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1.
A 12‐week feeding trial was conducted to evaluate the effects of replacing fishmeal (FM) with soybean meal (SBM), rapeseed meal (RM) and cottonseed meal (CSM) on growth, feed utilization and body composition of juvenile hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂ (initial body weight, 8.63 ± 0.24 g). Five isonitrogenous and isoenergetic diets were formulated as follows: a control diet (FM60) containing 600 g/kg FM and four other diets (FM45, FM30, FM15 and FM0 containing 450, 300, 150 and 0 g/kg FM, respectively) where protein from FM was substituted by a mixture of SBM, RM and CSM. Fish fed FM0 and FM15 had poorer growth performance, feed utilization, apparent digestibility coefficients of dry matter, protein, lipid and gross energy, and fed FM0 had poorer hepatosomatic index and survival compared with the fish fed FM60. The whole body lipid in fish fed FM0 was significantly higher than that in fish fed FM60 and FM15. This study indicates that 300 g/kg of FM can be replaced with a mixture of SBM, RM and CSM in the diet of juvenile hybrid sturgeon without compromising growth performance, feed utilization and body composition.  相似文献   

2.
An 8‐week feeding trial was conducted to evaluate the dietary arginine requirement of juvenile hybrid sturgeon. Seven isonitrogenous and isolipidic diets were formulated to contain graded levels of dietary arginine ranging from 1.74% to 3.54% (dry weight). The results indicated that the fish fed with 1.76% arginine diet had lower specific growth rate (SGR) and feed efficiency ratio (FER) than the fish fed the 2.64% to 3.24% arginine diets (< .05), and the fish fed the 2.64% arginine diet presented the highest SGR. The fish fed with 1.76% arginine diet had lower whole‐body crude protein content than the fish fed the 2.64% or 2.93% arginine diets (< .05). Compared with the 1.76% arginine diet, 2.36% to 2.93% arginine diets significantly increased the total amino acid (TAA) concentration and total nonessential amino acid (TNEAA) of carcasses. The fish fed with 1.76% arginine diet had lower activity of nitric oxide synthase (T‐NOS) and content of nitric oxide (NO) than the fish fed the 2.05% to 2.93% arginine diets in the liver. The fish fed with 1.76%, 2.05% or 2.36% arginine diets had lower gene expression of growth hormone (GH) and insulin‐like growth factor I (IGF‐I) in the liver than the fish fed the 2.64% to 3.53% arginine diets in the liver (< .05). A broken‐line analysis between SGR against the dietary arginine levels provided estimates for the optimal dietary arginine requirement of 2.47% corresponding to 6.18% of the dietary protein on a dry weight basis.  相似文献   

3.
This study was conducted to determine the optimal dietary myo‐inositol (MI) requirement of juvenile hybrid sturgeon (Acipenser baerii ♀ × A. schrenckii ♂). Fish with an initial average body weight of 28.28 ± 0.41 g were randomly divided into six groups with three repetitions in each group and fed the experimental diets with different graded MI concentrations (70.2, 130.0, 270.2, 443.0, 1,096.6 and 1997.3 mg/kg) three times per day for 12 weeks. The results showed that with the increase in dietary MI level from 70.2 mg/kg to 443.0 mg/kg, weight gain (WG) was increased significantly (p < .05); however, when the MI level was further increased, there was no significant difference in weight gain rate (WG) over time (p > .05). Specific growth rate (SGR) showed a similar trend. The feed conversion ratio (FCR), survival rate (SR), hepatosomatic index (HSI), viscerasomatic index (VSI) and condition factor (CF) were not affected by dietary MI supplementation (p > .05). Dietary MI did not affect whole‐body and muscle crude protein and ash content (p > .05), while dietary MI significantly affected the muscle and whole‐body crude lipid and moisture content (p < .05). Moreover, serum triglyceride (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were decreased by increasing dietary MI levels. Total antioxidant capacity (T‐AOC), malonic dialdehyde (MDA) and superoxide dismutase (SOD) activities in the liver were also affected by the dietary MI (p < .05). In summary, this study indicated that the optimal dietary MI requirement for juvenile hybrid sturgeon (Acipenser baerii ♀ × A. schrenckii ♂) was 335.84 mg/kg and 590.65 mg/kg based on the maximum WG and liver MI accumulation indices respectively.  相似文献   

4.
In aquaculture practices, fish commonly confront environmental alterations and unavoidable stresses. Thus, any substance that could attenuate stress responses could be potentially used in aquaculture. A total number of 90 hybrid sturgeons (Huso huso ♂ × Acipenser ruthenus ♀) with an average weight of 212.6 ± 0.7 g were fed experimental diets containing 0, 50 and 100 mg kg?1 green tea (Camellia sinensis L) for 6 weeks. Subsequently 15 fish from each treatment were exposed to air for 5 min prior to transfer to the recovery tank. Followed by blood sampling after 1, 2, 5 and 12 h, Serum cortisol increased in all treatments, but the intensity was significantly lower in fish fed green tea compared to the control group. Similarly, the green tea diet attenuated the increase in serum levels of glucose and lactate in comparison to the control. Our results showed that green tea could be added to fish diet to attenuate stress responses in Sturgeon hybrid (Huso huso ♂ × Acipenser ruthenus ♀).  相似文献   

5.
An 8‐week trial was conducted to determine the effects of total replacement of 12.9% fish oil (FO) with soybean oil (SBO), peanut oil (PNO), sunflower seed oil (SFSO), corn oil (CO) and canola oil (CNO) on growth performance, health status and fillet fatty acid composition of hybrid sturgeon (194.28 ± 0.14 g). Compared to the FO group, dietary SBO decreased growth performance (p < .05), increased serum glucose and hepatic lipid content (p < .05). No obvious adverse effects on growth performance and health status were observed in PNO, SFSO and CO groups (p > 0.05). The fish fed with CNO had increased growth performance (p < .05), reduced serum ALT, AST, LDL‐C (p < .05) and enhanced serum GSH‐Px, T‐AOC, and LZM, MPO, C4 (p < .05). The contents of C18:1n9, C18:2n6, and ∑n‐3 PUFA and ∑n‐6 PUFA in fillets showed a positive linear correlation with the diets (p < .05). In summary, PNO, SFSO and CO are probable alternative lipid sources to fully replace FO. Hybrid sturgeon prefers to use CNO as a lipid source with improved growth performance and health status. The fillet fatty acid composition mirrors the dietary fatty acid composition.  相似文献   

6.
The growth performance, body composition, fillet fatty acid content, serum hepatic enzymes and postprandial changes in serum lipid metabolism of hybrid sturgeon (70.8 ± 0.5 g) were investigated to determine the effects of total replacement of 80 g kg‐1 fish oil (diet A) with linseed oil (diet B) and soybean oil (diet C), respectively. No significant differences in weight gain rate and specific growth ratio were observed among all fish groups (p > .05). Diet A fish group had the highest, but diet B fish group had the lowest feed intake (p < .05). Feed efficiency of fish fed diet A was significantly lower than the other two fish groups (p < .05). Fish fed diet A had the lowest fillet and liver lipid contents (< .05). Serum lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase activities of fish fed diet A were significantly lower than those of fish fed diets B and C (< .05). The contents of linoleic acid (C18:2n6) and linolenic acid (C18:3n3) in fillets showed a significantly positive linear correlation with the diets. Serum glucose and non‐esterified fatty acid were just affected by the time point (< .05). The lipid source, time point and interaction of both factors had significant effects on serum triglyceride, high‐density lipoprotein cholesterol and low‐density lipoprotein cholesterol (< .05). Serum total cholesterol was only affected by interaction of time point and lipid source (< .05), and ketone body was not affected by lipid source, time point or interaction of both factors (> .05). In summary, total replacement of fish oil with linseed oil or soybean oil had no significant adverse effects on hybrid sturgeon growth during 84‐day period, and linoleic acid and linolenic acid in fillet were modified by dietary treatments.  相似文献   

7.
This study was conducted to determine the effects of dietary α‐ketoglutarate (AKG) supplementation on the antioxidant defense system and gene expression of heat shock protein (HSP) 70 and HSP 90 in hybrid sturgeons Acipenser schrenckii ♀ × A. baerii ♂ exposed to ammonia‐N stress. A 2 × 3 factorial experiment was arranged, in which each diet (0%, 1% AKG) was randomly assigned to 0.25 (control) 5 and 10 mg L?1 ammonia‐N groups with three replicate aquaria for each 72 h. The 10 mg L?1 ammonia‐N significantly increased serum ammonia concentrations and intestinal Gln concentrations and GS activity compared with the 0.25 or 5 mg L?1 ammonia‐N groups. The intestinal Gln concentration and GS activity increased, and the serum ammonia concentration decreased, in fish given dietary supplementation of 1.0% AKG compared with fish given diets without AKG. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in serum, gills and intestines decreased when fish were exposed to 5 or 10 mg L?1 ammonia‐N, and their activity increased in fish given diets with 1% AKG. Catalase in the serum and gills decreased when fish were exposed to 5 or 10 mg L?1 ammonia‐N and increased in fish given diets with 1% AKG. The 10 mg L?1 ammonia‐N or 1% AKG supplementation increased HSP 70 and HSP 90 gene expression in the liver. The increased activity of antioxidant enzymes, and increased HSP 70 and HSP 90 gene expression in fish fed diets containing 1% AKG suggested higher tolerance to ammonia‐N stress.  相似文献   

8.
9.
施氏鲟、达氏鳇及其杂交子代的分子鉴定   总被引:3,自引:1,他引:3  
采用39对微卫星引物扩增施氏鲟(Acipenser schrenckii)、达氏鳇(Huso dauricus)及其正反杂交子代[A.schrenckii(♀)×H.dauricus(♂),H.dauricus(♀)×A.schrenckii(♂)]的全基因组。其中5对引物无扩增产物,其余34对引物中,有3对只在施氏鲟中得到扩增产物,有31对能同时在3种鱼中进行有效扩增,其中均呈单态的有7对,均呈多态的有22对,位点LS19和LS22在施氏鲟中呈多态,在达氏鳇中呈单态。34个微卫星位点共得到96个等位基因,大小在80~394bp之间。检测到种间特异位点6个(HLJSX22,HLJSX23,HLJSX37,HLJSX41,HLJSX48,LS54),将这些位点部分组合,可以有效鉴别出施氏鲟、达氏鳇和其杂交子代。同时测定杂交子代的线粒体控制区序列,将测序结果与GenBank中施氏鲟和达氏鳇的同源序列进行比对,根据线粒体母性遗传特性,通过比对序列的差异大小来判断杂交子代的母本来源。结果表明,采用微卫星分子标记结合线粒体控制区同源序列比对的方法,可以很好地鉴别出施氏鲟、达氏鳇及其正反杂交子代。  相似文献   

10.
A 12‐week growth trial was conducted to evaluate the effect of low fishmeal and phytase replacing inorganic phosphorus on juvenile hybrid sturgeon (Acipenser baeri Brandt ♀ × Aschrenckii Brandt ♂). Four experimental diets were designed as FM100p, FM100, FM250p and FM250, which represented 10% and 25% fishmeal with or without phytase, respectively. The results showed that although growth parameters had no significant difference in all treatments, low fishmeal obviously decreased the culture cost of hybrid sturgeon. Lipid content of body composition was obviously increased in low fishmeal treatments (p < .05). The interaction of low fishmeal and phytase significantly enhanced apparent digestibility coefficients of crude protein (p < .05). Two‐way ANOVA analysis showed that input and output of phosphorus were significantly affected by fishmeal level, phytase and interaction of both factors (p < .05). For the immunological and hepatic function parameters, fishmeal level and phytase had significant effects on the activities of lysozyme, myeloperoxidase, malondialdehyde, alanine aminotransferase, lactate dehydrogenase and alkaline phosphatase (p < .05). The present study potentially justifies that a diet containing 10% fishmeal can be used for hybrid sturgeon. Moreover, replacement of monocalcium phosphate by phytase not only has no adverse effect on the growth of hybrid sturgeon, but also reduces phosphorus emission and protects aquaculture environment.  相似文献   

11.
A six‐week growth trial was conducted to evaluate the optimum dietary isoleucine requirement of juvenile hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂). Seven isoenergetic (3,400 kcal/kg of dry matter), isoproteic (496 g/kg of dry matter) and isolipidic (70 g/kg of dry matter) diets were formulated to contain graded Ile levels (7.3, 11.3, 15.7, 19.6, 23.5, 26.8 and 30.8 g/kg, dry‐matter basis). Each experimental diet was fed to triplicate groups of 12 hybrid grouper juveniles (average initial body weight: 6.00 ± 0.01 g/fish). Experimental fish were randomly distributed into 21 glass tanks (L 60 × W 45 × H 50 cm) connected to mechanical and biological water filters as a recycling system. Fish were fed twice daily (08:00 and 16:00) to apparent satiation. After the sampling of the growth trial, the remaining fish in each group were fed their corresponding diets for 2 d and then exposed to 4 mg Cu2+ · L?1 water for 24 hr. Results showed that growth performance and feed utilization were significantly affected by different dietary Ile levels (p < .05). Weight gain percentage (WG%), protein productive value (PPV), protein efficiency ratio (PER) and feed efficiency (FE) were increased as dietary Ile level increased, reaching a peak value at 19.6 g/kg dietary Ile, and thereafter, these four parameters declined as dietary Ile level continued to increase. Daily feed intake (DFI) showed an opposite tendency of variations as FE. The quadratic regression analysis of WG%, PPV, PER and FE against dietary Ile levels indicated that the optimum dietary Ile requirement for hybrid grouper was estimated to be 19.8, 20.8, 19.4 and 19.1 g/kg dry matter, respectively. Among all experimental treatments, fish fed 19.6 g/kg dietary Ile had the highest expression of growth and protein synthesis‐related genes, including growth hormone (GH) in pituitary, insulin‐like growth factor 1 (IGF‐1), growth hormone receptor 1 (GHR1), target of rapamycin (TOR) and S6‐kinase 1 (S6K1) in liver. Gut micromorphology was significantly influenced by dietary Ile levels. After the exposure to 4 mg Cu2+ · L?1 water for 24 hr, fish fed 19.6 g/kg dietary Ile had the highest survival and the best immunologic manifestation among all experimental treatments. Generally, the optimum dietary Ile requirement for maximum growth of hybrid grouper was estimated to be 19.8 g/kg dry matter, corresponding to 39.9 g/kg dietary protein.  相似文献   

12.
Interspecies hybridization is widely used in aquaculture as a beneficial strategy. Diploid and triploid hybrids have been detected from the interspecies hybridization of Epinephelus coioides ♀ × Epinephelus lanceolatus ♂. This is the first report of triploidization through hybridization in grouper. Confirmation has been obtained through flow cytometry, karyotyping and erythrocyte nuclei measurement. The chromosome numbers of E. coioides, E. lanceolatus, diploid hybrid grouper are 48 and triploid hybrid grouper are 72. Measurements of erythrocyte nuclei indicate that triploid fish have a larger nuclear surface than the diploid groupers, and the average ratio of triploid to diploid surface area is 1.59. During the first 1.5 years, triploid hybrid groupers grow faster than diploid hybrid groupers or either parent species. The average growth rate of triploid hybrids is 1.61 times greater than that of diploid hybrids at 6 months of age and 1.43 times greater at 18 months of age. The triploid hybrid groupers are inferior in gonadal development, with no primary‐growth‐stage oocytes appearing in the gonads at 18 months of age. Morphological studies indicate that triploid hybrid groupers have distinctive differences in snout length, eye diameter, body trunk shape, and tail shape development compared with diploid hybrid groupers. Triploid hybrid groupers have an advantage in growth ability, and artificial breeding of triploid groupers might be of great potential use in the grouper aquaculture industry.  相似文献   

13.
14.
This study determined the effect of dietary supplementation with taurine on plasma biochemical indices, blood cell apoptosis rate, survival rate and expression of catalase (CAT), glutathione reductase (GR) and heat‐shock protein 70 (HSP70) gene in juvenile hybrid snakehead under ammonia stress. Six diets were formulated to contain 0, 3.0, 6.0, 9.0, 12.0 and 15.0 g/kg taurine. Each diet was fed to triplicate groups of fish in cylindrical tanks. After 8 weeks of feeding, 20 fish per tank were exposed to ammonia stress (total ammonia nitrogen = 200 mg/L) for 48 hr. The results showed that, after ammonia stress, plasma alkaline phosphatase (ALP), triacylglycerol (TG) levels and survival rate significantly decreased (p < 0.05) while plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (BUN), respiratory burst, blood cell apoptosis rate, hepatic CAT, GR and HSP70 mRNA expression levels significantly increased (p < 0.05). On the other hand, dietary supplementation with taurine significantly reduced levels of BUN, respiratory burst and blood cell apoptosis rate. Supplemented groups significantly increased relative mRNA expression of hepatic CAT, GR and HSP70 as well as increased survival rate (p < 0.05). These results indicated that dietary supplementation with taurine improved ability to resist ammonia stress in hybrid snakehead.  相似文献   

15.
16.
Toxicity of aflatoxin B1 (AFB1) was investigated in juvenile hybrid sturgeon Acipenser ruthenus ♂ × A. baeri♀, an important coldwater finfish farmed in China and other countries. Seven experimental diets (Diet A–G) containing different levels of AFB1 (0, 1, 5, 10, 20, 40 and 80 μg kg?1 diet) were fed to juvenile sturgeon weighing 10.53 ± 0.17 g kg?1 to determine its effect on survival, growth, feed consumption, hematocrit, liver histology as well as muscular and hepatic toxin accumulation. The experiment lasted for 35 days and was conducted in two periods of 25 and 10 days each. No external changes or unusual behaviour was observed in the fish fed diets with AFB1. Mortality was observed in fish fed with highest levels of AFB1 (80 μg kg?1– Diet G) from day 12 onwards. After 25 days, fish fed the diet of 80 μg AFB1 kg?1 showed significant lower survival (50 ± 5.77%) followed by those fed 40 μg AFB1 kg?1 diet (80 ± 5.77%) and 20 μg AFB1 kg?1 diet (86.66 ± 3.33%). No significant difference was observed in specific growth rate (SGR) or hepatosomatic index (HSI) between groups. Hematocrit was significantly higher in the fish fed the diet of highest AFB1. The fish were weighed at day 25 in some treatments (Diets F and G) because of high mortality. However, feeding was continued for another 10 days to observe mortality or behavioural changes if any in the other groups. After 35 days, survival in the fish fed Diet F (40 μg AFB1 kg?1) was 40% and those fed Diet E (20 μg AFB1 kg?1) was 36.2%. Significant histopathological changes including nuclear hypertrophy, hyperchromasia, extensive biliary hyperplasia, focal hepatocyte necrosis and presence of inflammatory cells were observed in the liver of fish fed high levels of aflatoxin (40 and 80 μg kg?1). AFB1 accumulation in fish muscle and liver increased with increased dietary AFB1 levels. It could be confirmed that 10 μg AFB1 kg?1 diet was the maximum allowable level in hybrid sturgeon diet.  相似文献   

17.
This research assessed four levels of crude protein—200, 250, 300 and 350 g/kg—associated with two crude lipid concentrations—110 and 140 g/kg—in diets for juveniles of tambatinga (♀Colossoma macropomum × ♂Piaractus brachypomus) over 63 days. The fish (15.2 ± 0.2 g) were distributed in 24–160 L tanks (11 fish/tank) in a 4 × 2 completely randomized factorial design (n = 3). Increasing the lipid content in the diets reduced (p < 0.05) the protein requirements for weight gain from 326 g/kg (diets with 110 g/kg LIP) to 255 g/kg (diets with 140 g/kg). Protein retention in the fish increased (p < 0.05) when they were fed up to 293 g/kg CP and 140 g/kg LIP; in the diets with 110 g/kg LIP, protein retention decreased linearly (p < 0.05) as the protein content in the diets increased. Feed efficiency increased (p < 0.05) when the fish received up to 308 g/kg CP regardless of lipid concentration (p > 0.05). In conclusion, tambatinga juveniles at 15–120 g have a minimum requirement of 255 g/kg CP and 140 g/kg CL and a protein:energy ratio of 17.4 g CP kJ/digestible energy (DE).  相似文献   

18.
Hybrid seabream (Pagrus major♀ × Acanthopagrus schlegelii♂) grow quickly, with retarded gonadal growth and enhanced muscle nutritional composition. This F1 hybrid seabream is a new marine aquaculture fish in China. However, the response of hybrid seabream to transport is severe, which seriously restricts its promotion and development. Water quality and the physiological response of hybrid sea bream were studied at three fish transport densities (5, 10 and 20 g/L) during 8 hr of transport in a light van (60 km hr?1 and 25°C water temperature). We found that total ammonia–nitrogen and nitrite–nitrogen levels in the water of the highest density group increased sharply after 4 and 8 hr of transport. Cumulative survival of the fish in the 10 and 20 g/L groups (86.7% and 75% respectively) was significantly lower than in the 5 g/L group (100%) after 8 hr of transport (< .05). Serum cortisol and lactate levels were significantly higher after transport than pre‐stress levels, whereas the glucose level decreased significantly (< .05). Hepatic triglyceride and glycogen levels and superoxide dismutase and catalase activities were significantly lower in the 20 g/L group than in the 5 g/L group (< .05). The results show that high‐density transport increased ammonia–nitrogen and nitrite–nitrogen levels in the water as well as cortisol secretion and anaerobic metabolism in the F1 hybrid seabream, suggesting that total cholesterol and glycogen may be used to supply the energy demand and increased oxidative stress. These results will help to optimize the transport conditions for cultured hybrid seabream.  相似文献   

19.
20.
This study seeks to identify the optimal combination of temperature and salinity for the embryo development of the hybrid groupers, Epinephelus fuscoguttatus (♀) × Epinephelus polyphekadion (♂), using the central composite design and response surface methodology. Results have shown that the low hatching rates of fertilized eggs and high deformity rates of larvae were the result of lower or higher temperature/salinity levels. The linear effects of temperature and salinity were significant in both hatching rates and deformity rates (< .01). Similar results were observed in the quadratic effects of temperature and salinity (< .01). Effects of temperature were positively related to salinity effects (< .05). Salinity effects were more remarkable than temperature on hatching rates, but not the same on deformity rates. Model equations were established for temperature and salinity effects on hatching rates and deformity rates. A high coefficient of determination (R> .97) was found for the adequacy and predictive capability of model equations, indicating that these models can be applied to prediction. The optimal combination of temperature and salinity was 27.58°C/30.94, which was derived from the statistical optimization approach. In this condition, the hatching rate was the highest at 85.73%, and the deformity rate was the lowest at 5.96%, with a high desirability function of 0.957. The results of this study can be applied to improve hatching and decrease deformity in future cultures of hybrid groupers.  相似文献   

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