• Journal of Veterinary Science
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• 제22권5호
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• pp.71.1-71.12
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• 2021

Background: African swine fever (ASF) is a hemorrhagic fever occurring in wild boars (Sus scrofa) and domestic pigs. The epidemic situation of ASF in South Korean wild boars has increased the risk of ASF in domestic pig farms. Although basic reproduction number (R₀) can be applied for control policies, it is challenging to estimate the R₀ for ASF in wild boars due to surveillance bias, lack of wild boar population data, and the effect of ASF-positive wild boar carcass on disease dynamics. Objectives: This study was undertaken to estimate the R₀ of ASF in wild boars in South Korea, and subsequently analyze the spatiotemporal heterogeneity. Methods: We detected the local transmission clusters using the spatiotemporal clustering algorithm, which was modified to incorporate the effect of ASF-positive wild boar carcass. With the assumption of exponential growth, R₀ was estimated for each cluster. The temporal change of the estimates and its association with the habitat suitability of wild boar were analyzed. Results: Totally, 22 local transmission clusters were detected, showing seasonal patterns occurring in winter and spring. Mean value of R₀ of each cluster was 1.54. The estimates showed a temporal increasing trend and positive association with habitat suitability of wild boar. Conclusions: The disease dynamics among wild boars seems to have worsened over time. Thus, in areas with a high elevation and suitable for wild boars, practical methods need to be contrived to ratify the control policies for wild boars.

• 한국동물위생학회지
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• 제45권4호
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• pp.277-284
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• 2022

Salmonella is a pathogenic bacterium that has long been important industrially because it has a wide host range and can be transmitted to humans through direct contact as well as indirect contact such as food contaminated with animal waste. Understanding how to reduce Salmonella contamination in pig farms is important for public health and the livestock industry from an economic perspective. In the swine industry, high concentrations of disinfectants have been applied because it is difficult to effectively control Salmonella in environments contaminated with organic substances. In order to evaluate the synergetic effect of disinfectants, the efficacy of two commercial disinfectants diluted in hard water and microbubble water (MBW) were compared under the laboratory condition. Different concentrations of both disinfectants combined with 1% detergent diluted in the two diluents were evaluated for their antibacterial effect. In the case of monopersulfate-based disinfectant groups, the growth of Salmonella was not observed at 1:200 dilution with both the hard water and MBW combined with 1% detergent. In the case of citric acid-based disinfectant, the bacterial growth was not observed at 1:800 dilution with MBW combined with 1% detergent. Our results show that the use of MBW as a diluent might improve the biological activities of acid-based disinfectant.

• Journal of Veterinary Science
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• 제24권3호
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• pp.48.1-48.13
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• 2023

Background: Senecavirus A (SVA), a member of the family Picornaviridae, is newly discovered, which causes vesicular lesions, lameness in swine, and even death in neonatal piglets. SVA has rapidly spread worldwide in recent years, especially in Asia. Objectives: We conducted a global meta-analysis and systematic review to determine the status of SVA infection in pigs. Methods: Through PubMed, VIP Chinese Journals Database, China National Knowledge Infrastructure, and Wanfang Data search data from 2014 to July 26, 2020, a total of 34 articles were included in this analysis based on our inclusion criteria. We estimated the pooled prevalence of SVA in pigs by the random effects model. A risk of bias assessment of the studies and subgroup analysis to explain heterogeneity was undertaken. Results: We estimated the SVA prevalence to be 15.90% (1,564/9,839; 95% confidence interval [CI], 44.75-65.89) globally. The prevalence decreased to 11.06% (945/8,542; 95% CI, 28.25-50.64) after 2016. The highest SVA prevalence with the VP1-based RT-PCR and immunohistochemistry assay was 58.52% (594/1,015; 95% CI, 59.90-83.96) and 85.54% (71/83; 95% CI, 76.68-100.00), respectively. Besides, the SVA prevalence in piglet herds was the highest at 71.69% (119/166; 95% CI, 68.61-98.43) (p < 0.05). Moreover, our analysis confirmed that the subgroups, including country, sampling year, sampling position, detected gene, detection method, season, age, and climate, could be the heterogeneous factors associated with SVA prevalence. Conclusions: The results indicated that SVA widely exists in various countries currently. Therefore, more prevention and control policies should be proposed to enhance the management of pig farms and improve breeding conditions and the environment to reduce the spread of SVA.

• Journal of Veterinary Science
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• 제24권4호
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• pp.58.1-58.25
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• 2023

Porcine epidemic diarrhea virus (PEDV) has posed significant financial threats to the domestic pig industry over the last three decades in South Korea. PEDV infection will mostly result in endemic persistence in the affected farrow-to-finish (FTF) herds, leading to endemic porcine epidemic diarrhea (PED) followed by year-round recurrent outbreaks. This review aims to encourage collaboration among swine producers, veterinarians, and researchers to offer answers that strengthen our understanding of PEDV in efforts to prevent and control endemic PED and to prepare for the next epidemics or pandemics. We found that collaboratively implementing a PED risk assessment and customized four-pillar-based control measures is vital to interrupt the chain of endemic PED in affected herds: the former can identify on-farm risk factors while the latter aims to compensate for or improve weaknesses via herd immunity stabilization and virus elimination. Under endemic PED, long-term virus survival in slurry and asymptomatically infected gilts ("Trojan Pigs") that can transmit the virus to farrowing houses are key challenges for PEDV eradication in FTF farms and highlight the necessity for active monitoring and surveillance of the virus in herds and their environments. This paper underlines the current knowledge of molecular epidemiology and commercially available vaccines, as well as the risk assessment and customized strategies to control PEDV. The intervention measures for stabilizing herd immunity and eliminating virus circulation may be the cornerstone of establishing regional or national PED eradication programs.

• Animal Bioscience
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• 제37권4_spc호
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• pp.775-785
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• 2024

Pork production is a significant agricultural enterprise in the United States and Canada. The United States is the third-largest global producer of pork and Canada ranks seventh in pork production. The North American Free Trade Agreement and its successor, the U.S.-Mexico-Canada Agreement, have facilitated trade and integration between the two countries. The majority of production systems are modern and intensive, characterized by large vertically integrated farms using advanced technologies. Both nations benefit from their status as major producers of feed grains, with the United States leading in corn and soybeans, while Canada excels in canola and barley production. The regulatory frameworks for food safety, animal welfare, and environmental stewardship differ slightly, with the FDA and USDA overseeing these aspects in the United States, and Health Canada and the Canada Food Inspection Agency in Canada. The United States and Canada also have well-established distribution networks for pork products, relying on both domestic and international markets. Export markets play a crucial role, with the United States being a major importer of Canadian pigs, and both countries exploring opportunities in Asia. Despite a rise in global demand, domestic pork consumption trends differ, with per capita consumption remaining stable in the USA and declining in Canada. Changing consumer preferences, including a demand for ethically raised and locally sourced pork, may influence production practices. Future trends in pig production include a focus on consumer concerns, sustainability, disease prevention, reduction of antimicrobial use, and advancements in technology. The industry is adapting to challenges such as disease outbreaks and changing regulations, with a strong emphasis on animal welfare. Labor and workforce considerations, along with advancements in technology and automation, are expected to shape the efficiency of pork production in the future.

• Journal of Veterinary Science
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• 제25권2호
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• pp.28.1-28.11
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• 2024

Background: Porcine circovirus type 2 (PCV2) infection is ubiquitous around the world. Diagnosis of the porcine circovirus-associated disease requires clinic-pathological elements together with the quantification of viral loads. Furthermore, given pig farms in regions lacking access to sufficient laboratory equipment, developing diagnostic devices with high accuracy, accessibility, and affordability is a necessity. Objectives: This study aims to investigate two newly developed diagnostic tools that may satisfy these criteria. Methods: We collected 250 specimens, including 170 PCV2-positive and 80 PCV2-negative samples. The standard diagnosis and cycle threshold (Ct) values were determined by quantitative polymerase chain reaction (qPCR). Then, two point-of-care (POC) diagnostic platforms, convective polymerase chain reaction (cPCR, qualitative assay: positive or negative results are shown) and EZtargex (quantitative assay: Ct values are shown), were examined and analyzed. Results: The sensitivity and specificity of cPCR were 88.23% and 100%, respectively; the sensitivity and specificity of EZtargex were 87.65% and 100%, respectively. These assays also showed excellent concordance compared with the qPCR assay (κ = 0.828 for cPCR and κ = 0.820 for EZtargex). The statistical analysis showed a great diagnostic power of the EZtargex assay to discriminate between samples with different levels of positivity. Conclusions: The two point-of-care diagnostic platforms are accurate, rapid, convenient and require little training for PCV2 diagnosis. These POC platforms can discriminate viral loads to predict the clinical status of the animals. The current study provided evidence that these diagnostics were applicable with high sensitivity and specificity in the diagnosis of PCV2 infection in the field.

• Journal of Animal Science and Technology
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• 제45권6호
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• pp.917-922
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• 2003

This study was conducted to investigate effects of farm, type of sow Landrace${\times}$Yorkshire, LY; Yorkshire${\times}$ Landrace, YL; Yorkshire${\times}$Yorkshire, YY and multi-cross bred sow, MBS), parity, farrowing year, farrowing season and mating method on reproductive traits such as total number born per litter, number of born alive per litter, number of weaned per litter, number of mummified per litter, number of stillbirth. The Reproductive Records of 3,387 litters from January, 1999 to September, 2002 were obtained from four pig farms managed by Electronic Data Processing(EDP) system. Reproductive performances for two types of F1 Sows(YL and LY) were estimated as 11.34${\pm}$0.266 and 11.57${\pm}$0.263 heads for total number of born per litter, 10.56${\pm}$0.216 and 11.81${\pm}$0.251 heads for number of born alive per litter, and 10.05${\pm}$0.131 and 9.96${\pm}$0.153 heads for number of weaned per litter, respectively. These records are significantly higher(P〈0.05) than those of YY and MBS. However, number of mummified per litter, number of stillborn per litter, number of dead by diarrhea per litter, number of dead by other reasons during lactating period per litter and estrus interval did not show significant difference between types of sows. There were more total number of born per litter and number of weaned per litter in year 2001 than other year. As year passed, number of dead by crush per litter, number of dead by diarrhea per litter and number of dead by other reasons during lactating period per litter reduced from 0.18${\pm}$0.023 to 0.07${\pm}$0.022 head, 0.12${\pm}$0.21 to 0.02${\pm}$0.020 head and 0.43${\pm}$0.041 to 0.22${\pm}$0.040 head, respectively and weaning rate increased from 0.94${\pm}$0.005% to 0.97${\pm}$0.005%. The total number of born per litter and number of born alive per litter were higher(P〈0.05) in the case of mating twice than mating once. The number of weaned per litter, number of mummified per litter and number of stillborn per litter were not significant(P〈0.05) between mating methods. Estrus interval was shorter on the occasion of twice artificial insemination(5.24${\pm}$0.153days) than twice natural mating(6.51${\pm}$0.466days).

• Asian-Australasian Journal of Animal Sciences
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• 제28권12호
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• pp.1696-1702
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• 2015

The objective of this study was to compare the effects of body weight growth adjustment methods on genetic parameters of body growth and tissue among three pig breeds. Data collected on 101,820 Landrace, 281,411 Yorkshire, and 78,068 Duroc pigs, born in Korean swine breeder farms since 2000, were analyzed. Records included body weights on test day and amplitude (A)-mode ultrasound carcass measures of backfat thickness (BF), eye muscle area (EMA), and retail cut percentage (RCP). Days to 90 kg body weight (DAYS90), through an adjustment of the age based on the body weight at the test day, were obtained. Ultrasound measures were also pre-adjusted (ABF, EMA, AEMA, ARCP) based on their test day measures. The (co)variance components were obtained with 3 multi-trait animal models using the REMLF90 software package. Model I included DAYS90 and ultrasound traits, whereas model II and III accounted DAYS90 and pre-adjusted ultrasound traits. Fixed factors were sex (sex) and contemporary groups (herd-year-month of birth) for all traits among the models. Additionally, model I and II considered a linear covariate of final weight on the ultrasound measure traits. Heritability ($h^2$) estimates for DAYS90, BF, EMA, and RCP ranged from 0.36 to 0.42, 0.34 to 0.43, 0.20 to 0.22, and 0.39 to 0.45, respectively, among the models. The $h^2$ estimates of DAYS90 from model II and III were also somewhat similar. The $h^2$ for ABF, AEMA, and ARCP were 0.35 to 0.44, 0.20 to 0.25, and 0.41 to 0.46, respectively. Our heritability estimates varied mostly among the breeds. The genetic correlations ($r_G$) were moderately negative between DAYS90 and BF (-0.29 to -0.38), and between DAYS90 and EMA (-0.16 to -0.26). BF had strong $r_G$ with RCP (-0.87 to -0.93). Moderately positive $r_G$ existed between DAYS90 and RCP (0.20 to 0.28) and between EMA and RCP (0.35 to 0.44) among the breeds. For DAYS90, model II and III, its correlations with ABF, AEMA, and ARCP were mostly low or negligible except the $r_G$ between DAYS90 and AEMA from model III (0.27 to 0.30). The $r_G$ between AEMA and ABF and between AEMA and ARCP were moderate but with negative and positive signs, respectively; also reflected influence of pre-adjustments. However, the $r_G$ between BF and RCP remained non-influential to trait pre-adjustments or covariable fits. Therefore, we conclude that ultrasound measures taken at a body weight of about 90 kg as the test final should be adjusted for body weight growth. Our adjustment formulas, particularly those for BF and EMA, should be revised further to accommodate the added variation due to different performance testing endpoints with regard to differential growth in body composition.

• Journal of Animal Science and Technology
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• 제52권4호
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• pp.319-328
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• 2010

돼지의 성장단계별 사료섭취량, 음수량 및 분뇨 배설량과 분뇨특성 등에 대한 정확한 자료 제시로 양돈농가에서 돈분뇨 처리에 기본 자료로 활용하여 적절한 분뇨처리를 유도하고, 장기적인 축산분뇨 정책을 수립하기 위해 실시한 본 시험을 요약하면 다음과 같다. 공시돈은 평균체중 $19.00{\pm}0.33kg$의 3원교잡종(Landrace ${\times}$ Yorkshire ${\times}$ Duroc) 자돈 12두와 번식돈 12두를 공시하여, 육성 비육돈 성장 4단계(20, 50, 80, 110 kg)와 번식돈 2단계(임신돈, 포유돈)에 걸쳐 실시하였다. 돼지 평균 분뇨 배설량은 자돈에서 3.46 kg/두/일(분: 1.07 kg, 뇨: 2.39 kg)이고 분과 뇨의 평균 수분함량은 각각 70.54%와 97.39%이었다. 분 중 칼슘, 마그네슘, 구리, 납 및 비소의 함량은 각각 1.00%, 0.26%, 10.47 mg/kg, 2.43 mg/kg 및 1.02 mg/kg이었다. 본 시험에서 카드뮴과 수은은 모든 성장 단계에서 검출되지 않았다. 돼지 분뇨의 $BOD_5$, CODmn, SS, T-N, T-P의 오염물질농도는 각각 분에서 96,335 mg/${\ell}$, 61,073 mg/${\ell}$, 207,466 mg/${\ell}$, 8,104 mg/${\ell}$ 및 4,209 mg/${\ell}$, 뇨에서 7,364 mg/${\ell}$, 7,149 mg/${\ell}$, 2,715 mg/${\ell}$, 10,110 mg/${\ell}$ 및 613 mg/${\ell}$이었다. 돈 분뇨에서 BOD, $COD_{mn}$, SS, T-N 및 T-P의 오염물질 부하량은 분에서 각각 일일 두당 102.1 g, 61.8 g, 221.6 g, 8.7 g 및 3.9 g이었고, 뇨에서 19.3 g, 16.7 g, 8.0 g, 22.2 g 및 1.3 g이었다. 또한 분뇨의 비료성분인 N, $P_2O_5$ 그리고 $K_2O$의 함량은 각각 분에서 0.96%, 0.83% 및 0.42% 이었으며, 뇨에서 0.80%, 0.09% 및 0.53% 이었다.

• Journal of Animal Science and Technology
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• 제55권3호
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• pp.195-202
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• 2013

본 연구는 돼지 출하체중 증가가 '떡지방' 삼겹살 발생률, 도체등급 및 도체의 품질 특성에 미치는 영향을 구명하기 위해 수행되었다. 본 목적을 위해 85~150 kg 체중 범위의(Yorkshire ${\times}$ Landrace) ${\times}$ Duroc 교잡종 거세돼지와 암퇘지 각각 250두를 도살하여 그 도체를 분석하였다. 거세돼지와 암퇘지의 등지방두께(y; mm)는 각각 다음과 같이 생체중(x; kg)에 선형으로 회귀하였다: y = 0.1827x + 3.4825 ($r^2$ = 0.4671) 및 y = 0.2015x-0.6972 ($r^2$ = 0.4736). 삼겹살의 제 11~12 늑골부 5 cm 폭의 등쪽 반절편의 지방조직 중량비가 55%를 초과하는 경우를 떡지방의 기준으로 설정했을 때 떡지방 삼겹살은 거세돼지에서 10건 발생하였으나 소매상에서 떡지방 삼겹살로 판정된 경우는 없었다. 과중량으로 인해 도체등급이 강등된 도체는 총 101건(20.2%)에 달하였다. $1^+A$ 등급 도체는 다른 모든 등급 도체보다 근내지방도가 높았으나, 근내지방도와 도체 결함 특성을 제외하면 도체등급간 가시적인 품질 상의 차이는 발견되지 않았다. 결론적으로 도체 품질을 충분히 반영하지 못하고 크기만 클 뿐 정상적인 도체에 대해서는 평가절하는 현행 도체등급 판정 기준은 개정되어야 좋을 것이다. 또한 돼지 출하체중을 증가시킬 때 떡지방 삼겹살 발생률은 중요한 고려 사항이 아닌 것으로 사료된다.