• Korean Journal of Veterinary Research
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• v.55 no.1
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• pp.41-46
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• 2015

Increasing presence of wild boar around cities and suburban areas is a growing concern with respect to agronomy, environmental ecology, and public safety. In this study, antibiotic resistance profiles of Escherichia (E.) coli isolated from wild boar and domestic pig fecal samples were compared. Eighty E. coli samples were isolated from wild boars. Resistance of the bacteria to 14 common antimicrobial agents used in human and veterinary medicine was evaluated. Ninety-five E. coli isolates from domestic pig farms were used for comparison. Common and distinct antibiotic resistance patterns were observed when comparing wild boar and domestic pig isolates, indicating that wild boars may significantly influence environmental microbiology.

• IMMUNE NETWORK
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• v.16 no.3
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• pp.195-199
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• 2016

Fecal samples obtained from wild boar habitats are useful for the surveillance of diseases in wild boar populations; however, it is difficult to determine the species of origin of feces collected in natural habitats. In this study, a fecal IgA ELISA was evaluated as a method for identifying the porcine species from fecal samples. Both domestic pigs (Sus scrofa domestica) and wild boars (Sus scrofa coreanus) showed significantly higher levels of fecal IgA than other animal species. Additionally, age dependent changes in the level of Ig A in wild boars and domestic pigs were identified; Titers of Ig A were highest in suckling period and lowest in weanling period.

• Molecules and Cells
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• v.28 no.5
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• pp.423-430
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• 2009

In order to elucidate the precise phylogenetic relationships of Korean wild boar (Sus scrofa coreanus), a partial mtDNA D-loop region (1,274 bp, NC_000845 nucleotide positions 16576-1236) was sequenced among 56 Korean wild boars. In total, 25 haplotypes were identified and classified into four distinct subgroups (K1 to K4) based on Bayesian phylogenetic analysis using Markov chain Monte Carlo methods. An extended analysis, adding 139 wild boars sampled worldwide, confirmed that Korean wild boars clearly belong to the Asian wild boar cluster. Unexpectedly, the Myanmarese/Thai wild boar population was detected on the same branch as Korean wild boar subgroups K3 and K4. A parsimonious median-joining network analysis including all Asian wild boar haplotypes again revealed four maternal lineages of Korean wild boars, which corresponded to the four Korean wild boar subgroups identified previously. In an additional analysis, we supplemented the Asian wild boar network with 34 Korean and Chinese domestic pig haplotypes. We found only one haplotype, C31, that was shared by Chinese wild, Chinese domestic and Korean domestic pigs. In contrast to our expectation that Korean wild boars contributed to the gene pool of Korean native pigs, these data clearly suggest that Korean native pigs would be introduced from China after domestication from Chinese wild boars.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.59-66
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• 2023

Wild boar is closely related to domestic pigs in terms of genetic homogeneity and the possibility of a source of infection by contact. This study investigated the prevalence of viral diseases from wild boars inhabiting Gyeongsangnam-do, South Korea. A total of 374 blood samples were collected and subjected to antigen tests to detect African swine fever virus (ASFV), Porcine circovirus type-2 (PCV2), Porcine reproductive and respiratory syndrome virus (PRRSV). For seroprevalence, PCV2, PRRS, classical swine fever virus (CSFV), Aujezsky's disease (ADV), and foot and mouth disease virus (FMDV) were investigated. The antigenic analysis revealed 73 positive cases (19.5%) for PCV2, while no positive cases for ASFV and PRRSV. For the antibody test, 225 (60.2%), 2 (0.5%), and 48 (12.8%) cases were detected against PCV2, PRRSV, and CSFV, respectively. There were no antibodies detected against both ADV and FMDV. Our results suggest that the viruses infecting both wild boar and domestic pig, mainly PCV2, are circulating in the wild boar population thus, the consistent monitoring of prevalence in wild boar will be needed for transboundary spillover to the domestic pig.

• Journal of Veterinary Science
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• v.22 no.5
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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.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.435-450
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• 1992

To evaluate the fertilizing capacity of domestic animal spermatozoa by hamster test, semen were collected from 15 boars(Duroc, Landrace, and Yorkshire) and 2 mixed dogs which had been proved to be fertile in the past then, the semen were preserved in BWW medium at $4^{\circ}C$ or $18^{\circ}C$ for about 20 hours and coincubated with zona-free hamster ova for 5 hours. The ova were stained by lacmoid and examined under phase contrast microscope to investigate the rates of sperm binding to the ova, penetration and formation of a male pronucleus, and the numbers of both bound and penetrated sperm per ovum. Both the semen preserved at $18^{\circ}C$ for about 20 hours and that treated by swim up procedure showed considerably higher rates of sperm binding and penetration as well as higher number of penetrated sperm than that preserved at $4^{\circ}C$ for about 20 hours, respectively(p<0.01). Motility of boar sperm at insemination was from 40 to 90% and no difference in hamster test was obtained according to different degree of sperm motility. Abnormality in morphology of boar sperm at insemination was from 6 to 45% and no difference in hamster test was obtained according to different degree of sperm abnormality. The sperm concentrations of $7{\times}10^7$ and $7{\times}10^6$ showed considerably higher rates of sperm binding and penetration as well as higher number of bound sperm than that of $7{\times}10^4$ (p<0.01) along with the same higher results than that of $7{\times}10^5$(0<0.05), respectively. Boar sperm showed considerably higher rates of sperm binding and penetration as well as higher numbers of both bound and penetrated sperm than dog sperm, when both semen were treated by BWW＋heparin medium and swim up procedure, respectively. These results indicated that fertile boar sperm showed considerably lower rates in the results of hamster test, when preserved at $4^{\circ}C$ for about 20 hours and in lower concentration of sperm than when preserved at $18^{\circ}C$ for about 20 hours and in higher concentration of sperm, respectively, and at the same time considerably higher results than fertile dog sperm, consequently to prove that hamster test would be of great value in assaying the fertilizing capacity of boar sperm.

• Journal of Veterinary Clinics
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• v.9 no.2
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• pp.373-390
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• 1992

To assay the fertilizing capacity of domestic animal spermatozoa by hamster test, semen were collected from 13 boars(Duroc. Landrace and Yorkshire) which had been proved to be fertile in the past. then, were preserved in BWW medium or in raw state at 18$^{\circ}C$ or at room temperature. The preserved semen were given each different treatment according to the experimental design and coincubated with zona-free hamster ova for 5 hours. The ova were stained by lacmoid and examined under phase contrast microscope to investigate the rates of ova bound with sperm(sperm binding). ova penetrated by sperm(penetration) and formation of a male pronucleus(pronucleus formation) and also numbers of both bound and penetrated sperm per ovum. Between BWW and TBM medium for boar sperm. no difference in the results of hamster test was obtained. The boar spermatozoa in BWW medium, BWW with caffeine, BWW with heparin, and BWW with both caffeine and heparin showed no difference in the results of hamster test. The boar spermatozoa in BWW medium containing both calcium and RSA showed considerably higher rates of sperm binding, penetration and pronucleus formation as well as higher numbers of both bound and penetrated sperm than those not containing calcium with or without BSA( p<0.01) and also the same results higher than that containing calcium without BSA( p< 0.05). The boar spermatozoa irradiated by X-ray(70 KVP, 20mA) for 3 seconds. then, maintained at 18$^{\circ}C$ for 18 hours showed considerably lower rate of sperm binding than all the other groups including the control and X-ray groups irradiated by smaller dose or maintained for shorter period(p<0.01), and also showed lower number of bound sperm than the other groups(p<0.01, p<0.05). All the control groups of both raw and diluted sperm in BWM medium showed higher rates of sperm binding, penetration and pronucleus formation as well as higher number of penetrated sperm than all the X-ray groups irradiated for 3 seconds(70KVP, 20mA) and maintained for either 3 or 18 hours (p<0.01, p<0.05). At the same time the control groups of diluted sperm showed considerably higher rates of sperm penetration and pronucleus formation than the control group of raw sperm( p<0.01). These results indicates that fertile boar sperm showed considerably lower rates In the results of hamster test, when incubated in the medium without calcium and irradiated by X-ray than when incubated in the medium with calcium and not irradiated by X-ray, respectively, to prove consequently that hamster test would be of great value in assaying the fertilizing capacity of boar spermatozoa.

• Journal of Embryo Transfer
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• v.24 no.4
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• pp.275-279
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• 2009

The beneficial effect of glycerol as a cryoprotectant, especially for sperm cryopreservation, has been shown in many studies. However, glycerol is toxic to living cells, and boar sperm in particular show greater sensitivity to glycerol than sperm from other domestic animals. Amides have been studied as alternative cryoprotectants for freezing stallion sperm. Sperm frozen in methylformamide or dimethylformamide as cryoprotectants show similar motility when thawed compared with sperm frozen in glycerol. We evaluated the cryoprotective effects of dimethylformamide on boar sperm freezing. To test the effect of amides, the concentration of boar semen was adjusted to $10^9sperm/mL$, and seminal plasma was removed using Hulsen solution. After centrifugation, the pellet was diluted in modified-Modena B extender. Lactose-egg yolk (LEY) extender was used as the cooling extender. The freezing extender was madeed aaddition of the optimal amount of glycerol and amides to LEY-Glycerol-Orvus ES Paste extender, and this extender was used for the second dilution. Diluted sperm were frozen in liquid nitrogen using the 0.5 mL straw method. Sperm frozen in extender with glycerol as a cderol were compared with those frozen in extender including the different amides. Sperm were tested for motility, viability, the sperm chromatin structure assay, and normal apical ridge after thawing. The percent of motile sperm diluted in glycerol was as high as that in the stallion study (61%). Dimethylformamide showed positive effects on sperm quality and was better than glycerol. Methylformamide provided similar sperm quality as glycerol. Therefore, dimethylformamide is useful for reducing cryoinjury in boar sperm and is expected to be useful as an alternative cryoprotectant.

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.13-18
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• 2022

African swine fever (ASF) is fatal to domestic pigs and wild boars (Sus scrofa) and affects the domestic pig industry. ASF is transmitted directly through the secretions of infected domestic pigs or wild boars, an essential source of infection in disease transmission. ASFV is also very stable in the environment. Thus, the virus is detected in the surrounding environment where ASF-infected carcasses are found. In this study, ASF infection monitoring was conducted on the swab and whole blood samples from wild animals, various hematopoietic arthropod samples that could access infected wild boar carcasses or habitats to cause maintenance and spread of disease, and soil samples of wild boar habitats. ASF viral DNA detection was confirmed negative in 317 wildlife and environmental samples through a real-time polymerase chain reaction. However, ASF occurs in the wild boars and spreads throughout the Korean peninsula. Therefore, it is necessary to trace the route of ASF virus infection by a continuous vector. Additional monitoring of various samples with potential ASF infection is needed to help the epidemiologic investigation and disease prevention.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.103-112
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• 2022

Fipronil is a popular insecticide used in both agricultural and domestic fields. Factors that affect sperm and eggs have a direct influence on reproductive outcomes. This study was undertaken to assess the effect of varying concentrations (10 - 200 μM) of fipronil and incubation times (30 min and 2 hrs) on boar spermatozoa. Spermatozoa were evaluated for motility, motion kinematics, viability, chromatin stability, and for the generation of intracellular reactive oxygen species (ROS) and the results were compared to those from corresponding controls. The findings revealed a significant, dose-dependent reduction in sperm motility in all fipronil treatment groups at 30 min of incubation (p < 0.05). A similar dose-dependent reduction in sperm motility was observed subsequent to fipronil exposure for 2 hrs of incubation (p < 0.05). Groups treated with fipronil showed a gradual reduction in motion kinematics (p < 0.05). Moreover, a significantly higher percentage of dead sperm was observed at 200 μM fipronil, as compared to the highest live percentage obtained in controls (p < 0.05). Evaluating the sperm chromatin integrity revealed a significantly higher percentage of damaged chromatin in spermatozoa incubated with 200 μM of fipronil. Moreover, ROS production was significantly higher in fipronil-exposed sperm (p < 0.05). In conclusion, boar spermatozoa incubated with fipronil showed decreased levels of sperm motility and viability, weaker chromatin integrity, and increased levels of intracellular ROS generation, all of which indicate that exposure to fipronil potentially impairs the fertilization competence of boar spermatozoa.