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1.
The effect of feeding ratio on growth and body composition of juvenile olive flounder fed extruded pellets was determined during the summer season. Thirty juvenile olive flounder (initial body weight of 17 g) per tank were distributed into 21, 180-l flow-through tanks. Seven treatments that included triplicate groups of feeding ratio in 5% decrement were prepared for this study: 100% (satiation), 95%, 90%, 85%, 80%, 75% and 70% of satiation. Fish in the control group were hand-fed to apparent satiation twice a day. Then feed allowance in the rest of the six groups was determined based on average feed consumption in the control group. The feeding trial lasted for 7 weeks. Survival was over 97% and was not significantly (P > 0.05) affected by the feeding ratios. Weight gain and SGR of fish fed to 100% of satiation were not significantly different from those fed to 95% of satiation but significantly (P < 0.05) higher than those of fish fed to 90%, 85%, 80%, 75% and 70% of satiation. Weight gain, SGR and feed consumption of flounder linearly (P < 0.001) decreased with a decrease in feeding ratio. However, feed efficiency ratio, protein efficiency ratio and protein retention in fish body were not significantly (P > 0.05) affected by the feeding ratio. The crude protein levels of the whole body without liver or liver were significantly affected by the feeding ratio. Hepatosomatic index and condition factor of fish were not significantly (P > 0.05) affected by the feeding ratio. It can be concluded that optimum feeding ratio for growth of juvenile olive flounder could be lowered to 95% of satiation without growth suppression.  相似文献   

2.
Compensatory growth of juvenile olive flounder, Paralichthys olivaceus L., and changes in proximate composition and body condition indexes of fish during fasting and after refeeding were investigated during the summer season. Groups of 25 fish each (initial body weight of 16 g) were randomly distributed into fifteen 180‐L flow‐through tanks. Fish were fed the experimental diet containing crude protein 46.9% and crude lipid 8.0% with estimated energy level of 14.6 kJ/g diet for 6 d/wk. Five treatments in triplicate were prepared for this study: C, S1, S2, S3, and S4. Fish in the control group (C) were hand‐fed to apparent satiation twice daily. Fish in treatments S1, S2, S3, and S4 experienced 1, 2, 3, and 4 wk of starvation and were then hand‐fed to apparent satiation twice daily during the remaining 7, 6, 5, and 4 wk of the experiment, respectively. A group of starved fish in the similar size was stocked and fasted throughout the 8‐wk feeding trial for chemical and blood analysis. The feeding trial lasted for 8 wk. Weight of fish linearly decreased with week of starvation (P < 0.0001). Linear relationship between condition factor (CF) and hepatosomatic index (HSI) against week of starvation was observed in the starved group of fish. Survival was not significantly (P > 0.05) affected by feeding strategy. However, weight gain and specific growth rate (SGR) of olive flounder in C, S1, and S2 were significantly (P < 0.05) higher than those of fish in S3 and S4. The poorest weight gain and specific growth rate (SGR) were obtained in fish of S4. Feed consumption of olive flounder in C, S1, and S2 was significantly (P < 0.05) higher than that of fish in S3 and S4. Feed efficiency, protein efficiency ratio, and protein retention of olive flounder in C and S1 were not significantly (P > 0.05) different from those of fish in S2 but significantly (P < 0.05) higher than those of fish in S3 and S4. Hematocrit, CF, and HSI of olive flounder were not significantly (P > 0.05) affected by feeding strategy. Chemical composition of fish was not significantly (P > 0.05) affected by feeding strategy. In considering these results, it can be concluded that juvenile olive flounder have the ability to fully compensate for 2‐wk feed deprivation during the summer season. Besides, feed efficiency in fish fed for 7 and 6 wk after 1‐ and 2‐wk feed deprivation was comparable to that in fish fed for 8 wk.  相似文献   

3.
A factorial (3 × 4) feeding trial was conducted to investigate the effects of feeding frequency and feed type on the growth performance, feed utilization and body proximate composition of juvenile olive flounder. Three feed types including a sinking moist pellet (MP), a sinking dry pellet (DP) and a floating extruded pellet (EP) were used. Fish (average weight, 11.1 ± 0.4 g) were randomly distributed in thirty‐six 300 L tanks in a flowthrough system. Triplicate groups (30 fish per tank) of fish were fed each feed type to visual satiation at three meals per day, two meals per day, one meal per day and one meal every 2 days for 7 weeks. At the end of the feeding trial, the survival of fish was not significantly different among the treatments. Weight gain was affected by the feeding frequency. The highest weight gain was observed in fish fed the EP at three meals per day. The daily feed intake of fish fed the MP and DP tended to be higher than that of fish fed the EP at each feeding frequency. The feed efficiency and the protein efficiency ratio of fish fed the EP were higher than those of fish fed the MP and DP. The body proximate composition of fish was altered by the feeding frequency. The crude lipid content increased with the increase in the feeding frequency. The present findings suggest that three feedings per day at visual satiation of the floating EP may be sufficient for the maximal growth performance of olive flounder grown from 11 to 60 g.  相似文献   

4.
This study was carried out to investigate the effects of dietary inclusion of defatted Chlorella on growth performance, body composition, blood biochemistry, and antioxidant enzyme activity in olive flounder. Four isonitrogenous (51% crude protein) diets were formulated to contain 0 (control), 5, 10, or 15% Chlorella meal (CM) (designated as Con, CM5, CM10, and CM15, respectively) and fed to triplicate groups of fish (104.4 g) to apparent satiation twice daily for 8 wk. At the end of the feeding trial, significant enhancement (P < 0.05) in growth performance was obtained at over 10% CM compared to fish fed the control diet. No significant changes in dorsal muscle and liver proximate composition were found following CM administration. The groups fed CM‐containing diets revealed significantly lower plasma cholesterol concentration than those fed the control diet. Dietary CM affected antioxidant enzyme activity; significantly higher plasma catalase activity was found in fish fed ≥10% CM and total antioxidant capacity increased in CM5 and CM10 groups compared to the control. However, plasma glutathione peroxidase and superoxide dismutase activities were not significantly influenced by dietary CM. Also, significant enhancement in 1,1‐diphenyl‐2‐picryl‐hydrazyl radical scavenging activity was found in dorsal muscle of fish fed CM15 diet compared to the control. The findings in this study showed that dietary inclusion of 10–15% CM can enhance growth performance and affect antioxidant enzyme activity and lipid metabolism in olive flounder.  相似文献   

5.
Compensatory growth and changes in biochemical composition, hematocrit and body condition indices of juvenile flounder Paralichthys olivaceus were assessed during starvation and after refeeding. Twenty juvenile fish were stocked into each 200‐L flow‐through tank to give five treatments with three replicates per treatment: control group fish (C) were hand fed to apparent satiation twice daily for 8 wk, whereas the Sl, S2, S3, and S4 fish were hand fed to apparent satiation twice daily for 7, 6, 5, and 4 wk after 1, 2, 3, and 4 wk of starvation, respectively. During starvation, weight decreased linearly with periods of feed deprivation up to 3 wk. Survival was not significantly different among treatments. At the end of the feeding trial, weight gain (g/fish) and specific growth rate (SGR) of flounder in S2 was significantly (P < 0.05) higher than those of fish in S3 or S4, but not significantly different from those of fish in C or Sl. Feed consumption of flounder (g/fish) was proportional to duration of feeding except for that of fish in S2. Feed efficiency ratio (FER) and protein efficiency ratio (PER) values for flounder in S2 were significantly (P < 0.05) higher than those for fish in C, but not significantly different from those for fish in Sl, S3, or S4. During starvation, hepatosomatic index (HSI) and lipid content of flounder without liver decreased with periods of feed deprivation. However, HSI and condition factor (CF) for flounder in S2 were significantly (P < 0.05) higher than those for fish in Sl, S3, S4 and C except for CF in Sl at the end of the feeding trial. Proximate composition of flounder without the liver was not significantly different among treatments at the end of the feeding trial. In considering above results, juvenile flounder achieved compensatory growth with up to 2‐wk feed deprivation. Compensatory growth of flounder fed for 6 wk after 2‐wk feed deprivation was well supported by improvement in SGR, FER, and PER. HSI could be a good index to monitor changes in body condition during starvation and after refeeding.  相似文献   

6.
This study was conducted to evaluate the effects of dietary supplementation of Barodon, an anionic alkali mineral complex, on growth, feed utilization, humoral innate immunity and disease resistance of olive flounder. A basal experimental diet was used as a control and supplemented with 0.1, 0.2, 0.3, 0.4, or 0.5% Barodon. Triplicate groups of fish (26.4 ± 0.2 g) were fed one of the diets to apparent satiation twice daily for 10 wk. The growth performance was enhanced (P < 0.05) linearly and quadratically in fish fed diets containing Barodon compared with that in fish fed the control. Feed utilization was significantly improved by Barodon supplementation. Serum lysozyme and antiprotease activities were increased quadratically in Barodon fed groups. Also, significantly higher superoxide dismutase activity was found in Barodon‐fed fish. Dietary supplementation of 0.1–0.3% Barodon resulted in significant enhancement of fish disease resistance against Streptococcus iniae. The findings in this study indicate that dietary supplementation of Barodon can enhance growth, feed utilization, innate immunity, and disease resistance of olive flounder and that the optimum level seems to be 0.1% in diets.  相似文献   

7.
Two feeding trials were carried out to determine the optimum feeding rates in juvenile olive flounder, Paralichthys olivaceus, at the optimum rearing temperature. Fish averaging 5.0 ± 0.11 g (mean ± SD) in experiment 1 and 20.2 ± 0.54 g (mean ± SD) in experiment 2 were fed a commercial diet at the feeding rates of 0%, 3.0%, 4.0%, 4.25%, 4.5% and 4.75% body weight (BW) day?1 and satiation (5.52% BW day?1) in experiment 1 and 0%, 1.0%, 2.0%, 3.0% and 3.5% BW day?1 and satiation (4.12% BW day?1) in experiment 2 at 20 ± 1 °C. Both feeding trials lasted for 2 weeks. Results from experiment 1 indicated that weight gain (WG) and specific growth rate (SGR) of fish fed to satiation were significantly higher than those of fish fed at other feeding rates while feed efficiency (FE) and protein efficiency ratio (PER) of fish fed at 4.25% BW day?1 were significantly higher than those of fish fed to satiation and fish fed at 3.0% BW day?1 (P < 0.05). In experiment 2 WG, SGR and PER leveled out after the feeding rate of 3.5% BW day?1 whereas FE reached a plateau at 3.0% BW day?1. anova of FE indicated that the optimum feeding rates in 5.0 and 20 g juvenile olive flounder could be 4.25% and 3.0% BW day?1, respectively. Broken line analysis of WG suggested the optimum feeding rates of 5.17% and 3.47% BW day?1 in 5.0 and 20 g fish, respectively. Therefore, these results indicated that the optimum feeding rates could be >4.25 but <5.17% BW day?1 for 5.0 g, and it could be >3.0 but <3.47% BW day?1 for 20 g size of juvenile olive flounder at the optimum rearing temperature.  相似文献   

8.
A 10‐wk feeding experiment was conducted to evaluate the potential use of fermented soybean curd residues (FSCR) as an energy source in diets for juvenile olive flounder, Paralichthys olivaceus. Five isonitrogenous and isoenergetic diets were formulated to contain dry soybean curd residues to replace wheat meal (WM) at the levels of 0, 25, 50, 75, and 100% (FSCR0, FSCR25, FSCR50, FSCR75, and FSCR100, respectively). Fish averaging 6.00 ± 0.07 g (mean ± SD) were randomly distributed into 15 aquaria as groups of 15 fish and fed the experimental diets in triplicate at a rate of 4–5% of wet body weight per day twice daily on dry matter basis. At the conclusion of the feeding trial, weight gain (WG) and specific growth rate (SGR) of fish fed diet FSCR25 were significantly higher than those of fish fed diets FSCR50, FSCR75, and FSCR100 (P < 0.05); however, there were no significant differences in WG and SGR among fish fed diets FSCR0 and FSCR25 and among those fed diets FSCR0 and FSCR50. Feed efficiency and protein efficiency ratio of olive flounder fed diet FSCR25 were significantly higher than those of fish fed diets FSCR50, FSCR75, and FSCR100 (P < 0.05); however, there were no significant differences in these parameters among fish fed diets FSCR0 and FSCR25 and among those fed diets FSCR0, FSCR50, FSCR75, and FSCR100. Hematological characteristics, condition factor, hepatosomatic index, and survival rate of fish fed FSCR0 were not significantly different from those of fish fed the other diets. These results indicated that FSCR could replace up to 50% WM as an energy source in juvenile olive flounder diets based on ANOVA test.  相似文献   

9.
The effect on growth and body composition of various dietary additives with putative growth or health‐enhancing properties were determined in juvenile olive flounder (25 g initial weight). Nine experimental diets were prepared to contain one of the following additives: control (Con) with no additive, Opuntia ficus‐indica ver. saboten (OF), propolis (PP), lactic acid bacteria (LA), γ‐poly‐glutamic acid (PG), onion extract (OE), organic sulfur (OS), Biostone® (BS), and fig extract (FE). Fishmeal, dehulled soybean meal, and corn gluten were used as the protein source of the experimental diets. Wheat flour and soybean oil were used as the carbohydrate and lipid sources, respectively. Dietary additives were included in each experimental diet at 1% at the expense of wheat flour except for the FE (aqueous), which was substituted at 1% of the amount of water added to the diet. Fish were hand‐fed to satiation twice a day for 6 d/wk for 6 wk. Weight gain of fish fed the OE diet was higher than that of fish fed with the PP diet. Chemical composition of fish was not different among the experimental diets. OE was the most effective dietary additive to improve performance of olive flounder among additives used in this study.  相似文献   

10.
Two experiments were conducted for red sea bream (Pagrus major). In experiment 1, the optimum level of glutamic acid and natural feeding stimulants to enhance feed intake were determined and found that glutamic acid level of 0.5% and fish meat hydrolysate (FMH) were effective. In experiment 2, fish were fed with soy protein concentrate (SPC)‐based diet with synthetic feeding stimulants (Basal diet), the Basal diet with FMH (FMH diet), the FMH diet with glutamic acid (FMHG diet) and with fish meal diet (FM diet) as a control until satiation for 8 weeks. Feed intake of FMHG‐fed fish was significantly higher than others (p < 0.05). Specific growth rate and the feed conversion ratio of FMHG were comparable to those of FM‐fed fish (p > 0.05). Relative visceral fat ratio and crude lipid content of any SPC‐based diet‐fed fish tended to be lower than those of FM diet‐fed fish. There were no significant differences in trypsin and lipase activities hepatopancreas among treatments. SPC can be utilized as a sole protein source in a diet for red sea bream. The lower growth performance in SPC‐based diet‐ fed fish was not due to poor digestive enzyme secretion but could be associated with lipid utilization disorder.  相似文献   

11.
A 9‐week feeding trial was conducted to investigate the effects of dietary supplementation with protein hydrolysates on growth, innate immunity and disease resistance of olive flounder. A fishmeal (FM)‐based diet was regarded as a control, and three diets were prepared by partial replacement of FM with krill hydrolysate, shrimp hydrolysate or tilapia hydrolysate (designated as Con, KH, SH and TH, respectively). Triplicate groups of fish (24.5 ± 0.3 g) were fed one of the diets to apparent satiation twice daily for 9 weeks and then challenged by Edwarsellia tarda. Fish‐fed KH diet showed significantly (P < 0.05) higher growth performance and feed utilization compared with the Con diet. Dry matter digestibility of the diets was significantly increased by KH and TH supplementation. All the examined innate immune responses were significantly increased in fish fed KH diet. Significantly, higher respiratory burst and superoxide dismutase (SOD) activities were found in fish‐fed SH diet. Lysozyme and SOD activities were significantly increased in fish‐fed TH diet. However, no significant effect was found on fish disease resistance. This study indicates that dietary supplementation of the hydrolysates, particularly KH, can improve growth performance, feed utilization and innate immunity of olive flounder.  相似文献   

12.
ABSTRACT

The present study was conducted toestimate the optimum dietary supplementation level of Chlorella powder as a feed additive to optimize growth of juvenile olive flounder, Paralichthys olivaceus. Four experimental diets supplemented with Chlorella powder (CHP) at 0, 1, 2 and 4% (CHP0, CHP1, CHP2, and CHP4, respectively) of diet as a dry-matter (DM) basis were prepared. Three replicate groups of fish averaging 1.1±0.02 g were fed one of the four experimental diets for 12 weeks. After the feeding trial, fish fed the CHP2 diet had a higher (P < 0.05) weight gain (819%) than did fish fed CHP0 (707%) and CHP1(712%); however, there was no significant difference between fish fed CHP2 (8197%) and CHP4 (7559%) as among fish fed CHP0, CHP1, and CHP4 (P > 0.05). Fish fed CHP2 had a higher (P < 0.05) feed efficiency (134%) than did fish fed CHP0 (123%); however, there was no significant difference (P > 0.05) among fish fed CHP0 (123%), CHP1 (125%), and CHP4 (125%) as among fish fed CHP1 (125%), CHP2 (134%), and CHP4 (125%). Fish fed CHP2 and CHP4 had a lower (P < 0.05) serum glucose level (average 32.9 mg/dL) than did fish fed CHP0 and CHP1 (average 34.8 mg/dL). Fish fed CHP1 and CHP2 had a lower (P < 0.05) serum glutamic oxaloacetic transaminase (GOT) level than did fish fed CHP0 and CHP4. Glutamic pyruvic transaminase (GPT) levels significantly (P < 0.05) deceased as dietary CHP increased. Fish fed CHP2 and CHP4 had a less (P < 0.05) whole-body fat than did fish fed CHP0. These results indicate that the optimum dietary supplementation level of Chlorella powder as a feed additive in juvenile olive flounder could be approximately 2% of diet.  相似文献   

13.
An 11‐wk feeding trial was conducted to evaluate three different protein hydrolysates as feed ingredients in high‐plant‐protein diets for juvenile olive flounder. Five experimental diets were fed to juvenile olive flounder to examine the effect of three different protein hydrolysates on growth performance, innate immunity, and disease resistance against bacterial infection. A basal fishmeal (FM)‐based diet was regarded as a high‐FM diet (HFM) and a diet containing soy protein concentrate (SPC) as a substitute for 50% FM protein was considered as a low‐FM diet (LFM). Three other diets contained three different sources of protein hydrolysates, including shrimp, tilapia, and krill hydrolysates (designated as SH, TH, and KH), replacing 12% of FM protein. All diets were formulated to be isonitrogenous and isocaloric. Triplicate groups of fish (15.1 ± 0.1 g) were handfed one of the diets to apparent satiation twice daily for 11 wk and subsequently challenged against Edwardsiella tarda. Growth performance and feed utilization of fish fed hydrolysate‐supplemented diets were significantly improved compared to those of fish fed the LFM diet. Dietary inclusion of the protein hydrolysates significantly enhanced apparent digestibility of dry matter and protein of the diets. In the proximal intestine, histological alterations were observed in the fish fed the LFM diet. The fish fed the hydrolysate diets showed significantly longer mucosal fold and enterocytes and greater number of goblet cells compared to fish fed the LFM diet. Respiratory burst activity was significantly higher in fish fed the TH and KH diets than fish fed the LFM diet. Significantly higher immunoglobulin levels were found in fish fed SH and KH diets compared to those of fish fed the LFM diet. Dietary inclusion of the protein hydrolysates in SPC‐based diets exhibited the highest lysozyme activity. Significantly higher superoxide activity was observed in groups of fish fed the KH diet. Fish offered the protein hydrolysates were more resistant to bacterial infection caused by E. tarda. The results of this study suggest that the tested protein hydrolysates can be used as potential dietary supplements to improve growth performance and health status of juvenile olive flounder when they were fed a LFM diet.  相似文献   

14.
This study evaluated the effects of dietary fermented tuna by‐product meal (FTBM) in juvenile olive flounder, Paralichthys olivaceus. Five diets were formulated to replace fishmeal (FM) with FTBM at 0% (FTBM0), 12.5% (FTBM12.5), 25.0% (FTBM25), 37.5% (FTBM37.5), or 50% (FTBM50). After 8 wk, weight gain, specific growth rate, and feed efficiency of fish fed FTBM0 and FTBM12.5 diets were significantly higher than fish fed the other diets (P < 0.05). Also, mean cumulative survival rates (%) of fish fed the FTBM0 and FTBM12.5 diets were significantly higher than those fed FTBM50 diet at Day 9 postchallenge with Edwardsiella tarda (P < 0.05). Protein efficiency ratio of fish fed FTBM0 and FTBM12.5 diets was significantly higher (P < 0.05) than fish fed diets FTBM37.5 and FTBM50. Broken‐line regression analysis of weight gain showed an optimal FM replacement level of 10.65% with FTBM. Therefore, the optimal dietary inclusion of FTBM in juvenile olive flounder diets could be greater than 10.65% but less than 12.5% without any adverse physiological effects on fish health.  相似文献   

15.
Replacing dietary fish oil with DHA‐rich microalgae Schizochytrium sp. and EPA‐rich microalgae Nannochloropsis sp. for olive flounder (Paralichthys olivaceus) was examined. Three experimental isonitrogenous and isolipidic diets with lipid source provided by 50% fish oil (F50S50), 50% (M50F25S25) and 100% microalgae raw material (M100) respectively were compared with a soybean oil (S100) diet as control. Triplicate groups of olive flounder juveniles (16.5 ± 0.91 g) were fed the experimental diets, and a group was fed the control diets for 8 weeks in a recirculation system. Results showed feed efficiency and growth performance were not significantly changed when fish oil (FO) was totally substituted by soybean oil (SO) or microalgae raw material (MRM). The whole‐body composition, lipid content of liver and muscle, and lipid composition of plasma were not significantly influenced by the total substitution of FO by MRM. The polyunsaturated fatty acids (PUFA) content of muscle and liver declined in fish fed S100 diet, whereas it was not significantly reduced in fish fed M50F25S25 and M100 diets. The total substitution of FO by MRM not only maintained the levels of arachidonic acid, EPA or DHA but also increased n‐3/n‐6 ratio. In conclusion, MRM as the sole lipid source is sufficient to obtain good feed efficiency, growth performance and human health value in olive flounder juveniles.  相似文献   

16.
An 8‐week feeding trial was conducted in a recycling water system at 28 ± 1 °C to investigate compensatory growth and body composition in African catfish Clarias gariepinus (13.05 ± 0.05 g). A fishmeal‐based diet containing 350 g kg?1 protein and 17.5 kJ g?1 gross energy was fed to triplicate groups of 20 fish (per 30‐L tank). Fish were fed the diet either to satiation or feed restricted in six feeding schedules as satiation 56 days; restricted 28 days + satiation 28 days; restricted 14 days + satiation 14 days; restricted 7 days +satiation 7 days; restricted 3 days + satiation 4 days; and restricted 2 days + satiation 2 days. The restricted regime was achieved by offering fish 1% (maintenance ration) of their body weight per day adjusted after fortnightly weighing. African catfish showed partial compensatory growth under alternating periods of feed restriction and satiation feeding with significantly different values (P < 0.05) from fish fed in satiation throughout. However, significantly indifferent (P > 0.05) values of feed, protein, lipid and energy utilization were found under alternating periods of feed restriction and satiation feeding. Significantly higher (P < 0.05) feed intake was observed in treatment with satiation throughout than those in other treatments. All the feeding schedules showed no significant differences (P > 0.05) on body composition, organ indices, eviscerated carcass composition, viscera lipid and liver lipid. These studies reveals that C. gariepinus showed partial compensatory growth responses at alternating periods of restricted and satiation feeding.  相似文献   

17.
This experiment was conducted to determine the optimum dietary protein level for juvenile olive flounder Paralichthys olivaceus (Temminck et Schlegel) fed a white fish meal and casein‐based diets for 8 weeks. Olive flounder with an initial body weight of 4.1 ± 0.02 g (mean ± SD) were fed one of the six isocaloric diets containing 35%, 45%, 50%, 55% and 65% crude protein (CP) at a feeding rate of 4–5% of wet body weight on a dry‐matter basis to triplicate groups of 20 fish per aquarium. After 8 weeks of feeding, per cent weight gain (WG) and feed efficiency ratios of fish fed the 55% CP diet were not significantly higher than those from fish fed the 50% and 65% CP diets, but significantly higher than those from fish fed the 35% and 45% CP diets. Fish fed the 50%, 55% and 65% CP diets had significant higher specific growth rates than did fish fed the 35% and 45% CP diets; however, there was no significant difference among fish fed the 50%, 55% and 65% CP diets. The protein efficiency ratio was inversely related to the dietary protein level; that is, maximum efficiency occurred at the lowest dietary protein level. Broken‐line model analysis indicated that the optimum dietary protein level was 51.2 ± 1.8% for maximum weight gain in juvenile olive flounder. The second‐order polynomial regression analysis showed that the maximum WG occurred at 57.7% and it revealed that the minimum range of protein requirement was between 44.2% and 46.4%. These findings suggest that the optimum dietary protein level for maximum growth could be greater than 46.4%, but less than 51.2% CP in fish meal and casein‐based diets containing 17.0 kJ g?1 energy for juvenile olive flounder.  相似文献   

18.
This study was performed to determine compensatory growth of juvenile olive flounder fed the extruded pellet (EP) with different feeding regimes. Seven treatments with triplicates of different feeding regimes were prepared; α fish was daily fed for 6 d a week throughout 8 wk (8WF); α fish was starved for 1 wk and then fed for 3 wk twice [(1WS + 3WF) × 2]; β fish was starved for 2 wk and then fed for 6 wk (2WS + 6WF); χ fish was starved for 5 d and then fed for 9 d four times [(5DS + 9DF) × 4]; δ fish was starved for 10 d and then fed for 18 d twice [(10DS + 18DF) × 2]; δ fish was starved for 2 d, fed for 5 d, starved for 3 d, and then fed for 4 d four times [(2DS + 5DF + 3DS + 4DF) × 4]; and φ fish was starved for 4 d, fed for 10 d, starved for 6 d, and then fed for 8 d twice [(4DS + 10DF + 6DS + 8DF) × 2], respectively. Total feeding day was all same, 36 d except for control group (48 d). Weight gain of flounder in the 8WF treatment was higher than that of fish in other treatments. And weight gain of flounder in the 2WS + 6WF treatment was higher than that of fish in the (5DS + 9DF) × 4 and (4DS + 10DF + 6DS + 8DF) × 2 treatments. Feed consumption of flounder in the 8WF treatment was higher than that of fish experienced feed deprivation. Feed efficiency ratio (FER), protein efficiency ratio (PER), and protein retention (PR) were not significantly different among treatments. Chemical composition of the whole body of fish with and without liver, except for moisture content of liver, was not different among treatments. T3 level of fish in the 8WF and 2WS + 6WF treatments was higher than that of fish in the (5DS + 9DF) × 4 treatment. It can be concluded that juvenile olive flounder achieved better compensatory growth at 6‐wk refeeding after 2‐wk feed deprivation compared with that of fish with different feeding regimes. And T3 level of fish seemed to partially play an important role in achieving compensatory growth.  相似文献   

19.
Enzymatic hydrolysis of soy protein has the potential to be an excellent protein source in marine fish feeds. Here we assessed the effects of different inclusion levels of hydrolyzed soy protein (HSP) on growth performance, nutrient retention, body composition, and serum hormone levels in juvenile starry flounder to define HSP utilization. Five isoenergetic and isoprotein diets were formulated with 0 (control), 10, 20, 30, and 40% HSP (SP10–40) to replace 0, 25, 50, 75, and 100% soy protein concentrate (SPC), respectively. At the end of the feeding trial, fish fed diets SP20 and SP30 had significantly increased weight gain, percent weight gain, and feed efficiency (FE) compared with fish fed the control diet (P < 0.05). Diets SP20 and SP30 supported significantly higher levels of protein retention, and diet SP20 significantly increased energy retention (P < 0.05) in the fish offered these diets. In terms of nutritional composition of whole fish, feeding diets SP20 and SP30 increased crude protein content (P < 0.05) and diets SP10, SP20, and SP30 increased ash content (P < 0.05). Fish fed diets SP20 and SP30 had higher serum insulin‐like growth factor 1 (IGF‐1) level than that of the control treatment (P < 0.05). When SPC was included at 40% of the diet, 20–30% HSP (43% soluble nitrogen) is recommended to replace 50–75% SPC for maximal growth performance and FE of starry flounder.  相似文献   

20.
An 8‐week feeding trial was conducted to estimate the optimum dietary protein to energy (P/E) ratio in juvenile olive flounder Paralichthys olivaceus. Eight experimental diets were formulated with two energy levels and four protein levels at each energy level. Two energy levels of 12.5 and 16.7 kJ g?1 diets were included at crude protein (CP) levels of 25%, 30%, 35% and 45% with 12.5 kJ g?1, and CP levels of 35%, 45%, 50% and 60% with 16.7 kJ g?1. After 1 week of the conditioning period, fish initially averaging 8.1±0.08 g (mean±SD) were randomly distributed into the aquarium as groups of 15 fish. Each diet was fed on a dry‐matter basis to fish in three randomly selected aquariums at a rate of 3–5% of total wet body weight per day for 8 weeks. After 8 weeks of the feeding trial, weight gain (WG), feed efficiency ratio and specific growth rate of fish fed 45% CP with 16.7 kJ g?1 energy diet were significantly higher than those from the other dietary treatments (P<0.05). WG of fish fed 12.5 kJ g?1 energy diets increased with the increase of dietary protein levels. However, WG of fish fed 16.7 kJ g?1 energy diets increased with the increase of dietary protein levels up to 45% CP and then decreased when fish fed 50% and 60% CP diets. Both dietary protein and energy affected protein retention efficiency and energy retention efficiency. Haemoglobin (Hb) of fish fed 35% and 45% CP diets with 12.5 kJ g?1 energy were significantly high and not different from Hb of fish fed 45% and 50% CP diets with 16.7 kJ g?1 energy. Haematocrit of fish fed 45% CP diet with 16.7 kJ g?1 energy was significantly higher than those from fish fed 25% and 30% CP diets with 12.5 kJ g?1 energy (P< 0.05). Based on the results of this experiment, we concluded that the optimum dietary P/E ratio was 27.5 mg protein kJ?1 with diet containing 45% CP and 16.7 kJ g?1 energy in juvenile olive flounder.  相似文献   

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