• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.23-30
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• 2021

To examine the optimal temperature, light intensity, and shell-type for shell-living conchocelis production, we tested the shell infiltration of free-living conchocelis fragments under various environmental conditions. Under a combination of various temperatures (10, 15, 20, 25 and 30℃) and light intensities (1, 5, 10, 20, 40, and 80 μmol m-2 s-1), the optimal infiltration conditions of the evaluated three Pyropia species were 20-25℃ and 5-80 μmol m-2 s-1 for P. yezoensis, 20-30℃ and 20-80 μmol m-2 s-1 for P. seriata, and 20-25℃ and 20-80 μmol m-2 s-1 for P. dentata. The infiltration efficiency of free-living conchocelis for different shell types was greater in Korean and Chinese oyster Crassostrea gigas shells than that in scallop Argopecten irradians and clam Meretrix lusoria shells. These results suggest that oyster shells are suitable substrates for shell-living conchocelis production. In conclusion, the present results for optimal infiltration conditions for free-living conchocelis of the three examined Pyropia species will contribute significantly to the production of stable shell-living conchocelis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.4
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• pp.365-373
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• 2021

The purpose of this study was to investigate the improvement effect of biomarkers through the supply of natural diet in the juvenile hybrid abalone (Haliotis discus discus♀^*H. madaka♂). For the study, the shell length of about 17 mm and the total weight of 0.83 g were used. The feeding conditions were set as the natural diet group (dried laver) and the formulated diet group, and the experiment duration was 16 weeks. The survival rate was about 14% higher in the natural diet group than the formulated diet group, and growth was also faster in the natural diet group. Shell malformation rate was lower in the natural diet group (7.5%) than the formulated diet group (21.5%). In the biochemical composition, except for carbohydrates, both experimental groups showed similar values. The degeneration of epithelial cells in the hepatopancreatic tubule was lower in the natural diet group than the formulated diet group, and the activity of basophilic cell was higher in the natural diet group. These results indicate that it is worth considering the supply of natural diet for the breeding of juvenile hybrid abalone and the improvement of the quality of the formulated diet (H. discus discus♀^*H. madaka♂).

• Journal of Marine Life Science
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• v.7 no.2
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• pp.213-220
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• 2022

This study was conducted to investigate the effect of environmental factors such as water temperature and rearing density on the survival and growth of Litopenaeus vannamei under low salinity conditions. Overall, in the higher water temperature, the higher survival rate comes out and in the lower rearing density, the higher the survival rate does. In a study on feed efficiency, weight gain (WG) increased significantly as water temperature increased, and weight gain according to rearing density significantly decreased as rearing density increased. The growth rate of L. vannamei was faster when the water temperature was higher (water temperature 31℃) under low salinity conditions. In addition, in the evaluation of the growth rate according to the rearing density, it was confirmed that the growth rate was accelerated at a low rearinging density. It is believed that the results of this study will be usefully applied to the determination of the optimal rearinging density and breeding water temperature of L. vannamei in low salinity condition.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.55-63
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• 2022

Odors emitted from pig houses have been a constant root of legal issues in pig farming. These gases are among the main causes of health and mental stresses to nearby communities, so policymakers and researchers continuously study to reduce the concentration of odorous gases from pig facilities. A continuous field experiment proved that the concentration of odor emissions inside the pig houses is highly dependent on ventilation rate, breeding details, and animal activities. However, the standard odor emission rate worldwide widely varies due to differences in pig house designs and ventilation requirements. Thus, this study aimed to measure the odor emission rates, considering the actual condition of selected Korean pig houses, through field measurement. The odor measurements were performed at three different pig production facilities without odor abatement technologies. The target experimental pig houses were buildings for weaning, growing, and fattening pigs. Results showed that the actual ventilation rate in target pig houses falls below the standard ventilation requirement of pigs, resulting in high odor concentrations inside the pig houses.

• Ocean and Polar Research
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• v.44 no.4
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• pp.365-372
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• 2022

The present study measured the growth performance of juvenile hybrid of red-spotted grouper ♀ × giant grouper ♂ (RGGG) across four water temperatures (19, 23, 27, and 31℃) and compared it to those of maternal purebreds (red-spotted grouper ♀ × ♂, RG) for eight weeks. The specific growth rate (SGR) and weight gain (WG) of RGGG increased as temperature increased, with greater SGR and WG at higher temperatures (27 and 31℃) than RG. The condition factor of RGGG was higher than that of RG and there were no differences between temperature groups within breeding lines. Food consumption increased at higher temperatures for both RGGG and RG, and was the highest in the 31℃ group. Similar to the SGR and WG, the food conversion rate (FCR) in RGGG decreased with increasing water temperature, with the significantly lowest value at 31℃; in RG, however, FCR progressively decreased in the 27℃ group, then increased in the 31℃ group. Furthermore, the FCR of the 31℃ group of RGGG, which had the lowest value among the RGGG groups, was lower than that of the 27℃ group of RG, which had the lowest RG value. In the analysis of nonlinear regression curves within the range of experimental temperature, the optimum temperature for SGR and FCR in RGGG was 31℃, unlike in RG. In conclusion, the growth performance of juvenile RGGG seems to have largely improved from the influence of paternal traits, hybrid with giant grouper, and it is presumed to be more profitable for commercial production in tropics/subtropics.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.149-157
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• 2019

This study interested on management of broodstock and the effect of raise the temperature for promotion of maturity in Tresus keenae. For management of broodstock, we performed indoor and outdoor culture. In addition, broodstock was put in exposure and immersion condition. This experimental design is aimed at knowing the optimal management of broodstock. In addition, we investigated the promotion of maturity, growth and survival rate when raise the temperature of the breeding seawater of broodstock in winter season. Result that, the management of broodstock was shown to be more effective obesity and survival rate in outdoor culture than indoor culture. In addition, there is no anthropogenic food supply in management and it is easy to management because it is kept under natural environmental conditions. Therefore, It is considered appropriate to management to outdoor culture. In raise the temperature, survival rate was lower in the experimental group than in the control group. However, obesity was significantly increased compared with the control group. Also, gonad showed that the sex maturity was promoted. If sex maturation is not developed due to seasonal water temperature, the promotion of sexual maturity through heating is considered to be an effective method in terms of artificial seed production.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.206-206
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• 2022

Sustainable agriculture is a potential strategy to enable agricultural cultivation systems to feed the growing population under climate change. Sustainable agriculture consists of environment-friendly farming methods that allow the production of crops with minimal harm to the ecosystem. Early establishment in rice might be helpful to adopt sustainable agriculture with less inputs, such as water and phosphorus fertilizer. Two QTLs conferring tolerance to abiotic stress and low nutrition condition, DTY4.1 and Pup1, respectively, are effective for good establishment in the early growth stage under low water and phosphorus fertilizer application. We developed 'Sechanmi' and 'MSI 1-DTY' harboring Pup1 and DTY4.1 into MS11, a japonica rice variety adaptable to tropical regions, using Marker-Assisted Backcrossing (MABC). MS 11-PD lines were developed to meet the demand for less water and P fertilizer application throughout the growth stage of rice. In the F5 generation, water-saving or rainfed cultivation was performed in different P (phosphorus) content. Irrigation was applied only when severe drought was observed one month after transplanting. There was no significant difference observed between the parents and MS11-PD lines in low P conditions. However, MS11-PD lines had more tillers in P-supplied conditions compared to that of the parents 40 and 50 days after transplanting. Under the same amount of P, MS11-PD lines might have higher phosphorus uptake capacity than the parents, increasing the number of tillers and showing better early establishment. The better vegetative growth stage is one of the factors that can potentially increase production by way of higher number of panicles. Through this breeding strategy, it is possible to attain sustainable agriculture by applying less P and water to address the need of a growing population.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.289-289
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• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.

• Animal Bioscience
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• v.37 no.8
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• pp.1463-1473
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• 2024

Objective: Three experiments were conducted to evaluate the effects of Saccharomyces yeast postbiotics (SYP) in feeds for sows on the growth of offspring (Exp. 1), for nursery pigs on their growth (Exp. 2), and for nursery and finishing pigs on their growth (Exp. 3). Methods: Exp. 1 had 80 sows at breeding assigned to 4 groups with SYP at 0, 0.050, 0.175, and 0.500 g/kg. Offspring were fed a common diet for 126 d. Exp. 2 had 144 barrows at 8 kg body weight (BW) allotted to CON (no SYP); YPC (SYP at 0.175 g/kg; d 0 to 42); and YPD (SYP at 1.25, 0.75, and 0 g/kg; d 0 to 7, d 8 to 21, and d 22 to 42, respectively) with 8 pens/treatment (6 pigs/pen). Exp. 3 had 96 barrows at 8 kg BW allotted to CON (no SYP); YPN (SYP at 0.175 g/kg; d 0 to 42); YPF (SYP at 0.100 g/kg; d 43 to 119); and YPA (SYP at 0.175 and 0.100 g/kg; d 0 to 42 and d 43 to 119, respectively) with 8 pens/treatment (3 pigs/pen). Results: In Exp. 1, increasing SYP increased (p<0.05, quadratic) the sow body score (maximum at 0.30% SYP), reduced (p<0.05, quadratic) the days-wean-to-estrus (minimum at 0.27% SYP), and increased (p<0.05) offspring BW at weaning and their average daily gain (ADG) and feed efficiency (G:F) at d 126. In Exp. 2, ADG, average daily feed intake (ADFI), and G:F of YPC were the greatest (p<0.05). The ADG and ADFI of YPD were greater (p<0.05) than CON. Fecal score of YPC and YPD was smaller (p<0.05) than CON. In Exp. 3, YPA had the greatest (p<0.05) ADG and YPN and YPF had greater (p<0.05) ADG than CON. Conclusion: SYP enhanced sow performance, offspring growth, growth of nursery and growing pigs with the greater efficacy at 0.27 to 0.32 g/kg feed.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.1
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• pp.62-65
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• 2024

Dystocia, a challenging condition in obstetrics, can arise from various causes, including fetal monsters with structural abnormalities. This case report presents a unique case of dystocia due to a fetal monster known as Perosomus Elumbis in a beetal breed goat from Pakistan. The 4-years-old pregnant doe presented with prolonged straining and failure to deliver the fetus after 8 hours of labor. Upon examination, the cervix was dilated, and only the forelimbs of the fetus were visible in the birth canal. The subsequent delivery involved the application of manual traction by using a dystocia kit, and the removal of edematous fluid from the legs. The monster fetus exhibited absence of hair growth, along with the absence of thoracic vertebrae. Two other fetuses were present, with one found dead and the other alive. Posttreatment involved fluid therapy, antibiotics, and supportive care for the doe. This case report sheds light on the occurrence of Perosomus Elumbis fetal monsters and their impact on dystocia in goat breeding. Understanding the underlying causes and implementing appropriate management strategies are crucial for successful outcomes in similar cases.