Gunhyun Park

Evaluation of the Efficacy of Fermented By-product of Mushroom, Pleurotus ostreatus, as a Fish Meal Replacer in Juvenile Amur Catfish, Silurus asotus: Effects on Growth, Serological Characteristics and Immune Responses

The present experiment was conducted to evaluate the efficacy of dietary fermented by-product of mushroom, Pleurotus ostreatus, (FBPM) as a fish meal (FM) replacer in juvenile Amur catfish, Silurus asotus. A total number of 225 fish averaging 5.7±0.1 g (mean±standard deviation) were fed one of the five experimental diets formulated to replace FM with FBPM at 0%, 5%, 10%, 20%, and 30% (FBPM0, FBPM5, FBPM10, FBPM20, and FBPM30, respectively). At the end of eight weeks of the experiment, average weight gain (WG) of fish fed FBPM0 or FBPM5 were significantly higher than those of fish fed FBPM20 or FBPM30 diets (p<0.05). However, there was no significant differences in WG among the fish fed FBPM0, FBPM5 or FBPM10, and between fish fed FBPM10 or FBPM20, and also between those fed FBPM20 or FBPM30 diets. Lysozyme activity of fish fed FBPM0 or FBPM5 were significantly higher than those of fish fed FBPM10, FBPM20 or FBPM30 diets (p<0.05). The chemiluminescent response of fish fed FBPM5 was significantly higher than those of fish fed FBPM0, FBPM20 or FBPM30 diets (p<0.05). Broken line regression analysis of WG suggested that the maximal dietary inclusion level for FBPM as a FM replacer could be 6.3% without any adverse effects on whole body composition and on serological characteristics. Therefore, these results may indicate that the maximal dietary inclusion level of FBPM as a FM replacer could be 6.3% in juvenile Amur catfish.

Optimum Feeding Rates in Juvenile Olive Flounder Paralichthys olivaceus Fed Practical Expanded Pellet at Low and High Water Temperatures

Two feeding trials were conducted to investigate the optimum feeding rates in juvenile olive founder Paralichthys olivaceus fed practical expanded pellet(EP) containing 58.1% crude protein, 10.7% crude lipid, and 10.8% ash at low and high water temperatures. In the first experiment, triplicate groups of 15 fish with average weight of 7.7 g were fed at one of seven feeding rates(0, 1, 1.5, 2, 2.25, or 2.5% of body weight/day or to satiation) for 4 weeks at low water temperature. In the second experiment, quadruplicate groups of 20 fish with average weight of 5.5 g were fed at one of eight feeding rates(0, 3, 3.5, 4, 4.25, 4.5, or 4.75% of body weight/day or to satiation) for 4 weeks at high water temperature. Based on growth performance, we estimated that the optimum feeding rates for juvenile olive flounder were 1.97-2.51% and 4.82-6.36% of body weight/day at low and high water temperatures, respectively. Key words; Olive flounder, Optimum feeding rates, Low temperature, High temperature, Extruded pellet

Re-evaluation of the Optimum Dietary Vitamin C Requirement in Juvenile Eel, Anguilla japonica by Using L-ascorbyl-2-monophosphate.

This study was conducted to re-evaluate the dietary vitamin C requirement in juvenile eel, Anguilla japonica by using L-ascorbyl-2-monophosphate (AMP) as the vitamin C source. Five semi-purified experimental diets were formulated to contain 0 (AMP0), 30 (AMP24), 60 (AMP52), 120 (AMP108) and 1,200 (AMP1137) mg AMP kg-1 diet on a dry matter basis. Casein and defatted fish meal were used as the main protein sources in the semi-purified experimental diets. After a 4-week conditioning period, fish initially averaging 15±0.3 g (mean±SD) were randomly distributed to each aquarium as triplicate groups of 20 fish each. One of five experimental diets was fed on a DM basis to fish in three randomly selected aquaria, at a rate of 3% of total body weight, twice a day. At the end of the feeding trial, weight gain (WG) and specific growth rate (SGR) for fish fed AMP52 and AMP108 were significantly higher than those recorded for fish fed the control diet (p<0.05). Similarly, feed efficiency (FE) and protein efficiency ratio (PER) for fish fed AMP52 were significantly higher than those for fish fed the control diet (p<0.05). Broken-line regression analysis on the basis of WG, SGR, FE and PER showed dietary vitamin C requirements of juvenile eel to be 41.1, 41.2, 43.9 and 43.1 (mg kg−1 diet), respectively. These results indicated that the dietary vitamin C requirement could range from 41.1 to 43.9 mg kg−1 diet in juvenile eel when L-ascorbyl-2-monophosphate was used as the dietary source of vitamin C.

The dietary valine requirement for rainbow trout, Oncorhynchus mykiss, can be estimated by plasma free valine and ammonia concentrations after dorsal aorta cannulation

This study was carried out to evaluate the dietary valine requirement by measuring means of the plasma free valine and ammonia concentrations in rainbow trout, Oncorhynchus mykiss, after dorsal aorta cannulation. A total of 35 fish averaging 498±7.2 g (initial body weight, mean±SD) were randomly distributed into seven groups with five fish in each group. After 48 h of feed deprivation, each group was fed one of seven L-amino acid based diets containing graded levels of valine (0.45, 0.95, 1.20, 1.45, 1.70, 1.95 or 2.45% of diet, dry matter basis) by intubation at 1% body weight. Blood samples were taken at 0, 5 and 24 h after intubation. Post-prandial plasma free valine concentrations (PPval, 5 h after intubation) and post-absorptive free valine concentrations (PAval, 24 h after intubation) of fish fed diets containing 1.45% or more valine were significantly higher than those of fish fed diets containing 1.20% or less valine (P<0.05). Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) remained low or constant from fish fed diets containing 0.45–1.45% valine, but increased linearly from fish fed diets containing 1.45–2.45% valine. Post-absorptive plasma ammonia concentrations in the present study were not significantly different among the groups. Broken-line model analyses on PPval, PAval and PPA indicated that the dietary valine requirements of rainbow trout was between 1.41 (3.85) and 1.50% (4.10) of diet (% of dietary protein on a dry matter basis).

Effects of Different Dietary Cadmium Levels on Growth and Tissue Cadmium Content in Juvenile Parrotfish, Oplegnathus fasciatus

This feeding trial was carried out to evaluate the effects of different dietary cadmium levels on growth and tissue cadmium content in juvenile parrotfish, Oplegnathus fasciatus, using cadmium chloride (CdCl2) as the cadmium source. Fifteen fish averaging 5.5±0.06 g (mean±SD) were randomly distributed into each of twenty one rectangular fiber tanks of 30 L capacity. Each tank was then randomly assigned to one of three replicates of seven diets containing 0.30 (C0), 21.0 (C21), 40.7 (C41), 83.5 (C83), 162 (C162), 1,387 (C1,387) and 2,743 (C2,743) mg cadmium/kg diet. At the end of sixteen weeks of feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of fish fed C21 were significantly higher than those of fish fed C83, C162, C1,387 and C2,743 (p<0.05). Weight gain, SGR and FE of fish fed C0, C21 and C41 were significantly higher than those of fish fed C162, C1,387 and C2,743. Protein efficiency ratio of fish fed C0, C21 and C41 were significantly higher than those of fish fed C1,387 and C2,743. Average survival of fish fed C0, C21, C41 and C162 were significantly higher than that of fish fed C2,743. Tissue cadmium concentrations increased with cadmium content of diets. Cadmium accumulated the most in liver, followed by gill and then muscle. Muscle, gill and liver cadmium concentrations of fish fed C0, C21, C41 and C83 were significantly lower than those of fish fed C162, C1,387 and C2,743. Based on the ANOVA results of growth performance and tissue cadmium concentrations the safe dietary cadmium level could be lower than 40.7 mg Cd/kg diet while the toxic level could be higher than 162 mg Cd/kg diet.

Effects of dietary Macsumsuk® supplementation on growth performance, haematological parameters, disease resistance and body composition of juvenile Nile tilapia, Oreochromis niloticus L.

An eight-week feeding trial was conducted to evaluate the effects of dietary Macsumsuk® supplementation on growth performance, haematological parameters, disease resistance and body composition of juvenile Nile tilapia, Oreochromis niloticus. A total of 375 fish averaging 1.0 ± 0.05 g (mean ± SD) were randomly distributed into 15 tanks in groups of 25, and each tank was then randomly assigned to one of three replicates of five diets containing 0(M0), 0.3(M0.3), 0.6(M0.6), 1.2(M1.2) and 2.4(M2.4)% dietary Macsumsuk®. At the end of eight weeks of feeding trial, average weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency ratio (PER) of fish fed M1.2 diet were significantly higher than those fed M0 diet (P < 0.05). Significantly higher values for haematological parameters, such as red blood cell (RBC), haemoglobin (Hb) and haematocrit (HCT), were obtained in fish fed M0.6 diet compared to the fish offered M2.4 diet. Although an analysis of variance (ANOVA) test suggested that the optimum level of dietary Macsumsuk® in juvenile Nile tilapia, O. niloticus, could be 1.2%, broken-line analysis of WG indicated a level of 0.803% when Macsumsuk® is used as the dietary feed additive.

Optimal Feeding Frequency for Juvenile Korean Rockfish Sebastes schlegeli Fed Commercial Diet at Two Different Water Temperatures

We conducted two feeding trials to investigate the optimal feeding frequency of juvenile Korean rockfish Sebastes schlegeli fed a commercial diet of expanded pellets containing 47.2% crude protein, 9.2% crude lipid, and 14.5% ash at two different water temperatures. In the first experiment, triplicate groups of 20 fish with an average weight of 2 g were fed an equal amount of diet (5.97% based on body weight) at one of six feeding frequencies (2, 3, 4, 5, 7, or 9 meals/day) for four weeks at . After four weeks, we measured weight gain (WG), specific growth rate (SGR), feeding efficiency (FE), and protein efficiency ratio (PER). Fish fed diet five meals/day grew significantly better than those fed nine meals/day. The second experiment used identical experimental conditions and feeding regions, except the food ration was slightly less (5.92% based on body weight) and the water temperature was increased to . After four weeks, we again measured WG, SGR, FE and PER. Fish fed seven meals/day grew significantly faster than those fed 2, 3, 4, or 9 meals/day. Whole-body protein levels in fish fed three meals/day was higher than those fed four meals/day in water, but whole-body lipids in the fish fed four meals/day was higher than those fed two meals/day in water. A second-order polynomial analysis based on WG suggested the optimal feeding frequency for juvenile Korean rockfish was five meals/day at and six meals/day at , indicating that fish reared in higher water temperature require higher feeding frequencies.

Effects of Dietary Pro-biotics and Immunomodulator as an Alternative to Antibiotics in Korean Native Chicken

This study was conducted to investigate the effects of dietary probiotics and immunomodulator on growth performance, carcass characteristics, fecal content and pathogenic bacteria counts in ileum and cecum and ileum of broiler chicken (Korean native chicken, HanHyup No. 3). A total of 120 (day-old) chicks were randomly divided into 5 treatments with 3 replicates and there were 8 birds per replicate. Dietary treatments consisted of five diets; the corn-soybean based control diet (C), the diet containing antibiotics (Avilamycin) 10 ppm (T1), the diet containing probiotics 1 [(Lactobacillus () + yeast () + Bacillus subtilis ()] at 0.5% level (T2), probiotics 2 [(Lactobacillus () + yeast ()] at 0.5% level in diet (T3), and the diet containing probiotics 3 [T2 + -glucan + organic acid] (T4) and raised for 9 weeks. There were no significant differences among treatments in weight gain, feed intake and feed conversion. Carcass ratios of broilers were higher in T3 and T4 than other treatments, however, the differences were non-significant. Internal organs and liver, heart weight were significantly increased in T4 (p gas content was decreased (p

Synergistic Effects of Dietary Vitamins C and E on Methylmercury-Induced Toxicity in Juvenile Olive Flounder Paralichthys olivaceus

Abstract This experiment was conducted to evaluate the synergistic effects of vitamin C and E on methylmercury (MeHg) toxicity in juve -nile olive flounder Paralichthys olivaceus . In a 3×3 factorial design, 9 experimental diets containing three different vitamin C (0, 200 or 400 mg/kg diet in the form of l-ascorbyl-2-monophosphate) and vitamin E (0, 100 or 200 mg/kg diet in the form of dl-α-tocopheryl acetate) levels with the Hg toxicity level (20 mg/kg diet in the form of MeHg) were formulated. Triplicate groups of fish averaging 2.3 ± 0.05 g (mean ± SD) were fed one of the 9 diets in a flow through system for 8 weeks. Fish fed 400 mg vitamin C/kg diet with 100 or 200 mg vitamin E/kg diet showed significantly ( P < 0.05) higher weight gain (WG) than did fish fed the other diets. Fish fed 400 mg vitamin C/kg diet at all vitamin E levels and those which fed vitamin C and E equally at a rate of 200 mg/kg diet showed significantly ( P < 0.05) higher feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER) than did fish fed the other diets. Fish fed 200 and 400 mg vitamin C/kg diet exhibited significantly (

Optimum Feeding Rate and Frequency in Juvenile Korean Rockfish Sebastes schlegeli Fed a Commercial Diet

우리나라 주요 어류양식 어종인 조피볼락(Sebastes schlegeli) 은 2010년 생산량이 20,918톤(국내 어류양식 총 생산량의 20%)으로 국내 어류양식에서 두 번째로 생산량이 많은 어종 이다(FAO, 2012). 다른 어종과 마찬가지로 조피볼락의 생산성 및 양식경영비에서 가장 중요하게 영향을 미치는 것은 사료이 며, 총 양식경영비의 50-60%에 이른다(Cho et al., 2006). 현재 까지 조피볼락 양식의 효율적인 관리와 생산성 향상을 위해서 많은 연구들이 수행되었다. 배합사료 개발을 위해 영양소 요구 량과 사료 원료 이용성에 관한 연구들이 수행 되었고(Lee et al., 1993; Kim and Bae, 1999), 배합사료에 의한 생사료 대체 가능 성과 같은(Lee and Jeon, 1996), 환경 친화적인 고효율 배합사 료 개발을 위하여 많은 연구들이 수행되고 있다. 하지만 조피볼 락을 비롯한 양식 어류의 성장은 사료 이외에 망갈이, 선별, 수 온 등의 외부 환경요인에 의해서 많은 영향을 받는다(Choi et al., 2009). 따라서, 양식어종에 대한 적합한 사료가 개발되더라 도 외부환경에 따른 사료공급방법이 제대로 이루어지지 않으 면 성장 및 사료효율이 달라지고, 수질오염 발생 등 많은 부작용 이 일어날 수 있기 때문에(Kim et al., 2005), 효율적인 사료공급