• Journal of Aquaculture
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• v.20 no.2
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• pp.132-139
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• 2007

A four-week feeding trial was conducted to investigate the effects of dietary soybean meal (SBM) and powdered Cheongkukjang (CKJ) on non-specific immune responses of parrotfish Oplegnathus fasciatus. Three isonitrogenous (42% crude protein) and isocaloric (17.1 MJ/kg) diets were formulated to replace fish meal by 0, 25% SBM or 25% CKJ (designated as FM, 25SBM and 25CKJ, respectively). Ninety fish (initial body weight 122 g) were randomly allotted into nine 150 L tanks. One of the three experimental diets was fed to triplicate groups of fish for 4 weeks. After the feeding trial, no differences were observed in growth performances and feed utilization among fish groups. Liver superoxide dismutase activity of the fish fed CKJ containing diet was significantly higher than that of the control groups. DPPH radical scavenging and $Fe^{2+}-chelating$ activities of the experimental diets containing SBM or powdered CKJ were significantly higher than that of the control diet. The results of the present study suggest that dietary inclusion of powdered 25CKJ significantly increased liver superoxide dismutase activity and did not affect the growth performances, feed utilization, morphological parameters, as well as hematological values of parrotfish.

• Fisheries and Aquatic Sciences
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• v.21 no.8
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• pp.29.1-29.8
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• 2018

This study was conducted to evaluate the use of tuna by-product meal (TBM) as a substitute for fishmeal in juvenile Korean rockfish (Sebastes schlegeli) diets. Five isonitrogenous (52% crude protein) and isocaloric (4.9 kcal/g) diets were prepared. Control diet (Con) was formulated to contain brown fishmeal, whereas 25, 50, 75, and 100% of fishmeal was substituted with the same percentage of TBM in the TBM25, TBM50, TBM75, and TBM100 diets, respectively. Three replicate groups of fish (initial weight, $29.5{\pm}0.6g$) were fed one of the five diets for 12 weeks. The mean weight gain of fish fed the Con and TBM25 diets was significantly higher than that of fish fed the TBM100 diet (P < 0.05), but it was not significantly different from the weight gain of fish fed the TBM50 and TBM75 diets. The feed efficiency and protein efficiency ratios of fish fed the Con diet were significantly higher than those of fish fed the TBM100 diet (P < 0.05), but were not significantly different from those fed the TBM25, TBM50, and TBM75 diets. The TBM25, TBM50, TBM75, and TBM100 diets had significantly (P < 0.05) lower incidence cost and higher profit index than the Con diet. These results suggest that the tuna by-product meal used in this study could replace up to 75% of fishmeal protein in the diet without reducing growth and feed utilization in juvenile Korean rockfish weighing 29-53 g. By considering feed cost, the TBM 75 diet is recommendable for Korean rockfish farming.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.5
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• pp.468-473
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• 2019

A $2{\times}4$ factorial feeding trial was conducted to examine the effect of feed type and feeding frequency on the performance of sub-adult starry flounder Platichthys stellatus. Two feed types, sinking pellets (SP) and floating pellets (FP), were given to 480 fish housed in tanks. Triplicate groups of fish were fed each feed type at one of four feeding frequencies (one meal every two days, one meal per day, two meals per day, and three meals per day) for nine weeks. Weight gain (WG) and specific growth rate (SGR) of fish were affected by feeding frequency. However, WG and SGR were the same in fish fed SP at two and three meals per day; similarly, there was no difference in WG or SGR of fish fed FP at one meal, two meals, or three meals per day. Feed utilization of fish was affected by both feed type and feeding frequency. These findings suggest that two meals per day of the SP or one meal per day of FP are sufficient for optimum growth performance of sub-adult starry flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.373-379
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• 2023

The dietary inclusion of black soldier fly larvae meal Hermetia illucens (BSL) for starry flounder Platichthys stellatus was examined in a four-month trial at a Pohang fish farm. Two diets were prepared: a fish meal-based commercial diet (CD) and an experimental diet containing 7% BSL in the CD (BCD). Fish (average weight, 125.2 g) were reared in a square concrete tank (7×7 m) in triplicates. Feed efficiency was significantly higher in fish fed BCD compared to that of the fish fed CD. The DHA/EPA ratio in dorsal muscle was not significantly affected by the fatty acid composition of the experimental diets. Based on the growth performance, the feed cost for producing 1 kg of starry flounder was 1,797 won for CD and 1,814 won for BCD. With government subsidies the feed cost for producing 1 kg of starry flounder was 1,481 won for CD and 1,309 won for BCD. The results indicate that BSL can be included at 7% without adverse effects on growth performance, fillet composition, or feed cost. However, further research is needed to determine the optimum percentage of BSL as a replacement of FM in starry flounder diets.

• Journal of Aquaculture
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• v.16 no.2
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• pp.104-109
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• 2003

The present study aims to evaluate protein and phosphorus availabilities of five different dietary protein sources during the 6-week feeding trial in juvenile olive flounder, Paralichthys olivaceus as determined by growth performance and phosphorus retention. Five diets containing blood meal (BM), poultry by-product (PBP), squid liver powder (SLP), feather meal (FM) and soybean meal (SM) were prepared by mixing a basal diet (BD) with one of five test ingredients at the ratio of 7 to 3. As a reference diet, BD contains three different protein sources such as white fish meal, casein and gelatin. After 2 weeks of the conditioning period, fish initially averaging 2.7$\pm$0.02g (mean$\pm$SD) were randomly distributed into each aquarium as a group of 30 fish reared in the recirculating system. Fish of triplicate groups were fed one of six experimental diets (BD+five test diet). After 6-week feeding trial, pro- tein efficency ratio (PER) of fish fed BM diet was the lowest in experiment groups. While fish fed PBP diet showed a significant higher PER as compared to the FM diet, and fish fed SLP diet and BD were a higher PER than did fish fed PBP diet. However, there was no significant difference in PER among fish fed SLP diet, BD and SM diet, and between SM diet and PBP diet. Phosphorus retention efficiency of bone (PR $E_{b}$) of fish fed BM diet was the lowest in all the diets, and fish fed FM diet showed a higher PE $R_{b}$ than fish fed BD and SM diet. However, there was no significant difference in PER among fish fed FM diet, SLP diet and PBP diet, and among SLP diet, PBP diet, SM diet and BD. These results indicate that SLP could be a suitable protein source for low pollution diets of olive flounder in the future fish feeds market. Furthermore, PBP and SM are available protein source to reduce P waste in the oliver flounder aquaculture with the use of proper mixture of other protein sources and more processing to improve protein availibility of these.ese.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1319-1327
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• 2014

Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish, (Sebastes schlegeli) reared at the temperatures of $15^{\circ}C$ and $19^{\circ}C$. Fish averaging $92.2{\pm}0.7$ g (mean${\pm}$standard deviation [SD]) at $15.0{\pm}0.5^{\circ}C$ and $100.2{\pm}0.4g$ ($mean{\pm}SD$) at $19.0{\pm}0.5^{\circ}C$ water temperature were randomly distributed into each of 15 indoor tanks containing 250-L sea water from a semi-recirculation system. A total of five feeding frequency groups were set up in three replicates as follows: one meal in a day at 08:00 hour, two meals a day at 08:00 and 17:00 hours, three meals a day at 08:00, 14:00, and 20:00 hours, four meals a day at 08:00, 12:00, 16:00, and 20:00 hours, and one meal every 2 days at 08:00 hour. Fish were fed at the rate of 1.2% body weight (BW)/d at $15^{\circ}C$ and 1.5% BW/d at $19^{\circ}C$. At the end of 8 wks of feeding trial weight gain and specific growth rate were significantly higher at the fish fed groups of one meal a day and two meals a day at $15^{\circ}C$ and fish fed groups of 1 meal every 2 days at $19^{\circ}C$ were significantly lower than those of all other fish fed groups. Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase of fish fed group at 1 meal every 2 days was significantly higher than those of all other fish fed groups in both experiments. Weight gain, specific growth rate and condition factor were gradually decreased as the feeding frequency increased. The results indicate that growing Korean rockfish 92 and 100 g perform better at $15^{\circ}C$ than $19^{\circ}C$ water temperature. As we expected, current results have indicated that a feeding frequency of 1 meal a day is optimal for the improvement of weight gain in growing Korean rockfish grown from 92 g to 133 g at $15^{\circ}C$ and 100 g to 132 g at $19^{\circ}C$ water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.262-267
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• 2009

Two 15-week feeding trials were conducted to investigate feeding rate and feeding frequency for growth of sub-adult flounder in suboptimal water temperature ($12^{\circ}C$). In the first experiment, duplicated groups of fish (initial mean weight of 279 g) were fed a extruded pellet once a day at the different feeding rates of 0.1, 0.15, 0.2, 0.3% body weight per day (BW/d), and satiation (0.32% BW/d). Weight gain and feed efficiency were increased significantly (P<0.05) with increase in feeding rates from 0.1 to 0.3% BW/d, but there were no significant differences in weight gain and feed efficiency of fish fed the diet between 0.3% BW/d and to satiation. Crude protein content of dorsal muscle of fish fed the 0.1% BW/d diet was significantly (P<0.05) lower than that of the other groups. In the second experiment, duplicated groups of fish (initial mean weight of 281 g) were fed to apparent satiation with a extruded pellet at three different feeding frequencies (one meal every two days, one meal a day and two meals a day). Weight gain, feed efficiency and condition factor of fish fed one meal every two days were significantly (P<0.05) lower than those of fish fed one meal and two meals a day, but there were no significant differences in weight gain, feed efficiency and condition factor of fish fed between one meal and two meals a day. Based on the results of this study, optimum feeding frequency is one meal a day with satiation feeding for growth and feed efficiency of sub-adult flounder (270-350 g) in suboptimal water temperature ($12^{\circ}C$).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.141-148
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• 2019

This study examined the effect of insulin-like growth factor (IGF)-I expression in the liver and muscle on the growth of Paralichthys olivaceus fed diets low in fish meal. A feeding experiment was conducted at Jeju National University, Jeju Island, Korea. Groups of P. olivaceus (total initial weight: 200 g) were maintained for 20 weeks on one of five experimental diets containing different proportions of fish meal. Diets containing 0%, 20%, 30%, 40%, and 50% fish meal were labeled FM0, FM20, FM30, FM40, and FM50, respectively. Fish growth was observed every 4 weeks during the feeding experiment, and plasma and liver and muscle tissues were sampled. Plasma IGF-I levels were analyzed using an ELISA kit. The mechanism of IGF-I receptor signaling was examined using immunoblotting and reverse transcription-polymerase chain reaction. The greatest total weight increase was observed in the FM30 group. In parallel, plasma levels of IGF-I and IGF-binding protein were highest in the FM30 group, and mRNA and protein expression were also significantly higher in this group. The first step in the IGF-I signaling pathway, tyrosine-phosphorylation checking, occurred smoothly until 20 weeks. These results suggest that a dietary ratio of 30% fish meal best promotes growth in this species. The IGF-I signaling pathway in the liver and muscle is associated with growth in P. olivaceus.

• Journal of the Korean Society of Safety
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• v.7 no.1
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• pp.47-56
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• 1992

Spontaneous ignition charactenstics for fish meal were observed by performing experiments at constant ambient temperature and varying the ambient temperature sinusoidally. As the results of the experiments at a constant ambient temperature, the critical spontaneous ignition temperature of the sample for large, intermediate and small vessels was 170.5$^{\circ}C$, 177.5$^{\circ}C$ and 188.5$^{\circ}C$, respectively. The critical spontaneous ignition temperature decreased as the sample vessel size increased. Apparent activation energy of used fish meal calculated from the Frank-Kamenetskii's thermal ignition theory was 37.60Kcal/mol. In case of varying the ambient temperature sinusoidally, the amplitudes of temperature were 1$0^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$ respectively with the period in each amplitude 1hr, 2hrs and 3hrs. The results showed that the critical spontaneous ignition temperatures at the varied amplitudes of temperature were lower than that at the constant anbient temperature and increased as the amplitude increased. At the same amplitude, the critical spontaneous ignition temperature increased with the period.

• Fisheries and Aquatic Sciences
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• v.22 no.10
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• pp.23.1-23.10
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• 2019

Background: Taurine is a conditional essential amino acid for fish. A study was conducted to investigate the compensating effect of supplemental taurine in diets for red seabream (Pagrus major) on impaired growth performance by fish meal (FM) replacement with soybean meal (SM) at low water temperature (14.15 ± 1.95 ℃). Methods: A FM-based diet was considered as a high FM diet and three other experimental diets were formulated to replace FM with SM by 20, 35, or 50% (HFM, SM20, SM35, or SM50, respectively) without taurine and other four diets were formulated by adding 1% taurine to the diets (HFM-T, SM20-T, SM35-T, or SM50-T, respectively). Triplicate groups of fish (108.9 ± 1.58 g/fish) were distributed into 24 polyvinyl circular tanks (215 L) with 20 fish per tank and fed one of the diets to satiation for 20 weeks. Results: Growth performance and feed utilization of red seabream were significantly improved by the dietary taurine supplementation. SM20-T and SM35-T diets increased fish growth that are comparable to HFM diet. Feed intake, feed conversion ratio, and protein efficiency ratio of fish fed SM20-T and SM35-T diets were not significantly different from those of HFM group. Dietary taurine supplementation in each FM replaced group numerically increased innate immunity of the fish. Lysozyme and superoxide dismutase activities were significantly decreased in fish fed SM35, SM50, and SM50-T diets compared to those of fish fed HFM diet while they were not significantly lower in SM20, SM20-T, SM35, and SM35-T groups. Glutathione peroxidase activity was significantly lower in fish group fed SM50 diet while SM50-T group did not significantly lower compared to that of HFM group. The relative expression level of hepatic IGF-1 mRNA was improved in fish fed taurine-supplemented diets compared to their respective SM diets. Conclusions: Growth performance and feed utilization of red seabream can be accelerated or restored by 1% taurine supplementation when they are fed high level of SM up to 35% in diets during low water temperature season.