• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1239-1244
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• 2017

Objective: This study was conducted to estimate breed-specific variance components for total number born (TNB), number born alive (NBA) and mortality rate from birth through weaning including stillbirths (MORT) of three main swine breeds in Korea. In addition, the importance of including maternal genetic and service sire effects in estimation models was evaluated. Methods: Records of farrowing traits from 6,412 Duroc, 18,020 Landrace, and 54,254 Yorkshire sows collected from January 2001 to September 2016 from different farms in Korea were used in the analysis. Animal models and the restricted maximum likelihood method were used to estimate variances in animal genetic, permanent environmental, maternal genetic, service sire and residuals. Results: The heritability estimates ranged from 0.072 to 0.102, 0.090 to 0.099, and 0.109 to 0.121 for TNB; 0.087 to 0.110, 0.088 to 0.100, and 0.099 to 0.107 for NBA; and 0.027 to 0.031, 0.050 to 0.053, and 0.073 to 0.081 for MORT in the Duroc, Landrace and Yorkshire breeds, respectively. The proportion of the total variation due to permanent environmental effects, maternal genetic effects, and service sire effects ranged from 0.042 to 0.088, 0.001 to 0.031, and 0.001 to 0.021, respectively. Spearman rank correlations among models ranged from 0.98 to 0.99, demonstrating that the maternal genetic and service sire effects have small effects on the precision of the breeding value. Conclusion: Models that include additive genetic and permanent environmental effects are suitable for farrowing traits in Duroc, Landrace, and Yorkshire populations in Korea. This breed-specific variance components estimates for litter traits can be utilized for pig improvement programs in Korea.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.62-65
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• 2010

Salmonellosis is one of the most important wasting diseases that leads to economic damage in the swine industry. Many risk factors have been reported to increase the spread of Salmonella infection; therefore, it is important to understand how to treat the risk factors of Salmonella to effectively prevent salmonellosis in commercial pig farms. To accomplish this, we conducted a study to determine if the seasons and porcine production stages affected the serological response to Salmonella in Korea. A total of 1,592 serum samples submitted to the School of Veterinary Medicine of Kangwon National University between Jan. 2001 and Dec. 2004 from commercial farms were tested by ELISA. The overall apparent seroprevalence of salmonellosis was 38.1% (95% CI, 38.0-38.2), while the prevalence of Salmonella according to seasons and production stages ranged from 17.9% to 62.8% for the former (24.6% in spring, 17.9% in summer, 38.5% in autumn, and 62.8% in winter) and from 16.1% to 68.3% for the latter (17.9% in suckling pigs, 16.1% in weaning pigs, 37.50% in growers, 41.9% in finishers, 48.0% in gilts, and 68.3% in sows). In this study of seroprevalence by production stage, most pigs were naturally infected by Salmonella during the weaning stage. Also, seroprevalences were found to have a seasonal pattern in which most pigs were infected in autumn to winter.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.128-128
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• 2003

The aims of this study are 1) to test oocytes and embryos collected from in-vivo and in-vitro to achieving the valuable protocol by culturing, vitrifying and thawing of oocytes/embryos, and 2) to transfer them to recipient, and finally have resulted in pregnancies from recipient females after surgical or nonsurgical transfer. In vitro maturation and fertilization were performed according to the procedures of Funahashi et al. Fertilized oocytes were cultured in glucose-free NCSU 23 supplemented with 5 mM sodium pyruvate, 0.5 mM sodium lactate and 4 mg/ml bovine serum albumin for 2 days at 39$^{\circ}C$, and 10% fetal bovine serum was added to the culture medium thereafter. Embryos were treated with 7.5$\square$g/ml cytochalasin-B for 30 min, centrifuged at 13,000 ${\times}$ g for 13 min and then exposed sequentially to an ethylene glycol (EG) vitrification solution, aspirated into OPSs, and plunged/thawed into/from liquid nitrogen. In vivo embryos were surgically collected from three donors after Al. Forty-six embryos (18, 9 and 19 embryos, respectively) were washed 3 times in mPBS+10%FBS, followed treatments : cultured, centrifuged, vitrified, recovered and transferred to recipients as in vitro prepared embryos. Three recipients received surgically 34(control), 188 and 184 embryos (derived from abattoir), respectively. Another three recipients were received nonsurgically 150, 100 and 150 embryos, respectively. All recipient sows exhibited delayed returns to estrus. To our knowledge, these results suggest that required an improved techniques, more vigorous embryos preparation and cleaner uterous condition(use gilt).

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.463-469
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• 2003

Eight nursery to grower pigs exhibiting weight loss and sudden death were diagnosed as postweaning multisystemic wasting syndrome (PMWS) based on the results of gross findings, histopathology, immunohistochemistry, fluorescent antibody test, virus isolation, PCR, serology, and electron microscopy. Groosly, the pigs had a rough hair coats and were severely emaciated. And moot lymph nodes were pale and enlarged. Lungs were not fully collapsed and exhibited 10 to 40% pale red cranioventral consolidation. Histopathologically, typical lymphohistiocytic interstitial to bronchointerstitial pneumonia, chronic lymphadenitis, severe lymphoid depletion, and basophilic intracytoplasmic inclusions were noted in the most lymphoid tissues. Porcine circovirus panicles were observed in the inguinal lymph node of the pigs by electron microscopy. Porcine circovirus type 2 (PCV2) antigens or viral DNAs were detected in the lesions of all pigs using immunohistochemistry or PCR. Two PCV2 were isolated from a homogenate of pooled lung and lymph node in 2 of the 5 pigs. Additionally, antigens of porcine reproductive and respiratory syndrome virus (PRRSV) and Hemophilus (H.) parasuis were also detected by immunofluorescent antibody test. Serologically, 55% of randomly selected sows and fattening pigs was serum antibody positive to PCV2 by an indirect fluorescent antibody (IFA) test and approximately 18 % of animals in the herd were serologically pooitive by the ELISA kit for PRRSV. To our knowledge, this is the first report of PMWS co-infected with PCV-2, PRRS, and H. parasuis in Korea.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.53-60
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• 2008

We have investigated efficiency of a recombinant subunit Pasteurella multocida toxin (PMT) that was mixed with a vaccine consisted of inactivated whole cells of Bordetella bronchiseptica, P. multocida (types A and D). For verification of the efficacy of the vaccine, all experimental pigs (suckling piglets, sow and gilts) in the three farms were vaccinated. Antibody titers against B. bronchiseptica and P. multocida type A of the vaccinated pigs by microplate agglutination were significantly higher than those of the control pigs (p < 0.05). Similar patterns were observed in the analysis of anti- PMT neutralizing antibody by serum neutralizing method using Vero cell (p < 0.05). Anti- P. multocida type D antibody titer of the vaccinated sows and gilts by ELISA showed significant differences with those of the non-vaccinated pigs (p < 0.05). Although antibody titers increased, it was unable to find out the difference in the clinical signs between the vaccinated and non-vaccinated pigs. However, the increase in body weight of the vaccinated piglets was observed in comparison with the non-vaccinated piglets on a farm. At slaughtering of the pigs, pathological lesions in the turbinate bones of the vaccinated pigs were significantly lower than those of the non-vaccinated pigs (p < 0.001). These results suggested that efficacy of the vaccine in pigs demonstrated to protect against atrophic rhinitis in Korea.

• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.345-351
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• 2010

Toxoplasma gondii is a species of parasitic protozoa in the genus Toxoplasma. The definitive host of T. gondii is the cat, but the parasite can be carried by the vast majority of warm-blooded animals, including humans. It is often found in the tissues of food animals including pigs and sheep. To determine the regional prevalence of infection with T. gondii, bloods (n=300) from domestic pigs and tissues (n=200) from slaughter pigs in Gyeongnam province were tested using an enzyme-linked immunosorbent assay (ELISA) and a polymerase chain reaction (PCR) for detection of antibody and antigen. A total of 115 sero-positive pigs were identified for a prevalence rate of 38.3%. Of the 50 herds from domestic pigs tested, 34 had at least one sero-positive pig for a herd prevalence rate of 68.0%. Sero-positive rates of pigs in fattening farm were higher than that of pigs in breeding company. Sero-positive rates of sows were higher than that of growing pigs. Seasonally, sero-positive rates of pigs were highest in winter (80.0%) and lowest in spring (23.8%). According to farm size, sero-positive rates of pigs were higher in small size farms (${\leq}$2,000) than that of big size farms (>2,000). However, none of the bloods (n=300) from domestic pigs and tissues (n=200) from slaughter pigs were positive for T. gondii specific DNA by PCR.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.43-43
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• 2003

This study was conducted to produce transgenic pig harboring human tissue plasminogene activator (tPA) gene. Two different tPA genes containing bovine $\beta$-casein promoter and mouse uroplakin promoter were prepared for microinjection and confirmed the expression level of tPA protein from the CHO (Chinese hamster ovary) cell lines by gene transfection. Concentration of tPA expression from the six cell lines (all of CHO cells) were average 212.4 ng/ml. Reconstructed DNA to used the CHO cell were microinjected into the pronuclei of in vivo embryos The total of 2,307 zygotes were collected from 95 donors and 1,851 embryos were in 1-cell stage which were visualized the pronuclei for DNA microinjection. The concentration of linear DNA was 2.0 ng per microliter and injected into zygotes with two pronuclei on an inverted Nikon microscope equipped with narishige micromanipulator and modulation contrast optics. The 541 embryos injected with bovine $\beta$-casein promoter-tPA were transferred to 22 recipients. The 1,154 embryos injected with mouse uroplakin promoter-tPA were transferred to 51 recipients. Sixty nine offspring from 9 delivered sows were produced. We analysed the transgenes with PCR methods from 69 offsprings, but could not detect the PCR product from piglet tails DNA.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.227-232
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• 2011

This survey was conducted to investigate the current status of swine artificial insemination(AI) centers registered as 'semen processing business' in Korea. The survey responses were collected by direct visitation or telephone conversation for 5 months from May through September in 2008. The survey showed that sixty-four AI centers were enrolled in local government and those of fifty-two AI centers were under operation. Forty-nine AI centers surveyed owned a total of 3,334 boars and the Duroc breed accounted for the highest rate(73.1%) of all boar breeds. In type of ownership, agricultural management corporations was the highest(42.3%) and followed by private ownership(34.6%). Large-scale AI centers in terms of own over 151 boar were surveyed as 5.9% and most AI centers own less than 100 boars(86.5%). The average number of boars per AI center was 68. The amount of liquid semen provided by 52 AI centers were 1,791,000 doses and each AI center provides average of 39,000 does, which is represented for 90% consumption by sows in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.9
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• pp.1244-1251
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• 2015

A herd of Berkshire pigs was established in 2003 and subjected to selection without introduction of any genetic resources until 2007. The complete pedigree, including 410 boars and 916 sows, as well as the records from 5,845 pigs and 822 litters were used to investigate the results obtained from the selections. The index of selection for breeding values included days to 90 kg (D90kg), backfat thickness (BF) and number of piglets born alive (NBA). The average inbreeding coefficients of pigs were found to be 0.023, 0.008, 0.013, 0.025, 0.026, and 0.005 from 2003 to 2007, respectively. The genetic gains per year were 12.1 g, -0.04 mm, -3.13 days, and 0.181 head for average daily gain (ADG), BF, D90kg, and NBA, respectively. Breeding values of ADG, BF and D90kg were not significantly correlated with inbreeding coefficients of individuals, except for NBA (-0.21). The response per additional 1% of inbreeding was 0.0278 head reduction in NBA. The annual increase of inbreeding was 0.23% and the annual decrease in NBA due to inbreeding was 0.0064 head. This magnitude could be disregarded when compared with the annual gain in NBA (0.181 head). These results suggest that inbreeding and inbreeding depression on ordinary farms can be controlled with a proper breeding scheme and that breeding programs are economical and safe relative to the risks associated with importation of pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.237-244
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• 2018

Objective: Piglet pre-weaning mortality is an important variable indicating the efficacy of farrowing management and animal well-being during lactation. The present study determined the association of newborn traits measured soon after birth with piglet pre-weaning mortality and growth. Methods: In total, 805 piglets born from 57 multiparous sows were investigated. Their blood oxygen saturation, blood glucose and rectal temperature at 24 h after birth (RT24h) were monitored. Birth order, sex, skin color, integrity of the umbilical cord, attempts to stand and birth intervention were monitored. Piglets were weighed at day 0, 7, and 21 to evaluate average daily gain (ADG). Results: Piglet pre-weaning mortality for lactation period was 12.6% and cumulative mortality during the first 7 days of age was 8.6%. A higher proportion of piglets with pale skin color died compared to piglets with normal skin color (26.7% vs 7.7%, p<0.001). A higher (p<0.001) proportion of piglets that attempted to stand after 5 min (38.5%) died compared to piglets that attempted to stand within 1 min (6.3%) after birth. Piglet body weight at birth ($BW_B$), blood glucose and the number of piglets born alive (BA) were correlated with ADG (p<0.05). Piglets with $BW_B$ <1.30 kg had higher (p<0.001) mortality rate than piglets with $BW_B{\geq}1.80 kg$ (19.0% vs 3.3%) and piglets with $BW_B$ 1.30 to 1.79 kg (4.0%). Piglet with RT24h <$37.0^{\circ}C$ had higher (p<0.001) mortality rate (86.2%) than piglets with RT24h >$38.5^{\circ}C$ (3.9%). Conclusion: Low $BW_B$ and low RT24h compromise piglet survival during the lactation period in the tropical conditions. Piglets in the litters with a high BA, low $BW_B$ and low blood glucose have reduced ADG.