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1.
There is some evidence that single‐cell proteins such as yeast have the potential to improve feed utilization in aquaculture fish, but this has not been investigated in the economically important dusky kob, Argyrosomus japonicus. This study was, therefore, designed to determine the effect of graded levels of dietary inactivated brewer's yeast, Saccharomyces cerevisiae, on the growth performance and hemobiochemical parameters of dusky kob in a 6‐week feeding period. Five isonitrogenous and isoenergetic diets—consisting of three brewer's yeast‐containing diets at rates of 50,150, and 300 g/kg dry matter (BY5P0, BY15P0, and BY30P0, respectively); a commercial dusky kob diet containing 10% probiotic mix but no brewer's yeast (BY0P1, positive control); and a commercial dusky kob diet with neither the probiotic mix nor the yeast (BY0P0, negative control)—were formulated. A total of 65 fish, weighing an average of 7.02 ± 0.10 g, were randomly distributed to each of 20 replicate tanks. Each dietary treatment was randomly allocated to four tanks and offered to fish at a rate of 2.8% fish body weight per day. A total of 10 fish from each tank were randomly sampled once a week for length and weight measurements. Blood was drawn from five fish per tank (20 fish per treatment) for hematology and serum biochemical analyses at the end of the 6 weeks. Fish on the BY0P0 diet achieved the highest weight gain of 18.53 ± 0.69 g after 6 weeks. Growth rate was significantly reduced in the groups fed BY15P0 and BY30P0 diets compared to the BY0P0, BY0P1, and BY5P0 groups. Fish fed the BY0P0 diet recorded the highest average feed conversion efficiency (FCE) of 0.22, while the BY30P0‐fed group recorded the lowest FCE of 0.15. Hematocrit and alanine transaminase levels declined with increasing levels of yeast. It can be concluded that the maximum inclusion level of brewer's yeast that does not impair growth performance and health of dusky kob is 50 g/kg.  相似文献   

2.
An 8‐week feeding trial was conducted with extruded practical diets containing 320 g/kg of crude protein from plant‐based sources to determine the effects of L‐lysine on growth performances, muscle‐growth‐related gene (myoD, myogenine and myostatin) expression and haemato‐biochemical responses in juvenile genetically improved farmed tilapia (GIFT). Five isonitrogenous and isoenergetic diets were formulated to contain graded levels of lysine (14.3, 16, 17.5, 19 and 20.5 g/kg of diet). Each diet was randomly assigned to triplicate groups of 30 juvenile fish (5.2 ± 0.1 g), which were fed thrice a day (9:00, 13:00 and 17:00 hr). Maximum growth performances were observed in fish fed with lysine at 19 g/kg of diet. There was no significant (p > .05) effect on whole‐body composition and amino acids profile by dietary lysine supplementation. Significant (p < .05) changes were observed in relative expression of muscle‐growth‐related genes namely myoD and myogenine and in plasma metabolites by dietary lysine supplementation. In contrast, the relative expression of myostatin was not affected by dietary lysine supplementation. Broken‐line regression analysis and second‐order polynomial regression analysis of weight gain and N gain against dietary lysine levels showed that the dietary lysine requirement for juvenile GIFT tilapia was 18–18.3 g/kg of diet and 19.3–19.5 g/kg of diet, respectively.  相似文献   

3.
Two feeding trials of 8 and 10 weeks each were conducted to quantify the dietary lysine requirement of juvenile striped bass, Morone saxatilis. Diets in both experiments contained approximately 420 g crude protein kg–1 and 13.4 MJ digestible energy (DE) kg?1. L ‐Lysine‐HCl was added to the basal diet to yield five and six treatments in the two experiments. Diets in the first experiment were determined to contain 9.2, 14.1, 14.6, 19.9 and 21.0 g available lysine kg?1 on a dry‐matter basis. Diets in the second experiment were determined to contain 14.8, 18.1, 21.3, 24.5, 27.6 and 30.9 g available lysine kg?1 on a dry‐matter basis. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and apparent nitrogen utilization (ANU) were significantly (P < 0.05) improved by increasing dietary lysine concentrations to approximately 20 g kg?1 of diet. Least‐squares regression analysis of weight gain and SGR in the first experiment indicated a minimum dietary lysine requirement of 20.1 ± 2 g kg?1 dry diet. Least‐squares regression analysis of the same criteria measured in the second experiment yielded the following estimates of dietary lysine requirements (g kg?1 dry diet): 19.8 ± 2.3 for weight gain, 21.7 ± 1.5 for SGR, 23.7 ± 3.5 for FCR and 18.6 ± 1.3 for ANU. From these results the minimum recommended dietary lysine requirement for optimal growth of juvenile striped bass is approximately 21 g kg?1 dry diet which equates to 49 g kg?1 dietary protein or 1.57 mg kJ?1 DE. Although higher than that reported for hybrid striped bass, this requirement level is similar to those reported for many other fish species.  相似文献   

4.
An 8‐week feeding trial was conducted to determine dietary lysine requirement of juvenile Pseudobagrus ussuriensis (initial body weight: 0.60 g). Six isonitrogenous (crude protein, 400 g/kg) and isolipidic (crude lipid, 50 g/kg) diets were formulated to contain graded levels of dietary lysine (12.8, 19.9, 26.5, 34.0, 40.8 and 44.1 g/kg dry diets, respectively). The results indicated that weight gain, specific growth rate, productive protein value and protein efficiency ratio increased, while feed conversion ratio decreased with increasing dietary lysine level up to 34.0 g/kg dry diet and then levelled off. Fish fed diet with 12.8 g/kg lysine had the lowest lysine content (58.6 g/kg dry matter) in muscle, while fish fed diet with 34.0 g/kg lysine had the highest value (61.6 g/kg dry matter; p < .05). Broken‐line analysis on the basis of weight gain showed that the optimal dietary lysine requirement for maximum growth of juvenile Pseudobagras ussuriensis is 33.5 g/kg dry diet (82.4 g/kg dietary protein). Quadratic regression analysis of protein efficiency ratio against dietary lysine levels indicated that the optimal dietary lysine requirement of juvenile Pseudobagras ussuriensis is 36.4 g/kg dry diet (89.5 g/kg dietary protein).  相似文献   

5.
The objective of this study was to determine the minimum dietary requirements of the branched‐chain amino acids (BCAAs: leucine [Leu], isoleucine [Ile] and valine [Val]) for juvenile red drum, Sciaenops ocellatus. This was accomplished by conducting three independent 49‐day feeding trials with juvenile red drum. Experimental diets were prepared by supplementing a basal diet containing 370 g/kg crude protein from red drum muscle and crystalline amino acids with incremental levels of Leu (9.0, 13.0, 17.0, 21.0, 25.0 and 29.0 g/kg of dry diet), Ile (5.0, 8.0, 11.0, 14.0, 17.0 and 20.0 g/kg of dry diet) and Val (6.8, 8.0, 9.2, 10.4, 11.6, 12.8 and 14.0 g/kg of dry diet). Fish were fed to apparent satiation twice daily in each trial, after which growth performance parameters were calculated and body composition and concentrations of BCAAs in plasma were analysed. Incremental levels of dietary Leu, Ile and Val significantly affected weight gain, feed efficiency and protein retention. Analyses of the weight gain data using a broken‐line regression model estimated the minimum Leu, Ile and Val requirements for maximum growth of juvenile red drum to be 15.7 ± 1.7 g/kg (±95% confidence interval), 11.1 ± 2.3 g/kg and 12.4 ± 0.6 g/kg of dry diet, respectively.  相似文献   

6.
A 30‐day feeding experiment was conducted to estimate the lysine requirement of large yellow croaker larvae (2.75 ± 0.11 mg). Six isonitrogenous (509.5–519.7 g kg?1 crude protein) and isoenergetic (22.3–22.5 kJ g?1 energy) microdiets containing graded levels of lysine·HCl ranging from 24.8 to 41.0 g kg?1 diet in placement of glycine and glutamic acid were formulated. Mixture of crystalline amino acids (MAA) was supplemented to simulate the amino acid (AA) profiles of whole body of this larva, except for lysine. The MAA and supplemented lysine for each diet were coated with tripalmitin. Triplicate groups of 3000 fish were fed to apparent satiation by hand eight times per day. The results showed that specific growth rate (SGR), survival, body composition and the specific activity of digestive enzymes were significantly affected by dietary lysine levels (P<0.05). The optimal dietary lysine requirements estimated by second‐order polynomial model based on SGR and survival were 33.7 (65.5 g kg?1 dietary protein) and 33.4 (64.9 g kg?1 dietary protein) g kg?1 dry diet respectively. The estimated requirements for the other essential AAs were calculated by A/E ratios of whole body AA profile of this larva based on lysine requirement.  相似文献   

7.
An 8‐week feeding trial was conducted to determine the dietary leucine requirement for juvenile swimming crabs reared in cement pools. Six isonitrogenous and isolipidic practical diets (430 g/kg crude protein and 70 g/kg crude lipid) were formulated to contain graded leucine levels which ranged from 16.7 to 26.7 g/kg (dry weight). Each diet was randomly assigned to triplicate groups of 60 juvenile swimming crabs (initial average weight 3.75 ± 0.12 g) that were stocked in rectangle plastic baskets. The results of the present study indicated that dietary leucine levels significantly influenced weight gain (WG) and specific growth ratio (SGR) (p < .05), crab fed the diet containing 22.7 g/kg leucine had significantly higher WG and SGR than those fed the other diets. Feed efficiency and protein efficiency ratio were not significantly affected by the dietary leucine levels (p > .05). Total protein, cholesterol, triglyceride and glucose in serum were significantly affected by the dietary leucine levels. Aspartate aminotransferase (AST) and alanine aminotransferase activities in hemolymph, AST and superoxide dismutase activities in hepatopancreas were significantly affected by dietary leucine levels; moreover, crab fed the 16.7 g/kg leucine diet had higher malondialdehyde in hemolymph and hepatopancreas than those fed the other diets. Crab fed the diet containing 24.9 g/kg leucine had higher phenoloxidase activity in hemolymph than those fed the other diets. Based on two‐slope broken‐line model of SGR against dietary leucine levels, the optimal dietary leucine requirement for growth was estimated to be 22.1 g/kg of the dry diet (corresponding to 51.4 g/kg of dietary protein on a dry weight basis). In summary, findings of this study indicated that dietary leucine could improve growth performance and antioxidant status.  相似文献   

8.
This experiment was designed to investigate the effects of dietary valine on the growth performance, feed utilization, digestive enzymes, serum antioxidant and immune indices of juvenile Trachinotus ovatus and determine its valine requirement. Six diets with different concentrations of L‐valine (15.0, 16.6, 18.6, 20.7, 23.5 and 25.4 g/kg dry diet, defined as diet Val‐1 to Val‐6.), were formulated to contain 430 g/kg crude protein with fish meal, soybean meal, peanut meal and precoated crystalline amino acids. Each diet was randomly assigned to triplicate treatments of 20 fish (the initial body weight was 5.34 ± 0.03 g) for 8 weeks. The results indicated that the final body weight and percent weight gain (PWG) increased with increasing valine concentration up to 18.6 g/kg (diet Val‐3), whereas the diets containing higher valine concentration reduced the growth performance significantly (p < .05). Moreover, the protein efficiency ratio, body protein deposition (BPD), muscle protein content, intestinal amylase and pepsin activities, serum T‐AOC, LZM activities, IgM, complement 3 and complement 4 concentration had a similar trend with PWG, and the trend of feed conversion ratio, serum AST, ALT activities, urea and MDA content was opposite. Meanwhile, the lipid contents of whole fish and muscle in diet Val‐6 were particularly lower than other diets (p < .05). The survival rate of diet Val‐1 was lowest in this study and was significantly lower than diet Val‐2 (p < .05). The results of polynomial regression based on PWG and BPD indicated that the optimal dietary valine requirement for Trachinotus ovatus reared in seawater‐floating net cages was 19.87–20.17 g/kg valine of dry diet, correspondingly 46.22–46.91 g/kg of dietary protein.  相似文献   

9.
Five isonitrogenous and isocaloric diets containing dietary lipid concentrations from 71.90 to 142.70 g/kg were formulated and fed to Chinese rice field eel Monopterus albus fingerlings (5.00 ± 0.50 g). The highest values of weight gain, specific growth rate (SGR), together with the lowest feed conversion ratio (FCR) were found in fish fed with 89.10 g/kg lipid diet. Fish fed with 71.90 g/kg diet (F1) had higher hepatosomatic index, viscerosomatic index and whole‐body crude lipid than fish in the other four treatments (p < .05). Plasma concentration of triacylglycerol and the activity of alanine aminotransferase were also higher in fish fed with F1 diet. Whole‐body fatty acid profile varied exclusively, but with a stable value of n?3/n?6 ratio. Gas chromatography–mass spectrometry‐based metabolomics identified eighteen differential metabolites (including idose, alanine, glutamic acid, serine and hypotaurine) in liver affected by dietary lipid content using PLS‐DA analysis. The subsequent pathway enrichment revealed ten affected pathways, with the top three pathways being glycine, serine and threonine metabolism; starch and sucrose metabolism; and D‐glutamine and D‐glutamate metabolism. The broken‐line model of SGR suggested that a dietary lipid concentration of 83.50 g/kg was appropriate for M. albus fingerlings.  相似文献   

10.
A 6‐week feeding trial was conducted for determining the effects of dietary essential amino acids (EAA) deficiencies on growth performance and non‐specific immune responses in silvery‐black porgy juveniles (4.7 ± 0.1 g initial weight). Eleven isoproteic (ca. 47%) diets were formulated including a control diet containing the optimum quantity of EAA, and ten EAA‐deficient diets. All diets contained 36% fish meal and 18.5% crystalline EAA and non‐essential amino acids (NEAA) as the main source of dietary proteins. All the EAA and NEAA incorporated in the crystalline amino acids mixture of the control diet simulated the amino acids profile of the fish meal. The other 10 EAA‐deficient diets were formulated by the deletion of each of the 10 EAA (crystalline form) from the control diet and replaced by a mixture of NEAA for the adjustment of dietary nitrogen contents. At the end of the experiment, fish fed with threonine‐deficient diet showed the lowest survival rate (p < .05), whereas growth performance decreased in fish fed all EAA‐deficient diets, although the reduction in body growth varied depending on the EAA considered. Plasma total protein decreased in all experimental groups except for fish fed the phenylalanine‐deficient diet. Fish fed with arginine‐ and lysine‐deficient diets had the lowest plasma C3, C4, lysozyme, total immunoglobulin and total superoxide dismutase activity (p < .05). Present results indicated that lysine, methionine and threonine were the most limiting EAA in terms of growth performance; however, arginine, threonine and lysine were the most limiting EAA for innate immunity responses in silvery‐black porgy juveniles.  相似文献   

11.
Recommended dietary crude protein (CP) requirements (210 to ≥360 g/kg) for optimal growth of juvenile yellow perch Perca flavescens (YEP) vary. This study determined the optimal CP requirement for YEP using semi‐purified diets containing essential amino acid ratios of YEP whole body. Six diets were formulated to contain 337, 379, 415, 453, 495 and 540 g/kg CP, but similar gross energy (~20 MJ/kg). Eighteen fish (~5.3 ± 0.5 g each) were stocked per 110‐L tank of a 30‐tank recirculating system, providing five replicates per treatment. Fish were fed sinking feeds at 3% body weight per day, and feed amounts were adjusted every 21 days. After 15 weeks, weight gain increased with increasing CP up to 415 g/kg. Relative growth (RG) and specific growth rate (SGR) increased up to 453 and 415 g/kg, respectively. Feed conversion ratios improved with increasing CP up to 453 g/kg. Protein efficiency ratios decreased with increasing CP. Whole‐body composition did not differ with increasing CP. Protein deposition did not differ beyond 415 g/kg, and apparent net protein utilization of 540CP was the lowest. Broken‐line non‐linear regression of RG conservatively estimated optimal dietary CP to be 457 g/kg, which is supported by the peak (CP456) in SGR.  相似文献   

12.
A 12‐week feeding trial was conducted to determine the dietary phosphorus requirement of Heteropneustes fossilis fingerlings (7.7 ± 0.04 g). Fish were fed casein–gelatine‐based purified diets in triplicate groups near satiation with seven different levels of dietary phosphorus (3.2, 5.2, 7.2, 9.2, 11.2, 13.2 and 15.2 g/kg dry diet). All diets were formulated to be isoproteic (400 g/kg) and isoenergetic (17.89 kJ/g). Highest absolute weight gain (68.38 g/fish), best feed conversion ratio (1.48), protein retention efficiency (30.74%), protein gain (12.44 g/fish), haemoglobin (11.19 g/dL), RBCs (3.12 x106/mm3), haematocrit (33.44%) and serum phosphate (2.82 mg/L) were found at 9.2 g/kg phosphorus. Hepatic superoxide dismutase and catalase activity were also significantly influenced by the dietary phosphorus levels. Whole body and vertebrae phosphorus concentrations increased significantly as the amount of dietary phosphorus increased from 3.2 to 11.2 g/kg dry diet and then plateaued. More accurate information on dietary phosphorus requirement was obtained by subjecting the AWG, FCR, vertebrae phosphorus and whole body phosphorus concentrations data against various levels of dietary phosphorus to broken‐line analysis, which yielded the requirement in the range of 9.0–11.0 g/kg for optimum growth and mineralization of H. fossilis.  相似文献   

13.
A 60‐day trial was conducted to investigate the effect of dietary protein on growth, whole‐body composition, hepatopancreas enzymes, digestion and absorption in the juveniles of Schizopygopsis younghusbandi. Six graded levels of dietary protein (200.0, 248.7, 303.5, 351.2, 395.8 and 449.3 g/kg diet) were formulated and assigned to triplicate groups of 60 fish (8.16 ± 0.02) for each aquarium. Results showed a significantly increased specific growth rate (SGR) in fish fed protein containing 351.2 g/kg diet (p < .05). Besides, intestinal ratio (IR), intestinal somatic index (ISI) and hepatosomatic index (HSI) were decreased and the condition factor (CF) was increased with dietary protein up to 351.2 g/kg diet, then altered reversely. Fish fed the optimal dietary protein showed the highest crude protein calcium, phosphorous and lowest crude lipid contents of the whole body in fish. Additionally, plasma ammonia content (PAC), and activities of GOT and GPT were enhanced by dietary protein levels (p < .05). The digestive enzymes of hepatopancreas were generally increased with the quadratic response to dietary protein levels. Optimal dietary protein level increased the intestinal enzyme activities of Na+, K+‐ATPase (NKA), alkaline phosphatase (AKP), gamma‐glutamyl transpeptidase (γ‐GT) and creatine kinase (CK). Based on the 2‐slope broken‐line model analysis of PWG, dietary protein requirement was determined to be 349.6 g/kg diet.  相似文献   

14.
A feeding trial was conducted to determine the dietary threonine requirement of juvenile large yellow croaker (Larmichthys crocea). Six diets were formulated containing 45% crude protein with six graded levels of threonine (0.71–2.46% in about 0.35% increment). Each diet was randomly assigned to triplicate groups of 60 juvenile fish (initial body weight 6.00 ± 0.10 g). Fish were fed twice daily (05:00 and 16:30) to apparent satiation for 8 weeks. The result indicated that significant difference was observed in the weight gain among all treatments. Specific growth rate (SGR), feed efficiency (FE), protein efficiency ratio (PER) and nitrogen retention (NR) increased with increasing levels of threonine up to 1.75% diet (P < 0.05), and thereafter, declined. No significant differences in body dry matter, crude protein, crude lipid or ash content were found among dietary treatments. Theronine contents of fish muscle were significantly affected by dietary threonine levels (P < 0.05). Fish fed the diet with 0.71% threonine showed the lowest threonine content (2.94%) in fish muscle, while fish fed the diet with 1.75% threonine had the highest value (3.16%). Other essential amino acid contents of muscle were not significantly different among the dietary treatments. On the basis of SGR, FE or NR, the optimum dietary threonine requirements of juvenile L. crocea were estimated to be 1.86% of diet (4.13% of dietary protein), 1.90% of diet (4.22% of dietary protein) and 2.06% of diet (4.58% of dietary protein), respectively, using second‐order polynomial regression analysis.  相似文献   

15.
Quantitative l-lysine requirement of juvenile grouper Epinephelus coioides   总被引：3，自引：0，他引：3  
An 8‐week feeding trial was conducted to determine the quantitative lysine requirement of juvenile grouper Epinephelus coioides (initial mean weight: 15.84 ± 0.23 g, mean ± SD) in eighteen 500‐L indoors flow‐through circular fibreglass tanks provided with sand‐filtered aerated seawater by feeding diets containing six levels of l ‐lysine ranging from 19.2 to 39.5 g kg?1 dry diet in 4 g kg?1 increments. The diets, in which 250 g crude protein kg?1 diet came from fish meal and soybean protein concentrate, and 230 g kg?1 from crystalline amino acids, were formulated to simulate the amino acid profile of 480 g kg?1 whole chicken egg protein except for lysine. Each diet was assigned to three tanks in a completely randomized design. Grouper were fed to apparent satiation twice daily during the week and once daily on weekends. Weight gain and specific growth rate increased with increasing levels of dietary lysine up to 27.2 g kg?1 (P < 0.05) and remained nearly the same thereafter (P > 0.05). Feed efficiency was the poorest for fish fed the lowest lysine diet (P < 0.05) and showed no significant differences among other treatments (P > 0.05). Survival could not be related to dietary treatments. Body composition remained relatively constant except for lipid contents in muscle and liver. Total essential amino acid contents in liver increased with dietary lysine level although there was a slight decline for fish fed the highest lysine level of diet. Plasma protein content increased with increasing dietary lysine level (P < 0.05), but cholesterol, triacylglycerol and glucose contents were more variable and could not be related to dietary treatments. Dietary lysine level significantly influenced morphometrical parameters (condition factor, hepatosomatic index and intraperitoneal fat ratio) of juvenile grouper (P > 0.05). Broken‐line analysis of weight gain indicated the dietary lysine requirement of juvenile grouper to be 28.3 g kg?1 diet or 55.6 g kg?1 dietary protein.  相似文献   

16.
An 8‐week feeding trial was conducted to estimate the optimum dietary manganese (Mn) requirement for juvenile hybrid grouper, Epinephelus lanceolatus × E. fuscoguttatus. The basal diet was formulated to contain 520 g/kg crude protein from casein and fishmeal. Manganese methionine was added to the basal diet at 0 (control group), 2.5, 5, 10, 20 and 40 mg Mn/kg diet providing 7.48, 10.34, 13.76, 19.72, 31.00 and 53.91 mg Mn/kg diet, respectively. Each diet was randomly fed to triplicate groups of juveniles, and each tank was stocked with 20 fish (initial weight, 60.06 ± 0.68 g). The manganese content in rearing water was monitored and kept below 0.01 mg/L. Results showed that the weight gain ratio (WGR), protein efficiency ratio (PER), specific growth rate (SGR), Mn contents in whole body, liver and vertebra, and activities of hepatic Mn superoxide dismutase (Mn‐SOD), total SOD (T‐SOD) and glutathione peroxidase (GSH‐PX) were significantly improved by dietary Mn supplementation (p < .05). However, dietary Mn did not affect arginase (DArg) activity. The highest feed conversion ratio (FCR) was observed in fish fed the basal diet (p < .05). No significant differences were found on the Cu and Zn contents in whole body by supplementing dietary Mn. Supplemented Mn in diets had significantly effect on liver and vertebral trace element deposition (p < .05). Fish fed the basal diet had the highest Fe and Zn contents in vertebra (p < .05). There were no significant differences on hepatic pyruvate decarboxylase (PDC) activity with supplemented Mn levels below 13.76 mg/kg. As biomarker of oxidative stress, malondialdehyde (MDA) content in liver was significantly higher in fish fed the basal diet (p < .05). Using the broken‐line models based on SGR, dietary Mn requirement of the juvenile hybrid grouper was estimated to be 12.70 mg/kg diet.  相似文献   

17.
Spirulina has been highlighted as a valuable complementary ingredient in aquafeeds due to its high protein and vitamin content, in addition to other nutritional benefits. To evaluate the effect of dietary spirulina inclusion in fish meal sparing (FMS) on juvenile Caspian brown trout as a slow‐growth fish, a complete randomized experimental design was developed with five treatments: 0% (control), 2% FMS (13.2 g/kg spirulina in diet), 4% FMS (26.4 g/kg spirulina in diet), 6% FMS (39.6 g/kg spirulina in diet) and 8% FMS (52.8 g/kg spirulina in diet). Six hundred juveniles (11.0 ± 1.0 g) were assigned to 15 experimental tanks. Although this fish is sensitive to diet composition, fish fed the 6% FMS and 8% FMS diets had a significantly higher weight gain rate (239.51% and 231.27%) and specific growth rate (1.74% bw per day and 1.71% bw per day) compared with those fed the control diet. Furthermore, 6% FMS and 8% FMS treatments had statistically higher protein efficiency (0.76 and 0.78), lipid efficiency (1.89 and 1.94) and statistically lower feed conversion ratio (2.47 and 2.41) compared with other treatments, respectively (p < 0.05). In terms of whole‐body composition, the higher amount of protein and lower content of lipid were observed in fish fed the 8% FMS diets as compared to control. Although no significant differences in ash and moisture content were observed, the highest protein deposition (157.3 g/kg) and the lowest lipid content (77 g/kg) in whole body were reported in fish fed 8% FMS diet. Based on the fillet fatty acid outcome, fish fed the 8% FMS diet had significantly higher saturated fatty acids (SFAs), C20:3n‐6, C18:3n‐3, polyunsaturated fatty acids (PUFAs) and total n‐3 fatty acids as compared to those fed the control diet (p < 0.05). Accordingly, increasing dietary spirulina content significantly enhanced the amount of these fatty acids in fish fillet. As regards of whole‐body amino acid profile, arginine and lysine in fish fed 6% FMS and 8% FMS diets were higher and lower than in those fed the control diet, respectively (p < 0.05). Fillet and skin colour parameters, such as luminosity, redness and yellowness, significantly increased with spirulina supplementation with the 8% FMS treatment displaying higher values than the control. In summary, according to our results, 8% FMS (52.8 g/kg spirulina in diet) treatment improved juvenile Caspian brown trout growth, carcass composition and pigmentation.  相似文献   

18.
A 16‐week experiment was conducted to determine the dietary riboflavin requirement of the fingerling Channa punctatus (6.7 ± 0.85 cm; 4.75 ± 0.72 g) by a feeding casein–gelatin‐based (450 g/kg crude protein; 18.39 kJ/g gross energy) purified diet containing graded levels of riboflavin (0, 2, 4, 6, 8, 10 and 12 mg/kg diet) to triplicate groups of fish near to satiation at 09:30 and 16:30 hr. Absolute weight gain (AWG), protein efficiency ratio (PER), specific growth rate (SGR, % per day), protein retention efficiency (PRE%) and RNA/DNA ratio were positively affected by increasing concentrations of dietary riboflavin to 6 mg riboflavin per kg diet. Feed conversion ratio (FCR) decreased up to 6 mg riboflavin per kg diet but did not decrease further with higher riboflavin supplementation. Hepatic thiobarbituric acid‐reactive substance (TBARS) concentration also supported the pattern of FCR, whereas superoxide dismutase and catalase activities increased with increasing concentrations of dietary riboflavin from 0 to 6 mg/kg. Liver riboflavin concentrations increased with increasing levels of riboflavin up to 8 mg/kg diet. Broken‐line regression analysis of AWG, PRE and liver riboflavin concentrations of fingerling C. punctatus with dietary riboflavin level indicated optimum growth and liver riboflavin saturation at 5.7, 6.1 and 7.7 mg riboflavin per kg diet, respectively.  相似文献   

19.
The dietary folic acid requirement of fingerling Catla catla (3.4 ± 0.17 g; 7.6 ± 0.41 cm) was evaluated by feeding casein–gelatin‐based isonitrogenous (350 g/kg crude protein) and isocaloric (16.72 kJ/g GE) diets containing different concentrations of folic acid (0, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0 mg/kg) to triplicate groups to apparent satiation at 08:00, 12:30 and 17:30 hr for 16 weeks. Absolute weight gain (AWG; 40.07 g/fish), specific growth rate (SGR; 2.25%), feed conversion ratio (FCR; 1.53), protein retention efficiency (PRE; 31.42%) and protein gain (PG; 6.74) improved significantly (p < .05) with increasing folic acid levels up to 0.4 mg/kg diet and then reached a plateau. However, maximum liver folic acid concentration increased up to 0.6 mg/kg diet. Dietary folic acid levels also significantly affected (p < .05) body composition of fish. No significant change (p > .05) in haematological parameters except in fish fed folic acid‐free diet was noted. Antioxidant and immune parameters increased with increasing concentration of dietary folic acid up to 0.4 mg/kg diet. Broken‐line regression analysis of AWG, FCR, PRE, PG, HCT and liver folic acid concentrations of fingerling C. catla against dietary folic acid levels indicated optimum growth, FCR, PRE, PG, HCT and liver folic acid saturation ranging between 0.22 and 0.56 mg/kg diet, respectively.  相似文献   

20.
This study investigated the effect of two lipid sources on reproduction performance and growth in pearl gourami. For this purpose, 180 fish (3.32 ± 0.25 g) were fed with three isoenergetic (19.80) and isonitrogenous diets (480 g/kg protein) including FO (80 g/kg fish oil), FS (40 g/kg fish oil and 40 g/kg soybean oil) and SO (80 g/kg soybean oil) for 10 weeks before maturation. At the end of the trial, there was no significant difference in weight gain, feed conversation ratio and body composition between fish fed FO and FS diets. Individuals fed dietary FO had significantly higher levels of n‐3 long‐chain polyunsaturated fatty acids in the muscle (130.5 g/kg lipid) and ovary (140.4 g/kg lipid) as compared with those fed SO diet (64.5, 103.6 g/kg, respectively) (p < .05). Feeding pearl gourami with FO and FS diets enhanced regarding absolute fecundity, relative fecundity, the fertilization rate, larvae total length and survival at 3 day posthatch (p < .05). Also, 17 beta‐estradiol in plasma of fish fed dietary FO (6.2 ng/L) was higher than those fed SO diet (1.7 ng/L) (p < .05). In conclusion, we suggest FS diet for broodstock nutrition of pearl gourami as a model for asynchronous multi‐batch spawning fish.  相似文献   

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