• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.679-685
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• 2012

A study was carried out to observe the effects of feed types on the growth, feed preference, and enteric feed transition rate of juvenile starry flounder, Platichthys stellatus for 45 days. Fifty fish (avg. 135 g) were stocked each in replication, and fed a commercial extruded pellet diet (EP, 45% protein) and a moist pellet diet (MP, 65% raw mackerel+35% feed powder in wet basis), respectively. The MP presented the higher performance than that of the EP on the feed efficiency ($68.3{\pm}0.9%$ for EP and $92.3{\pm}4.3%$ for MP) and the specific growth rate ($1.07{\pm}0.07$ for the EP and $1.20{\pm}0.05%$ for the MP). In contrast, the EP showed the higher feed preference in terms of the daily feed intake ($1.57{\pm}0.08%$ for the EP and $1.30{\pm}0.01$ for the MP) and the ad libitum feeding rate after a fast of 72 hours (1.73% for the EP and 1.35% for the MP). The feed transition rate through intestinal canals decreased exponentially in both the EP and the MP, showing the faster transition rate with the EP. In the result, starry flounder appeared to have the better feed preference to the EP, but have the higher feed efficiency and growth performance to the MP.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.818-823
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• 2014

This study compared the effects of feeding diets consisting of an experimental extruded pellet with tapioca starch (EEP), commercial extruded pellet (CEP), and raw-fish-based pellet (MP) on the growth, flesh quality, and apparent digestibility coefficient of the olive flounder Paralichthys olivaceus. Two replicated groups of 4,000 fish each (initial mean weight: $81.8{\pm}3.5g$) were fed one of the experimental diets for 5 months. After the feeding trial, the final mean weight, weight gain, specific growth rate, and feed efficiency of fish fed the EEP was significantly higher than those of fish fed the CEP and MP. Moisture content in the whole-body of fish fed MP was significantly higher than those of fish fed other diets. However, the highest crude protein in the whole-body was found in fish groups fed the EEP. Significantly higher contents of 24:1n-9, 20:5n-3, 22:6n-3 and lower 18:1n-7 was observed in fish fed the EEP compared with fish fed the MP. The amino acid contents in the whole-body showed significant differences in the composition depending on the feed, but the distribution of free amino acids showed similar patterns. Among amino acids, glutamic acid showed the highest content in all the experimental groups, and the threonine, cysteine, and lysine contents were significantly higher in the groups fed with EEP and CEP than in the group fed with MP. Digestibility of nutrients of the EEP was significantly higher than that of fish fed the CEP. This suggests that extruded pellets can be used to feed olive flounder without compromising growth and flesh quality in comparison to raw-fish-based moist pellets. Formulation of the EEP could be used as a practical feed for olive flounder.

• Journal of Aquaculture
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• v.9 no.4
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• pp.377-384
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• 1996

A 15-week of growth trial was conducted to evaluate practical diets for growing Korean rockfish (Sebastes schlegeli). Two replicate groups of the fish average weighing 125 g were fed one of four experimental diets containing $41\~45\%$ protein and $6\~8\%$ lipid. A control diet with $58\%$ fish meal as protein source was included and practical form diets with $40\%$ fish meal and various practical ingredients such as meat meal, blood meal, soybean meal, and corn gluten meal were included. These experimental dry pellet diets were compared with commercial diets containing $51\~53\%$ protein and $5\~13\%$ lipid for marine fish or raw fish-based moist pellet (RMP) diet containing $58\%$ protein and $9\%$ lipid consisted of $50\%$ frozen horse mackerel and $50\%$ commercial binder meal. Weight gain, feed efficiency, daily feed intake and protein efficiency ratio in the fish fed the experimental diets and commercial diets were not significantly different to those in the fish fed the control diet. However weight gain, feed efficiency and protein efficiency ratio in the fish fed the RMP diet were significantly higher than those in the fish fed the experimental diets and commercial diets. These differences of growth performance between experimental diets and RMP diet may be reason for different dietary protein and energy levels. The experimental diet can save up to $20\%$ cost of fish production compare with control diet, whereas RMP diet is more expensive than other diets in the fish production.

• Journal of Aquaculture
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• v.16 no.3
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• pp.190-195
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• 2003

Dietary optimum ratio of frozen raw fish and commercial compound meal (CCM) in moist pellet (MP) were investigated to improve the growth rate, and feed and economical efficiency in the flounder, Paralichthys olivaceus. Experimental fish (average body weight, about 48 g) were divided into 6 groups and each group was fed with raw fish (FRF), and MPs (ratio of raw fish and CCM=9:1, 8:2, 7:3, 6:4 and 5:5) for 10 weeks. The 9:1, 8:2, 7:3, 6:4, 5:5 groups showed no significant difference in weight gain as 203.5~217.3%, while the FRF group showed significantly low growth rate as 183.1%(P<0.05). The feed efficiency gradually increased with the increase in the ratio of CCM and was the highest in the 5:5 group as 89.7%. As a result of analysis of body composition after the experiment, moisture was significantly low in the 7:3 group (P<0.05) and crude protein was significantly low in the 9:1 group (P<0.05). The crude lipid increased as the ratio of raw fish increased, and it was the highest in the raw fish group (8.3%) and the lowest in the 5:5 group (4.6%). There were no significant difference in hepatosomatic index (HSI) and condition factor(CF) among the experimental groups. Visceralsomatic index (VSI) increased with the increase in the ratio of raw fish and was significantly high in the raw fish group as 5.49 (P<0.05). For the unit cost of feed, it was found that raw fish was economical when mackerel, a source of raw feed, was 400 won/kg, while the ratio of 5:5 was economical when it was more than 500 won/kg. Results of this study concluded that sole use of raw feed is not desirable in view of growth, environment and economy, and the 5:5 group showed highest effect under the least use of raw feed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.801-809
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• 2014

This study was conducted to compare an experimental extruded pellet (EP) and raw fish-based moist pellet (MP) on growth performance, whole-body and dorsal muscle composition, and textural properties of dorsal muscle for olive flounder Paralichthys olivaceus. Four groups of 8,000 fish (initial mean weight $27.1{\pm}0.05g$) per concrete tank ($10{\times}10m$) were fed the experimental diets for 16 months. After the feeding trial, no significant differences were observed in final mean body weight, weight gain, specific growth rate, feed intake, survival, and condition factor between EP and MP groups. However, feed efficiency of fish fed the EP was significantly higher than that of fish fed the MP. Moisture content in the whole-body of fish fed the MP was significantly higher than that of fish fed the EP. Significantly higher contents of polyunsaturated fatty acid (PUFA) in whole-body and dorsal muscle were observed in fish fed the EP compared with fish fed the MP. Any notable differences in amino acid contents or textural properties of the dorsal muscle were not observed in fish fed either the EP or the MP. The results of this study indicated that the EP could be developed to replace MP for the market size of production in olive flounder without the adverse effects on growth performance. Formulation of the EP could be used as a practical feed for olive flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.604-608
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• 2009

This study was conducted to evaluate extruded pellet (EP) diet compared with a raw fish moist pellet (MP) diet for flounder, Paralichthys olivaceus on field feeding experiments in Jeju area. The experimental EP diet (juvenile, growing and adult) was prepared based on the former studies on nutrient requirements and feed ingredient of flounder. Fish were distributed randomly to each aquarium as a group of 102,300 fish (initial mean weight 97 g) in field experiment I and reared randomly to each aquarium as a group of 40,000 fish (initial mean weight 120 g) in field experiment II. In field feeding experiment I conducted in commercial flounder farm, survival, wt. gain (94-1,090 g), feed efficiency and condition factor of fish fed experimental EP were comparable to those of fish fed MP, but considerably higher protein efficiency ratio were observed in fish fed experimental EP. In field feeding experiment II, no significant difference was observed in final mean weight of fish fed the experimental EP (1,234 g) and MP (1,286 g), and any noticeable problem caused by feeding the experimental EP was not found during the whole period of feeding trial. Survival of fish fed the experimental EP was lower than that of MP, and there was no significant difference in feed efficiency between the fish fed experimental EP and MP. Therefore, these results strongly suggest that diet EP could be developed to replace MP diet for the marketable size (1.3 kg) of production for flounder without adverse effects on growth performance. In particular, abdominal dropsy and reduction of condition factor, which are frequently occurred in commercial EP feeding farms, were not observed in flounder fed experimental EP.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.777-784
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• 2013

This study compared the effects of diets consisting of experimental extruded pellets (EP), commercial soft extruded pellets (SEP), and raw-fish-based moist pellets (MP) on the growth, flesh quality, and histology of the Korean rockfish Sebastes schlegeli. Three replicated groups of 60 fish each (initial mean weight 152 g) were fed one of two experimental EPs (EP1 and EP2), two commercial SEPs (SEP1 and SEP2), or MP for 11 weeks. The survival, weight gain, and final mean weight of the fish did not differ significantly among the groups. The highest feed efficiency was in fish fed MP (P<0.05), and the protein efficiency ratio of fish fed MP was significantly higher than that of fish fed EP1, EP2, or SEP1, but not significantly different from that of fish fed EP2. The daily feed intake of the fish fed the EPs and SEPs was significantly higher than that of the fish fed MP (P<0.05). The condition factor, Hepatosomatic Index, and Viscerasomatic Index of the fish did not differ significantly among the groups. No notable differences in the textural properties of the dorsal muscle, plasma biochemical parameters, or histological features of the fish were observed in fish fed any diet. This suggests that extruded pellets can be used to feed growing Korean rockfish without compromising growth, flesh quality, or histopathological change in comparison to raw fish-based moist pellets.

• Journal of Aquaculture
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• v.18 no.4
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• pp.225-230
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• 2005

This experiment was conducted to compare the effects of extruded pellets and raw fish-based pellet on olive flounder Paralichthys. olivaceus. Six diets were prepared for this study: two formulated extruded pellets (FEP1 & FEP2), three commercially available extruded pellets (CEP1, CEP2 & CEP3) and moist pellet (MP). Weight gain offish fed FEP1 and CEP3 were significantly higher (P<0.05) than those of fish fed FEP2, CEP1, CEP2 and MP, while that of fish fed MP was not significantly different (f<0.05) from those of fish fed the FEP2, CEP1 and CEP2. Feed efficiency of fish fed CEP2 was significantly lower (P<0.05) than those of fish fed FEP1, FEP2, CEP1, CEP3 and MP. There was no significant difference in protein efficiency ratio and hepatosomatic index between fish fed FEP1 and CEP3, and among fish fed FEP2, CEP1 and CEP2. There was no significant difference in condition factor among fish fed the FEP1 and CEP3, and between fish fed FEP2, CTP1 and MP. However, fish fed MP had a lower survival rate than fish fed the other five EP These results suggest that diet FEPl could be developed to replace MP for the owing stage of flounder without adverse effects on growth performance.

• Food Science and Preservation
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• v.18 no.5
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• pp.729-738
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• 2011

This study was conducted to investigate the effect of extruded pellets (EP) containing different levels of protein (51%-55%) and lipid (9%-15%) on flesh quality of flounder (Paralichthys olivaceus) comparing with raw fish-based moist pellet (MP). Two replicate groups of 40 fish per each tank (initial mean weight 106 g) were fed one of three experimental EP (EP1, EP2 and EP3) containing different protein and lipid levels, a commercial EP (EP4) and MP for 16 weeks. Moisture content of fish fed MP was significantly higher than that of fish fed all EP. Significantly higher contents of 16:1n-7, 20:4n-6, 20:5n-3 and lower 18:2n-6 were observed in fish fed EP4 and MP compared with fish fed EP1, EP2, EP3. The 22:6n-3 content was not significantly different among all groups. Taurine content of fish fed MP was significantly higher than that of fish fed all EP. Asparagine content of fish fed EP1 was significantly higher than that of fish fed EP2, EP, EP4 and MP. Significant difference were observed in lysine and serine contents of fish fed experimental diets. In nucleotides and their related compounds, ATP and AMP content was not affected by diets. Significant difference were observed in IMP contents of fish fed experimental diets. Textural properties, no significant difference was observed among the fish groups fed different diets.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.868-872
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• 2008

This experiment was conducted to evaluate the long term effects of dehulled soybean meal (DHSM) as fish meal (FM) replacer in the diet for olive flounder, Paralichthys olivaceus, for 42 wk at a commercial fish farm. The four experimental diets were MP (moist pellet based on raw fish), $DHSM_0$ (fish meal based dry pellet), $DHSM_{30}$ (30% fish meal was replaced by DHSM) and COMD (commercial dry pellet). Fish were fed one of the four diets containing 50% crude protein and 16.7 kJ available energy/kg diet for 42 wk. Fish averaging $3.20{\pm}0.04g$ ($mean{\pm}SD$) were initially distributed to each tank as a group of 6,000 fish reared in a flow-through system. At the end of the experiment, average body weight of fish was $315{\pm}9.3g$ ($mean{\pm}SD$) ). Weight gain (WG) and feed efficiency (FE) of fish fed MP, DHSM0 and DHSM30 showed no significant difference among the diet treatments. However, WG and FE of fish fed MP were significantly higher than those of fish fed COMD (p<0.05). Specific growth rate (SGR), protein efficiency ratio (PER) and survival of fish fed all diets were not significantly different among the dietary treatments. Therefore, these results indicate that DHSM could replace up to 30% white fish meal with amino acid supplementation in olive flounder diets for long-term feeding practice at the commercial farm.