Pigs are considered a “mixing vessel” that can produce new influenza strains through genetic reassortments, which threaten public health and cause economic losses worldwide. We performed surveillance of swine influenza virus (SIV) using 114,140 nasal swabs from 11,414 Korean farms from 2009 to 2022, and characterized their genetic evolution at each farm level. A total of 169 farms out of the 11,414 (1.48%) were SIV-positive. The positivity rate for the H1N2 subtype, which is most dominant in the pig population, was 37.87% (64/169). Through hemagglutinin (HA) gene analysis, 64 H1N2-positive farms were classified into Eurasian avian-like (46/64, 71.88%), triple-reassortant (14/64, 21.88%), pdm09 (3/64, 4.69%), and classical swine (1/64, 1.56%) groups. The estimated evolutionary rate of HA in H1N2 from 2009 to 2022 in Korea is 1.5309 × 10-3/site/year (95% HPD intervals from 1.0003 × 10-3 to 2.1735 × 10-3) with an estimated mean growth rate of 0.0114. Estimates of the relative genetic diversity of clades over time suggested that the HA of H1N2 exhibited an increase in population size. The results of this study showed that the Eurasian avian-like-HA of the H1N2 subtype was dominant in the pig population. The continued evolution of the HA of H1N2, which is critical for cell entry, might lead to genetic diversity and the loss of vaccine cross-protection. These results indicate that continus surveillance is imperative for monitoring the evolution of the swine influenza virus.

Previous studies have shown that proline mutations in the heptad repeat region stabilize the coronavirus spike (S) protein in a pre-fusion state. To understand the impact of proline substitutions on the fusogenicity of the S protein, we engineered the swine acute diarrhea syndrome coronavirus (SADS-CoV) S protein with two proline substitutions (S-PP) and examined its fusogenicity using dual-split-protein based cell-cell fusion assay. Unlike the wild-type S (S-WT), S-PP rarely formed syncytia. Additionally, protein expression of S-PP was impaired compared to S-WT, as previously reported. Our results indicate that pre-fusion stabilized S protein is unable to induce membrane fusion and provide a better understanding of SADS-CoV S and vaccine antigen design.

This study was carried out to investigate the growth characteristics, yield and chemical compositions of whole crop barley (Hordeum vulgare L.) according to mixing ratio of chemical fertilizer (CF) and liquid swine manure (LSM) in the paddy field cultivation. The experimental design was arranged in a randomized block design with five treatments and three replications. The manure fertilizer ratio of five treatments were CF 100% (T1), CF 70% + LSM 30% (T2), CF 50% + LSM 50% (T3), CF 30% + LSM 70% (T4), and LSM 100% (T5) of whole crop barley. At this time, the application of liquid swine manure was based solely on the nitrogen. Plant length was higher at T1 as compared to other treatments (T2, T3, T4 and T5). Fresh yield, dry matter yield and total digestive nutrients (TDN) yield were the highest in T1, whereas the lowest in T5 treatment (p<0.05). Chemical compositions (crude protein, crude fat, neutral detergent fiber, acid detergent fiber and TDN) did not show significant difference among treatments. Ca and Na contents were significantly lower at T1 as compared to other treatments (T2, T3, T4 and T5). However, Mg and P contents were significantly higher at T1 as compared to other treatments(p<0.05). There was no significant difference in total free sugar content among T2, T3, T4 and T5 treatments, but the chemical fertilizer (T1) was significantly lower than the other treatments (p<0.01). Considering the above results, liquid swine manure application showed lower dry matter yield and TDN yield than chemical fertilizer, but higher free sugar content. Therefore, in order to increase the productivity of whole crop barley, it is considered desirable to mix liquid fertilizer with chemical fertilizer, taking into account the decomposition rate and insufficient components (P, K) of the liquid swine manure.

The annual number of odor complaints increased about 10 times over 14 years from 4,302 in 2005 to 40,854 in 2019, in Korea. Especially, livestock facilities account for more than 50% of the odor complaints and the swine farms account for the most odor complaints among livestock. It is therefore necessary to manage swine farms as the major odor emission source. In this study, a real-time odor monitoring system equipped with PTR-TOF-MS (proton transfer reaction time-of-flight mass spectrometric) was used to measure the odorous substances in two swine farms. Odorous substances emitted from outlets were sampled and measured at the two types of swine farms. In addition, the boundary spots were designated as measurement points. As a result, the rankings of the odorous substances in order, from highest to lowest, were ammonia, acetaldehyde, methyl mercaptan, fatty acids, etc. and the level of odor intensity was 0.8-4.4 at the outlet of the swine farms. The concentration at the boundary decreased between 1/100 ~ 1/10000 compared to the concentration emitted from outlets. Base on the results of evaluating odor activity values, Skatole and p-Cresol were estimated as major odor substances in swine farms.

본 실험은 논 토양에서 호밀 재배시 화학비료와 발효 돈분 액 비 혼용 시용이 생육특성 및 영양성분에 미치는 영향을 조사하고 자 실시하였다. 실험설계는 화학비료 100% 처리구(C), 화학비료 70% +돈분액비 30% 처리구(T1), 화학비료 50% +돈분액비 50%처리구(T2), 화학비료 30% +돈분액비 70% 처리구(T3) 그리고 돈분액비 100% 처리구(T4)로 한, 5처리 3반복 난괴법으로 배치 하였다. 이때 돈분 액비 시용은 질소량만을 기준으로 하였다. 초 장은 처리구들 간에 유의적인 차이를 보이지 않았다. 이삭길이, 엽장 및 엽폭은 각각 C, T3 및 T2구에서 각각 높게 나타났다 (p<0.05). 경의 굵기는 T4 > T3 > T2 > T1 > C구 순으로 돈분 액비 시용량이 높을수록 높게 나타났다(p<0.05). 건물수량 및 TDN 수량은 T4구가 가장 높게 나타난 반면 C구가 가장 낮게 나 타났다(p<0.05). 조단백질, NDF, ADF 및 조섬유 함량에서는 처 리구들 간에 유의적인 차이는 나타나지 않았다. 그러나 조지방 및 조회분 함량에 있어서는 각각 T2 및 T3구에서 높게 나타났다 (p<0.05). 총무기물 함량은 돈분액비 시용 비율이 증가할수록 유 의적으로 감소하였다(p<0.05). 그러나 총 유리당 함량은 돈분액 비 시용 비율이 높았던 T3 및 T4구가 높게 나타난 반면 화학비료 처리구(C) 및 돈분액비 시용 비율이 낮은 구(T1)에서는 낮게 나 타났다(p<0.05). 이상의 결과를 종합해 볼 때, 수량성(건물수량, TDN수량)과 사일리지 품질에 영향을 미치는 유리당을 고려한다 면 화학비료와 돈분액비 혼용하거나 돈분액비를 시용하는 것도 효과적이라고 사료된다.

African swine fever (ASF) is a hemorrhagic viral disease of pigs requiring laboratory diagnosis for confirmation. Though tissue and blood samples are considered optimal for ASF diagnosis, collection of these samples can be laborious, time-consuming, and pose a risk of contaminating the environment. Here, we suggest an alternative non-invasive sampling method, hair plucking, for ASF diagnosis. ASF virus was detected in plucked hair samples from experimentally infected pigs. Although the sensitivity was inferior to whole blood, the results suggest that hair plucking can be an alternative method that can also improve animal welfare.

This study aims to establish a modified analytical method with sensitivity and reliability for streptomycin (STP) and dihydrostreptomycin (DHS) of residues level in pig tissues, plasma and urine by LC-MS/MS on the basis of previous studies. The mass parameters of quantitative and qualitative ions for STP and DHS were optimized using multiple reaction monitoring in positive mode. The separation of compounds was conducted using BEH Amide column according to material’s characteristics. The analytes in plasma were extracted with only organic solvents. In muscle and kidney, KH2PO4 buffer solution containing 2% CCl3COOH and EDTA-Na was used as extraction solvent. The WCX cartridege was selected as SPE cartridge in considering high recoveries for STP and DHS. The analytes in urine were extracted by organic solvents with acid and addition of EDTA. The limits of detection (LODs) in STP and DHS ranged 0.45~3.66 μg/kg and 0.22~0.78 μg/kg, respectively. The limits of quantification (LOQs) were 1.35~11.10 μg/kg in STP and 0.66~2.36 μg/kg in DHS. The recoveries (%) were 94.29~104.5% in STP and 92.32~108.45% in DHS except for plasma with lower values (61.45/68.5%, respectively). In the precision evaluation, the coefficient of variation (CV, %) of STP showed <10.50% on intra-day and <18.04% on inter-day. The CV (%) of DHS showed <8.42% on intra-day, whereas <17.98% on inter-day. The modified method is reliable for continuous residual monitoring in pig to ensure food safety for consumer’s health. In addition, this method could be used in study relation to residue depletion and pharmacokinetics of veterinary drug.

A laboratory-scale experiment was conducted to evaluate the effect of supplementing commonly used effective microorganisms on the chemical properties of swine liquid manure. Effective microorganisms used in this study were Bacillus subtilis (1.3×109 colony-forming unit (CFU)/ml), Enterococcus faecium (1.9×1010 CFU/ml), Aspergillus oryzae (2.0×109 CFU/ml), Saccharomyces cerevisiae (6.4×109 CFU/ml), Rhodobacter sphaeroides (1.2×108 CFU/ml), and Streptomyces griseus (6.2×108 CFU/ml). Swine liquid manure collected and decanted from a swine farm was used in this study. Treatments included control (distilled water supplementation), Treatment 1 (T1) (mixed microbes, 109 CFU/ml), and Treatment 2 (T2) (mixed microbes, 107 CFU/ml). Microbial mix was supplemented every 3.5 days and aerated six times (15 min each) a day to facilitate compositing. Ten ml of sample was collected at 2-, 4-, 6-, and 7-week intervals for the measurement of pH, ammonia-N, volatile fatty acid (VFA), total nitrogen, total phosphorus, and total potassium. At seven weeks, samples were further collected to analyze biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Ammonia-N was significantly (p<0.05) decreased in T1 and T2 by 36% and 30%, respectively, compared with control (23%). VFAs including butyrate, iso-butyrate, valerate, iso-valerate, and caproate were not detected in T1 from the four-week aerated sample. The BOD and COD were significantly (p<0.05) decreased in T1 by 96% and 58%, respectively. In conclusion, ammonia-N, VFA, BOD, and COD, known as odor indicators, were decreased in T1 and T2 compared with control, suggesting that effective microorganisms are useful for compositing swine liquid manure

In this study, the near-complete genome sequence of the novel reassortant H1N2 influenza A virus strain A/swine/Korea/KS60/2016 is reported. Sequences of the hemagglutinin (HA), neuraminidase (NA), and polymerase basic 2 (PB2) genes were analyzed, revealing that the isolates contain segments from previous Korean swine H1N2 strains. Additionally, the remaining genes of this strain originated from human H1N1 strains in 2009.

Since the first detection of African swine fever (ASF)-infected wild boar in October 2019, the ASF virus has been circulating among wild boars in the Republic of Korea. The priority for ASF control is to understand the epidemic situation correctly. The basic reproduction number (R0) can be used to describe the contagious disease epidemic situation since it can assess the contagiousness of infectious agents by presenting the average number of new cases generated by an infected case. The current study estimated R0 for the 2019/20 ASF epidemics in wild boars in the Republic of Korea using the reported number of ASF cases and a serial interval of the ASF virus. The estimated mean R0 was 2.10 (range: 0.06 – 10.24) for the 2019/20 ASF epidemics, 2.94 (range: 0.43 – 9.89) for the 2019 ASF epidemics, and 2.00 (range: 0.06 – 11.10) for the 2020 ASF epidemics. In addition, the estimated mean R0 was 3.82 (range: 1.16 – 8.78) in winter, 1.39 (range: 0.16 – 6.30) in spring, 4.82 (range: 0.26 – 17.08) in summer, and 2.21 (range: 0.51 – 5.86) in fall. Even though the Korean government has applied ASF control measures, including hunting or fencing, the ASF epidemic situation in wild boars has intensified. For ASF control in wild boars, tailor-made hunting, wild boar management, or active searching for carcasses are required to reduce the ASF virus. For ASF prevention in domestic pigs, no contact between wild boars and domestic pigs and a biosecurity plan by veterinarians are needed to decrease the risk of ASF virus transmission from wild boars to domestic pigs.

This ammonia prediction study was performed using the time-series artificial neural network model, Long-short term memory (LSTM), after long-term monitoring of ammonia and environmental factors (ventilation rate (V), temperature (T), humidity (RH)) from a slurry finishing pig farm on mechanical ventilation system. The difference with the actual ammonia concentration was compared through prediction of the last three days of the entire breeding period. As a result of the analysis, the model which had a low correlation (ammonia concentration and humidity) was confirmed to have less error values than the models that did not. In addition, the combination of two or more input values [V, RH] and [T, V, RH] showed the lowest error value. In this study, the sustainability period of the model trained by multivariate input values was analyzed for about two days. In addition, [T, V, RH] showed the highest predictive performance with regard to the actual time of the occurrence of peak concentration compared to other models . These results can be useful in providing highly reliable information to livestock farmers regarding the management of concentrations through artificial neural network-based prediction models.

Since the first detection of the African swine fever (ASF) virus in the Republic of Korea in 2019, the Korean government has applied interventions, including fencing, increasing the biosecurity level at domestic pig farms, and the capture-and-removal of wild boars. In particular, wild boars are an important risk factor for ASF control because they can spread disease among susceptible animals, such as wild boars or domestic pigs. A capture-and-removal method aims to reduce the likelihood of ASF transmission from wild boars to domestic boars or among wild boars by decreasing the number of susceptible wild boars. This study estimated the required number of wild boars captured and removed for ASF control using population viability analysis. Population factors, such as a life span, sex ratio, or an inbreeding depression with different capture-and-removal proportions of wild boars, were included in the analysis. Ten scenarios with different capture-and-removal proportions of wild boars and different periods of culling were considered. According to the results, a method in which 75% of wild boars are captured-and-removed for at least three years showed long-term effectiveness for more than ten years. The current ASF control method, in which 33% of wild boars are captured-and-removed, decreased the number of wild boars for three years, after which the wild boar population increased to more than its initial number. Given the limited human and material resources for controlling ASF in the Republic of Korea, it is recommended that resources be prioritized to increase the capture-and-removal proportion of wild boars to take full advantage of the ASF-control effectiveness.

Influenza A virus (IAV) causes respiratory disease in birds and mammals, including pigs and humans. Infection by IAV in pigs increases not only economic losses in the swine industry but also the emergence of novel IAV variants via gene reassortment, which is important due to the susceptibility of both birds and humans to IAV. This study provides serological data obtained during a study to detect IAV infections in pigs in the Republic of Korea during 2018 and 2019. A total of 1,559 samples were collected from 74 domestic pig farms. Hemagglutination inhibition (HI) assays were performed using the A/Swine/Korea/25-13(H1N1), A/Swine/Korea/E102 (H1N2), and A/Swine/Korea/Cy10/2007 (H3N2) viruses as antigens. The HI assay results showed that 266 of the 1,559 samples were seropositive (17.0%). Among these, H1N1, H1N2, and H3N2 comprised 7.3% (114), 6.0% (93), and 8.8% (137) of the 1,559 samples, respectively. Co-infections of H1N1/H1N2, H1N1/H3N2, H1N2/H3N2 and H1N1/H1N2/H3N2 were observed in 2.1% (31), 1.5% (23), 1.5% (24), and 0.8% (13) of the 1,559 samples, respectively. Interestingly, IAV infections were detected in all nine provinces of the country.

축산 폐수는 고농도의 영양염류와 중금속을 함유하고 있어, 배출될 때 수질을 악화시킨다. 기존 처리 기술과 비교하여 bioremediation은 축산 폐수 처리에 유능하다. 특히, 미세조류는 오염물질 제거에 잠재력을 가지고 있다. 본 연구에서는 Ankistrodesmus bibraianus를 이용하여 축산 폐수 내 영양염류 (질소 (N), 인 (P))와 중금속 (구리 (Cu), 아연 (Zn))의 제거 가능성을 평가하고, A. bibraianus의 최적배양조건을 확립하였다. 연구결과, 최적 배양조건은 28°C, pH 7, 광주기는 14 : 10 h로 설정되었다. N과 P의 단일 처리구 (500, 1,000, 5,000, 10,000 mg L-1)에서 제거효율은 각각 22.9~80.6%와 11.9~50.0%였다. 또한, N과 P의 복합 처리구에서 제거효율은 각각 16.4~58.3%와 7.80~49.8%였다. Cu와 Zn의 단일 처리구 (10, 30, 50 mg L-1)에서 제거효율은 각각 15.5~81.5%와 6.28~34.3%였다. 유사하게, Cu와 Zn의 복합 처리구에서 제거효율은 각각 16.7~74.5%와 5.58~27.5%였다. 또한 영양염류 (N 및 P)와 중금속 (Cu 및 Zn)의 성장 및 제거효율을 축산 폐수에 적용할 수 있음을 나타냈다. 본 연구의 결과에 따르면 A. bibraianus는 축산 폐수 내 영양염류와 중금속 제거에 이용할 수 있을 것으로 사료된다.

In this study, the main odorous substances were selected for each swine facility by investigating the concentration and occurrence characteristics of odorous substances according to farm facilities. The objective was to find a solution to manage odor effectively in swine farms. Samples collected from the boundary site, manure storage, fan, and indoor the swine building were analyzed for concentration, odor activity value (OAV), and odor contribution. As a result, there was a difference in the concentration of odorous substances as well as the tendency of OAV in each swine facility. Also, the main substances of odor in the farms were similar, but odor contribution differed from facility to facility. Therefore, it is considered that the odor management efficiency will be improved only if the proper odor reduction method is applied according to the types of main odorous substances in swine facilities.

본 연구는 돈분액비에 화학비료를 첨가한 양분조정 맞춤액비 시용효과를 평가하기 위하여 기존의 3요소 단비 처리 및 돈분 맞춤액비 시용에 따른 고구마 생육과 수량 그리고 품질에 미치는 효과 등을 평가하였다. 돈분액비구의 10a당 괴근수량은 관행 화학비료 재배구(2,966 kg/10a)보다 약 5% 감수되었으나, 양분조정 맞춤액비 처리구 (NBSLM)에서는 3,217 kg/10a로 관행시비구(CF)와 돈분액비 시용구(SLM)에 비하여 각각 8, 14% 높았다. 관행시비구에 비하여 8% 높았다. 고구마 유리당 함량은 양분조정 맞춤액비구 (NBSLM)에서 6,11%로 관행재배구의 3,11% 보다 높았다. 특히 sucrose 함량이 양분조정 맞춤액비 시용구가 대조구보다 높았다. 고구마의 색도(Hunter value)를 조사한 결과 적색도의 정도를 나타내는 a값은 양분조정 맞춤액비(NBSLM)가 화학비료구보다 높았다. 결과적으로 양분조정 맞춤액비 시용 (NBSLM)은 고구마 괴근 수량이 돈분액비 시용구(SLM)에 비하여 14% 높은 수량 증수와 고구마 유리당 함량 증가, 고구 마의 적색도(a값) 증가에 의한 품질 향상 증대 뿐만아니라 화학비료를 대체할 수 있을 것으로 판단되었다.

본 연구의 목적은 악취 발생 저감을 위해 국내에서 최근 권고되는 밀폐(무창)형 돈사와 기존 개방형 돈 사의 비용 편익을 분석하여 이러한 추진 방향의 객관적 타당성을 확보하는 데 있다. 두 돈사 유형의 비용은 설치비와 운용비로 구분한 후 관련 문헌 자료와 현장 조사 결과를 근거로 추정하였고, 편익은 축산 환경 전문가들을 대상으로 한 델파이 설문 조사 기법 적용을 통해 추정하였다. 비용 편익 분석 결과, 양돈 규모에 상관없이 개방형과 밀폐형 돈사 모두 편익/비용 비율이 1 초과로 추정되어 돼지 생산에 따른 경제적 이익이 창출되는 것으로 분석되었다. 하지만 소규모, 중규모, 대규모 양돈 농가 모두 밀폐(무창)형 돈사의 편익/비용 비율(B/C ratio)이 개방형 돈사보다 상대적으로 모두 높은 것으로 추정되었다. 결론적으로 기존 양돈 농가들의 인·허가 시 경제성 우위 측면뿐만 아니라 축산 악취의 효율적 관리를 위해서도 개방형 돈사를 밀폐(무창)형 돈사로 변경하도록 권고해야 하며, 특히 편익/비용 비율이 상대적으로 가장 높은 수치를 보인 대규모 농가인 경우 이를 이행 조치하는 것이 합리적이라 판단된다.