• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.407-417
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• 2000

The present study was to examine effects of various electrical stimulus treatments used for electro-fusion on the preimplantation development of bovine nuclear transfer (NT) embryos with fetal fibroblast cells. Fetal fibroblast cells were isolated from one fetus at day 45 of gestation in Holstein cow, and passaged 3 to 4 times before being transferred into enucleated oocytes. Single fibroblast cells were individually placed into the perivitelline space of enucleated oocytes by using a micromanipulator. At first, the fusion and developmental rates of reconstructed oocytes were compared between different electric stimulation conditions. When fusion of the reconstructed oocyte was induced by different electric pulse periods (15, 30 and 45 $\mu$sec) at a DC pulse of 1.8 kV/cm, 15 (45.5%, 120/264) or 30 $\mu$ sec group (43.9%, 106/241) showed a higher fusion rate than 45 $\mu$sec group (23.2%, 58/250, P＜0.05). However, no difference was detected in the development rate of the fused oocytes to blastocysts between groups. Next experiment was to examine the effects of different electrical field strengths (1.5, 1.8 and 2.1 kV/cm) for 15 $\mu$sec at electrofusion on in vitro development of the NT embryos. As results, there was no difference in the fusion and developmental rates of the NT embryos between electrical strength (P＞0.05). Finally, developmental competence of bovine NT embryos with somatic cells was compared with IVF-derived embryos. Of enucleated oocytes fused with fibroblast cells, 27.4% (75/274) developed to the blastocyst stage, which is similar to that (24.5%, 58/237) of IVF-derived embryos. However, mean nuclei number of NT blastocysts was smaller than that of IVF-derived blastocysts. Thus, we have established an optimal condition (1.8 kV/cm, 15 $\mu$sec) for electric fusion of bovine NT oocytes with somatic cells. The present study indicates that bovine reconstructed embryos with somatic cells normally develop to blastocyst stage in vitro, although having smaller nuclei numbers of blastocysts as compared to IVF-derived embryos.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.211-222
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• 2016

This study was conducted to investigate the physico-chemical meat quality and sensory properties of Holstein steers(n=18, 4 months old, average body weight 160kg) which were divided into 3 groups and fed 2 different energy levels of total mixed rations(TMR)(T1, TDN 74~84%; T2, TDN 77~85%) until 18, 20 or 22 months old, respectively. For loin muscles, 22-month group of T1 and 20- and 22-month groups of T2 had higher fat contents than the other groups (P<0.05). T2 had higher WHC values for 18-month groups among 3 feeding groups (P>0.05). In sensory properties, T1 had higher tenderness, flavor-likeness and overall likeness for 20-month group than the other groups (P<0.05). T2 had higher tenderness, juiciness, flavor likeness and overall likeness in 20- and 22-months groups than 18-month group (P<0.05). For top round muscles, 22-month group had higher fat contents than the other groups of T1 and T2 (P<0.05). T1 had higher in redness(a* value) and yellowness (b* value) of 22-month group (P<0.05). T2 had higher WHC values, lower WBS and CL values in 18-month group than the other groups (P<0.05). In sensory properties, T1 had higher tenderness for 18 and 20-month groups and overall likeness (P<0.05). T2 had higher tenderness in 18-month group. The results of this study showed that longer feeding of agricultural by-product TMR increased the intramuscular fat contents, however, the 18 and 20-months finishing groups were advantageous for the meat quality and sensory properties of Holstein steers.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.119-127
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• 2016

The current disinfection method of vehicles being applied in South Korea has various shortcomings. So, the epidemic has generated continuously at livestock farms. It is very important to develop an effective disinfection system for reduction of the epidemic. And various basic data is required for this development. Therefore, this study was performed to identify the nozzle type and proper discharge pressure of sprayers. The experiment was conducted from January 10, 2012 until February 28, 2012. All the performance measurement experiments were repeated five times. The subjects of experiment were the A, B and C company's products. The sprayed capacity, angle of spray and the covering area ratio were measured for each product. As a result, the sprayed capacity, angle of spray and the covering area ratio were increased as the discharge pressure of the sprayer was increased. In conclusion, the conical shaped of the nozzle is considered more appropriate than V-shaped, and the proper discharge pressure is expected to be at least 20kg/㎠.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.12-18
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• 2023

Beef traceability systems help prevent the distribution of Hanwoo (Korean native cattle) meat as imported beef. In particular, assigning a traceability number to each cattle can provide all information regarding the purchased Hanwoo meat to the consumers. In the present study, a DNA identity test was conducted on 344 samples of Hanwoo meat from large livestock product stores in Seoul between 2021 and 2022 to determine the authenticity of important label information, such as the traceability number. Traceability number mismatch was confirmed in 45 cases (13.1%). The mismatch rate decreased to 11.3% in 2022 from 14.7% in 2021, and the mismatch rate was higher in the northern region (16.9%) than in the southern region (10.2%). In addition, of the six brands, B and D showed satisfactory traceability system management, whereas E and A showed poor traceability system management, with significant differences (P<0.001). The actual traceability number confirmation rate was only 53.9% among the mismatch samples. However, examination of the authenticity of label information of the samples within the identified range revealed false marking in the order of the traceability number (13.1%), sex (2.9%), slaughterhouse name (2.2%), and grade (1.6%); no false marking of breed (Hanwoo) was noted. To prevent the distribution of erroneously marked livestock products, the authenticity of label information must be determined promptly. Therefore, a legal basis must be established mandating the filling of a daily work sheet, including the traceability number of beef, in partial meat subdivisions. Our findings can be used as reference data to guide the management direction of traceability systems for ensuring transparency in the distribution of livestock products.

• Journal of the Korean Society of Food Culture
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• v.21 no.6
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• pp.653-660
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• 2006

Some quality characteristics of tofu prepared with cuttlefish ink were investigated to study the effects of various of coagulants. Each concentration of coagulant was determined as 0.2% of GDL, 0.3# of $MgCl_2$, 1%^ of $CaCl_2$, 1.5% of $CaSO_4$ and 0.6% D-gluconic acid calcium by pre-experiment. Also, the optimum concentration of added cuttlefish ink was chosen as 3%(diluted in twenty times). The yield of inky tofu prepared with GDL as coagulant was the highest. According to prepared with $MgCl_2$ was the highest. The result of microstructure was examined by SEM, the particles of inky tofu coagulated with GDL and D-gluconic acid calcium were small and uniformity. In overall acceptability of sensory properties, inky tofu coagulated with GDL was the highest in score. In the color of inky tofu, L value and a value were the highest coagulated with GDL, but that coagulated with $CaCl_2$ had the highest b value. In the texture properties of inky tofu, hardness, gumminess and brittleness were the highest coagulated with D-gluconic acid calcium. A positive correlation was observed between the pH of tofu whey and acidity. Sensory properties of roasted nutty flavor, hardness, cohesiveness and springiness were positively correlated with the acceptability.

• Journal of the Korean Society of Food Culture
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• v.23 no.2
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• pp.222-227
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• 2008

This study examined the chemical composition of lotus root and functionally evaluated a fermented lotus root drink. Electron-donating ability using DPPH along with nitrite-scavenging ability were used to compare the antioxidative activities of unfermented and fermented lotus root drinks. The electron-donating abilities of the unfermented lotus root drink (1%) and fermented lotusroot drink (1%) were 22.55% and 23.88%, respectively. At pH 6.0, the nitrite-scavenging abilities of the unfermented lotus root drink and the fermented lotus root drink (100%) were 27.64% and 40.3%, respectively, and their scavenging ability increased in a dose-dependent manner at all pH values. In order to study the anti-obesity effects of the two drinks, male Sprague-Dawley rats were divided into four groups (A: basal diet, B: high fat diet, C: high fat diet+unfermented lotus root drink, D: high fat diet+fermented lotus root drink). Net weight gains were not significantly different among the four groups. Plasma total cholesterol concentrations significantly decreased in the groups receiving the unfermented and fermented lotus root drinks. Also, plasma total lipid and triglyceride contents were lower in the groups receiving the unfermented and fermented lotus root drinks as compared to the high fat diet group; however, the differences among the three groups were not significant.

• The Korean Journal of Zoology
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• v.13 no.3
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• pp.68-74
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• 1970

In the previous studies, the present author found that high proportion of the follicular oocytes from mouse and rabbit ovaries are able to resume their maturation division in the anterior chamber of the eye in which they have been incubated by auto- or homoplastic transplantation. Especially in the case of the homoplastic transplantation, it was known that no trouble has been detected in the process of resumption of the oval maturation in particular connection with the antigen-antibody reaction between donor and recipient. These findings provide a possibility that the follicular oocytes from various animals would be matured in the eye even after the xenoplastic transplantation. Under such an assumption, the present studies were performed to examine the behavior of the follicular oocytes in the eye chamber of the animals of different species. For the donor of the follicular oocytes, domestic rabbits, albino rats of Sprague-Dowley strain, and albino mice of A-strain bred in our laboratory were used. The oocytes obtained from the ovarian follicules were introduced to the anterior chamber of the eye of different species of animals, with an exception of rabbit in which only the female animals were used as a recipient. The procedures of collection of ova, introduction to the eye, harvest from the eye ball, fixation, and staining were the same as mentioned in the previous reports (Cho, 1967b; Cho and Kim, 1968). The conclusions obtained are summarized as below. 1. The rabbit follicular oocytes are able to mature in the eye chambers of both male mouse and rat, although the proportion of the maturation is lower than when they are incubated autoplastically in the eye. When the ova were incubated in the male mouse eye for 24 hours, 21 per cent of them showed chromosomes at metaphase I and II, whereas the rate was 32 per cent when they were incubated in the eye of the male rat. These are apparently low comparing to the rate of 52 per cent of autoplastic transplantation. 2. When rat follicular oocytes were transferred into the mouse eye chamber and recovered after 24 hours, 43 per cent of them produced the mataphase I and II chromosomes. This proportion was higher than the result of the homoplastic transplantation which yielded 23 per cent of the ova on maturation. 3. The most striking result was found in the experiment with mouse follicular oocytes. Seventy-six per cent of the oocytes resumed their maturation division within 24 hours after they were transferred into the male rat eye chamber, and this figure was significantly high compared to the result o 55 per cent obtained by the homoplastic transplantation. In the rat eye, the induction of the degenerative ova also was low (19%). On the other hand, the proportion of the oval maturation decreased to 45 per cent, while that of degeneration increased 33 per cent when they were incubated in the eye of the female rabbit. 4. It was apparent from the present experiments that the follicular oocytes can reveal their activation to maturation in the eye chamber which contains aqueous humor which is known to be composed of low protein content and of very little gamma-globulin which acts as an antibody(Oser, 1965), and that it shows higher osmolarity than blood serum(Levene, 1958). Taking these properities into consideration the humor may provide unfavourable environment to the cells and tissues incubated in. However, it could be noteworthy finding that only the follicular oocytes in the eye of the different species can grow in healthy condition although the maturation rates are varied with the animal species. The fact that the rabbit follicular oocytes show the lower proportion in maturation may be due to the greater amount of the yolk granules in the egg cytoplasm than those in the mouse and rat oocytes. That the mouse oocytes incubated in the eye of the rat mouse and rat oocytes. That the mouse oocytes incubated in the eye of the rat resumed their maturation process in greater proportion would e explained by the fact that the rat eye chamber particularly provides the better environment to the mouse oocytes than the eye chamber of mouse does.

• Korean Journal of Culture and Social Issue
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• v.15 no.1
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• pp.1-28
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• 2009

This study examines factors influencing stress and depression among Korean and Japanese university students and the role that parental social support, resiliency of efficacy and stress management behavior play. Four hypotheses are presented. First, parental social support will have a direct influence on resiliency of efficacy. Second, resiliency of efficacy will have a direct influence on stress management behavior and stress and depression symptoms. Third, resiliency of efficacy will have a mediating influence between parental social support and stress and depression symptoms. Fourth, stress management behavior will have a direct influence on stress and depression symptoms. A total 469 participants, consisting of 289 Korean university students (male=156, female=133) and 180 Japanese university students (male=112, female=68) completed a questionnaire that included Rhode Island Stress Inventory-Short Version (Horiuchi, Tsuda, Tanaka, Yajima & Tsuda, in press), Stress Management Behavior (Evers et al., 2006), CES-D (Radloff, 1977), BDI-II (Beck, Steer & Brown, 1996), Resiliency of Efficacy (Bandura, 1995) and Parental Social Support (Kim & Park, 1999). The results supported the first three hypotheses for both samples. Hypothesis 4 was not supported for the Japanese sample and it was partially supported for the Korean sample. The results indicate that parental social support had a direct and positive influence on resiliency of efficacy. Second, resiliency of efficacy had a direct and positive influence on stress management behavior and stress and depression symptoms. Third, resiliency of efficacy had a mediating influence between parental social support and stress and depression symptoms. Fourth, stress management behavior did not have a direct influence on stress symptoms. Overall, parental social support had a direct positive influence on resiliency of self-efficacy, which in turn had a direct negative influence on stress and depression symptoms.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.496-507
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• 2023

The in vitro organogenesis is one of important issues in plant embryology, and somaclonal variations are existing in calli and/or regenerants induced from a process of the organogenesis with in vitro circumstances. In this study, expressions of organogenesis-related genes were evaluated and genetic stability of regenerants derived from the process of in vitro organogenesis were measured using ISSR markers in Imperata cylindrica 'Rubra', Poaceae. The expressions of organogenesis-related genes were detected all of regenerants at the process of the organogenesis. All ISSR markers produced with an average of 71 bands per in vitro-cultured regenerants, and the scorable bands were varied from two to eight with an average of 5.14 bands per a primer. The polymorphism rates of the in vitro regenerants were higher than that of mother plants (1.4%), showing 4.1% (pot-cultured regenerants), 4.3% (field-cultured regenerants), 4.2% (in vitro-cultured regenerants), 5.6% (calli with green shoots) and 1.4% (calli), respectively. The genetic similarity matrix (GSM) among all accessions ranged from 0.747 to 1.0 with a mean of 0.868. GSM of the regenerants showed differences (from 0.972 to 1.00) compared with that of mother plants (0.991). According to the clustering analysis, two independent groups were divided into; the one is mother plants and regenerants cultured at room and open field, the other is regenerants cultured in vitro. The results give a new insight for understanding the dynamics of organogenesis in monocot plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.188-196
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• 2023

Wheat (Triticum aestivum L.) is an important crop in Korea, with a per capita consumption of 31.6 kg in 2019. In the southern region, wheat is grown after paddy rice, and it is harvested during the rainy season in mid-June. This timing, in combination with high humidity and untimely rainfall, activates the enzyme alpha-amylase, which breaks down starch in the wheat grains. As a result, sprouted grains have lower quality and value for flour. However, seeds that absorb water before sprouting are expected to maintain better quality. The aim of the study was to identify the critical period during wheat maturation when rainfall has the greatest impact on grain quality, to prevent price declines due to quality deterioration. Two wheat cultivars, Jokyoung and Hwanggeumal, were grown in a speed breeding room, and artificial rainfall was applied at different times after heading (30, 35, 40, 45, 50, and 55 days). The proportion of vitreous grains decreased from 40 to 55 days after heading (DAH). Both cultivars had chalky grain sections from 35 DAH, with Hwanggeumal having a higher proportion of vitreous grains. Starch degradation was observed using FE-SEM (Field Emission Scanning Electron Microscope) at 40 DAH for Jokyoung and 50 DAH for Hwanggeumal. Color measurements indicated increased L and E values from 40 DAH, with rain treatment at 55 DAH leading to a significant increase in L values for both cultivars. Ash content increased at 45 DAH, whereas SDSS decreased at 35 DAH. Overall, grain quality from 40 DAH until harvest was found to be affected to the greatest extent by direct exposure of the spikes to moisture. Red wheat showed better quality than white wheat. These findings have implications for the cultivation of high-quality wheat and can guide future research efforts in this area.