Japanese encephalitis (JE) is an important zoonosis caused by the mosquito-transmitted JE virus (JEV), which is a causative agent of reproductive failure in pregnant sows. Detection of JEV antibodies in swine is performed by hemagglutination inhibition (HI), virus neutralization (VN), and the plaque reduction neutralization test (PRNT). The most stringent PRNT is the 90% endpoint PRNT (PRNT∧90). These conventional assays are difficult to carry out in diagnostic laboratories with insufficient instruments or cell culture systems. An alternative assay that is easily conducted and time efficient is required. In this study, we improved the indirect enzyme-linked immunosorbent assay (I-ELISA) with clarified antigen for the detection of JEV antibodies. The I-ELISA results obtained from 175 swine serum samples were compared with HI, VN, and PRNT∧90 results. The sensitivity of I-ELISA was 91.8%, 95.0%, and 94.7% compared with HI, VN, and PRNT∧90 results, respectively. The specificity of I-ELISA was 92.2%, 94.7%, and 94.7% compared with HI, VN, and PRNT∧90 results, respectively. Moreover, the I-ELISA results were significantly correlated with the HI (r = 0.93), VN (r = 0.95), and PRN∧T90 (r = 0.92) results. These results suggest that the improved I-ELISA is useful for serosurveillance of JEV in swine.

The purpose of this study was to investigate the prevalence of Brachyspira species and antimicrobial susceptibility of Brachyspira (B.) hyodysenteriae isolates in Korea. A total of fifty-five Brachyspira species were isolated; five (1.0%) beta-hemolytic Brachyspira species and 50 (10.4%) weak hemolytic Brachyspira species from 116 different diarrheic pig samples and 367 apparently normal pig samples. In farm level, beta hemolytic and weak hemolytic Brachyspira species were detected in 7.4% (5/68) and 19.1% (13/68) of tested pig farms, respectively. By phenotypic and genotypic characterization, all beta hemolytic Brachyspira isolates was classified as group Ⅰ (B. hyodysenteriae), whereas weak hemolytic Brachyspira species isolates were group Ⅲ (B. innocens or B. murdochii). B. hyodysenteriae isolates showed high level of minimum inhibition concentrations to macrolide antimicrobials. This study shows that the prevalence of pathogenic B. hyodysenteriae in pigs is low but antimicrobial resistance of the pathogens is high in Korea. This is the first report of the prevalence of Brachyspira group Ⅲ and antimicrobial susceptibility of B. hyodysenteriae in pigs in Korea. Our results could provide basic data for the management and treatment guidelines of Brachyspira infection.

Swine diseases could be caused by unrecognized or minor pathogens. In this study, two unknown cytopathogenic agents were isolated from swine, through cell culture. In order to identify these two cytopathogenic agent (designated CP129 and No.2045-7), a particle associated nucleic acids PCR (PAN-PCR) from previous paper was used with simple modification. The cloning procedure was more specified in this study by adding cell control system. According to the modified PAN-PCR, two and four agents-specific DNA sequences were obtained from CP129 and No.2045-7, respectively, and they were identified as Mycoplasma (M.) hyorhinis and Mammalian orthoreovirus by nucleotide BLAST. Since M. hyorhinis (CP129) was filterable and non-visible by microscope, this unusual virus-like nature of M. hyorhinis (CP129) was discussed. Especially, the reovirus (No.2045-7) was a serotype 3 and a triple reassortant among three serotypes of reoviruses. It was grouped with recently reported reoviruses from disease cases (swine, human and feline), based on the genetic analysis of L1 and S1 partial sequences. In conclusion, two unknown cytopathogenic agents were successfully identified using modified PAN-PCR with cell control system and they were characterized in this study.

From January to June 2006, 54 suckling pigs had been submitted in virology lab., College of Veterinary Medicine, Seoul National University. All pigs had suffered from various symptoms such as respiratory, sign, enteric signs, neurologic signs, etc. Among 54 pigs, 24 pigs (44.4%) were positive for porcine hemagglutinating encephalomyelitis virus (HEV) through reverse transcription-nested polymerase chain reaction. According to this result, HEV infections seemed to be prevalent and widespread in Korean swine farms, and the infection is associated with respiratory signs and neurologic signs more than enteric signs.

Epidemiological characteristics of a total of 48 swine herd with diarrhea or a history of diarrhea in Gyeongsang-do between 1999 and 2000 were performed to evaluate the prevalence of Salmonella spp., their serotypes and antibiotic resistance patterns with respect to the different stages of swine production system. A total of 139 Salmonella spp. (21%) were isolated from 662 fecal samples and the overall herd prevalence of Salmonella spp. ranged from 12.5% to 88%. The average prevalence of Salmonella spp. from swine stages of suckling/nursery, grow/finisher and sow stage were 25.7%, 19.2% and 18.4%, respectively.

This study investigated the effects of gonadotropin-releasing hormone (GnRH) vaccine on pig growth, carcass quality, and sensory perceptions of pork meat by Thai consumers. Male crossbred pigs (n = 30) were separated into three groups of 10 pigs each: boars, immunocastrated pigs, and surgically castrated pigs. The immunocastrated group was immunized at 13 and 19 weeks of age with GnRH vaccine (400 킽/dose). All pigs were slaughtered at 24 weeks of age. Blood samples were collected and testes size determined. Testes weight and back fat thickness were recorded at the time of slaughter, and meat samples were collected for sensory assessment by Thai consumers. Testosterone and progesterone concentration levels decreased significantly two weeks after the second dose of GnRH (p less than 0.05), and the GnRH antibody titer of the immunocastrated pigs was significantly high two weeks after the second dose of GnRH (p less than 0.05). GnRH vaccine significantly reduced the weight and size of testes. Thai consumers reported no significant differences in odor or flavor among meat samples from the three groups. In conclusion, immunocastration improved growth performance, removed the need for castration surgery, and avoided "boar taint" in the meat. It has also no distinct trace of the boar taint same as pork that is currently produced from physically castrated pig which is making it acceptable to consumers.

This study investigated changes in certain blood parameters in calves and pigs after foot-and-mouth disease (FMD) vaccination. In this study, five calves and five pigs were selected from groups of 10 calves and pigs, respectively, and were vaccinated with an FMD vaccine. The remaining animals formed two non-treatment control groups. Blood samples were collected from all animals on the 1st, 3rd, 5th, and 7th days post-vaccination. In the FMD-vaccinated calves and pigs on day 7 post-vaccination, white blood cell counts, blood urea nitrogen levels, and alanine aminotransferase and aspartate aminotransferase activities were higher than those in the respective controls. The present data suggested that the certain hemato-biochemical parameters on cattle and pigs were meaningfully changed between before and after FMD vaccination.

This study investigated the effects of vitamin C on oxidative stress induced by volatile anesthetics in pigs. One group of pigs was used as an anesthesia control group (group 1), and they were anesthetized with isoflurane in oxygen and saline (0.9% NaCl) was injected intravenously. The other group (group 2) was anesthetized with isoflurane and injected intravenously with vitamin C. Total oxidant status, total antioxidant status, and the oxidative stress index in group 2 were significantly different compared with those in group 1. The results showed that intravenous administration of vitamin C decreased oxidative stress during isoflurane anesthesia in pigs.

To determine the prevalence of Escherichia (E.) coli O157 : H7 from pigs after the Hazard Analysis and Critical Control Point (HACCP) system has been applied to Korean swine farm since 2006, 291 fecal samples were tested between May and December in 2008. Four E. coli O157:non-H7 (1.4%) were isolated from 4 different non-HACCP-accredited farms and they didn't have virulent genes which can cause illness for human. Also, Clostridium (C.) perfringens, Salmonella spp. and E. coli enterotoxins were tested using multiplex PCR. The positive rate for these pathogens of non-HACCP-accredited farms was higher than that of HACCP-accredited farms, and especially in case of C. perfringens, E. coli enterotoxins LT and STa, it was statistically significant (p less than 0.05). Thus, the early implementation of the HACCP program is expected to greatly contribute to the safety of livestock products as well as food hygiene.

This study describes thoracic radiographic features of normal premature minipigs at the age of 4, 8, 12 and 20 weeks. The evaluation for appearance, shape, contour, location and extent of distribution of thoracic organs was recorded through right lateral and ventrodorsal thoracic radiographs. The size of the tracheal diameter, cranial mediastinum, and the heart were measured, and information about the correlation of each organ in their thoracic conformation could be obtained. Although there were limitations with plain thoracic radiographs, basic characteristics and data for thoracic radiographs of normal premature minipigs according to each age were useful.