• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.600-606
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• 2016

The effects of feeding frequency on the growth, food consumption, body composition, and hematological response of the Korean rockfish Sebastes schlegelii were investigated for 77 days at ambient water temperatures (17.2-24.5℃) in a sea cage in Tongyeong, Korea. Three replicate groups of fish were hand-fed to satiation with a commercial diet in one of four different feeding frequency trials (one meal every 2 days, and one, two and three meals per day). At the end of the experiment, the mean weight gain, specific growth rate, and daily feed intake of fish fed one and two meals per day were significantly higher than those of fish fed one meal every 2 days or three meals per day. The feed efficiency of the fish fed three meals per day was significantly lower than that of the fish in the other groups. The glucose concentration of fish fed one meal every 2 days was significantly higher than that of the other groups. We conclude that the optimum feeding frequency for improving the growth of Korean rockfish weighing 100-200 g reared in sea cages is one meal per day under our experimental conditions.

• Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.257-264
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• 2015

A 10-week feeding trial was carried out to investigate the feasibility of using spent coffee ground (CG) as a potential feed ingredient for olive flounder. Growth, feed utilization, body composition and antioxidant enzyme activity were examined. A control diet was formulated and three other diets were prepared to contain 5, 10 or 15% CG (designated as Con, CG5, CG10 and CG15, respectively) by replacing for wheat flour. Two hundred forty fish ($104{\pm}0.7g/fish$) were allotted to 12 circular tanks of 400 L capacity at a density of 20 fish per tank and fed the experimental diets twice daily. At the end of the feeding trial, fish fed the CG5 diet exhibited significantly (P < 0.05) higher growth performance than those fed the control diet. Also, fish fed the CG10 diet had a comparable growth to that of the control group, but further increase of dietary CG inclusion level to 15% resulted in significant decrease of growth performance. Fish fed the CG15 diet showed significantly lower feed efficiency and protein efficiency ratio than other treatments. Significantly lower muscle protein content was observed in fish fed CG15 diet compared to the control. Significant reduction in plasma cholesterol concentration was found in fish fed CG15 diet compared to control. No significant changes were found in alkyle and superoxide radicals scavenging activities of plasma, muscle and liver among dietary treatments. Also, liver total protein, total antioxidant capacity, catalase and glutathione peroxidase activities were not significantly influenced by dietary inclusion of CG. According to these results, we concluded that CG can be included up to 10% in the diet for olive flounder without any adverse effects on growth, feed utilization and antioxidant enzyme activity.

• ALGAE
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• v.22 no.3
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• pp.185-192
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• 2007

A study was carried out in nine fertilized fish ponds under three treatments (T-I, T-II and T-III) at Bangladesh Agricultural University, Mymensingh to see the bloom of euglenophytes with the intention of observing its impact on the growth of fish in culture condition. Some water quality parameters viz., temperature, dissolved oxygen, pH, PO4-P and NO3-N concentration and some biological parameters viz., phytoplankton population and growth of fish were monitored at fixed intervals. Euglenophytes showed a heavy bloom in late August in the ponds of T-II. The bloom was occurred by the genera, Euglena, Phacus and Trachelomonas of which Euglena was the most dominant genus. In relation of water quality parameters with euglenophytes bloom, it was hypothesized that euglenophytes prefers higher temperature and acidic environment with higher nutrient concentrations. Acidic environment and nutrient enrichment enhanced the bloom of euglenophytes which hampered the growth of other beneficial algal groups (chlorophytes and bacillariophytes) and fish. Due to heavy bloom, the fishes breathed with difficulty at the surface. The fishes in the heavy bloom ponds presented the weight values were lower than verified for those in the ponds where the bloom did not occur. Total production (calculated) of fish in different treatments ranged from 1355.89 to1760.63 kg ha–1 with significantly (p < 0.05) lowest in the ponds of T-II.

• Journal of Aquaculture
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• v.22 no.1
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• pp.11-15
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• 2009

Effect of fasting and refeeding on growth and blood chemistry of juvenile olive flounder Paralichthys olivaceus L. was investigated when fish achieved compensatory growth. Fish were fed the experimental diet for 6 days a week. Five treatments in triplicate were prepared: C, S1, S2, S3 and S4. Fish in the control group (C) were hand-fed to apparent satiation twice a day. Fish in treatments of S1, S2, S3 and S4 experienced 1, 2, 3 and 4 weeks of starvation and were then hand-fed to satiation twice daily during the remaining 7, 6, 5 and 4 weeks of the experiment, respectively. Weight gain of fish in C, S1 and S2 were higher than those of fish in S3 and S4. A significant difference in plasma total protein, glucose, triglyceride, $T_3$ and $T_4$ was observed in between starved and refed fish for the rest periods of the feeding trial. Plasma total protein and $T_3$ of flounder decreased with week of fasting and following correlationships were obtained; Y (Total protein) = -0.13X (week of fasting) + 1.54, $R^2=0.9792$ and $Y(T_3)=-11.48X$ (week of fasting) + 79.57, $R^2=0.8822$, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2259-2277
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• 2023

We propose a probabilistic fish growth model for smart aquaculture systems equipped with IoT sensors that monitor the ecological environment. As IoT sensors permeate into smart aquaculture systems, environmental data such as oxygen level and temperature are collected frequently and automatically. However, there still exists data on fish weight, tank allocation, and other factors that are collected less frequently and manually by human workers due to technological limitations. Unlike sensor data, human-collected data are hard to obtain and are prone to poor quality due to missing data and reading errors. In a situation where different types of data are mixed, it becomes challenging to develop an effective fish growth model. This study explores the unique characteristics of such a combined environmental and weight dataset. To address these characteristics, we develop a preprocessing method and a probabilistic fish growth model using mixed data sampling (MIDAS) and overlapping mixtures of Gaussian processes (OMGP). We modify the OMGP to be applicable to prediction by setting a proper prior distribution that utilizes the characteristic that the ratio of fish groups does not significantly change as they grow. We conduct a numerical study using the eel dataset collected from a real smart aquaculture system, which reveals the promising performance of our model.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.577-583
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• 2012

This study was carried out to investigate the supplemental effects of dietary garlic extract (GE) on growth performance of juvenile sterlet sturgeon (Acipenser ruthenus). The first experiment was designed to determine the optimum levels of garlic extract as growth promoter during 10 weeks. Three groups (two replicates/group) of 240 fish with mean body weight of 85 g were fed with diets containing 0 (control), 0.5 and 1.0% of GE. The highest weight gain (%) and feed efficiency (%) were found in fish groups fed with diet containing 0.5% GE. Subsequently, the supplemental effects of dietary GE was studied on growth of juvenile sterlet sturgeon (Acipenser ruthenus) with an average body weight of 59.6 g. Fish cultured in freshwater were randomly allotted to each of 10 tanks (two groups of five replicates, 20 fish/tank) and fed diets with 0.5% GE or without GE (control), respectively, at the level of 2.0% of fish body weight per day for 5 weeks. Weight gain (51.1%), feed efficiency (79.1%), specific growth rate (1.18%) and protein efficiency ratio (1.50) of fish fed 0.5% GE were significantly (p<0.05) higher than those fish fed the control diet. Significantly higher protein (PRE 20.4%) and lipid retention efficiencies (LRE, 74.5%) were also found in 0.5% GE group (p<0.05). The present results suggested that dietary GE could improve growth and feed utilization of juvenile sterlet sturgeons.

• Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.219-227
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• 2021

The effects of various feeding ratios on the growth, body composition, and blood chemistry of the juvenile mandarin fish Siniperca scherzeri (initial body weight 9.6 g) were examined in recirculating freshwater system equipped with 21, 300 L tanks at 20 fish per tank. The triplicate groups of seven feeding ratios treatments were prepared: 100% (control), 95%, 90%, 85%, 80%, 75%, and 70% of satiation. The feed amount of control group was determined by supplying with apparent satiation and then the feed amounts of the other six feeding groups were determined based on the feed amount of the control group. Fish were hand-fed with test diet (55.4% crude protein) for 10 weeks. Weight gain (WG) and specific growth rate of fish fed to 100% satiation were not significantly (p > 0.05) different from those of fish fed to ≥ 80% satiation but were significantly higher than those of fish fed to 75% and 70% satiation. Feed efficiency, protein efficiency ratio, and protein retention of 100% satiation were not significantly different from those of 95% and 90% satiation but were significantly (p <0.05) lower than ≤ 85% satiation. Condition factor, hepatosomatic index, and coefficient variation were not significantly (p > 0.05) affected by feeding ratio. Whole body composition and contents of hematocrit, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, glucose, total protein, and high-density lipoprotein cholesterol in blood serum were not significantly (p > 0.05) affected by the feeding ratio; however, content of total cholesterol tended to decrease as the feeding ratio decreased. Using broken-line analysis of WG, it was suggested that the optimum feeding ratio of juvenile mandarin fish, ranging from 9.0 g to 37.0 g, appeared to be 87.7% of satiation without growth inhibition.

• Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.128-131
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• 2005

The effects of alternate-week feeding strategies on growth and feed efficiency ratio of juvenile Nile tilapia were investigated in a recirculating aquaculture system. Twenty fish initially weighing 25.5 g were randomly distributed into each of 18 tanks to conduct three replicates for each of six different feeding strategies. Weight gain of fish in the control that were fed daily for 6-week feeding trial was significantly higher than those of fish subjected to various alternate-week feeding regimes. Weight gain of fish that were starved for 3 weeks and then fed daily for 3 weeks (3WS+3WF) was not significantly different from that of fish, starved and fed daily for alternate 1-week period during the trial (1WS+1WF), but was significantly higher than those of fish starved for 2 weeks, and fed for 2 weeks (2WS+2WF); fish starved for 4 weeks and fed for 2 weeks (4WS+2WF); and fish fed for 5 weeks and fed for 1 week (5WS+1WF.) The amount of feed supplied to fish in the groups of 1WS+1WF and 3WS+3WF was significantly lower than that fed to fish in the control group, but significantly higher than the amount feed supplied to fish in the other three groups. Feed efficiency ratio for fish in the control group did not differ from that for fish in the groups of 1WS+1WF, 2WS+2WF and 3WS+3WF, but was significantly higher than that for fish in the groups of 4WS+2WF and 5WS+1WF. In conclusion, juvenile Nile tilapia that were subject to starvation for 1 to 5 weeks did not exhibit compensatory growth sufficient to attain the same weight as fish fed daily for 6 weeks. In addition, fish subjected to starvation exhibited low feed efficiency ratio compared to fish fed daily, which were probably attributable to poor weight gain.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.90-96
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• 2013

Effects of dietary Scutellaria baicalensis extract (SBE) on growth, feed utilization and challenge test of olive flounder (Paralichthys olivaceus) were determined. Six hundred thirty fish averaging 5.0 g were distributed into 18, 180-L tanks. Six experimental diets were prepared in triplicate: SBE-0, SBE-0.5, SBE-1, SBE-2, SBE-3 and SBE-5 diets containing SBE at the concentrations of 0, 0.5, 1, 2, 3 and 5%, respectively. Fish were hand-fed to apparent satiation twice a day for 8 wks. At the end of 8-wk feeding trial, ten fish from each tank were infected by Edwardsiella tarda for challenge test. Survival and weight gain of fish were not affected by dietary concentrations of SBE. However, specific growth rate of fish fed the SBE-2 diet was higher than that of fish fed the SBE-0, SBE-1, SBE-3 and SBE-5 diets. Neither feed efficiency nor serum chemical composition of fish was affected by dietary concentrations of SBE. The cumulative mortality of fish fed the SBE-0 diet was 100% at 96 h after E. tarda infection, but 77 to 87% for fish fed the other diets. Dietary inclusion of 2% SBE appears to be recommendable to improve specific growth rate of fish and SBE had the potential to mitigate mortality of fish at E. tarda infection.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.476-480
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• 2009

This study was conducted to evaluate the effect of extruded pellets (EP) containing different levels of protein (51%-55%) and lipid (9%-15%) for growth 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. Survival was not significantly different among all groups. Final mean weight of fish fed MP was significantly lower than that of fish fed EP1, EP2 and EP4 (P<0.05), but not significantly different from fish fed EP3. Feed efficiency of MP-fed fish was significantly lower than fish fed all EP formulations (P<0.05), but no significant difference was observed among the EP groups. Daily feed intake of MP-fed fish was significantly higher than fish fed all EP formulations (P<0.05). Condition factor was not significantly different among all groups. Whole body moisture and crude lipid contents were significantly affected by diet (P<0.05). Growth and feed efficiency of flounder was not affected by EP protein and lipid levels. Dietary formulation used in EP1, EP2 and EP3 can be applied to the practical feeding of flounder.