This study was designed to determine the effect of electric field strength, duration and fusion buffer in fusion parameters on the rate of membrane fusion between the somatic cell and cytoplast for Korean cattle (HanWoo) somatic cell nuclear transfer (SCNT) procedure. Following electrofusion, effect of 5 or 10 μM Ca2+-ionophore of activation treatment on subsequent development was also evaluated. Cell fusion rates were significantly increased from 23.1% at 20 V/mm to 59.7% at 26 V/mm and 52.9% at 27 V/mm (p<0.05). Due to higher cytoplasmic membrane rupture or cellular lysis, overall efficiency was decreased when the strength was increased to 30 V/mm (18.5%) and 40 V/mm (6.3%) and the fusion rate was also decreased when the strength was at 25 V/mm or below. The optimal duration of electric stimulation was significantly higher in 25 μs than 20 and 30 μs (18.5% versus 9.3% and 6.3%, respectively, p<0.05). Two nonelectrolyte fusion buffers, Zimmermann’s (0.28 M sucrose) and 0.28 M mannitol solution for cell fusion, were used for donor cell and ooplast fusion and the fusion rate was significantly higher in Zimmermann’s cell fusion buffer than in 0.28 M mannitol (91.1% versus 48.4%, respectively, p<0.05). The cleavage and blastocyst formation rates of SCNT bovine embryos activated by 5 μM Ca2+-ionophore was significantly higher than the rates of the embryos activated with 10 μM of Ca2+-ionophore (70.0% versus 42.9% and 22.5% versus 14.3%, respectively; p<0.05). This result is the reverse to that of parthenotes which shows significantly higher cleavage and blastocyst rates in 10 μM Ca2+-ionophore than 5 μM counterpart (65.6% versus 40.3% and 19.5% versus 9.7%, respectively; p<0.05). In conclusion, SCNT couplet fusion by single pulse of 26 V/mm for 25 μs in Zimmermann’s fusion buffer followed by artificial activation with 5 μM Ca2+-ionophore are suggested as optimal fusion and activation methods in Korean cattle SCNT protocol.

One-step dilution and direct transfer would be a practical technique for the field application of frozen embryo. This study was to examine whether Jeju Black Cattle (JBC, Korean Cattle) can be successfully cloned from vitrified and one-tep diluted somatic cell nuclear transfer (SCNT) blastocyst after direct transfer. For vitrification, JBC-SCNT blastocysts were serially exposed in glycerol (G) and ethylene glycol (EG) mixtures〔10% (v/v) G for 5 min., 10% G plus 20% EG (v/v) for 5 min., and 25% G plus 25% EG (v/v) for 30 sec.〕which is diluted in 10% FBS added D-PBS. And then SCNT blastocysts were loaded in 0.25 ml mini straw, placed in cold nitrogen vapor for 3 min. and then plunged into LN2. One-step dilution in straw was done in 25℃ water for 1 min, by placing vertically in the state of plugged- end up and down for 0.5 min, respectively. When in vitro developmental capacity of vitrified SCNT blastocyst was examined at 48 h after one-step dilution, hatched rate (56.4%) was slightly lower than that of control group (62.5%). In field trial, when the vitrified-thawed SCNT blastocysts were transferred into uterus of synchronized 5 recipients, a cloned female JBC was delivered by natural birth on day 299 and healthy at present. In addition, when the short tandem repeat marker analysis of the cloned JBC was evaluated, microsatellite loci of 11 numbers was perfectly matched genotype with donor cell (BK94-14). This study suggested that our developed vitrification and one-step dilution technique can be applied effectively on field trial for cloned animal production, which is even no longer in existence.

본 연구는 우분액비 및 녹비작물 도입에 의한 답리작 사료작물을 재배하여 수확한 다음 우분액비시용이 벼 및 후작물인 답리작 사료작물의 생산성, 토양의 지력증진 효과 및 양분이동에 미치는 영향을 조사하기 위하여 전라북도 축산진흥연구소내 식양토의 논에서 2006년 4월부터 2009년 4월까지 3개년에 걸쳐 수행하였다. 우분액비 시용은 벼는 이앙 전에 전량 기비로 시용하였으며 총체보리 및 호밀은 파종전과 봄 생육 개시 전에 2회 균등분할 시용하였는데, 화학비료

The objective of this work was to determine the effect of corpus luteum (CL) grade on pregnancy rate after embryo transfer in Korean cattle and we found that CL development was linked to pregnancy rate. The in vivo derived blastocyst-stage embryos were transferred to 15 recipients synchronized in the estrus cycles. Based on size and palpable characteristics, CLs were categorized into three grade. The grade three CL is not to be identified by rectal palpation. The pregnancy rates tended to increase with the increase in CL size of recipients. In grade one, two, and three, the pregnancy rates were 62.5%, 50.0%, and 0%, respectively. This result suggests that pregnancy rates after embryo transfer might be affected by the CL status of recipients.

Grossly, a lot of soft white nodules, 0.5～1.5 cm in diameter, were randomly scattered in liver of a slaughtered Korean Native Cattle. The surface of liver was roughened by those nodules. Histopathologically the nodules were consisted of numerous mature blood vessels, which had variable size and wall thickness, and which were encircled by much connective tissue. Masson's trichrome stain clearly revealed the proliferated blood vessels and perivascular stroma and, immunohistochemical staining revealed that endothelial cells of proliferated blood vessels were positive for Von Willebrand Factor. Based on gross and histopathological lesions, and immunohistochemical staining, the case was confirmed as hepatic vascular hamartoma and it is the first case report in Korea, as far as we know.

Nontuberculous mycobacteria (NTM) often confounds the interpretation of skin test in tuberculosis diagnosis, resulting in false-positive reaction. And, NTM are emerging pathogens that cause opportunistic infections in both humans and animals. The prevalence of NTM on human disease has been well investigated, whereas that of NTM on animal disease is not well established in Korea. The aim of this study was to determine the prevalence of NTM on cattle, which did not have symptoms of tuberculosis disease. A total of 426 isolates were collected in Korean native cattle and dairy cattle from 2007 to 2010. The most frequently isolated organisms were Mycobacterium peregrimum (n=5, 28%), Mycobacterium fortuitum (n=3, 17%), Mycobacterium intracellulare (n=2, 11%), Mycobacterium phlei (n=1, 5.6%), Mycobacterium terrae (n=1, 5.6%), Mycobacterium llatzerense (n=1, 5.6%), and Norcadia spp. (n=1, 5.6%). It seems to be necessary to further study the prevalence of NTM on environment (water, soil, feces) as well as animals.

To control mastitis in dairy cattle, National Mastitis Control Program (NMCP) has been conducted in Korea since early 2000s. Nevertheless, mastitis still remains one of the most important disease in dairy cattle in Korea as other countries worldwide. Under the NMCP, a total of 343,090 lactating cows nationwide were tested for mastitis during 2004～June 2010 based on California Mastitis Test (CMT), and 7.8% (26,782/343,090) and 13.8% (47,335/343,090) of the cows tested were infected with clinical and subclinical mastitis, respectively. Relative frequency of 2,058 bacteria isolated from bovine milk samples with somatic cell count of ≥200,000 cells/㎖ during 2006～2010 were analyzed. The most frequently isolated bacteria were Staphylococcus spp. including Staphylococcus aureus, accounting for over 50% of the total number of isolates. The highest frequency was observed for coagulase-negative staphylococci (CNS), followed by Gram negative bacteria (GNB), S. aureus, Streptococcus spp., and Enterococcus spp. Based on the results of recent studies in Korea, the majority of pathogens isolated from subclinical mastitis in dairy cattle in Korea are environmental minor pathogens. Therefore, more attention should be paid to control of environmental pathogens such as CNS, GNB, and Streptococcus uberis in dairy farms in Korea.

This study was to evaluate the protein profile of seminal plasma using 2-DE in Hanwoo. Seminal plasma was harvested from five mature Hanwoo, and seminal plasma protein was extracted by M-PER Mammalian Protein Extraction Reagent. Proteins were refined by clean-up kit and quantified by Bradford method until total protein was . Immobilized pH gradient (IPG) strip was used 18 cm and 3~11 NL. SDS-PAGE was used 12% acrylamide gel. Each gels were visualized by comassie brilliant blue and silver staining. These spots were analyzed by MALDI-TOF MS and searched on NCBInr. The result, 20 proteins of 36 protein spots were searched through peptide sequencing on the NCBInr. 8 proteins profiled by 2-DE were proved through previous bovine studies and the name of each protein was albumin, nucleobindin, clusterin, TIMP-2, spermadhesin Z13, spermadhesin-1 and BSP proteins (BSP 30 kDa and BSP A1/A2). 12 new proteins were ATP synthase, protein MAK16 homolog, Transmembrane protein 214, E3 ubiquitin-protein ligase BRE1A, dual serine/threonine and tyrosine protein kinase, tissue factor pathway inhibitor 2, alpha-actinin-4, RUN domain-containing protein 3B, catenin alpha-1, protein-glutamine gamma-glutamyltransferase 2, plakophilin-1 and inter-alpha-trypsin inhibitor heavy chain H1 has not been previously described in the bovine seminal plasma study. These proteins may be contribute to define the type of proteins affecting fertility of male and improve the fertilizing ability of semen in Hanwoo.

본 연구는 국내에서 생산된 주요 동계 사료 작물인 청보리 및 호밀 사일리지를 이용하여 거세 한우의 비육 중기용으로 조제된 TMR의 소 체내 이용성을 배합사료 및 볏짚으로 구성된 관행 사료와 비교하고자 반추위 누관이 장착된 소 3두를 이용하여 3 3 Latin square design 방법으로 실시되었다. 관행사료 급여구(대조구)에는 1일 두당 7kg (비육 중기용 배합 사료 5.6kg 및 볏짚 1.4kg, 건물 기준)을, 그리고 청보리 사일리지 TMR구

쌀 소비 감소로 인해 발생하는 중산간지 휴경답에서 노동력 절감을 위해 한번 파종으로 다년간 이용이 가능한 목초의 도입을 위해 본 시험을 수행하였다. 장소는 충남 금산이며 처리는 화학비료를 이용한 톨페스큐 위주 혼파조합(대조구)과 퇴비를 시용한 톨페스큐(Fawn) 단파구, 페레니얼 라이그라스(Reveille)단파구, 톨페스큐위주 혼파조합(톨페스큐 16, 오차드그라스 6, 페레니얼 라이그라스 4, 켄터키블루그라스 2, 화이트클로버 2 (kg/ha)), 극만

There are four (yellow, brindle, black, black in Jeju) kinds of native cattle in Korea. But only twelve hundred Korean brindle cattle (KBC) are remaining in limited areas of Korea and the genetic lineage, diversity, polymorphisms of KBC has not been identified. To analysis genetic polymorphism of KBC, 33 KBC were characterized using 11 microsatellite markers. Size of microsatellite marker was decided using Gene Mapper software after analysis ABI 3130XL. The average of allele numbers of KBC was 6.7 in this study, but that of Hanwoo was 10.0 in our previous report. The observed and expected heterozygosities of KBC were 0.719 and 0.738 but those of Hanwoo were 0.751 and 0.760 in our previous report. Also polymorphism information content (PIC) values were average 0.690 in KBC but 0.725 in Hanwoo. These results demonstrate that genetic polymorphism of KBC have decreased because the population was limited.

젖소는 분만전후기에 당 및 지방대사를 조절하여 태아와 유선에서 요구하는 영양소를 충족하고자 한다. 이러한 대사적 적응과정에서 중요한 역할을 하는 호르몬으로 insulin을 꼽을 수 있으며, 특 히 지방조직에 작용하여 동물체내 필요한 에너지를 충족시키기 위해 지방산의 재배치를 촉진하고 분만전 말기에 insulin resistance를 야기시킨다. 분만전에 혈중 유리 지방산의 농도가 증가됨에 따라 insulin resistance가 발생하며 이것은 사료섭취량의 감소와 밀접한 관계가 있다. Insulin resistance을 완화시키는 물질로 PPARγ agoinst인 thiazolidinedione (TZD)는 분만전후기에 발 생하는 대사성 질병의 발생을 억제하여 젖소의 건강 및 유생산 증가를 도모할 수 있다고 사료된다.