• 한국수산과학회지
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• 제51권2호
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• pp.148-156
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• 2018

This study was conducted to evaluate dietary hydrolyzed pig bristle meal (PBM) for juvenile olive flounder Paralichthys olivaceus. In Experiment 1 (EXP-1), six experimental diets were prepared to contain 0, 3, 6, 9, 12 and 15% PBM (designated Con, PBM3, PBM6, PBM9, PBM12 and PBM15, respectively). Triplicate groups of olive flounder (initial body weight, 8.69 g) were fed the diets to apparent satiation for 8 weeks during the optimal water temperature season ($20.5{\pm}2.12^{\circ}C$). All PBM supplemented groups except for PBM3 showed significantly lower growth performance and feed utilization compared to the control group. The protein digestibility of PBM3, PBM6, and PBM9 diets did not significantly differ from that of the control diet. In Experiment 2, 1% mono-calcium phosphate was added into the experimental diets used in Exp-1. Triplicate groups of olive flounder (10.6 g) were fed the diets to apparent satiation for 8 weeks during the low water temperature season ($12.5{\pm}1.12^{\circ}C$). The growth performances and feed utilization of fish fed all diets except for PBM15 diet did not significantly differ from those of the control diet. This study indicates that hydrolyzed PBM can replace fish meal by up to 12% with limiting amino acids and mono-calcium phosphate in diets for juvenile olive flounder.

• 한국수산과학회지
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• 제53권4호
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• pp.577-582
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• 2020

This study was conducted to investigate the replacement of fish meal (FM) with a plant and animal protein mixture (wheat gluten, soy protein concentrate, tankage meal and poultry by-product meal) in the diets of juvenile olive flounder Paralichthys olivaceus. The basal diet was formulated to contain 65% FM (Con). Four other experimental diets were formulated with alternative proteins replacing 20%, 30%, 40% and 50% of FM (FM20, FM30, FM40 and FM50, respectively). Taurine and betaine were added to the FM replacement diets. Triplicate groups of fish (mean±SD, 5.41±0.01) were fed the diets to apparent satiation for 15 weeks. After the feeding trial, no significant differences were found between any dietary groups in growth performance, feed utilization, survival, hematological parameters or whole-body composition. This result indicates that a proper mixture of the four protein sources with taurine and betaine supplements can be used as FM replacement to reduce FM levels from 65% to 32.5% in juvenile olive flounder diets.

• Journal of Animal Science and Technology
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• 제56권1호
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• pp.3.1-3.7
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• 2014

We examined the effects of Prunella vulgaris Labiatae (P. vulgaris L.) on specific and non-specific immune responses of Nile tilapia, Oreochromis niloticus. The optimal concentration without toxicity of P. vulgaris was determined to $30-40{\mu}g/ml$ in vitro and $120{\mu}g$/100 g of fish in vivo. P. vulgaris significantly elicited an antibody titer compared to FCA or ${\beta}$-glucan. ${\beta}$-glucan plus P. vulgaris group synergistically enhanced antibody production. No significant difference in antibody production was observed between P. vulgaris and P. vulgaris plus ${\beta}$-glucan group. A respiratory burst activity of head kidney (HK) leucocytes of tilapia administered with 300 or $500{\mu}g$ P. vulgaris was significantly (p < 0.05) enhanced compared with the PBS-injected control group and FCA-treated group. Maximum increase in the NBT reduction value was observed in $500{\mu}g$ P. vulgaris group but no significant difference was found between 300 and $500{\mu}g$ P. vulgaris group. The level of serum lysozyme activity was significantly (p < 0.05) higher in the 300 and $500{\mu}g$ P. vulgaris than $100{\mu}g$ P. vulgaris and FCA group. The phagocytic activities of HK leucocytes from tilapia administered with 300 and $500{\mu}g$ P. vulgaris were significantly (p < 0.05) higher than $100{\mu}g$ P. vulgaris and the control group. P. vulgaris was revealed with a good immunoadjuvant evoking the specific and non-specific immune responses of tilapia.

• Fisheries and Aquatic Sciences
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• 제22권11호
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• pp.27.1-27.6
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• 2019

Background: In order to assess the high value-added use of the alginate-free residue of sea tangle, an animal study was performed to evaluate the functional activities and key compounds present. In the animal study, sea tangle and the alginate-free residue demonstrated good anti-hyperlipidemic and anti-arteriosclerotic abilities. Results: The functional compounds in the alginate-free residue of the sea tangle were effectively extracted by supercritical fluid extraction (SFE). The optimum extraction temperature and pressure were 40 ℃ and 6500 psi (M1) in the SFE, a better method in comparison to the conditions of 70 ℃ and 4500 psi (M2), respectively. The anti-atherosclerotic effects of the alginate-free residue of sea tangle (M1, M2) were investigated in Sprague-Dawley rats treated with poloxamer 407, Triton WR 1339, corn oil, and a high-fat diet. The M1 fraction reduced the serum lipid levels with greater efficacy than the M2 fraction. In the hyperlipidemic rats, treatment with M1 decreased the serum triglyceride (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) levels when compared to the levels in normal rats. Conclusion: Our results demonstrated that the alginate-free residue of sea tangle reduces serum TC, TG, and LDL-C. These results suggest that the alginate-free residue of sea tangle contains physiologically active components, such as fucosterol, that may exert beneficial effects in the prevention of atherosclerosis.

• 한국축산시설환경학회지
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• 제6권2호
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• pp.83-89
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• 2000

In general, livestock wastewater consists of many pollutants such as nitrogen, phosphorus, carbonic compounds and inorganic substances. Most carbonic and organic compounds are sufficiently removed by conventional secondary processes, but nitrogen, phosphorus and soluble inorganic compounds are little removed by traditional clarification process. These remained substances in wastewater, for instances, phosphorus and nitrogen are efficiently eliminated by advanced wastewater treatment or botanical removing process. Concentrations of $BOD_s$, SS, T-N and T-P in influent livestock wastewater used in this study were 126mg/l, 115mg/l, 45mg/l and 13mg/l, respectively. The hydraulic retention time(HRT) of wastewater was about 10 days in the pond packed with aquatic plants. A water-hyacinth and a water-dropwort were used as an experimental stuff plant. The removal ratios of nitrogen was 44.3% for the water-hyacinth and 40.2% for the water-dropwort. The removal efficiency of phosphorus in experimental ponds reached by 57.9% for the water-hyacinth and 58.5% for the water-dropwort for 10 days, respectively. Removal ratios of BODs and SS of livestock wastewater for 10 days were reached by 80.1%, 91.0% for he water-hyacinth, respectively. At the same condition, the removal ratios of BODs and SS were reached by 75.0%, 87.6% for the water-dropwort, respectively.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.1-11
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• 2014

The Kenyan aquaculture sector is broadly categorized into freshwater aquaculture and mariculture. Whereas freshwater aquaculture has recorded significant progress over the last decade, the mariculture sector has yet to be fully exploited. The Kenyan aquaculture industry has seen slow growth for decades until recently, when the government-funded Economic Stimulus Program increased fish farming nationwide. Thus far, the program has facilitated the alleviation of poverty, spurred regional development, and led to increased commercial thinking among Kenyan fish farmers. Indeed, national aquaculture production grew from 1,000 MT/y in 2000 (equivalent to 1% of national fish production) to 12,000 MT/y, representing 7% of the national harvest, in 2010. The production is projected to hit 20,000 MT/y, representing 10% of total production and valued at USD 22.5 million over the next 5 years. The dominant aquaculture systems in Kenya include earthen and lined ponds, dams, and tanks distributed across the country. The most commonly farmed fish species are Nile tilapia Oreochromis niloticus, which accounts for about 75% of production, followed by African catfish Clarias gariepinus, which contributes about 21% of aquaculture production. Other species include common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, koi carp Cyprinus carpio carpio, and goldfish Carassius auratus. Recently, Kenyan researchers have begun culturing native fish species such as Labeo victorianus and Labeo cylindricus at the National Aquaculture Research Development and Training Centre in Sagana. Apart from limited knowledge of modern aquaculture technology, the Kenyan aquaculture sector still suffers from an inadequate supply of certified quality seed fish and feed, incomprehensive aquaculture policy, and low funding for research. Glaring opportunities in the Kenyan aquaculture industry include the production of live fish food, e.g., Artemia, daphnia and rotifers, marine fish and shellfish larviculture; seaweed farming; cage culture; integrated fish farming; culture of indigenous fish species; and investment in the fish feed industry.

• 한국수산과학회지
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• 제52권2호
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• pp.159-172
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• 2019

This study investigated the effects of dietary monobasic potassium phosphate (MKP) on the growth of the far eastern catfish Silurus asotus and four leafy vegetables in a hybrid biofloc technology aquaponic system. To an experimental diet containing 45% protein and 7% lipid, 1, 2, 3 or 4% MKP was added and was designated as MKP1, MKP2, MKP3, and MKP4, respectively. The optimum MKP levels were determined for the growth of fish and four leafy vegetables over 10 weeks. After the 10-week feeding trial, weight gain, feed efficiency, specific growth rate and protein efficiency ratio were higher in the fish groups fed MKP2 and MKP3 than in the other groups (P<0.05). The growth of the four leafy vegetables was also higher in the fish groups fed MKP2 and MKP3. Water quality [dissolved oxygen, pH, water temperature, electrical conductivity, turbidity, total ammonia nitrogen (TAN), $NO_2-N$, $NO_3-N$ and $PO_4-P$] was measured six times a week using a portable water quality meter and reagent measurements. The TAN (4.58-20.40 mg/L), $NO_3-N$ (24.12-52.40 mg/L) and $PO_4-P$ (20.38-48.48 mg/L) levels increased with time, while the $NO_2-N$ level remained below 0.1 mg/L throughout the study.

• Fisheries and Aquatic Sciences
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• 제25권4호
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• pp.202-213
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• 2022

Antibiotic resistant Escherichia coli cases are increasing high especially in Southeast Asia. Illegal use of the antibiotic in the aquaculture farming may become the culprit of the outbreak and spread into environmental source. A study was conducted to: 1) detect the chloramphenicol (CAL)-resistant gene in E. coli isolated from three aquaculture farms and six rivers of northwestern Borneo and 2) investigate the correlation between cat gene with five common antibiotics used. Isolation of E. coli was done on Eosin methylene blue agar and characterized using indole, methyl red, Voges-Proskauer, citrate tests. E. coli isolates were subsequently tested for their susceptibility to five antibiotics commonly used in aqua-farming. The CAL-resistant E. coli were further analyzed for the presence of resistant genes (cat I, cat II, cat III, cat IV) using multiplex polymerase chain reaction. 42 bacterial colonies were isolated from a total of 80 individual water samples, 34 of which were identified as E. coli. Result showed 85.3% of the E. coli isolates were resistant to amoxicillin, 35.3% were resistant to tetracycline, 29.4% were resistant to CAL, 17.6% were resistant to nitrofurantoin and 8.8% were resistant to nalidixic acid. All of the 10 CAL resistant E. coli isolateswere detected with cat II genes; five isolates detected with cat IV genes; three isolates detected with cat III genes; and another two detected with cat I genes. Pearson correlation coefficient shows highly significant relationship between resistance pattern of CAL with amoxicillin; and CAL with tetracycline. Our findings provide the supplementary information of the CAL resistance gene distribution, thereby improving our understanding of the potential risk of antibiotic resistance underlying within this microbial ecosystem.

• Fisheries and Aquatic Sciences
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• 제25권1호
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• pp.12-19
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• 2022

In the present study, we investigated the effects of recombinant eel gonadotropins (rec-GTHs) on maturation induction in immature ovarian culture in vitro and sex steroid hormones in vivo in the Japanese eel Anguilla japonica. To study the in vitro effects of rec-GTHs on estradiol-17β (E2) production in immature ovarian tissues, ovarian tissues were incubated with different doses of rec-follicle-stimulating hormone (rec-FSH) or rec-luteinizing hormone (rec-LH). The results revealed that the E2 levels in the rec-FSH (0.1, 0.5, or 1 ㎍/mL)- and rec-LH (0.1 or 0.5 ㎍/mL)-treated groups were significantly higher than those in the female eels from the control group. Furthermore, to investigate the in vivo effects of rec-GTHs on the gonadosomatic index (GSI) and plasma sex steroid hormone levels, the eels were injected intraperitoneally with eel's ringer (control), salmon pituitary extract (SPE; for female eels), human chorionic gonadotropin (hCG; for male eels), rec-FSH, rec-LH, and rec-FSH + rec-LH once a week. The results revealed that except for the SPE and the hCG groups, none of the groups exhibited a significant difference in GSI values. However, in vivo plasma E2 levels increased at the end of 4 weeks after rec-FSH treatment in female eels. Based on these results, it is suggested that rec-GTHs may have a positive effect on sexual maturation in female eels; however, further studies on complementary rec-protein production systems and additional glycosylation of rec-hormones are needed to elucidate hormone bioactivity in vivo and in vitro.

• Fisheries and Aquatic Sciences
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• 제24권8호
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• pp.284-295
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• 2021

Red sea cucumber Stichopus japonicus is an invertebrate animal inhabiting in coasts of Korea, China, and Japan. They are traditionally used for food and medicine and well known for their distinctive biologically and pharmacologically important compounds. We investigated the effect of amyloglucosidase (AMG) enzymatic extracts of S. japonicus (AESJ) on the proliferation and cytokine secretion of murine splenocytes stimulated with concanavalin A (Con A). AESJ enhanced the proliferation of splenocytes and the production of IL-2 (Th1 cytokine), IL-1β (Th1 promoting cytokine), and IL-4, IL-10 (Th2 type cytokines) when treated alone. However, under Con A stimulation, AESJ suppressed the proliferation of splenocytes, attenuated the secretion of IL-2, IL-4, IL-10, and enhanced IL-1β secretion. These results suggest that AESJ exhibits immunomodulatory effect by moderating the proliferation of splenocytes and the secretion of IL-2, IL-1β, IL-4, and IL-10 differently depending on the absence and presence of Con A stimulation. These data evidence the immunomodulatory potential of AESJ, which can be further developed into a functional food mediating homeostasis.