• 한국수정란이식학회지
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• 제15권2호
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• pp.129-136
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• 2000

This study was carried out to investigate the effect of biological factors on the in vitro production(IVP) of bovine oocytes for development of simple culture methods and medium. Oocytes from the slaughterhouse ovaries were matured and fertilized using general protocol and this study was examined if there were necessary to co-culture, media change, media type and embryo density. This results were as follows: 1. The development rate according to co-culture with cumulus cells and non co-culture as drop culture was not significantly different in cleavage (68.9 vs 71.7%), 8-cell stage (41.2 vs 44.1%) and blastocyst stage (12.2 vs 13.8%), respectively (p<0.05) 2. The blastocyst development rates in YS and CRIaa were higher than that in TCM199 (12.4, 10.4$ vs 3.7%), but the cleavage (69.0, 77.8 and 61.0%) and 8-cell stage (31.7, 37.0 and 35.7%) development accoring to YS, TCM199 and CRIaa ws not significantly different, respectively (p<0.05). 3. There was no significantly different in cleavage (62.6, 59.5 and 61.2%), 8-cell(34.7, 37.9 and 34.0%) and blastocyst (9.5, 11.6 and 12.8%) development among medium change time as control, Group I and Group II, respectively (p<0.05). 4. Blastocyst formation of 8-cell stage according to embryo density was not significantly different in 1, 10 and 25 embryos (27.3, 22.5 and 34.0%), respectively (p<0.05). These results indicated that simple culture system could reduce bovine IVP embryos as drop culture as non co-culture system, high density embryo (25 embryos/50 $\mu$1 drop). YS defined medium and no medium change for whole culture period, although other biological factors need to examine in order to produce efficient IVP bovine embryos.

• 대한수의학회지
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• 제55권2호
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• pp.75-80
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• 2015

Calf losses have an economic impact on larger Korean native cattle (KNC) breeding farms due to replacement, productivity, and marketing. However, little research on KNC calf mortality or causes of calf death on large-scale breeding farms has been conducted. Based on medical records and autopsy findings from the Hanwoo experimental station of the National Institute of Animal Science, calf death records from 2002 to 2011 were used to identify the causes of mortality. Mortality rate of KNC calves was 5.7%. Large differences (1.8~12.6%) in yearspecific mortalities were observed. Calf deaths were due to digestive diseases (68.7%), respiratory diseases (20.9%), accidents (6.0%), and other known diseases (2.2%). The main cause of calf death was enteritis followed by pneumonia, rumen indigestion, and intestinal obstruction. The greatest number of calf deaths occurred during the fall followed by summer. These results indicated that enteritis and pneumonia were the main reasons for calf death. However, autopsy findings demonstrated that other factors also caused calf death. This study suggested that seasonal breeding and routine vaccinations are the most important factors for preventing calf death, and improving calf health in high land areas with low temperature.

• 대한수의학회지
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• 제50권2호
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• pp.117-124
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• 2010

Members of the genus Brucella are facultative intracellular bacteria and cause brucellosis, a chronic disease in humans and abortion in animals. In this study, we tested sera for brucellosis of 15 Hanwoo farms in the western part of Gyeong-buk province, resulting 5 farms were brucellosis positive in 2008. We collected blood from 277 heads in the brucellosis positive 5 farms, and performed serological diagnosis, brucella positive cattle which had shown higher than 200 antibody titer in tube agglutination test were slaughtered, supramammary lymph nodes were collected, and Brucella spp. wild type isolation and identification were performed. From these results, 15 of Brucella spp. wild type strains were isolated and all strains were identified as B. abortus biotype 1 by biological and molecular analysis. In the antimicrobial susceptibility test, all 15 strains had a similar susceptibility and resistance pattern. This study may be useful for bacteriological and epidemiological understanding of cattle brucellosis in Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.728-733
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• 2005

The frequency and distribution of lymphoma caused by bovine leukemia virus (BLV) infection in various organs were investigated. Lymphoma samples were obtained from slaughtered cattle or from cattle submitted to the National Veterinary Research and Quarantine Service, Korea. Thirty female Holstein-Friesian dairy cattle aged over three years with the BLV-associated lymphoma were studied. None of the Korean native cattle (Hanwoo) had lymphoma in this study however. Lymphoma tissues were gray to pink in color, soft in consistency, and bulged from the cut surface. In advanced lymphoma tissues, there was great variety in the appearance of involved structures due to hemorrhage, necrosis, and/or calcification. Neoplastic tissues were observed in lymph nodes in all lymphoma cases. Intestine (96.4%), heart (88.9%), stomach (73.1%), and diaphragm (62.5%) were frequently involved with lymphoma. However, there was no lymphoma detected in liver. Large neoplastic masses, sometimes reaching the size of over 20 cm, were found in the abdominal cavities. It is suggested that metastasis of lymphomas occurs mainly via lymph based on gross observations; neoplasia may have been initiated in the serosal surface of the lung, heart, peritoneum, and numerous hollow organs in the abdominal cavity. Also many organs in the abdominal and thoracic cavity were affected by neoplastic tissues simultaneously. Characteristics observed in this study could be used as criteria to differentiate BLV-associated lymphoma from other nodular lesions in the slaughterhouse and as fundamental data to make clear the mechanism of metastasis or pathogenesis of EBL.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1229-1238
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• 2016

This study was conducted to determine the relationships of five intragenic single nucleotide polymorphism (SNP) markers (protein kinase adenosine monophosphate-activated ${\gamma}3$ subunit [PRKAG3], fatty acid synthase [FASN], calpastatin [CAST], high mobility group AT-hook 1 [HMGA1], and melanocortin-4 receptor [MC4R]) and meat quality traits of Duroc breeding stocks in Korea. A total of 200 purebred Duroc gilts from 8 sires and 40 dams at 4 pig breeding farms from 2010 to 2011 reaching market weight (110 kg) were slaughtered and their carcasses were chilled overnight. Longissimus dorsi muscles were removed from the carcass after 24 h of slaughter and used to determine pork properties including carcass weight, backfat thickness, moisture, intramuscular fat, $pH_{24h}$, shear force, redness, texture, and fatty acid composition. The PRKAG3, FASN, CAST, and MC4R gene SNPs were significantly associated with the meat quality traits (p<0.003). The meats of PRKAG3 (A 0.024/G 0.976) AA genotype had higher pH, redness and texture than those from PRKAG3 GG genotype. Meats of FASN (C 0.301/A 0.699) AA genotype had higher backfat thickness, texture, stearic acid, oleic acid and polyunsaturated fatty acid than FASN CC genotype. While the carcasses of CAST (A 0.373/G 0.627) AA genotype had thicker backfat, and lower shear force, palmitoleic acid and oleic acid content, they had higher stearic acid content than those from the CAST GG genotype. The MC4R (G 0.208/A 0.792) AA genotype were involved in increasing backfat thickness, carcass weight, moisture and saturated fatty acid content, and decreasing unsaturated fatty acid content in Duroc meat. These results indicated that the five SNP markers tested can be a help to select Duroc breed to improve carcass and meat quality properties in crossbred pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.483-491
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• 2009

In vitro produced porcine embryos have potential application in reproductive biotechnology. However, their development potential has been very low. This study evaluated the in vitro developmental ability and quality of cloned and parthenogenetic porcine embryos having 2-4 cells or 5-8 cells on Day 2 of in vitro culture. Analysis of results showed that 2 to 4 cell embryos had higher ability to form blastocysts than 5 to 8 cell embryos (p<0.05). Blastocysts produced from culture of 2 to 4 cell embryos also contained higher cell numbers and had lower BAX:BCLxL transcript ratio than those produced from 5 to 8 cell embryos (p<0.05), thereby suggesting 2 to 4 cell embryos have higher development potential. Further investigation revealed that 5 to 8 cell embryos had higher incidence (100${\pm}$0.0%) of blastomeric fragmentation than 2 to 4 cell embryos (15.2${\pm}$5.5% for parthenogenetic and 27.7${\pm}$7.1% for cloned embryos). This suggests that low development potential of 5 to 8 cell embryos was associated with blastomeric fragmentation. In conclusion, we have shown that morphological selection of embryos based on cell number on Day 2 of in vitro culture could offer a practical and valuable non-invasive means to select good quality porcine embryos.

• Asian-Australasian Journal of Animal Sciences
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• 제25권11호
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• pp.1521-1528
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• 2012

Previously identified QTL regions on BTA1 and BTA5 were investigated to validate the QTL regions and to identify candidate genes for growth and carcass traits in commercial cattle populations from the USA and Korea. Initially, a total of 8 polymorphic microsatellite (MS) markers in the BTA1 and 5 QTL regions were used for Chi-square tests to compare the frequencies of individual alleles between high and low phenotypic groups for the US (Michigan Cattleman's Association/Michigan State University; MCA/MSU) cattle. For a subsequent study, 24 candidate genes containing missense mutations and located within the QTL regions based on bovine genome sequence data were analyzed for genotyping in the two commercial cattle populations. Re-sequencing analyses confirmed 18 public missense SNPs and identified 9 new SNPs. Seventeen of these SNPs were used for genotyping of the MCA/MSU cattle (n = 98) and Korean native cattle (n = 323). On BTA1, UPK1B, HRG, and MAGEF1 polymorphisms residing between BM1312 and BMS4048 were significantly associated with growth and carcass traits in one or both of the MCA/MSU and Korean populations. On BTA5, ABCD2, IL22 and SNRPF polymorphisms residing between BL4 and BR2936 were associated with marbling and backfat traits in one or both of the MCA/MSU and Korean cattle populations. These results suggested that BTA 1 and 5 QTL regions may be segregating in both Korean Hanwoo and USA commercial cattle populations and DNA markers tested in this study may contribute to the identification of positional candidate genes for marker-assisted selection programs.

• Asian-Australasian Journal of Animal Sciences
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• 제26권3호
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• pp.316-322
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• 2013

In order to evaluate the genetic diversity and discrimination among five Korean native chicken lines, a total of 86 individuals were genotyped using 150 microsatellite (MS) markers, and 15 highly polymorphic MS markers were selected. Based on the highest value of the number of alleles, the expected heterozygosity (He) and polymorphic information content (PIC) for the selected markers ranged from 6 to 12, 0.466 to 0.852, 0.709 to 0.882 and 0.648 to 0.865, respectively. Using these markers, the calculated genetic distance (Fst), the heterozygote deficit among chicken lines (Fit) and the heterozygote deficit within chicken line (Fis) values ranged from 0.0309 to 0.2473, 0.0013 to 0.4513 and -0.1002 to 0.271, respectively. The expected probability of identity values in random individuals (PI), random half-sib ($PI_{half-sibs}$) and random sibs ($PI_{sibs}$) were estimated at $7.98{\times}10^{-29}$, $2.88{\times}10^{-20}$ and $1.25{\times}10^{-08}$, respectively, indicating that these markers can be used for traceability systems in Korean native chickens. The unrooted phylogenetic neighbor-joining (NJ) tree was constructed using 15 MS markers that clearly differentiated among the five native chicken lines. Also, the structure was estimated by the individual clustering with the K value of 5. The selected 15 MS markers were found to be useful for the conservation, breeding plan, and traceability system in Korean native chickens.

• Asian-Australasian Journal of Animal Sciences
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• 제33권4호
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• pp.651-661
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• 2020

Objective: We hypothesized that Cr source can alter adipogenic-related transcriptional regulations and cell signaling. Therefore, the objective of the study was to evaluate the biological effects of chromium acetate (CrAc) on bovine intramuscular (IM) and subcutaneous (SC) adipose cells. Methods: Bovine preadipocytes isolated from two different adipose tissue depots; IM and SC were used to evaluate the effect of CrAc treatment during differentiation on adipogenic gene expression. Adipocytes were incubated with various doses of CrAc: 0 (differentiation media only, control), 0.1, 1, and 10 μM. Cells were harvested and then analyzed by real-time quantitative polymerase chain reaction in order to measure the quantity of adenosine monophosphate-activated protein kinase-α (AMPK-α), CCAAT enhancer binding protein-β (C/EBPβ), G protein-coupled receptor 41 (GPR41), GPR43, peroxisome proliferator-activated receptor-γ (PPARγ), and stearoyl CoA desaturase (SCD) mRNA relative to ribosomal protein subunit 9 (RPS9). The ratio of phosphorylated-AMPK (pAMPK) to AMPK was determined using a western blot technique in order to determine changing concentration. Results: The high dose (10 μM) of CrAc increased C/EBPβ, in both IM (p = 0.02) and SC (p = 0.02). Expression of PPARγ was upregulated by 10 μM of CrAc in IM but not in SC. Expression of SCD was also increased in both IM and SC with 10 μM of CrAc treatment. Addition of CrAc did not alter gene expression of glucose transporter 4, GPR41, or GPR43 in both IM and SC adipocytes. Addition of CrAc, resulted in a decreased pAMPKα to AMPKα ration (p<0.01) in IM. Conclusion: These data may indicate that Cr source may influence lipid filling in IM adipocytes via inhibitory action of AMPK phosphorylation and upregulating expression of adipogenic genes.