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1.
In the present study, konjac mannanoligosaccharide (KMOS) was evaluated as a prebiotic in yellow catfish. The fish were fed with diets containing KMOS in four concentrations: 0 g kg?1 (C), 1.0 g kg?1 (KM1), 2.0 g kg?1 (KM2), and 3.0 g kg?1 (KM3) for 49 days, respectively. Another group fed with diets containing 3.0 g kg?1 yeast cell wall mannanoligosaccharide (MOS) (M3) was set as positive control. The results indicated that fish receiving the diets supplemented with KMOS or MOS showed higher relative gain rate (RGR), specific growth rate (SGR), and lower feed conversion ratio (FCR) with significantly differences (P < 0.05) than those fed with the basal diets. Moreover, fish receiving the diets with 2.0 g kg?1 KMOS inclusion showed higher RGR, SGR, and lower FCR (P < 0.05) than that feeding the diets supplemented with 3.0 g kg?1 MOS. The quantities of Bifidobacterium spp. were significantly increased (P < 0.05). Meanwhile, Escherichia coli and Aeromonas spp. were significantly reduced (P < 0.05) in the fish-feeding diets with 2.0 g kg?1 KMOS supplement. Compared with the control group, the significantly enhancement of protease and amylase activity (P < 0.05) in intestine and pancreas was observed in fish fed with diets containing KMOS or MOS. Collectively, an optimum level of KMOS inclusion in diets could modulate intestinal microflora, induce digestive enzyme activity, and improve the growth performance of yellow catfish significantly.  相似文献   

2.
The effect of graded levels of dietary available phosphorus (AP) on large Nile tilapia (145.87 ± 9.51 g) performance, feed efficiency, body composition and mineral retention in vertebrae was evaluated. All male fish were distributed into three replicates in fiberglass aquaria (800 L each; 12 fish per tank) for 87 days and hand fed to pelletized diets three times a day until apparent satiation. Diets with approximately 302 g kg?1 of digestible protein and 15.2 kJ g?1 of digestible energy with graded levels of dibasic phosphate yield AP levels of 2.39, 4.17, 6.12 and 8.91 g kg?1. At the end of the trial, feed intake, hepatosomatic index, fillet yield, whole body moisture and crude protein of fish fed 2.39–8.91 g kg?1 of AP diets were not significantly different. The supplementation of 6.12 and 8.91 g kg?1 of AP resulted in significantly increased weight gain, whole body ash and calcium. Whole body crude lipids significantly decreased with increasing AP from 6.12 to 8.91 g kg?1. However, concentration of zinc in the vertebrae was not affected by dietary treatments. The magnesium contents of the fish vertebrae were lower in fish fed lower dietary AP level. No effects of the dietary AP on apparent digestibility coefficients of energy and nutrients were observed. The study indicated that the dietary AP level of at least 6.12 g kg?1 satisfies the needs for growth performance, body composition and bone mineralization of large Nile tilapia.  相似文献   

3.
The effect of dietary mannan oligosaccharide (MOS; activeMOS®) on growth, survival, and body composition in giant sturgeon juvenile (Huso huso) with initially average weight 46.89 ± 2.57 was investigated for a period of 46 days. Basal diet were supplemented with 0 (control), 2, and 4 g kg?1 MOS in a totally randomized design trial in triplicate groups. The results showed no significant differences in growth and feeding parameters between control and treatment groups (MOS supplementation diets) (P > 0.05). There was a statistically significant decrease (P < 0.05) in feed per fish level in only group treated with 4 g kg?1 MOS. The highest and the lowest growth performances were observed in 2 and 4 g kg?1 MOS, respectively. There were no significant differences in survival rate among all treatment groups (P > 0.05). In group treated with 2 g kg?1 MOS was a significant difference in lipid carcass (P < 0.05), whereas protein, ash, and moisture remained unaffected (P > 0.05). However, no significant difference was observed in intestinal lactic acid bacteria between all treatment groups (P > 0.05). There were no significant differences in hematological parameters between control and MOS treatment groups (P > 0.05). These results suggested that the prebiotic mannan oligosaccharide did not influence the growth performance in giant sturgeon juvenile, and it is not appropriate for supplementation in the diet of cultured juvenile giant sturgeon.  相似文献   

4.
A feeding trial was conducted to evaluate the effect of replacing fish meal protein with fermented soybean meal (FSM) on the growth performance, feed utilization, amino acid profile, body composition, morphological parameters, activity of antioxidant and digestive enzymes of black sea bream (Acanthopagrus schlegeli) juvenile. Five isonitrogenic and isolipidic diets were prepared with levels of 0 (control), 80, 160, 240 and 320 g kg?1 FSM. Triplicate groups (40 fish per tank) of juvenile black sea bream with initial weight of 1.17 ± 0.04 g were hand‐fed to visual satiation at three meals per day for 8 weeks. The fish fed diets containing different levels of FSM had no significant differences regarding survival and specific growth rate compared with control group. Feed and protein efficiency ratios of fish fed diet containing 320 g kg?1 FSM were significantly lower than those of control group. Daily feed intake and daily protein intake of fish fed diet containing 240–320 g kg?1 were significantly higher than those of control group. Hepatosomatic index and condition factor of fish were not affected by different dietary FSM level. Fish fed diets containing 240–320 g kg?1 FSM had significantly higher visceral somatic index than control group. Whole body proximate and amino acid compositions of fish were not affected by dietary FSM level. The activity of digestive enzymes in the intestine was not affected by dietary FSM level. The activity of glutathione peroxidase in liver was significantly higher for fish fed the diet containing 160 g kg?1 FSM compared with control group. This study showed that up to 40% fish meal in the diets of juvenile black sea bream could be replaced by fermented soybean meal with supplementation of methionine, lysine and taurine.  相似文献   

5.
An 84‐day feeding trial was conducted to study the effect of different levels of dietary protein, 250 (P25), 300 (P30), 350 (P35), 400 (P40) and 450 g (P45) kg?1 dry matter (DM) on growth, feed intake, feed utilization and carcass composition of bagrid catfish Horabagrus brachysoma fingerlings. Triplicate groups of fingerlings with mean initial body weight of 2.2 g were fed the experimental diets twice daily, till satiation, in 150‐L tanks supplied with flow‐through freshwater. Daily dry matter intake by the fingerlings decreased significantly (P < 0.05) when fed P25 diet, containing 250 g protein kg?1. The highest body weight gain, specific growth rate (SGR) and protein efficiency ratio (PER), and the lowest feed conversion ratio (FCR) were observed in fish fed 350 g protein kg?1 diet. The fish fed with P45 diet had the lowest (P < 0.05) carcass lipid content. The polynomial regression analysis indicates that H. brachysoma fingerlings require 391 g dietary crude protein kg?1 diet.  相似文献   

6.
A 10‐week feeding trial with four dietary protein levels (400, 450, 500 and 550 g kg?1 crude protein) and two dietary lipid levels (80 and 160 g kg?1 crude lipid) was conducted to assess optimum dietary protein and lipid levels for the growth, feed utilization and body composition of juvenile Manchurian trout (initial weight 11.80 ± 0.15 g). Fish were fed twice daily (08:30 and 16:30 h) to apparent satiation. The results showed that fish fed the diet with 500 g kg?1 protein and 80 g kg?1 lipid had the highest growth and feed efficiency. However, fish fed the diet with 450 g kg?1 protein and 160 g kg?1 lipid showed comparable growth to that of the fish fed diet 5 (500/80) and had higher protein efficiency ratio (PER), nitrogen retention (NR) and energy retention (ER) than other groups (P < 0.05). Growth, PER, NR and ER of fish fed the 160 g kg?1 lipid diet was significantly higher (P < 0.05) than that of fish fed the 80 g kg?1 lipid diet at 400 and 450 g kg?1 protein diet, whereas these values showed an opposite trend at 500 and 550 g kg?1 protein diet, and the lowest PER, NR and ER was found by fish fed the 400 g kg?1 protein diet with 80 g kg?1 lipid. Fish fed diets with 400 g kg?1 protein had lower feed intake (FI) than that of other groups. Feed intake of fish fed 80 g kg?1 lipid level was significantly lower than that of fish fed 160 g kg?1 lipid diet at 400 g kg?1 protein (P < 0.05), while no significant differences were observed at 450, 500 and 550 g kg?1 protein‐based diets. Contrary to moisture content, lipid content of whole body and muscle increased significantly (P < 0.05) with increasing lipid levels. The results of this study indicated that the diet containing 450 g kg?1 protein and 160 g kg?1 lipid, with a P/E ratio of 23.68 g protein MJ?1 would be suitable for better growth and feed utilization of juvenile Manchurian trout under the experimental conditions and design level used in this study.  相似文献   

7.
Five isocaloric‐isonitrogenous diets containing 0, 150, 300, 450 and 600 g kg?1 of fungi Trichoderma reesei‐degraded date pits (DDP), as a replacement for dietary corn, were fed to triplicate groups of Nile tilapia Oreochromis niloticus L. fingerlings (1.88 g initial weight), for 9 weeks, in 70 L fibreglass tanks. Each tank was considered as an experimental unit and was part of a water recirculating system utilizing filtered and aerated ground well water (24 ± 3 °C). Tilapia growth performance, namely, weight gain, feed conversion, specific growth rate and protein efficiency ratio were similar and superior in fish fed diets containing 150 and 300 g kg?1 DDP, when compared with those fish fed the other diets. Fish fed the control diet with 450 g kg?1 DDP had better growth efficiency performance than those fed diets containing 0 and 600 g kg?1. Fish fed the diet with 600 g kg?1 DDP were inferior to all other groups. Tilapia body composition was affected by increasing DDP level in the diets as body fat was decreased, while body moisture was increased. In conclusion, DDP could replace 300 g kg?1 of dietary corn with better growth results. Further increase of date pits replacements to 450 g kg?1 will affect growth performance, when compared with the control.  相似文献   

8.
This study was conducted to estimate the dietary biotin requirement for maximum growth of zebrafish Danio rerio. Six isonitrogenous and isocaloric purified diets containing 0.031 (biotin‐unsupplemented diet), 0.061, 0.263, 0.514, 1.741 and 2.640 mg biotin kg?1 diet were fed in triplicate tanks for a total of 12 weeks to juvenile zebrafish (initial mean body mass 0.13 ± 0.001 g). From 4 weeks of feeding, fish fed diets with ≤0.061 mg biotin kg?1 showed biotin deficiency signs, such as retarded growth and skeletal deformity, was observed on some dead fish. At the end of the study, gill disorders were observed on some fish and liver glycogen accumulation were also observed in fish fed these diets. Fish fed the biotin‐unsupplemented diet exhibited a lower final body weight, protein efficiency ratio and feed utilization than the fish fed the biotin‐supplemented diets, whereas the highest values were observed with the diet containing 0.51 mg biotin kg?1 diet (P < 0.05). A linear relationship (r2 = 0.77; P < 0.0001) was observed between whole‐body biotin content and dietary biotin level. A broken‐line analysis indicated that the optimum dietary biotin content for maximal growth expressed as final body weight is 0.51 mg kg?1 diet.  相似文献   

9.
Protein requirement of silver barb, Puntius gonionotus fingerlings   总被引：2，自引：0，他引：2  
Five iso‐energetic (15.05 MJ kg?1) semi‐purified diets with graded levels of crude protein, i.e. 200 (D‐1), 250 (D‐2), 300 (D‐3), 350 (D‐4) and 400 (D‐5) g kg?1 diet were fed to Puntius gonionotus fingerlings (average weight 0.88 ± 0.03 g) in triplicate groups (15 healthy fish per replicate) for a period of 90 days to determine the optimum protein requirement of the fish. Fifteen flow‐through cement tanks of 100‐L capacity with a flow rate of 0.5 L min?1 were used for rearing the fish. Specific growth rate (SGR), food conversion (food gain) ratio (FCR), nutrient digestibility and retention, digestive enzyme activity, RNA : DNA ratio and tissue composition were used as response parameters with respect to dietary protein levels and feed intake. The mean weight gains of fish after 90 days were 10.84 ± 0.27, 11.07 ± 0.12, 14.09 ± 0.20, 11.27 ± 0.12 and 10.91 ± 0.25 g for D‐1, D‐2, D‐3, D‐4 and D‐5, respectively. Maximum SGR (3.13 ± 0.02% per day), RNA : DNA ratio (10.09 ± 0.09), tissue protein content (160 ± 0.1 g kg?1 wet weight), protease activity (25.27 ± 0.47 μg of leucine liberated mg tissue per protein h?1 at 37 °C) and minimum FCR (1.60 ± 0.02) was found in D‐3 group fed with 300 g kg?1 protein level. All these parameters were negatively affected with the further increase in protein level in the diet. Digestibility of protein, lipid and energy was not affected because of variation in dietary protein levels and nitrogen intake of fish. Maximum energy retention (27.68 ± 0.12%) was recorded at 300 g kg?1 dietary crude protein fed group. However, using broken line regression analysis, the maximum growth was found to be at 317.7 g kg?1 dietary protein. Hence, it may be concluded that the protein requirement of P. gonionotus fingerling is 317.7 g kg?1 diet with a resultant P/E ratio of 21.1 g protein MJ?1.  相似文献   

10.
The objective of the present work was to determine the optimum dietary protein level for juvenile mullets. Five isocaloric diets were formulated to contain increasing levels (300, 350, 400, 450 and 500 g kg?1) of crude protein (CP) corresponding to 18.7 MJ metabolizable energy kg?1. All diets were tested in triplicate. Each experimental unit was composed of a 50 L tank with 50 juveniles (mean ± SE initial weight and length equal to 1.17 ± 0.02 g and 4.34 ± 0.03 cm respectively). Diets were offered five times a day until apparent satiation for 35 days. No significant difference (P>0.05) was observed in survival rate, feed efficiency and body composition between treatments. However, weight gain, feed consumption and specific growth rate were higher in fish fed the 350 g kg?1 CP level than those fed the highest protein content diet (500 g kg?1 CP). The amount of postprandial ammonia excreted by mullet was linearly related to protein intake. Intestinal tryptic activity was inversely proportional to the percentage of dietary CP. It is likely that diets containing <350 g kg?1 CP will be needed for on‐growing mullet, especially when reared in ponds with abundant natural food.  相似文献   

11.
This study was conducted to investigate the prebiotic effect of different Dietary Fibre Concentrates (DFC) (Mucilage =MG; Pectin = PN or β‐glucan + mannan = βg + M) on growth and somatic parameters, body composition and digestive enzyme activities of jundiá (Rhamdia quelen). After acclimation, fish (7.16 ± 0.06 g) were allocated into 24 tanks (30 fish per tank) and triplicate groups were fed with Control diet (0 g kg?1 of DFC); diet supplemented with 5 g kg?1 commercial prebiotic (CP) or diets supplemented with 5 or 10 g kg?1 diet of MG; PN or βg + M. At the end of the trial (8 weeks), growth was significantly (P < 0.05) higher in fish fed diets supplemented with DFCs and did not differ from animals supplemented with CP. The animals that were fed Control diet presented a body protein content higher compared to those supplemented with diets containing pectin or β‐glucan + mannan (P < 0.05). However, fish fed diets added with β‐glucan + mannan yielded a higher level of protein deposited in the whole body. The activity of digestive enzymes was lower in the group supplemented with Pectin. Results indicate that supplementation with DFCs in the diet had positive effects on the performance of jundiá and are prebiotic potential candidate.  相似文献   

12.
Rainbow trout (initial body weight 4.16 ± 0.25 g) were fed diets [crude protein 420 g kg?1; gross energy 18.7 MJ kg?1 dry matter (DM); crude fat 110 g kg?1] containing graded levels of either a canola meal (crude protein 350 g kg?1 DM) supplemented with DL‐methionine as partial fish meal protein. A growth trial was conducted over 16 weeks at a water temperature of 12 ± 1 °C. At the end of the growth trial, in addition to body composition analyses, plasma tri‐iodothyronine (T3) and thyroxine (T4), cholesterol and liver fatty acid composition were measured. Replacement of fish meal with canola meal (100–570 g kg?1 replacement) did not affect on growth performance. At 16th week, plasma cholesterol levels were reduced in fish fed all diets in comparison with 8th week. Plasma T4 levels were significantly higher in the canola meal‐fed fish sampled after 16 weeks, but no significant differences in T3 levels were obtained (P > 0.05). Proximate compositions were affected by dietary treatments. The liver fatty acid composition reflected that of the diet with a higher level of polyunsaturated (n‐6) fatty acids in fish fed diet canola meal and a higher content in n‐3/n‐6 ratio in fish fed diet without canola meal. These studies show that canola meal has potential to replace substantial levels of fish meal in diets for carnivorous fish without compromising performance.  相似文献   

13.
Nucleotides (NT) are widely used as an immunostimulant in aquaculture. A 10-week feeding trial was conducted to evaluate the effects of dietary NT on the growth performance, immune response, disease resistance and intestinal morphology of the Pacific white shrimp Litopenaeus vannamei (initial mean body weight: 0.39 ± 0.00 g). Five isolipidic (about 7 % crude lipid) and isonitrogenous (about 39 % crude protein) practical diets were supplemented with graded levels of NT (0, 60, 90, 120 and 1200 mg kg?1), respectively. These diets were named as N1, N2, N3, N4 and N5. Each diet was randomly fed to six tanks of shrimps, and each tank contained 40 shrimps. The shrimps were fed four times daily (07:00, 11:00, 16:00 and 21:00 h). The results showed that there were no significant differences in survival, final weight, specific growth rate, feed intake, feed conversion ratio and whole-body compositions among all the treatments (P > 0.05). Shrimps fed the control diet had the significantly lowest activities of superoxide dismutase, total nitric oxide synthase and lysozyme (P < 0.05). However, those parameters increased when dietary NT increased from 60 to 120 mg kg?1 and decreased as inclusion level increased to 1200 mg kg?1 (P < 0.05). The cumulative mortality of the shrimps challenged with Vibrio parahaemolyticus was significantly higher in the treatments without dietary NT supplementation than those in treatments with dietary NT (≥90 mg kg?1) (P < 0.05). The jejunum wall thickness in shrimps fed the control diet was significantly lower than that in the treatments of N2, N3 and N4 (P < 0.05). For the villus height, the highest value (49.29 µm) was found in N3. In summary, the present study showed that 90 mg kg?1 of dietary NT is the optimum dietary level for good gut health, immune response and disease resistance of Pacific white shrimp fed a diet with 18 % fish meal.  相似文献   

14.
Economical, nutritious diets for hybrid striped bass (HSTB) are required for the continued expansion and sustainability of this industry. Turkey meal (TM) is a by‐product of the US turkey industry and is a potentially‐valuable local, alternative protein source for use in aquaculture diets because of its excellent nutritional composition and quality. TM may substitute for more expensive fish meal (FM)‐based diets; however, there are no published data with regard to using this ingredient in sunshine bass diets. Therefore, a 16‐week feeding trial was conducted with juvenile (36 g) sunshine bass (Morone chrysops × Morone saxatilis) to evaluate growth, feed conversion and body composition when fed diets with decreasing levels of FM (300, 200, 100 and 0 g kg?1) and increasing levels of turkey meal (0, 97, 175 and 264 g kg?1). Four practical diets were formulated to contain 400 g kg?1 protein and similar energy levels. Twenty fish were stocked into each of the 12, 1200‐L circular tanks and were fed twice daily ad libitum. At the conclusion of the feeding trial, there were no significant (P > 0.05) differences in final mean weight, percentage weight gain, specific growth rate and feed conversion ratio among treatments, which averaged 363.7 g, 904.3%, 2.02% day?1 and 1.73, respectively. Percentage survival of fish fed diet 4 (0 g kg?1 FM and 264 g kg?1 TM) was significantly (P > 0.05) lower (survival = 88.3%) than fish fed diet 3 (100 g kg?1 FM and 175 g kg?1 TM; survival = 95%), but not different from fish fed diet 1 (survival = 92.5%) and fish fed diet 2 (survival = 93.3%). Fillet weight and amount of abdominal fat were not significantly different among all treatments and averaged 258 and 58 g kg?1, respectively. Fish fed diet 1 (300 g kg?1 FM, 0 g kg?1 TM) and diet 2 (200 g kg?1 FM and 970 g kg?1 TM) had a significantly (P < 0.05) lower hepatosomatic index (2.83 and 3.01, respectively) than fish fed diet 4 (3.33), but not different (P > 0.05) compared to fish fed diet 3 (3.14). Lipid in the fillet of fish fed diet 2 (197 g kg?1) was significantly (P < 0.05) higher than fish fed all other diets; and the percentage lipid in the fillet of fish fed diet 1 (126 g kg?1) was significantly lower than fish fed diets 2 and 4, but not different (P >0.05) compared to fish fed diet 3. Fillet moisture, protein and ash were similar among fish fed all diets and averaged 748, 798 g kg?1 and 51.0 g kg?1 (dry‐matter basis), respectively. The amino acid composition of fillets was similar among all treatments with a few slight significant differences. Results from the present study indicate that tank‐grown sunshine bass can be fed a diet containing 264 g kg?1 TM with 0 g kg?1 FM, compared to diets containing up to 300 g kg?1 FM, without adverse effects on weight gain, growth rate, feed conversion and body composition. Further research should be conducted using lower‐protein diets to determine minimum protein level for tank‐grown sunshine bass.  相似文献   

15.
This study aimed to evaluate the fat deposition pattern and lipid metabolic strategies of grass carp in response to dietary lipid levels. Five isonitrogenous diets (260 g kg?1 crude protein) containing five dietary lipid levels (0, 20, 40, 60, 80 g kg?1) were fed to quadruplicate groups of 15 fish with initial weight 200 g, for 8 weeks. The best growth performance and feed utilization was observed in fish fed with lipid level at 40 g kg?1. MFI and adipose tissue lipid content increased with increasing dietary lipid level up to 40 g kg?1, and higher lipid level in diet made no sense. Fish adapted to high lipid intake through integrated regulating mechanisms in several related tissues to maintain lipid homeostasis. In the present study, grass carp firstly increased PPARγ and CPT1 expressions in adipose tissue to elevate adipocyte differentiation and lipolysis to adapt to high lipid intake above 40 g kg?1. In liver, fish elevated hepatic lipid uptake but depressed biosynthesis of hepatic FAs, resulted in no difference in HSI and liver lipid content among the groups. Only in muscle, fish showed a significant fat deposition when the lipid intake above 40 g kg?1. The excess lipid, derived from enhanced serum TC and TG contents, was more likely to induce deposition in muscle rather than lipid uptake by adipose tissue in grass carp fed with high dietary lipid, indicating the muscle of grass carp might be the main responding organ to high lipid intake.  相似文献   

16.
A 10-week feeding experiment was conducted to evaluate the effects of dietary protein to lipid ratios (P/L) on growth, intestinal digestive enzyme activities and body composition in juvenile rice field eel (Monopterus albus) (initial mean body weight of 65.76 ± 1.07 g, mean ± SEM). Nine test diets were formulated in a 3 × 3 factorial design to contain three protein levels (350, 400 and 450 g kg?1) for each of three lipid levels (40, 80 and 120 g kg?1), respectively. Each diet was randomly assigned to triplicate groups of 60 fish per net cage (1.5 × 2.0 × 1.5 m). Results showed the survival was above 96 % and was not affected by dietary treatments. Fish fed the diet with 450 g kg?1 protein and 40 g kg?1 lipid showed the best weight gain (WG) (103.95 %) and feed conversion ratio (1.60) (P < 0.05). WG, protein efficiency ratio and energy retention increased with the increasing in lipid at 350 g kg?1 protein level (P < 0.05). However, WG showed a little decline with increasing dietary lipid when fish fed the diets with 400 and 450 g kg?1 protein level, but no significant difference was observed (P < 0.05). Hepatosomatic index, visceralsomatic index and intestinal lipase activity increased with the increasing of dietary lipid level irrespective protein level. Intestinal trypsin activity increased with the increasing of dietary lipid level when fish fed the diets with 350 g kg?1 protein, but showed converse trend when fish fed the diets with 400 and 450 g kg?1 protein. Serum triglyceride, body lipid and energy were positively correlated with the dietary lipid. Results of the present study showed that the dietary protein/lipid ratio of 450/40 g kg?1 is considered optimum for rice field eel under culture conditions, and the increase in dietary lipid level has no efficient protein-sparing effect when fish fed the diets with 400 and 450 g kg?1 protein level.  相似文献   

17.
Nine isoenergetic (18.5 kJ g?1) diets were formulated in a 3 × 3 factorial design to contain three protein levels (350, 400 and 450 g kg?1) for each of three lipid levels (65, 90 and 115 g kg?1), respectively, and fed twice daily for 8 weeks to fish of mean initial weight 3.34 ± 0.02 g reared in a re‐circulatory water system. Temperature, pH and dissolved oxygen (DO) were maintained within the range 28–30 °C, 5.6–6.8 and 4.82–6.65 mg L?1 respectively throughout. Results show that fish survival was better in the groups fed 65 g kg?1 lipid while growth performance (% weight gain, WG; specific growth rate, SGR) and nutrient utilization (feed conversion ratio, FCR; protein efficiency ratio, PER; protein intake, PI) in the 65/450 and 90/450 g kg?1 treatments were similar and significantly (P < 0.05) higher than in fish fed the other lipid/protein ratio combinations. The body indices monitored (Hepatosomatic index, HSI and viscerosomatic index, VSI) were similar among the treatments whereas intestinal lipase activity was not significantly (P < 0.05) affected by increase in dietary lipid and protein levels. Carcass composition showed that dietary protein level affected body protein content positively in the 65 and 90 g kg?1 lipid treatments, but dietary lipid level did not affect body lipid content. A lipid/protein ratio of 65/450 g kg?1 is considered adequate for good growth performance and survival of Channa striatus fry.  相似文献   

18.
The effects of tank color on the growth, stress responses, and skin color of snakeskin gourami (Trichogaster pectoralis) were investigated in this study. Fish with initial body weights of 5.03±0.00 g were reared in five experimental tank colors (white, red, green, blue, and black) for 8 weeks. Each tank color was tested in triplicate with an initial stocking density of 15 fish per tank. Fish were fed with commercial sinking pellets at 4% of the average body weight per day. Growth performance, feed utilization efficiency, stress indicators (hematocrit, blood glucose, plasma cortisol levels), and skin color parameters were investigated. The fish reared in blue tanks had a significantly higher average final body weight (9.73?±?0.14 g) and significantly lower average feed conversion ratio (3.42?±?0.12) than the fish reared in black tanks (P?<?0.05). The fish reared in black tanks exhibited higher average hematocrit (36.63?±?1.11%), blood glucose (48.33?±?1.45 mg dL?1), and plasma cortisol (9.00?±?0.56 μg dL?1) levels than those reared in the other tank colors. However, the blood glucose levels in only the fish reared in black tanks were significantly higher than those in the fish reared in the other tank colors. The fish skin color ranged from very pale (high skin lightness) in the white tanks to very dark (low skin lightness) in the black tanks, and 80% of the variation in skin lightness were explained by the tank lightness. The use of a blue tank resulted in normal skin color; hence, blue tanks will not affect the customer acceptance of the fish. Our study revealed that blue is the most appropriate tank color for culturing snakeskin gourami.  相似文献   

19.
A 10‐week feeding experiment was conducted to evaluate the effect of different protein to energy ratios on growth and body composition of juvenile Litopenaeus vannamei (initial average weight of 0.09 ± 0.002 g, mean ± SE). Twelve practical test diets were formulated to contain four protein levels (300, 340, 380 and 420 g kg?1) and three lipid levels (50, 75 and 100 g kg?1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260 L). The water temperature was 28.5 ± 2 °C and the salinity was 28 ± 1 g L?1 during the experimental period. The results showed that the growth was significantly (P < 0.05) affected by dietary treatments. Shrimps fed the diets containing 300 g kg?1 protein showed the poorest growth. However, shrimp fed the 75 g kg?1 lipid diets had only slightly higher growth than that fed 50 g kg?1 lipid diets at the same dietary protein level, and even a little decline in growth with the further increase of dietary lipid to 100 g kg?1. Shrimp fed the diet with 420 g kg?1protein and 75 g kg?1 lipid had the highest specific growth rate. However, shrimp fed the diet with 340 g kg?1 protein and 75 g kg?1 lipid showed comparable growth, and had the highest protein efficiency ratio, energy retention and feed efficiency ratio among dietary treatments. Triglycerides and total cholesterol in the serum of shrimp increased with increasing dietary lipid level at the same dietary protein level. Body lipid and energy increased with increasing dietary lipid level irrespective of dietary protein. Results of the present study showed that the diet containing 340 g kg?1 protein and 75 g kg?1 lipid with digestible protein/digestible energy of 21.1 mg kJ?1 is optimum for L. vannamei, and the increase of dietary lipid level has not efficient protein‐sparing effect.  相似文献   

20.
Preliminary experiments were undertaken to investigate the effects of oligofructose on beluga sturgeon (Huso huso) growth performance, survival and culturable autochthonous intestinal microbiota. Juveniles (20 g) were fed diets containing varying levels of oligofructose (10, 20 and 30 g kg?1) at 2–3% body weight per day for 7 weeks. Compared to the control group, no significant (P > 0.05) effect on growth performance was observed in fish fed diets supplemented with oligofructose at 10 and 20 g kg?1. However, compared to the 20 g kg?1 group, feeding oligofructose at 30 g kg?1 resulted in adverse effects on growth performance. Dietary supplementation of oligofructose at 20 g kg?1 significantly increased survival rate. Microbiological assessment indicated that the viable culturable autochthonous levels were not affected by dietary oligofructose. Although lactic acid bacteria (LAB) were not a dominant component of the endogenous autochthonous microbiota, LAB levels were significantly elevated in fish fed 20 g kg?1 dietary oligofructose. This elevated LAB population was able to persist for at least 1 week after reverting the prebiotic group back to a control diet. This study encourages further research on different aspects of oligofructose in sturgeon culture with clear emphasis on optimizing dosage levels.  相似文献   

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