• Journal of Fisheries and Marine Sciences Education
• /
• v.25 no.6
• /
• pp.1315-1323
• /
• 2013

The purpose of this research is to evaluate the effects of a commercial mixed extruded pellet(EP) and raw fish moist pellet(MP) diet on diseases prevalence and serological constituents and HSI of korean rockfish, Sebastes schlegeli grown in two commercial-scale aquaculture farms from June to December in 2009. The growth of MP-fed rockfish was slightly faster than EP-fed rockfish during experimental period, but did not show significant differences. The levels of TCHO, TG, Glucose and TP in the MP-fed rockfish group were higher than those of EP-fed group, whereas there was no significant difference in other biochemical factors of blood between two groups. In addition, bacteria and virus were not detected in both MP- and EP-fed rockfish groups, and the infection rates of gill fluke between two groups did not show clear difference. In conclusion, there was no comparable difference in growth and the health extents of one year rockfish by administration of the commercial mixed extruded pellet(EP) and raw fish moist pellet(MP) diets.

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

• Journal of Aquaculture
• /
• v.10 no.2
• /
• pp.163-169
• /
• 1997

An experiment was conducted to determine the effects of feeding extruded-floating (EP), slow-sinking (SP), fast-sinking (FP) or moist (MP) prepared with two different levels of fish meal, respectively, on the growth, feed efficiency and body composition in Korean rockfish (Sebastes schlegeli). Triplicate groups of the 50 fish averaging 75g were fed each of the following diets : high fish meal (72% in diet)-EP, low fish meal SP, low fish meal-FP and low fish meal-MP for 15 weeks. Dietary fish meal levels or pellet types did not influence weight gain, feed efficiency and bo요 composition of the fish (P>0.05). Findings showed that each of EP, SP or FP can by used as a practical type of diet for Koran rockfish.

• Journal of Aquaculture
• /
• v.18 no.4
• /
• pp.287-292
• /
• 2005

An 8-week of growth feeding trial was conducted to evaluate effects of the experimental extruded pellet (EP), commercial EP and raw fish-based moist pellet (MP) for growing flounder (Paralichthys olivaceus). Three replicate groups of the fish average weighing 43.5 g were fed four experimental diets (EP1, EP2, EP3 and EP4), four commercial diets (EP5, EP6, EP7 and EP8) and MP. Weight gain of fish fed the EP2, EP3 and EP4 was the highest among treatments, but not significantly different to that of fish fed the EPl, EP7 and MP. Feed efficiency and protein efficiency ratio of fish fed the MP were the lowest among treatments, but daily feed intake and daily protein intake of fish fed the MP were the highest among treatments. Moisture, lipid and ash contents of whole body were affected by diets, but protein content was not affected by diets. It is concluded that the dietary formulations used in the EP2, EP3 and EP4 can be applied in the practical exuded pellet feeds for growing flounder of 42-108g size.

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

• Journal of Fisheries and Marine Sciences Education
• /
• v.21 no.4
• /
• pp.562-567
• /
• 2009

This study was conducted to evaluate of improving extruded pellet (EP) for growth of juvenile flounder by comparing with raw fish-based moist pellet (MP) diet. Two replicate groups of 80 fish per each tank (initial weight of $36.0{\pm}1.2 g$) were fed one of the three EPs (EP1, EP2 and CEP) and (MP for 16 weeks. Survival was not significantly affected by experimental diets (P>0.05). Weight gain of fish fed the MP was not significantly different from that of fish fed the EP1 & EP2 (P>0.05), but that of fish fed CEP was significantly lower than that of fish fed MP (P<0.05). Specific growth rate of fish fed the CEP was significantly lower than those of fish fed EP1, EP2 and MP (P<0.05). Feed efficiency of fish fed the EP1 was significantly higher than those of fish fed CEP and MP (P<0.05), but not significantly different from those of fish fed EP2 (P>0.05). The Contents of crude protein and crude lipid in whole body were significantly different among all groups (P<0.05). Therefore, these results strongly suggest that EP1 & EP2 diets could be developed to replace MP diet for flounder without adverse effects on growth performance.

• Journal of Fisheries and Marine Sciences Education
• /
• v.21 no.4
• /
• pp.556-561
• /
• 2009

This study was conducted to evaluate the laboratory formulated extruded pellet (EP) for olive flounder Paralichthys olivaceus in the East Sea. Three replicate groups of 3,200 fish per each tank (initial weight of $28.1{\pm}0.2g$) were fed one of the two EPs (EP and CEP) and Moist pellet (MP) for 16 months in a commercial farm (Pohang, Korea). Survival was not significantly affected by experimental diets (P>0.05). Weight gain and specific growth rate of fish fed the EP were not significantly different from those of fish fed the MP, but that of fish fed CEP was significantly lower than that of fish fed EP and MP (P<0.05). Feed efficiency and protein efficiency ratio of fish fed the EP was significantly higher than those of fish fed MP (P<0.05), but not significantly different from those of fish fed CEP (P>0.05). The Contents of moisture, crude protein and crude lipid in the dorsal muscle were not significantly different among all groups (P>0.05). These results clearly indicated that the laboratory formulated extruded pellet used in this study can be developed to replace the moist pellet without affecting any growth performance of olive flounder in the commercial farm feeding trail.

• Journal of Fisheries and Marine Sciences Education
• /
• v.24 no.4
• /
• pp.602-608
• /
• 2012

This study was conducted to evaluate the effect of commercial extruded pellet (EP) diet on the growth and water quality compared with a raw fish moist pellet (MP) diet for flounder on field feeding experiments. Three replicate groups of 130 fish per each tank (initial weight of 380 g) were fed one of the EP and Moist pellet (MP) for 7 months. In field feeding experiment, no significant difference was observed in final mean weight of fish fed the experimental EP (1,233 g) and MP (1,237 g), and any noticeable problem caused by feeding the experimental EP was not found during the whole period of feeding trial. Feed efficiency of fish fed the experimental EP was higher than that of MP, and there was no significant difference in survival between the fish fed experimental EP and MP. The concentrations of SS, COD, TN and TP of seawater in tanks of MP groups were 1-5 times higher than those of EP groups. Therefore, these results strongly suggest that diet EP could be developed to replace MP diet for the marketable size of production for flounder without adverse effects on growth performance and water quality.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.3
• /
• pp.282-286
• /
• 2013

This study was conducted to compare extruded pellets (EP) and soft extruded pellets (SEP) with a raw fish-based moist pellet (MP) diet on the growth and flesh quality of Korean rockfish Sebastes schlegeli. Three groups of 20,000 fish (initial mean weight 133 g) per net-cage ($6{\times}12{\times}7m$) were fed commercial EP, SEP or MP for 16 months. The survival of fish fed SEP was higher than those of fish fed EP or MP. The highest growth performances were observed in the mean weight gain, total weight gain, and feed efficiency of fish fed MP, followed by those fed EP and SEP. Among the fish fed on extruded pellets, the total weight gain of fish fed SEP was higher than that of those fed EP, while fish fed EP grew faster than those fed SEP. No notable differences in body composition, sensory scores or textural properties of the dorsal muscle were observed in fish fed on EP, SEP or MP. Thus, it is suggested that extruded pellets, rather than raw fish-based moist pellets, could be fed to Korean rockfish without compromising flesh quality.

• Journal of Aquaculture
• /
• v.21 no.2
• /
• pp.102-106
• /
• 2008

This study was conducted to evaluate extruded pellets(EP) for the growth of sub-adult flounder Paralichthys olivaceus by comparing with raw fish-based moist pellet(MP). Two replicate groups of 150 fish per each tank(initial mean weight $594{\pm}6.5g$) were fed one of two EPs(EP1 and EP2) and a MP for 32 weeks. Survival was not significantly affected by experimental diets. Final mean weight of fish fed the EP1 was not significantly different from that of fish fed the MP, but that of fish fed EP2 was significantly lower than that of fish fed EP1 and MP (P<0.05). Feed efficiency and protein efficiency ratio of fish fed the EP1 and EP2 were significantly higher than those of fish fed MP(P<0.05). Daily feed intake of fish fed the EPs was significantly lower than that of fish fed MP(P<0.05). Condition factor was not significantly different among all groups. The contents of moisture, crude protein and lipid in dorsal muscle were significantly affected by experimental diets(P<0.05). Based on the results of this study, the dietary formulations used in EP1 and EP2 could be applied in the practical extruded pellet feeds for sub-adult flounder(594-1,126 g).