover, supplementation of limiting methionine in low‐fishmeal diets seems to improve the digestive proteolytic activity, improving digestibility of dry matter and protein, and eventually to promote growth of juvenile white shrimp in fishmeal reduction diets.  相似文献   

9.
A feeding experiment was carried out to determine the efficiency of different commercial sources, chemical forms and levels, of dietary astaxanthin, to appropriately pigment the red porgy (Pagrus pagrus) skin. According to this, total carotenoid content, profiles and chemical forms present in the skin were determined. In order to establish the potential for antioxidant protecting role of astaxanthin supplemented diets, peroxide levels and lipid composition of skin were also determined.

Red porgy alevins were fed six dietary treatments in triplicate; a basal diet (B) without carotenoids; two diets (N25 and N50) formulated to supply either 25 or 50 mg kg− 1 of an esterified source of astaxanthin (Haematococcus pluvialis, NatuRose™); two diets (CP25 and CP50) with either 25 or 50 mg kg− 1 of unesterified astaxanthin (Carophyll® Pink); and a positive control diet (B + S) proved as a successful pigmenting-diet in previous experiences (B + S, 88% basal diet:12% frozen shrimp) [Cejas, J., Almansa, E., Tejera, N., Jerez, S., Bolaños, A., Lorenzo, A., 2003. Effect of dietary supplementation with shrimp on skin pigmentation and lipid composition of red porgy (P. pagrus) alevins. Aquaculture 218, 457–469].

All fish fed carotenoid supplemented diets displayed a pink-coloured skin after 4 months of feeding in contrast to the greyish appearance displayed by fish fed the basal diet not supplemented with carotenoids (B). Furthermore, astaxanthin diesters were the major carotenoid in the skin of pink fish. A second carotenoid, tentatively identified as tunaxanthin diester, was also detected. The best results in terms of skin natural reddish hue, total carotenoid and astaxanthin contents were found by using the esterified forms of dietary astaxanthin (N25, N50 and B + S). Interestingly, the lowest levels of lipid peroxides were found in the fish fed these three treatments. However, no effect of treatment on lipid composition was found. In conclusion, red porgy alevins are able to efficiently utilise dietary natural or synthetic astaxanthin, and deposit this pigment in its esterified form to acquire an acceptable pink-coloured skin compared to that of the wild fish.  相似文献   


10.
A 90-day feeding experiment was conducted using flow through system to evaluate the requirement of vitamin E for rohu fry in relation to growth performance and to assess the relationship between the dietary vitamin E levels and carcass composition. Five semi-purified diets supplemented with 0, 50, 100, 150, 200 mg vitamin E/kg dry diet as --tocopheryl acetate were fed to rohu fry (av. wt.±S.E.=0.58±0.01 g) in triplicate groups. At the end of the experiment, growth and dietary performance were evaluated and vitamin E deposition in the tissue, erythrocyte fragility, thiobarbituric acid reactive substances (TBARs) were analyzed. The average net weight gains were 6.82±0.09, 7.38±0.03, 8.20±0.03, 8.07±0.09 and 8.12±0.08 (g/90 days), respectively, for fish fed diets 0, 50, 100, 150, 200 mg vitamin E/kg. The fish fed diets containing less than 100 mg supplemental vitamin E/kg had significantly (P<0.05) reduced weight gain, feed efficiency and other nutritional indices compared to those fed diets supplemented with vitamin E at 100–200 mg/kg. With the increasing level of vitamin E, both TBARs and erythrocyte fragility values were reduced. Regression analysis of weight gain data using broken-line model indicated a minimum vitamin E requirement of 131.91 mg/kg dry diet. The erythrocyte fragility and TBARs were maximum in fish fed the vitamin E-deficient diet. From the present experiment, it may be concluded that the vitamin E requirement of Labeo rohita fry for optimum growth and other dietary performances is 131.91 mg/kg of dry diet.  相似文献   

11.
An 8‐week feeding trial was conducted to evaluate the effects of dietary choline levels on growth performance, antioxidant capacity and lipid metabolites in juvenile Pacific white shrimp. Six isonitrogenous and isolipidic diets were formulated to supply 0, 1,000, 2,000, 4,000, 6,000, 10,000 mg/kg choline chloride, and dietary choline levels were analysed to be 1,317 (basal diet), 1,721, 2,336, 3,294, 5,421 and 9,495 mg/kg, respectively. Dietary choline levels significantly influenced percent weight gain (PWG) and protein efficiency ratio (PER), with the highest PWG was observed in shrimp fed the 5,421 mg/kg choline diet. However, there were no significant differences in proximate composition of whole body and muscle. Shrimp fed the diet containing 2,336 mg/kg choline had lower HDL and LDL in haemolymph than those fed the basal diet (1,317 mg/kg diet). Dietary choline prevented the accumulation of free radicals and improved antioxidant capacity by increasing catalase activity and reducing malondialdehyde content. Based on broken‐line regression and quadratic regression analysis between PWG against dietary choline levels, the optimal choline requirements were estimated to be 3,254.1 and 6,488.3 mg/kg for juvenile L. vannamei, respectively.  相似文献   

12.
Effects of dietary supplementation of β-glucans and nucleotides on growth, survival and immune responses of the Pacific white shrimp (Litopenaeus vannamei) at a low salinity (5 ppt) were evaluated during a 30 d feeding trial. Final mean weight of shrimp fed nucleotides at 0.5%?was highest and significantly different from those fed the basal diet or diets supplemented with β-glucans. Survival was significantly higher for shrimp fed the diet with 0.2%?β-glucans compared to all other diets and was lowest for shrimp fed the basal diet. Shrimp fed diets containing β-glucans and nucleotides had generally better immune responses than shrimp fed the basal diet with higher total hemocyte count (THC) recorded for shrimp fed 0.2%?β-glucans followed by those fed 0.2%?nucleotides. Shrimp fed diets with 0.2%?and 0.5%?nucleotides and 0.2%?β-glucans had significantly higher respiratory burst values than shrimp fed the basal diet. These results indicated that dietary supplementation of either nucleotides or β-glucans has beneficial effects in improving shrimp performance when cultured at low salinity.  相似文献   

13.
An 8-week growth experiment was conducted to estimate the dietary requirement of myo-inositol (MI) for juvenile hybrid tilapia. MI was supplemented at 0, 150, 250, 350, 450, 600, and 1200 mg/kg diet in the basal diet providing 0, 167, 259, 367, 479, 612, and 1253 mg MI/kg diet. Basal diet without MI but with succinylsulfathiazole to suppress MI synthesis by intestinal bacteria was included for comparison. Each diet was fed to triplicate groups of tilapia (mean initial weight 0.51±0.01 g, n=3). Fish fed ≥367 mg MI/kg diet had significantly (P<0.05) higher weight gain, followed by fish fed 259 mg MI/kg diet, and lowest for fish fed the unsupplemented basal diet. Fish fed ≥367 mg MI/kg diet had higher feed efficiency than fish fed the basal diet. Supplementation of dietary inositol did not affect survival of tilapia. The MI concentrations in liver were highest in fish fed the ≥479 mg MI/kg diet, followed by fish fed the 259 and 167 mg MI/kg diets, and lowest in fish fed the basal diet. Hepatic lipid concentrations were higher in fish fed 367 mg MI/kg diet than fish fed ≤259 mg MI/kg diet. Weight gain percentage and MI concentrations in the liver for the different treatments were analyzed by broken-line regression and indicated that the requirement for dietary MI in growing tilapia is about 400 mg/kg diet. Addition of an antibiotic to basal diet did not affect the growth and hepatic inositol concentration of tilapia, suggesting that the intestinal microbial synthesis was not a significant source of inositol for tilapia.  相似文献   

14.
研究了饲料铜离子含量对亚硝酸盐胁迫下斑节对虾（Penaeus monodon）血细胞参数的影响。向斑节对虾投喂不同铜离子添加量（0,10,25,40,55和110 mg/kg）的饲料8周后,进行24 h 的20 mg/L亚硝酸氮胁迫,取样测定对虾的血细胞总数（THC）、血细胞活性氧（ROS）含量和血细胞凋亡率。结果显示,经亚硝酸盐胁迫后,25-55 mg/kg饲料组对虾能保持较高的THC,以及较低血细胞ROS含量和凋亡率;110 mg/kg饲料组对虾的THC最低,血细胞ROS含量和凋亡率均最高。这些结果表明饲料中添加25-55 mg/kg的铜离子能有效降低亚硝酸盐胁迫对血细胞造成的氧化损害,但过量添加（110 mg/kg）反而对血细胞造成更为严重的损害。  相似文献   

15.
选取体质量(74.52±1.03)g的团头鲂480尾,随机分成4组,每组4个重复,每个重复30尾,分别投喂添加0(对照组)、20mg/kg(试验Ⅰ组)、40mg/kg(试验Ⅱ组)和80mg/kg(试验Ⅲ组)植物甾醇的配合饲料,进行为期81d的饲养试验。试验结果表明,40、80mg/kg植物甾醇可提高团头鲂质量增加率及特定生长率(P0.05),其中40mg/kg组效果更佳,对肌肉粗蛋白含量影响不显著,对肌肉粗脂肪含量有一定提高(P0.05);添加40mg/kg植物甾醇显著降低了81d血浆低密度脂蛋白胆固醇水平(P0.05)。在本试验条件下,添加40mg/kg植物甾醇效果最佳。  相似文献   

16.
A feeding trial was conducted to evaluate the dietary copper requirement of red drum (Sciaenops ocellatus) and compare the bioavailability of copper sulphate (CuSO4) and copper‐ethanolamine. A basal diet was formulated using semi‐purified ingredients and analysed to contain 3 mg Cu/kg. Both copper sources were supplemented to the basal diet at either 5, 10 or 20 mg Cu/kg of dry diet. No significant differences were observed in growth performance of fish fed the various diets. However, red drum fed all copper‐supplemented diets retained more copper in liver and whole‐body tissues compared to fish fed the basal diet. Within both inorganic and organic copper treatments, the highest tissue copper concentrations were observed in fish fed diets supplemented with 10 mg Cu/kg. No significant differences were detected in net copper retention regardless of the nature of the copper source; hence, the bioavailability of copper sulphate and copper‐ethanolamine complex was not different in the diets for juvenile red drum. Furthermore, the minimum copper requirement for growth performance of juvenile red drum appeared to be satisfied when fish were fed the basal diet containing 3 mg Cu/kg diet, and no detrimental effects were observed in red drum fed diets supplemented with 20 mg Cu/kg.  相似文献   

17.
An experiment was conducted to investigate the effect of dietary iron supplement on growth, haematology and microelements of juvenile grouper, Epinephelus coioides. Casein–gelatine‐based diets supplemented with 0, 50, 100, 150, 200 and 250 mg kg−1 iron from ferrous sulphate were fed to grouper (mean initial weight: 21.0 ± 0.2 g) for 8 weeks. Weight gain was highest in fish fed the diet supplemented with 100 mg kg−1 iron, intermediate in fish fed diets with 50, 150, 200 and 250 mg kg−1 iron and lowest in fish fed the basal diet. Feed efficiency followed a similar trend except that the lowest value was in fish fed the basal diet and the diet supplemented with 250 mg kg−1 iron. Hepatic iron was highest in fish fed diets supplemented with iron ≥100 mg kg−1, followed by fish fed diet with 50 mg kg−1 iron and lowest in fish fed the basal diet. The whole‐body iron was lowest in fish fed the basal diet but not significantly different from other groups, as judged by anova . Iron supplement to the basal diet had no significant effect on haematological parameters (red blood cell count, haematocrit and haemoglobin), hepatic copper concentration or manganese, zinc concentration in liver and whole body. Broken‐line analysis of hepatic iron indicated that iron supplementation of 100 mg kg−1 satisfied the hepatic iron storage and that further supplementation did not expand the iron status.  相似文献   

18.
家蝇抗菌肽对凡纳滨对虾生长性能及免疫相关指标的影响   总被引：9，自引：1，他引：8  
通过8周的生长实验研究了饲料中添加家蝇幼虫抗菌肽提取物对初始体质量为(0.86±0.01)g的凡纳滨对虾(Litopenaeus vannamei)的生长性能、体成分及免疫相关指标的影响。家蝇抗菌肽提取物添加量分别为0、1000mg/kg、2000mg/kg、3000mg/kg、4000mg/kg、5000mg/kg,每组饲料设4个重复,每个重复饲养40尾虾。结果显示,在一定添加水平范围内,家蝇抗菌肽能显著提高凡纳滨对虾成活率、增重率、特定生长率、饲料效率(P0.05),当抗菌肽提取物添加量为2000～3000mg/kg时,以上4个指标均达最高,且显著高于对照组(P0.05)。以增重率为评价指标,凡纳滨对虾饲料中家蝇抗菌肽提取物的最适添加量为2900mg/kg。当抗菌肽提取物添加量为2000～3000mg/kg时能显著提高虾体的粗蛋白和灰分含量,虾体粗脂肪不受添加抗菌肽水平的显著影响。添加2000～5000mg/kg抗菌肽提取物组与对照组相比能显著提高对虾血细胞数量;添加3000mg/kg抗菌肽提取物时对虾血细胞吞噬率最高。当抗菌肽提取物添加量为2000～3000mg/kg时,对虾血清中酚氧化酶PO、过氧化物酶POD、碱性磷酸酶AKP、溶菌酶LZM的活性和总抗氧化能力T-AOC均维持在一个较高的水平,且显著高于对照组;超氧化物歧化酶SOD的活性在各组组间差异不显著(P0.05)。肝胰腺中AKP、SOD、T-AOC活性各组间差异均不显著(P0.05);LZM活性以3000mg/kg组最高,显著高于其他组。结果表明,饲料中添加适量的家蝇抗菌肽对凡纳滨对虾有一定的促生长作用,并能提高对虾的免疫相关指标。  相似文献   

19.
A 25‐day experiment was conducted to evaluate the optimal lipid level for postlarval Litopenaeus vannamei. Shrimp (1.7 mg) were fed five isonitrogenous diets containing grade levels of lipid (96.6, 114.3, 128.5, 136.5 and 154.5 g/kg diet, respectively). Each diet was assigned to four tanks (500 shrimp), and shrimp were fed six times a day. Weight gain was increased with the increasing dietary lipid levels, and the highest weight gain was observed in shrimp fed diet with 154.5 g/kg lipid (p < 0.05). On the contrary, the survival was lowest in shrimp fed the L15.45 and highest in shrimp fed the L11.43. Triglyceride in hepatopancreas was increased, and cholesterol was decreased with the increasing dietary lipid. Pyruvate kinase and AMPK mRNA expression were highest in shrimp fed the L12.85. Malondialdehyde in whole body was positively correlated with the dietary lipid levels. The mRNA expression of SOD and Caspase 3 was highest in shrimp fed the L12.85. After hypoxia stress, shrimp fed the L12.85 showed highest survival. The mRNA expression of superoxide dismutase and Akirin was highest in shrimp fed the L11.43 and L15.45, respectively. Based on the survival after 25‐day feeding trail and after the hypoxia stress, the optimal dietary lipid for postlarval L. vannamei should be 118–124 g/kg.  相似文献   

20.
An 8‐week feeding trial was conducted to establish the dietary vitamin E requirement of juvenile cobia. The basal diet was supplemented with 10, 20, 30, 40, 60, 120 mg vitamin E kg?1 as all‐rac‐α‐tocopheryl acetate. The results indicated that fish fed the diets supplemented vitamin E had significantly higher specific growth rate, protein efficiency ratio, feed efficiency and survival rate than those fed the basal diet. It was further observed that vitamin E concentrations in liver increased significantly when the dietary vitamin E level increased from 13.2 to 124 mg kg?1. Fish fed the basal diet had significantly higher thiobarbituric acid‐reactive substances concentrations in liver than those fed the diets supplemented vitamin E. Fish fed the diets supplemented with 45.7 and 61.2 mg kg?1 vitamin E had significantly higher red blood cell and haemoglobin than those fed the basal diet, while fish fed the diets supplemented with 61.2 and 124 mg kg?1 vitamin E had higher immunoglobulin concentration than those fish fed the basal diet. Lysozyme and superoxide dismutase were significantly influenced by the dietary vitamin E level. The dietary vitamin E requirement of juvenile cobia was established based on second‐order polynomial regression of weight gain and lysozyme to be 78 or 111 mg all‐rac‐α‐tocopheryl acetate kg?1 diet, respectively.  相似文献   

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