Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Accumulating evidence indicates that Se compounds possess anticancer properties. Se is specifically incorporated into proteins in the form of selenocysteine and non-specifically incorporated as selenomethionine in place of methionine. This study evaluated protection by Se in the bone repair process in ovariectomized rats after irradiation. For such purpose, 80 ovariectomized female Sprague-Dawley rats were randomly divided into 4 experimental groups: ovariectomized (Ov), Ov/Se, Ov/irradiated (Irr) and Ov/ Se/Irr. A bone defect was created on the tibia of all animals 40 days after ovariectomy. Two days after surgery, only the Ov/Se and Ov/Se/Irr rats received 0.8 mg Se/kg. Three days after surgery, only the Ov/Irr and Ov/Se/Irr rats received 10 Gy of X-rays on the lower limb region. The animals were euthanized at 7, 15, 22 and 29 days after surgery to assess the repair process, which was evaluated by analysis of trabecular bone number (Masson Trichrome) and birefringence analysis (Picrosirius). It was possible to observe a delay in the bone repair process in the ovariectomized/irradiated group and similarity between the ovariectomized, Ov/ Se and Ov/Se/Irr groups. Our findings suggest that sodium selenite may influence a radioprotective effect in the bone repair of tibia of ovariectomized rats without toxicity.

The objective of this study was to evaluate the toxicities of permeable cryoprotectants and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Toxicities of permeable cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), Glycerol, and 1,2-PROH were investigated using a murine embryo model. Female F-1 mice were stimulated with gonadotropin, induced ovulation with hCG and mated. Two cell embryos were collected and cultured after exposure to among DMSO, EG, Glycerol, and 1,2-PROH. Embryo development was evaluated up to the blastocyst stage. The total cell count of blastocysts that were treated with DMSO and Glycerol at the 2-cell stage was significantly lower than that were treated with EG (81.1±15.1), 1,2-PROH (88.0±21.1) or the control (99.9±21.3) (p<0.001). On comparison of four cryoprotectant treated groups, the DMSO and Glycerol treated group showed a decreased cell count compared with the EG and 1,2-PROH treated group (p<0.05). Both DMSO (14.7±1.3), EG (12.1±1.1), Glycerol (15.2±1.8), and 1,2-PROH (11.5±1.3) treated groups showed higher apoptosis rates of cells in the blastocyst compared with the control (6.5±0.7, p<0.0001). In addition, the DMSO or Glycerol treated group showed more apoptotic cells than the EG or 1,2-PROH treated group (p<0.001). The potential toxicity of cryoprotectants was uncovered by prolonged exposure of murine embryos to among DMSO, EG, Glycerol, and 1,2-PROH at room temperature. When comparing four permeable cryoprotective agents, EG and 1,2-PROH appeared to be less toxic than DMSO and Glycerol at least in a murine embryo model.

The objective of this study was to monitor health conditions of genetically identical somatic cells cloned Korean white cattle, endangered indigenous cattle (EIC) and indigenous cattle (IC) by analysis of hematologic characteristics. Naturally ovulated oocytes and donor cells were used for somatic cell nuclear transfer (SCNT). Donor cells and enucleated oocytes were followed by electric fusion, chemical activation and surgical embryo transfer into the oviducts of surrogate females. Two recipients became pregnant; two maintained pregnancy to term, and one live cattle were delivered by caesarean section. The cloned Korean white cattle were genetically identical to the nuclear donor cattle. As a result, the mean values of RBC and platelet of cloned cattle and white cattle were significantly decreased by age (P<0.05). The mean values of RBC, HCT, MCV and MCHC between cloned cattle and IC of the same age (1∼2 years) showed the statistical significance (P<0.05). Also, in the WBC of Korean white cattle, the estimated values were decreased according to the age from 12.0×103/μl under 1 year to 11.0×103/μl over 1 years respectively. Although clone-cattle had lower numbers of RBC than reference range, the most of RBC and WBC related heamatologic results of cloned cattle were not different when compared to reference range. This study suggests that cloned Korean white cattle derived from SCNT did not have remarkable health problems, at least in the growth pattern and hematological parameters. In addition, this study provides a valuable resource for further investigations of the preservation of rare genetic stocks underlying traits of interest in cattle.

산불피해지의 복원과정은 산불 후 장기간에 걸친 천이의 영향으로 조류군집에 많은 변화가 예상되므로 장기적인 조사가 필요하다. 본 연구는 대형 산불 발생 13년 후 복원 방법에 따른 번식기 조류 군집의 차이를 파악하기 위해 강원도 삼척시 검봉산 지역에서 산불 미피해지와 산불 후 자연복원지, 산림시업복원지 등 3개 지역을 대상으로 하였으며, 2013년 봄철 번식기 동안 108개 지점의 정점을 조사하였다. 조사 결과, 평균 종수와 개체수, 종다양도는 모두 자연복원지역이 피해목 벌채 및 식재와 같은 산림시업복원지역에 비해 높게 나타났으며, 미피해지역과 자연복원지역은 유의한 차이를 보이지 않았다. 길드 분석 결과, 수관 탐색 조류(foliage searcher)와 수간 및 나무줄기 천공 조류(timber driller), 일차 수동성 조류(primary cavity nester), 이차 수동성 조류(secondary cavity nester) 모두 산불 후 산림시업복원지역이 다른 두 지역보다 서식 밀도가 낮게 나타났으며, 미피해지역과 자연복원지역은 차이를 보이지 않았다. 따라서 산불 후 개벌 및 조림으로 대표되는 복원 방법은 번식기 조류의 밀도 및 종 다양성 회복을 저해할 수 있으므로, 가능한 인위적인 산림시업 방법을 지양하고 자연복원 방식을 채택하는 것이 효율적인 방법이라 생각된다.

이 연구에서는 정소가 제거된 흰쥐에 비타민 E와 셀레늄(Selevit)을 5주간 투여 후 체중, 장기 무게, 혈액학적 그리고 생화학적 변화를 관찰하였다. 체중의 변화에서는 모든 실험군에서 증가가 나타냈다. Orch+Selevit군의 체중 증가는 11.2±10.25 g으로 가장 낮았으며, Intact군, Sham군, Orch군과 비교 시 유의적으로 감소되었다. 장기 무게의 변화에서는 Orch+Selevit군의 심장과 간장 무게는 Intact군, Sham군과 비교 시 유의적으로 감소되었다. Intact군, Sham군, Orch군의 신장 무게는 Orch+Selevit군 비교 시 유의적인 증가를 확인하였다. 백혈구 수의 혈액학적 변화에서는 Orch+Selevit군은 다른 모든 군과 비교해 유의적인 증가를 확인하였으며, 적혈구수, 평균적혈구용적, 평균적혈구혈색소량, 평균적혈구색소농도 등과 같은 혈액학적 측정치에서는 유의성은 인정되지 않았다. 생화학적 변화에서는 Orch+Selevit군의 혈청총단백질, 알부민은 Orch군과 비교 시 유의적으로 증가하였으며, 알부민은 Intact군, Sham군 그리고 Orch군과 비교 시 유의적으로 감소했다. AST와 ALT는 모든 실험군에서 유의성이 없었다.

본 연구에서 배아의 생식세포 동결에 가장 흔히 쓰이고 있는 두 가지 동결 보호제, 즉 DMSO와 EG의 독성을 비교하고자 생쥐 수정란 모델을 이용한 실험을 하였다. 생후 6주령의 암컷 생쥐 F1 hybrid mice에 10 IU의 PMSG를 복강 주사하여 과배란을 유도하고, 2-세포기 배아를 획득하고 DMSO와 EG 각각 노출시킨 후, 배양을 하였다. 배반포의 전체 세포수는 2-세포기 단계에서 DMSO(68.1±24.1)로 EG(81.2±27.0) 혹은 control(99.0±18.3)(p<0.001) 처리구에 비해서 유의적으로 낮았다. DMSO 처리구가 EG 처리구에 비해 세포수가 적었다. DMSO(15.4±1.5)와 EG(10.2±1.4) 두 처리구는 대조구(6.1±0.9, p<0.0001)와 비교해서 배반포에서 세포사 비율이 더 높음을 확인했다. 또한, DMSO 처리구는 EG 처리구(p<0.001)보다 더 많은 세포사멸된 세포가 확인되었다. DMSO 또는 EG 처리군과 대조군 사이에는 배아 부화율에 있어서 차이가 있었으며, 이는 배아에 대한 동결 보호제의 잠재적인 독성을 확인한 결과였다. 이번 연구에서 장기간 처리했을 때 EG 처리군보다 DMSO 처리군에서 배아발달과 세포수가 저하된 것은 DMSO의 독성이 더 높을 것으로 사료된다.

The purpose of this study is to produce wanted sex progeny of genetically confined White Hanwoo (albinism) with preselected sex sperm. One bull of White Hanwoo was chosen for semen donor and X sperm was sorted by MoFlo XDP cell sorter. To compare the pregnancy and birth rates, KPN straw was used as control, total number of unsorted sperm was 20×106/straw. Sexed X frozen semen with 2×106 cells or 4×106 cells per straw were in seminated twice on Hanwoo heifers. The abnormality of the sexed X semen was 24.9 ± 7.31% and distal reflex abnormality of mid piece was significantly (p<0.05) higher (11.7%) compared with that of KPN 768 (5.6%). There were no differences on the pregnancy and birth rates between 2×106 cells or 4×106 cells of X-sperm but KPN semen showed significant differences (p<0.05). The pregnancy rates of KPN 768, 2×106 cells and 4×106 cells X-sperm of White Hanwoo cattle were 85.0%, 26.3% and 50%. The birth rates were 80.0%, 15.8% and 21.4%, respectively. The female offspring rates of KPN 768, 2×106 cells and 4×106 cells X-sperm of White Hanwoo cattle were 43.8%, 100% and 100% (p<0.05). These results indicated that sex sorted White Hanwoo could be used for the production of wanted progeny with 2×106 cells/straw for AI. To increase the efficiency of calf production, the sperm number of sex sorted semen will be optimized for sex selection of White Hanwoo progeny.

Alteration in ion channel or transporter expression levels affects cell volume which is produced by movement of water and ion across the plasma membrane. In particular, aquaporin (AQP) channels among ion channels play a crucial role in movement of water across the cell membrane. This study was performed to identify whether AQP expression is changed in bovine follicular cystic follicles using microarray, RT-PCR and Western blotting analyses. In microarray data, AQP4 expression was decreased, whereas AQP7 was increased in cystic follicles. Additional experiments were focused on the AQP7 expression increased in cystic follicles. The microarray data was confirmed by semi-quantitative polymerase chain reaction (PCR) and Western blot analysis. AQP7 mRNA and protein expressions were significantly increased in the cystic follicles (p<0.05). Application of estrogen (10 μg/ml) to bovine ovarian cells showed a trend of increase in AQP7 expression. From these results, we suggest that the increase in AQP7 expression in cystic follicles may play an important role in movement of water in bovine ovary. In addition, AQP7, a aquaglyceroporin permeating water and glycerol, could be a good target in development of methods for the cryopreservation of bovine ovary.

The importance of genetic resource preservation has been highlighted in the literature as a means of maintaining genetic diversity. Investigations for hematologic values and the differential count of white blood cell count (WBC) for Korean indigenous cattle (KIC) and endangered indigenous cattle (EIC) are rarely performed. Therefore, the objective of this study was to investigate the hematologic values of total 40 EIC (White, Black, Mini cattle) and 35 KIC as control by analysis of hematologic characteristics. As a result, the mean values of RBC and platelet of EIC were significantly decreased by age (p<0.05). The mean values of RBC, HCT, MCV and MCHC between EIC and KIC of the same age (2 ～3 years) showed the statistical significance (p<0.05). Also, in the WBC of EIC, the mean values were decreased according to the age from 13.9×103/μL～12.7×103/μL under 1 year to 9.1×103/μL～11.5×103/μL over 2 years respectively. In the differential count of WBC of EIC (White, Black, Mini cattle), it showed generally the rates of 40.2%, 52.2%, 49.0% lymphocyte and 27.2%, 33.9%, 32.0% segmented neutrophil from 2～3 years respectively. Result of this study will be used for establishing reference range for blood analysis in EIC such as white, black and mini cattle. This study reported hematological values which could serve as baseline information for comparison in conditions of nutrient deficiency, physiological and health status of endangered Korean native cattle. In addition, this study provides a valuable resource for further investigations of the preservation of rare genetic stocks underlying traits of interest in cattle.

The occurrence of mastitis in diary cattle has been caused by genetic, physiological, managemental and environment factors accounted for the highest percentage of worldwide disease in dairy cattle. The purpose of this study was to analyze the occurrences and causative bacteria of subclinical mastitis in milking cows and also examine the distribution of bacteria in milk by isolating and identifying bacteria both in whole milk and quarter milk. 31.4% of the milking cows suffered subclinical mastitis, and 9.5% had it in terms of quarter milk. According to the results of analyzing bacteria in quarter milk of which somatic cell count (SCC) was over 500 thousand, 15 kinds of bacteria were isolated, and among them, Pantoea spp. formed the biggest part as 15.8%. From whole milk, 37 kinds of bacteria were identified, and among them, Klebsiella oxytoca showed the highest identification rate as 30.1%. According to the results of bacteria analyzed from the quarter milk of entire milking cows, 52 kinds of bacteria were identified. Among them, 17 kinds of Staphylococci were isolated, and CNS (Coagulase-Negative Staphylococci) formed a large part as 44.9%. The findings of this study showed that various kinds of bacteria were isolated from cows having subclinical mastitis; therefore, when managing specifications about milking or such, dairy farm will have to take proper action like performing sanitary control or counting somatic cells regularly in order to do their best for reducing mastitis.

Programmed cell death or apoptosis is associated with changes in K+ concentration in many cell types. Recent studies have demonstrated that two-pore domain K+ (K2P) channels are involved in mouse embryonic development and apoptotic volume decrease of mammalian cells. In cerebellar granule neurons that normally undergo apoptosis during the early developmental stage, TASK-1 and TASK-3, members of K2P channels, were found to be critical for cell death. This study was performed to identify the role of K+ channels in the H2O2-induced or cryo-induced cell death of mouse and bovine embryos. Mouse and bovine two-cell stage embryos (2-cells) exposed to H2O2 for 4 h suffered from apoptosis. The 2-cells showed positive TUNEL staining. Treatment with high concentration of KCl (25mM) inhibited H2O2-induced apoptosis of 2-cells by 19%. Cryo-induced death in bovine blastocysts showed positive TUNEL staining only in the cells near the plasma membrane. Cryoprotectant supplemented with 25 mM KCl reduced apoptosis slightly compared to cryoprotectant supplemented with 5 mM KCl. However, the combination of antioxidants (β-mercaptoethanol) with 25 mM KCl significantly decreased the rate of H2O2-induced and cryo-induced apoptosis compared to treatments with only antioxidants or 25 mM KCl. These results show that blockage of K+ channel efflux for a short-time reduces H2O2- and cryo-induced apoptosis in mouse and bovine embryos. Our findings suggest that apoptosis in mouse and bovine embryos might be controlled by modulation of K+ channels which are highly expressed in a given cell type.

Computational algorithms and their implementations are studied for the treatments of kernel function’s shadow effects, which occurs in the application of the BEM(boundary element method) for radiation heat transfer analysis. In this problem, surfaces are assumed to be diffuse and gray placed in two-dimensional enclosures with transparent medium. Self-blocking or third party blocking is possible when the radiosity from the BEM nodes cannot reach the destination points. Also the third party blocking can be the partial or total blocking case. Algorithms, which can accurately recognize the each blocking cases and reflect the shadow effects to the BEM kernel function, are studied in this paper. Effective implementation methods are presented, and their results are verified by the test problem

The objective of this study was to analyze the accuracy of estrus detection of heat detector and analysis of estrus behavior (mounting and mounted), and the evaluation of conditions required for improving reproductive efficiency in Holstein dairy cows fitted with a estrous detector. The heat detection system consists of estrous detector based on wireless sensor and an electric bulletin board displayed estrus behavior data. When cow mounting other cows, the accuracy of estrus behavior displayed an electric bulletin board were 87.5% (mounting other cows only), 100% (mounting other cows but not standing), 80.0% (mounting other cows with standing for 1∼4 seconds), 90.0% (mounting other cows but not standing for 1∼4 seconds), 80% (mounting other cows with standing for more than 5 seconds) and 90.0% (mounting other cows but not standing for more than 5 seconds). When cow mounted other cows, the accuracy of estrus behavior displayed an electric bulletin board were 100% (mounted other cows but not standing), 100% (mounted other cows with standing for 1∼4 seconds), 100% (mounted other cows but not standing for 1∼4 seconds) and 100% (mounted other cows with standing for more than 5 seconds). Circadian distribution of first observed in estrus were 59.1% (am 8∼pm 6) and 40.9% (pm 6∼am 8). Distribution for the number of estrus behavior were 40.9% (less than 3 times), 36.4% (4∼6 times) and 22.7% (more than 4 times). The conception rates relative to interval from first estrus behavior to insemination for estrus periods were 23.1% (less than 11 hours) and 55.6% (12∼20 hours).

Embryo transfer (ET) technology is of high importance in modern cattle breeding programs. ET is one step in the process of removing one or more embryos from the reproductive tract of an outstanding donor female and transferring them to one or more recipient females. Embryos also can be produced in the laboratory via techniques such as in vitro fertilization (IVF). But the actual transfer of an embryo is only one step in a series of processes that may include some or all of the following: superovulation and insemination of donors, collection of embryos, isolation, evaluation and short-term storage of embryos, micromanipulation and genetic testing of embryos, freezing of embryos and embryo transfer. Cryopreservation and direct transfer of frozen-thawed embryos is common-place with pregnancy rates near that of fresh embryos. Polymerase chain reaction (PCR) technology is currently being used for sexing embryos, and this technology will be used for “embryo diagnostics” and “embryo genomics” in the future. Although, many limitations and problems remain to overcome, these and other new technologies promise to change livestock breeding drastically in the next decade.

This study aimed to improve the reproductive efficiency of dairy herds by comparison and analyzing estrous appearance rate, conception and non-conception rate according to the stage of lactation using the lactation and reproductive records of average (less than 10,000 liters milk in 305 days) and high yielding (more than 10,000 liters milk in 305 days) Holstein cows (n=102). Milk production and reproduction data were collected between January 2010 and December 2012 from Holstein cows kept in the commercial dairy farms. Average (n=32) and high yielding (n=24) Holstein cows used to analyze the relationship between milk yield and reproductive performance. Our results showed that estrous appearance rate according to the stage of lactation was 25.0% (30∼59d), 40.6% (60∼ 89d), 25% (90∼110d) and 9.4% (>111d) in average yielding cows and 16.7% (30∼59d), 20.8% (60∼89d), 12.5% (90 ∼110d) and 50.0% (>111d) in high yielding cows, respectively. Conception rate according to the stage of lactation was 87.5% (30∼59d), 61.5% (60∼ 89d), 75.0% (90∼110d) and 66.7% (>111d) in average yielding cows and 25.0% (30∼59d), 0% (60∼89d), 33.3% (90∼ 110d) and 50.0% (>111d) in high yielding cows, respectively. Days between parturition and conception was 23.7% (<149d), 0% (150∼209d) and 0% (>210 d) in average yielding cows and 69.0% (<149 d), 77.8% (150∼209d) and 38.9% (>210d) in high yielding cows, respectively. Conception rate from 110 days postpartum in high yielding cows was 41.7% (110∼150d), 50.0% (151∼180d) and 50.0% (>181d). Body condition score (BCS) in 120 days postpartum was 2.64±0.1 in average yielding cows and 2.28±0.1 in high yielding cows, respectively.

The objective of this study was to investigate the effects of abnormal ovarian cycles after superovulation treatment of Holstein Donor Cows. CIDRs were inserted into the vaginas of twenty two head of Holstein cows, regardless of estrous cycle. Superovulation was induced using folliclar stimulating hormone (FSH). For artificial insemination, donor cows were injected with PGF2α and estrus was checked about 48 hours after the injection. Then they were treated with 4 straws of semen 3 times, with 12-hour intervals. Embryos were collected by a non-surgical method 7 days after the first artificial insemination. The cows were considered to have resumed ovarian cyclicity on the day of ovulation if followed by regular ovarian cycles. Seventy two point seven percentage of the cows(16/22) had normal resumption of ovarian cyclicity(resumption within 40 days after superovulation), and 27.3%(6/22) had delayed resumption(resumption did not occur until＞40 days after superovulation). Delayed resumption Type Ⅱ(first ovulation did not occur until ≥40 days after superovulation, i.e. delayed first ovulation 13.6%) were the most common types of delayed resumptions. The mean numbers of total ova from < 10 and 10≤ of corpora lutea(CL) was 7.8±1.8 and 12.7±2.7, respectively. The number of transferable embryos differed between < 10 and 10≤ CL was 5.4±1.3 and 8.1±3.4, respectively. Four point five percentage of the cows(1/22) did not resumption their ovarian cyclicity until 60 days after superovulation treatment. Diverse researches on the superovulation treatment method that is suitable for high-producing Holstein donor cows would contribute to preventing ovarian cyclicity disorder, as well as to the early multiplication of cows with superior genes by increasing the utilization value of donor cows.

The objective of this work was to analyze the concentrations of progesterone (P4) and estrogen (E2) hormones changed during estrus synchronization in dairy heifers. Estrus synchronization was carried out with CIDRⓇ (Controlled Intravaginal Drug Release) devices. Corpus luteum (CL) was classified into three grades based on its size and palpable characteristics. The concentrations of P4 and E2 were measured by enzyme-amplified chemiluminescence. Serum P4 concentration was markedly low at the estrus stage (36 hrs after removal of CIDR) compared to other stages, while E2 concentration was kept high during estrus stage. The serum P4 concentration was highest in the CL classified into gradeⅠ. These results indicate that P4 concentration could be used as a criteria for determining recipients for artificial insemination or embryo transfer in dairy cattle.