Pigs are considered as optimal donor animal for the successful xenotransplantation. To increase the possibility of clinical application, genetic modification to increase compatibility with human is an important and essential process. Genetic modification technique has been developed and improved to produce genetically modified pigs rapidly. CRISPR/Cas9 system is widely used in various fields including the production of transgenic animals and also can be enable multiple gene modifications. In this study, we developed new gene targeting vector and enrichment system for the rapid and efficient selection of genetically modified cells. We conducted co-transfection with two targeting vectors for simultaneous inactivation of two genes and enrichment of the genetically modified cells using MACS. After this efficient enrichment, genotypic analysis of each colony showed that colonies which have genetic modifications on both genes were confirmed with high efficiency. Somatic cell nuclear transfer was conducted with established donor cells and genetically modified pigs were successfully produced. Genotypic and phenotypic analysis of generated pigs showed identical genotypes with donor cells and no surface expression of α-Gal and HD antigens. Furthermore, functional analysis using pooled human serum revealed dramatically reduction of human natural antibody (IgG and IgM) binding level and natural antibody-mediated cytotoxicity. In conclusion, the constructed vector and enrichment system using MACS used in this study is efficient and useful to generate genetically modified donor cells with multiple genetic alterations and lead to an efficient production of genetically modified pigs.

The osmolarity of a medium that is commonly used for in vitro culture (IVC) of oocytes and embryos is lower than that of oviductal fluid in pigs. In vivo oocytes and embryos can resist high osmolarities to some extent due to the presence of organic osmolytes such as glycine and alanine. These amino acids act as a protective shield to maintain the shape and viability in high osmotic environments. The aim of this study was to determine the effects of glycine or/and alanine in medium with two different osmolarities (280 and 320 mOsm) during IVC on embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. To this end, IVC was divided into two stages; the 0-2 and 3-7 days of IVC. In each stage, embryos were cultured in medium with 280, 320, or 360 mOsm and their combinations with or without glycine or/and alanine according to the experimental design. Treatment groups were termed as, for example, "T(osmolarity of a medium used in 0-2 days of IVC)-(osmolarity of a medium used in 3-7 days of IVC)" T280-280 was served as control. When PA embryos were cultured in medium with various osmolarities, T320-280 showed a significantly higher blastocyst formation (29.0%) than control (22.2%) and T360-360 groups (6.9%). Glycine treatment in T320-280 significantly increased blastocyst formation (50.4%) compared to T320-280 only (36.5%) while no synergistic was observed after treatment with glycine and alanine together in T320-280 (45.7%). In contrast to PA embryonic development, the stimulating effect by the culture in T320-280 was not observed in SCNT blastocyst development (27.6% and 23.7% in T280-280 and T320-280, respectively) whereas the number of inner cell mass cells was significantly increased in T320-280 (6.1 cells vs. 9.6 cells). Glycine treatment significantly improved blastocyst formation of SCNT embryos in both T280-280 (27.6% vs. 38.0%) and T320-280 (23.7% vs. 35.3%). Our results demonstrate that IVC in T320-280 and treatment with glycine improves blastocyst formation of PA and SCNT embryos in pigs.

Nitric oxide (NO) has an important role in oocyte maturation and embryonic development in mammals. This study examined the effect of exogenous NO donor S-nitroso-N-acetylpenicillamine (SNAP) in a maturation medium on meiotic progression and embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. When oocytes were exposed to 0.1 μM SNAP for first 22 h of in vitro maturation (IVM) in Experiment 1, SNAP significantly improved blastocyst development in both defined and standard follicular fluid-supplemented media compared to untreated control (48.4 vs. 31.7-42.5%). SNAP treatment significantly arrested meiotic progression of oocytes at the germinal vesicle stage at 11 h of IVM (61.2 vs. 38.7%). However, there was no effect on meiotic progression at 22 h of IVM (Experiment 2). In Experiment 3, when oocytes were treated with SNAP at 0.001, 0.1 and 10 μM during the first 22 h of IVM to determine a suitable concentration, 0.1 μM SNAP (54.2%) exhibited a higher blastocyst formation than 0 and 10 μM SNAP (36.6 and 36.6%, respectively). Time-dependent effect of SNAP treatment was evaluated in Experiment 4. It was observed that SNAP treatment for the first 22 h of IVM significantly increased blastocyst formation compared to no treatment (57.1% vs. 46.2%). Antioxidant effect of SNAP was compared with that of cysteine. SNAP treatment significantly improved embryonic development to the blastocyst stage (49.1-51.5% vs. 34.4-37.5%) irrespective of the presence or absence of cysteine (Experiment 5). Moreover, SNAP significantly increased glutathione (GSH) content and inversely decreased the reactive oxygen species (ROS) level and mitochondrial oxidative activity in IVM oocytes. SNAP treatment during IVM showed a stimulating effect on in vitro development of SCNT embryos (Experiment 7). These results demonstrates that SNAP improves developmental competence of PA and SCNT embryos probably by maintaining the redox homeostasis through increasing GSH content and mitochondrial quality and decreasing ROS in IVM oocytes.

This study examined the overdose toxicity of Super-Neophensan, containing florfenicol and acetaminophen, upon pigs. SNP-3.0 (n=10) was administered at the dosage level of 3 kg/ton feed for 7 consecutive days, which is 3 times the recommended dose based on the guidelines of the manufacturer, and the control group (CON) (n=10) was administered the normal diet without the drug. The body weight, weight gain and feed efficiency in SNP-3.0 treated with the drug for 14 days post-administration showed no significant differences compared with those in CON. In hematological and blood biochemical analyses, all parameters were not affected by over-dosage of the drug. In the same way, there were no significant differences between SNP-3.0 and CON on markers for liver and kidney functions. As no adverse effects were observed with the drug in an overdose oral toxicity test, this study suggests that the drug was identified as a safe agent in pigs administered with three times the recommended dose.

본 연구는 돼지 농가의 생산성 향상 및 수익성 증대를 위한 분자 육종 기술에 적용할 유전자 마커를 개발하기 위해 수행 되었다. 분석 결과에 따르면, 돼지의 간 조직을 이용하여 RNA-Sequencing을 수행한 결과 ECI2 유전자의 SNP를 발견 하였고 발견된 SNP chr 7:g.2302809는 c.608로 608번째 C가 G로 변환되어 Threonine에서 Serine으로 아미노산이 치환되는 단일염기다형성임을 확인하였다. Berkshire 돼지 430으로 ECI2 유전자형과 육질 형질과의 연관성 분석 결과 도 체중, 적색도, 육즙 손실, 수분 함량 및 pH24hr에서 유의성을 확인할 수 있었다. 그중 GG 유전자형은 pH24hr에서 다른 유전자형에 비해 수치가 증가시키는 경향을 확인하였다. 성별에 따른 유전자형과 육질 형질과의 연관성은 거세돈에서 GG 유전자형이 육즙 손실의 감소와 pH24hr에서 유의성이 확인되었고, 암퇘지의 GG 유전자형도 수분함량이 증가되었다. 따라서 ECI2 유전자의 GG 유전자형을 가진 돼지가 육질이 더 좋은 것으로 판단된다. 이러한 결과를 바탕으로 ECI2의 GG 유전자형을 고정시킨다면 육질이 우수한 돼지고기 생산이 가능할 것이다. 또한 ECI2 유전자를 이용하여 품종개량 및 조기 선발 기술에 바이오마커로 활용한다면 농가의 경쟁력 강화 효과에 도움이 될 것으로 사료된다.

본 연구는 저영양 비육돈 사양이 고영양 사양에 비해 도체 및 돈육의 질을 개선시킬 수 있을지를 조사하기 위해 수행되었다. 체중 약 50kg의 LYD 교잡종 암퇘지와 거세돼지 각각 68두씩을 8돈방에 배치하고 3.54Mcal DE/kg과 1.00% 라이신을 함유한 고영양사료 혹은 3.02Mcal DE/kg과 0.68% lysine을 함유한 저영양사료를 약 120kg까지 급여하고 도살하였다. 총 20개의 도체로부터 삼겹살, 등심, 뒷다리 및 목심을 잘라내고 삼겹살과 등심, 뒷다리 및 목심의 대표적인 근육의 질에 관한 이화학적 분석과 관능검사를 수행하였다. 일당증체량, 사료효율 및 등지방두께는 고에너지구보다 저에너지구가 낮았다(p<0.05). 목심의 가열감량, 경도 및 씹힘성 수치는 저영양구가 고영양구보다 낮았다. 신선육(근육)에 대한 관능평가에서 등심의 색깔, 상강도 및 기호도 평점은 저영양구가 고영양구보다 높았고, 삼겹살의 근육:지방 균형 평점은 저영양구가 고영양구 보다 높은 경향을 나타냈다(p<0.10). 또한 뒷다리 가열육에 대한 관능평가에서는 풍미 및 다즙성 평점이 저영양구가 고영양구보다 높았다. 결론적으로, 이상의 결과는 저영양으로 비육돈을 사양하면 고영양 사양에 비해 성장성적은 저하되지만 도체 및 돈육의 질을 향상시킬 수도 있음을 시사한다.

본 연구는 돼지의 정자와 난소내 과립막세포에서 bisphenol S(BPS)가 생존성과 활성산소 생산에 미치는 영향을 알아보고자 연구하였다. 돼지정액은 0, 5μM BPS를 처리하여 3, 6시간동안 배양하였다. 정자의 생존성은 SYBR14/PI를 이중 염색하여 분석하였으며, 활성산소의 생산을 측정하였다. 또한, BPS(0, 5, 10, 20μM)를 과립막세포에 처리하여 24, 48, 72시간동안 처리하였다. 처리 후, 세포의 생존율과 활성산소 생산(단, 5μM BPS)을 측정하였다. 그 결과, 돼지에서 정자의 생존율은 BPS에 의해 감소하였고, 활성산소의 생산은 모든 처리시간에서 증가하였다(p<0.05). 또한 과립막세포의 생존은 BPS에 의해 억제되었고, 활성산소는 유의적으로 증가하였다(p<0.05). 이상의 결과를 토대로, BPS의 노출은 정자의 활성과 번식과 관련된 세포에 나쁜 영향을 미칠 것이다.

본 연구는 Canada에서 수입한 동결정액으로 인공수정된 모돈의 번식성적을 조사하여 동결정액을 이용한 인공수정(동결정액 인공수정)의 효율을 개선할 수 있는 통찰력을 얻기 위해 수행되었다. 이를 위해 A(GGP) 농장에서 2016년 5월과 9월 사이 총 626회의 동결정액 인공수정과 B(GGP) 농장에서 2015년부터 2017년 기간 동안 수행한 총 2,429 동결정액 인공수정의 결과 기록을 분석하였다. A종 돈장에서 동결정액을 썼을 때 총산자수 및 실산자수는 9월 보다 5월에 높았다(p<0.05). B종돈장의 분만율, 총산자수 및 실산자수는 조사연도 간에 차이가 없었다. A종돈장 결과와 B종돈장 결과를 통합하여 분석했을 때, 분만율은 A종돈장이 높았으나(p<0.01) 총산자수와 실산자수는 두 종돈장간에 차이가 없었고, 동결정액 인공수정을 했을 때가 액상정액 인공수정을 했을 때보다 낮았다(동결정액:액상정액 인공수정에 대한 총산자수와 실산자수는 각각 10.9±0.3:13.4±0.1두 및 10.0±0.3:12.0±0.1두 이었음; p<0.01). 결론적으로, 이상의 결과는 동결정액 인공수정이 액상정액 인공수정보다 번식 효율이 낮긴 하지만 연중 적절한 시기에 동결정액 인공수정을 실시하면 번식 효율이 증가될 수도 있음을 시사한다.

Secretory leukocyte protease inhibitor (SLPI), also known as neutrophil elastase and cathepsin-G protease inhibitor, functions in protection of epithelial cells from proteases. SLPI is expressed and secreted by many mucosal tissues, including lungs, seminal vesicles and cervix in women. SLPI plays an important role in protection of endometrial epithelial cells during pregnancy from degradation by degradation by proteases derived from trophoblast at the maternal-conceptus interface. In pigs, SLPI mRNA is known to be expressed in endometrial tissues, but the expression of SLPI in the endometrium throughout the estrous cycle and pregnancy has not been determined. Therefore, we analyzed the expression and regulation of SLPI mRNA in the endometrium throughout the whole stages of the estrous cycle and pregnancy in pigs. We obtained endometrial tissues from gilts on Days 0 (day of estrus), 3, 6, 9, 12, 15, and 18 of the estrous cycle and on Days 10, 12, 15, 30, 60, 90, and 114 of pregnancy. Real-time RT-PCR analysis showed that the expression of SLPI mRNA in the endometrium increases during midt-o late pregnancy. During the estrous cycle, levels of SLPPI mRNA in estrus and proestrus were higher than those in diestrus and metestrus. In situ hybridization analysis showed that SLPI mRNA was specifically localized to the glandular epithelial cells in the endometrium during pregnancy with strong signal intensity during mid-to late pregnancy. SLPI mRNA was not detectable in conceptus tissues on Days 12 and 15 of pregnancy, but SLPI mRNA was expressed in chorioallantoic tissues during mid-to term pregnancy with increasing levels toward term pregnancy. To determine the effects of steroid hormones, estrogen and progesterone, on the expression of SLPI mRNA, endometrial explant tissues from immature pigs were treated with increasing doses of estradiol-17β (E2) and progesterone (P4). Increasing doses of E2 and P4 increased the expression of SLPI mRNA in endometrial tissues. These results showed that SLPI was expressed in the endometrium in a pregnancy stage-and cell type-specific manner and the expression of SLPI was regulated by E2 and P4 in endometrial tissues, suggesting that SLPI may play an important role in regulating the endometrial epithelial cell function during mid-to late pregnancy in pigs. Further analysis to determine the roles of SLPI at the maternal-conceptus interface is still needed.

U0126 is a highly selective inhibitor of both MEK1 and MEK2, a type of MAPK/ERK kinase. This study was conducted to evaluate the effect of U0126 treatment during in vitro maturation (IVM) on nuclear maturation, intra-oocyte glutathione content, and embryonic development after parthenogenesis (PA). U0126 (5 μM) was supplemented to IVM medium during the first 0 (control), 2, and 4 h. The basic medium used for IVM was medium-199 supplemented with 10% (v/v) porcine follicular fluid (standard), 0.6 mM cysteine, 0.91 mM pyruvate, 75 μg/ml kanamycin, and 1 μg/ml insulin. Immature pig oocytes were matured for 44 h and then oocytes reached metaphase II stage were electrically activated to induce PA. The in vitro culture medium for embryonic development was porcine zygote medium-3 containing 0.3% (w/v) fatty acid-free BSA. When immature oocytes were treated with U0126 during the first 0, 2, 4 h of IVM culture, nuclear maturation was significantly (P < 0.05) increased by the U0126 treatment for 4 h (96.2 ± 1.3%) compared to standard IVM (90.6 ± 2.1%). Cleavage of PA embryos was significantly increased by 4 h- treatment (90.6 ± 2.2%) compared to standard medium (83.9 ± 1.8%). In addition, blastocyst formation of PA embryos was significantly (P < 0.05) increased by the treatment for 4 h (55.8 ± 5.7%) compared to 2 h (38.1 ± 6.1%). The glutathione contents in IVM oocytes were not altered by the U0126 treatments for 0, 2, and 4 h (1.28 ± 0.10, 1.16 ± 0.09, and 1.10 ± 0.09, respectively). Our results demonstrated that 5 μM U0126 treatment during the first 4 h of IVM showed positive effects on nuclear maturation, cleavage, and embryonic development in pigs.

In our previous study, exogenous plasminasminogen activators (PAs) influenced to fertility of boar spermatozoa via reduction of zona pellucida (ZP) resistance against protease and number of sperm binding ZP. plasminasmin (plasmin), is converted by PAs, is an important enzyme to degrade extracellular matrix and it is closely associated with fertilization process. Therefore, the aim of present study was to confirm changes of sperm penatration and ZP solubility by plasmin during in vitro fertilization (IVF). The cumulus-oocyte complasminexes (COCs) were aspirated from the antral follicles 3-6 mm in diameter and matured for 44 hours. Then, the cumulus cells were removed and denuded oocytes were co-incubated with spermatozoa for 18-20 hours in IVF medium containing 100 ng/ml plasmin. The number of sperm binding ZP and ZP solubility were measured using hoechst 33342 and 0.5% (w/v) pronase, respectively. Aceto-orcein stain was used to assess fertilization parameters. In results, sperm penetration did not affect by plasmin treatment during fertilization. Hoewever, treatment of plasmin decreased monospermic fertilization and IVF efficiency compared with control group (p<0.05). Furthermore, the number of penetrated sperm and pronucleus formation per zygote in plasmin group was significantly increased compared with control group (p<0.05). Despite of reduced monospermic fertilization by plasmin treatment, the number of sperm binding ZP was significantly higher in non-treated zygote than plasmin-treated zygote (p<0.05). Similar with previous study, ZP digestion time was reduced by plasmin treatment (p<0.05). These findings shown that plasminasmin during fertilization enhance the penetration of spermatozoa into ZP via increasing of ZP solubility and it was correspond with our previous results that fertility of spermatozoa during IVF was increased by exogenous urokinase-type PA treatment via sperm-ZP binding and increase of ZP solubility. Therefore, during the fertilization process, plasmin that is converted by PAs from oviduct epithelial cells might be closely associated with degradation of ZP proteins for penetration of sperm. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Education) (2016R1D1A1B03931746).

Poor embryo quality and low blastocyst formation have been major limitations in establishment of cloned embryonic stem cells and production of cloned animals through somatic cell nuclear transfer (SCNT). Aggregation of embryos is a promising method for improving developmental competence of blastocysts. The aim of this study was to improve the blastocyst formation and the quality of parthenogenetic (PA) pig embryos by the aggregation of blastomeres at the 4-cell stage that were cultured in various type of culture dishes with or without phytohemagglutinin (PHA). The PA embryos were produced by the general method of our laboratory. On Day 2 after PA, the zona pellucida of 4 cell-stage embryos were removed by treatment with 0.5% (wt/vol) pronase solution. The 3x zona-free blastomere (ZFB) were randomly distributed in each of the following treatments for aggregation. ZFB were cultured for 5 days at 39℃ in an atmosphere 5% CO2, 5% O2, and 90% N2. In Experiment 1, effect of culture dishes on the aggregation efficiency and developmental competence of PA embryos were investigated. ZFB were cultured on non-coated (control) culture dish or dishes coated with 1% (wt/vol) agarose substrate (AS) or Well of the Well in dishes coated with 1% (wt/vol) agarose substrate (WAS). The ZFB cultured in WAS showed significantly higher (P<0.05) aggregation (81.2%) than AS and control (21.6-45.5%). The mean cell number in blastocysts derived from AS and WAS (81.4-89.3 cells/blastocyst) was significantly higher (P<0.05) than that of control (63.8 cells/blastocyst). In Experiment 2, effects of 150 ug/ml PHA treatment on the aggregation efficiency and developmental competence of embryos were investigated. The ZFB cultured in AS with PHA showed a higher (P<0.05) aggregation rate (90.0%) than that in AS without PHA, control with PHA, and control (39.2%, 57.9% and 17.5%, respectively). In conclusion, aggregation of porcine ZFB treated with PHA and agarose substrate could be a useful technique for producing improving blastocyst development with increased mean cell number of blastocysts in pigs.

Sow longevity is important for efficient and profitable pig farming. Recently, there has been an increasing interest in social genetic effect (SGE) of pigs on stress-tolerance and behavior. The present study aimed to estimate genetic correlations among average daily gain (ADG), stayability (STAY), and number of piglets born alive at the first parity (NBA1) in Korean Yorkshire pigs, using the SGE model. The phenotypic records of ADG and reproductive traits of 33,120 and 11,654 pigs, respectively, were evaluated. The direct effect on ADG had a significantly negative genetic relationship with STAY, whereas the social effect on ADG had a neutral genetic relationship. In addition, the genetic correlation between the social effects on ADG and NBA1 tended to be positive, unlike the direct effects. The genetic correlation of the total effect on ADG with that of STAY was negative but non-significant, owing to the social effect. These results suggested that total genetic effect on growth in the SGE model might reduce the negative effect on sow longevity owing to the growth potential of pigs. We recommend including social effects as selection criteria in breeding programs to obtain satisfactory genetic changes in both growth and longevity.

Caspases are a family of cysteine protease enzymes composed of more than 10 members that play essential roles in apoptosis and inflammation. It has been reported that caspases play a critical role in regulating apoptosis at the maternal-conceptus interface in many species. However, the expression and regulation of caspases have not been determined in the endometrium in pigs. Therefore, we analyzed the expression, localization, and regulation of caspases in the endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that caspases were expressed in the endometrium during the estrous cycle and pregnancy. The expression of CASP6, CASP7, and CASP8 during the estrous cycle and CASP3, CASP6, CASP7, and CASP10 changed during pregnancy. Levels of CASP3 mRNA in the endometrium were higher on Day 12 of pregnancy than the estrous cycle and levels of CASP7 mRNAs were highest on Day 15 of estrous cycle and pregnancy. Immunohistochemistry analysis showed that CASP3 protein was localized to endometrial epithelial cells on Days 12 and 15 the estrous cycle and pregnancy, but cleaved CASP3 was localized only to luminal epithelial (LE) cells on Days 12 and 15 of pregnancy in the endometrium. CASP7 protein was localized to endometrial LE cells only on Day 15 of pregnancy. CASP3, CASP6, CASP7, CASP8, and CASP10 mRNAs were detectable in conceptus on D12 and D15 of pregnancy, and chorioallantoic tissues expressed CASP3, CASP6, CASP7, CASP8, CASP8, and CASP10 with increasing levels toward term pregnancy, except CASP3 mRNA. The effect of steroid hormones and interleukin-1βß (IL1B) on CASP3 expression and the effect of interferon-γ(IFNG) on CASP7 expression was determined by endometrial explant cultures and we found that CASP3 expression was increased by IL1B and CASP7 expression was increased by IFNG in a dose-dependent manner. These results showed that caspases were expressed in the endometrium during the estrous cycle and pregnancy in a stage- and/or pregnancy-specific dependent manner and some caspases were regulated by IL1B or IFNG in the endometrial tissues, suggesting that caspase may play an important role in regulating apoptosis for the establishment and maintenance of pregnancy at the maternal-conceptus interface in pigs.

Porcine Reproductive and Respiratory Syndrome (PRRS) is the most economically important disease in swine in North America, Europe and Asia. PRRS is caused via infection of the pulmonary alveolar macrophages (PAMs) with the PRRS virus (PRRSV) causing respiratory illness and high fever in young growing pigs that predisposes them to secondary bacterial infections. PRRSV also causes severe reproductive failure in sows and boars. Although research is ongoing, PRRSV continues to elude a successful vaccine. In 2014, piglets were born with a gene edit in exon 7 of the Cluster of differentiation 163 (CD163) gene introduced by using the CRISPR/Cas9 site-directed nucleases system. The resulting litters of pigs were either challenged with multiple PRRSV isolates at 3 weeks of age or bred at maturity for a challenge with pregnant sows. The challenges demonstrated that the pigs were completely resistant to infectivity to both Type 1 and 2 isolates as measured by clinical signs, viremia, antibody response and lung histopathology. In a follow-up study, pregnant CD163-/- pigs were also challenged with PRRSV to determine if absence of CD163 in the dam should be sufficient to protect the CD163+/- fetuses that have functional CD163 protein. The wild-type sow and fetuses were actively infected with the PRRSV and one sow aborted. The CD163-/- sows carrying both the CD163-/- and CD163+/- fetuses were all negative for PRRSV nucleic acid and showed no sign of fetal or placental failure. The results of this study clearly demonstrate that the absence of CD163 in the sow is sufficient to protect a PRRSV-susceptible CD163+/- fetus. Gene editing of CD163 in pigs, via CRISPR/Cas9, successfully blocked PRRSV infectivity in young growing pigs and pregnant sows and their fetuses. This is a great example of the potential of utilizing gene editing to improve animal agriculture.

The objectives of this study were to determine in vitro dry matter and energy utilization of hatchery waste products and to confirm whether in vivo energy digestibility of hatchery waste products could be estimated using in vitro data. Two in vitro assays were conducted for infertile eggs, unhatched eggs, culled chicks, and a mixture(20% dried infertile eggs, 20% dried unhatched eggs, and 60% dried culled chicks). In Exp.1, in vitro dry matter disappearance (IVDMD) of hatchery waste products was determined. In Exp.2, in vitro energy disappearance (IVED) was determined using undigested residues from Exp.1. The IVDMD of infertile eggs, unhatched eggs, culled chicks, and the mixture were 81.7, 88.7, 83.9, and 85.4%, respectively. The IVED of the test ingredients were 74.4, 85.1, 77.6, and 79.8%, respectively. Both IVDMD and IVED were greater in unhatched eggs compared with infertile eggs and culled chicks (p<0.05). In vivo energy digestibility was estimated well using prediction equations for hatchery waste products developed in the present study: In vivo energy digestibility(%) = 2.52 × IVDMD (%) – 133.95 with r2 = 0.70 and in vivo energy digestibility(%) = 1.63 × IVED(%) – 50.03 with r2 = 0.67. In conclusion, energy utilization of unhatched eggs was the greatest among test ingredients and energy utilization of hatchery waste products can be estimated using data from in vitro procedures.

본 연구는 경기지역 도축돈 및 도축우의 폐렴병변에서 Mycoplasma spp.의 발생 분포를 조사하고자 수행하였다. 부천 소재 도축장에 출하된 소와 돼지의 폐에 대하여 육안적 검사를 하고, 이 중 병변을 보인 소 192두와 돼지 257두의 폐에 대한 PCR 검사 결과, Mycoplasma spp.는 소에서 147두(76.5%), 돼지에서는 203두(80.9%) 에서 각각 검출되었다. 소, 돼지 각각의 Mycoplasma spp.에 대한 세부 primer를 이용한 검사 결과에서는 소에서 M. agalactiae가 16두(8.3%)에서 검출되었으나, M. dispar, M. bovis 및 M. bovirhinis는 검출되지 않았다. 돼지에서는 M. hyo-pneumoniae가 74두(28.8%), M. hyorhinis가 13두(5.1%) 검출되었다. M. hyosynoviae는 검출되지 않았다. 본 연구를 통해 경기지역 도축우 및 도축돈에서 Mycoplasma성 폐렴이 상재하고 있음을 확인하였다.

Mycoplasma spp. are extracellular bacteria that colonize on the respiratory epithelium of humans and animals. It is a causative agent of pneumonia commonly complicated by opportunistic infectious bacteria. Mycoplasma spp. infection cause relatively mild disease in the absence of environmental stressors, but when complicated by secondary bacterial invaders the resultant disease can cause obvious clinical disease and severe production losses in intensively reared pigs Mycoplasma spp. are highly fastidious bacteria, difficult to culture and slow growing. Many species of Mycoplasma spp. are important pathogens causing respiratory infection in animals and known to induce huge economic losses. The aims of the present study were to develop a rapid isolation and culture method of wild type Mycoplasma spp. in pigs. We used Mycoplasma spp. genus specific direct PCR without DNA extraction procedure using PhireⓇ Animal Tissue Direct PCR Kit from the lung tissues with pneumonia lesions. Therefore, we could save the time for tissue processing and increase the accuracy of Mycoplasma spp. inclusion prediction in lung tissues. Thereafter, we used the optimized media to isolate and culture Mycoplasma spp. As the results, Mycoplasma spp. could be isolated and cultured quickly and efficiently. These results could provide an efficient strategy and method for the rapid and accurate isolation and culture of wild type Mycoplasma spp. in pigs.

Exudative epidermitis (EE) is a generalized skin disease of pigs, mainly caused by Staphylococcus hyicus (S. hyicus). Antibiotic resistant S. hyicus leads to the failure of antimicrobial treatments. This necessitates proper identification of the strains in the field and determination of their antimicrobial susceptibility. This study was carried out to isolate Korean S. hyicus and determine its antimicrobial resistance. Isolate was sensitive to ceftiofur, ciprofloxacin, enrofloxacin, gentamicin, neomycin, and tylosin, but remarkably resistant to amoxicillin, lincomycin, penicillin, streptomycin, and tetracycline. Our study contributes to the understanding of the characteristics and antimicrobial resistance of Korean S. hyicus, which in turn will provide an antimicrobial treatment strategy to control EE.