• Korean Journal of Animal Reproduction
• /
• v.26 no.2
• /
• pp.95-104
• /
• 2002

This study was performed during the four seasons for the production of transgenic pigs containing the human erythropoietin(hEPO) transgene. Purebred Landrace gilts and sows approximately 8∼15 months of age (n=42) were used fur the collection of 1-cell zygotes for DNA microinjection and transfer. Retrospectively, estrus synchronization and superovulation schemes were evaluated to assess practicality for zygote collection. Synchronization and superovulation procedures were used that cyclic gilts were synchronized with 20mg altrenogest (ALT) per day for 9days after PG600 administration followed by superovulation with 1500IU pregnant mares serum gonadotropin (PMSG) and 500IU human chorionic gonadotrophin (hCG). Preparation of recombinant gene for microinjection is mice whey acidic protein promoter (mWAP) linked to human erythropoietin (hEPO) gene. After hormone treatment, 650 embryos were collected from 23 donors and 83.1% (540/650) embryos were in 1-cell stage which can be visualized the pronuclei for DNA microinjection. A total of 543 DNA microinjected embryos fiom donors were transferred to 19 synchronized recipients, seven of them maintained pregnancy and delivered 47 piglets. One of the 47 offsprings were determined to have transgene by PCR analysis. The overall rate of transgenic production was 2.13% (tansgenic/offspring). This study provides the success and useful information regarding production of transgenic pig for bioreactor research.

• Korean Journal of Animal Reproduction
• /
• v.26 no.2
• /
• pp.87-94
• /
• 2002

This study was performed during the four seasons for the production of transgenic pigs containing the Cellulase Digest Gene. Purebred Landrace gilts and sows approximately 8∼15 months of age (n=126) were used for the collection of 1-cell zygotes for DNA microinjection and transfer. Retrospectively, estrus synchronization and superovulation schemes were evaluated to assess practicality fur zygote collection. Synchronization and superovulation procedures were used that cyclic gilts were synchronized with 20mg altrenogest (ALT) per day for 9 days after PG600 administration followed by superovulation with 1000 IU pregnant mares serum gonadotropin (PMSG) and 750IU human chorionic gonadotrophin (hCG). The cellulase digestion gene for microinjection is rat elasterase promoter (rEl) linked to CelD gene. After hormone treatment, 1,422 embryos were collected from 91 donors and 95.6% (1,359/1,422) embryos were in 1-cell stage which can be visualized the pronuclei for DNA microinjection. A total of 725 DNA microinjected embryos transferred into 35 recipients and produced 65 piglets from 13 litters. Pregnancy rate according to the number of transferred embryos to recipients was higher the group which received 21 to 24 embryos (50.0%) than other groups 20.0% in less and 33.3% in more. A tail tissue was collected from 65 piglets for biopsy. PCR screening was performed on each DNA sample using two separate sets of primers specific for the 5'- and 3'-flanking region of the rEl-CelD gene. Five of the 65 piglets (7.69%) were positive for the transgene. This study provide useful information regarding production of transgenic pig for bioreactor research.

• Korean Journal of Animal Reproduction
• /
• v.26 no.2
• /
• pp.119-124
• /
• 2002

This study was carried out to investigate the effects of packing materials of frozen boar semen to improve reproductive performance efficiency in pig. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. We compared packing protocols for frozen boar semen among 5$m\ell$ maxi-straw, 5$m\ell$ cryogenic-vial, and aluminum-pack. Cryogenic-vial packing material showed similar sperm characteristics compared with maxi-straw packing material when the sperm was frozen above 15cm from liquid nitrogen and thawed at 52$^{\circ}C$ for 190 seconds. We investigated different thawing times to find out the optimal condition of freezing and thawing protocol with cryogenic-vial. Freezing above 15cm from liquid nitrogen and thawing at 52$^{\circ}C$ for 190 seconds were the optimal protocol compared with 120 and 150 seconds. However, normal acrosome rates did not show any differences among thawing times. Post-thawing results of maxi-straw in water at 52$^{\circ}C$ for 45 seconds had better total motility and curve linear velocity than those of cryogenic-vial in water 52$^{\circ}C$ for 190 seconds. However, there were no differences on straightness and normal apical ridge of sperm between maxi-straw and cryogenic vial. Non-return rate, farrowing rate and litter size of sows inseminated with frozen boar semen of commercial farms were higher in the maxi-straw than cryogenic-vial, but there were no significant differences between maxi-straw and cryogenic-vial. In conclusion, there were no significant differences between maxi-straw and cryogenic-vial and so, we may replace cryogenic-vial packing method instead of maxi-straw packing method by improvement of freezing and thawing rate.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.9
• /
• pp.1475-1481
• /
• 2019

Objective: The objective of the present study was to investigate pork quality from Hereford${\times}$Berkshire female and intact male pigs reared outdoors in an alternative production system. Methods: Berkshire purebred sows were artificially inseminated, once in the fall and again in the spring of the following year, with semen from Hereford boars and managed free of antibiotics in an outdoor hoop structure until the last month of pregnancy, after which they were moved to a pasture-based unit of 0.8 hectares with individual lots with a farrowing hut, shade, and water ad libitum. Piglets were weaned at 4 weeks of age and housed in a deep-bedded hoop structure, grouped by sex. Animals were harvested at market weight of 125 kg, approximately 200 days of age. Hot carcass weight was collected at the time of the harvest. After 24 hours of refrigeration, carcass characteristics were measured. Longissimus dorsi samples collected from the right side loin. Loins were cut into 2.54-cm thick chops and were used to measure marbling score, color score, drip loss, and ultimate pH. Sensory panel tests were conducted as well at North Carolina State University. For pork characteristics and sensory panel data, trial and sex were included in the statistical model as fixed effects. Hot carcass weight was included in the model as a covariate for backfat thickness. Results: Neither the subjective nor the objective color scores displayed any differences between the boars and the gilts. No difference was found for pH and marbling score between trials or sexes. Gilts had a thicker backfat measurement at the last lumbar and a narrower longissimus muscle area measurement when compared to the boars. The only difference in the sensory characteristics was found between the trials for texture and moisture scores. Conclusion: Consumers were not able to detect boar taint under the condition of this study, which is that the intact males were reared outdoors. Additional trials would be necessary; however, based on the results of the present study, outdoor rearing can be suggested as a solution to the issue of boar taint.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.514-520
• /
• 2019

The reduction in performance due to inbreeding (i.e. inbreeding depression) has long been documented in plant and animal populations. The population of Korean native pigs are small and this breed is valuable in Korea.. This study was aimed to investigate effects of inbreeding depression on total number of piglets born (TNB) and number of piglets born alive (NBA) in Korean native pigs. We used 2,806 pedigree and 303 sows's data with 483 phenotypic records. After estimating genetic parameters for each traits, inbreeding depression was estimated using a mixed model in which the inbreeding coefficient was included as a covariate. Korean native pigs had high heritability for each traits. Inbreeding coefficient constantly increased from 1998 to 2017~2018 but there is no reduction for each traits in 2017~2018 in compared with those in 1998. Significant inbreeding depression was detected for TNB (p=0.03) but not for NBA (p=0.41). In addition there are significantly positive interactions between inbreeding coefficient and breeding value for both traits (p<0.05). These results suggest that Korean native pigs are still having genetic variation for TNB and NBA, which could overcome reproductive risks from inbreeding coefficient increase.

• Journal of Veterinary Science
• /
• v.21 no.3
• /
• pp.36.1-36.9
• /
• 2020

Background: Pseudorabies, also known as Aujeszky's disease, is caused by the pseudorabies virus (PRV) and has been recognized as a critical disease affecting the pig industry and a wide range of animals around the world, resulting in great economic losses each year. Shandong province, one of the most vital food animal-breeding regions in China, has a very dense pig population, within which pseudorabies infections were detected in recent years. The data, however, on PRV epidemiology and coinfection rates of PRV with other major swine diseases is sparse. Objectives: This study aimed to investigate the PRV epidemiology in Shandong and analyze the current control measures. Methods: In this study, a total number of 16,457 serum samples and 1,638 tissue samples, which were collected from 362 intensive pig farms (≥ 300 sows/farm) covered all cities in Shandong, were tested by performing enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Results: Overall, 52.7% and 91.5% of the serum samples were positive for PRV-gE and -gB, respectively, based on ELISA results. In addition, 15.7% of the tissue samples were PCR positive for PRV. The coinfection rates of PRV with porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus, and classical swine fever virus were measured; coinfection with PCV2 was 35.0%, higher than those of the other two viruses. Macroscopic and microscopic lesions were observed in various tissues during histopathological examination. Conclusions: The results demonstrate the PRV prevalence and its coinfection rates in Shandong province and indicate that pseudorabies is endemic in pig farms in this region. This study provides epidemiological data that can be useful in the prevention and control of pseudorabies in Shandong, China.

• Korean Journal of Veterinary Service
• /
• v.45 no.2
• /
• pp.71-77
• /
• 2022

African swine fever (ASF) is a fatal viral disease in pigs, with a short incubation period and causing immediate death. Few studies exist on the Asian epidemic ASF virus (ASFV) challenge in older pigs, including growing and fattening pigs and sows. We aimed to investigate clinical outcomes, pathomorphological lesions, and viral distribution in organs of 3-month-old growing pigs that were inoculated with the ASFV isolated in Vietnam. The clinical outcomes were recorded daily, and the dead or euthanized pigs immediately underwent necropsy. Viral loads were determined in 10 major organs using quantitative polymerase chain reaction. The average incubation period in growing pigs was more delayed (5.2±0.9 dpi) than that in weaned pigs, and the clinical signs were milder in growing pigs than in weaned pigs. The digestive and respiratory clinical signs in growing pigs showed at the end period of life, but these were observed at an early stage of infection in weaned pigs. The pathomorphological features were severe and nonspecific with hemorrhagic lesions in various organs. The viral loads in organs from growing pigs were higher than those from piglets, and the number of viral copies was related to gross lesions in the tonsil and intestine. In the absence of vaccines against ASF, early clinical detection is important for preventing the spread of the virus. Our findings elucidated that the clinical signs and gross lesions in growing pigs differed from those in weaned pigs, which provide valuable information for diagnosis of pigs with suspected ASF infection.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.10 no.1
• /
• pp.91-99
• /
• 2008

Gnotobiotic piglets were routinely produced by hysterectomy. In this study, 22 pregnant miniature pigs (111th to 113th day of gestation) were used for hysterectomy. Before surgery, 14 pigs were insensibilizated by Ketamine 50^® plus CO₂ gas and 8 pigs by a slaughter pistol. The high level of Ketamine 50^® (0.09㎖/kg) was faster (146 vs 283 seconds) in surgery but the time taken for complete revival of one piglet was more prolonged (427 vs 64 seconds) than 0.03㎖/kg level. In hysterectomies with a slaughter pistol, surgery time was faster (470 vs 155 seconds) and the rate of alive piglets was higher (97.0 vs 83.8%) than in those with Ketamine 50^®. There were no problems in the rate of alive newborn piglets even when sows were hysterectomized at 3 days prepartum.

• Animal Bioscience
• /
• v.36 no.6
• /
• pp.861-868
• /
• 2023

Objective: Loin muscle area (LMA) is an important target trait of pig breeding. This study aimed to identify single nucleotide polymorphisms (SNPs) and genes associated with LMA in the Duroc×(Landrace×Yorkshire) crossbred pigs (DLY). Methods: A genome-wide association study was performed using the Illumina 50K chip to map the genetic marker and genes associated with LMA in 511 DLY pigs (255 boars and 256 sows). Results: After quality control, we detected 35,426 SNPs, including six SNPs significantly associated with LMA in pigs, with MARC0094338 and ASGA0072817 being the two key SNPs responsible for 1.77% and 2.48% of the phenotypic variance of LMA, respectively. Based on previous research, we determined two candidate genes (growth hormone receptor [GHR] and 3-oxoacid Co A-transferase 1 [OXCT1]) that are associated with fat deposition and muscle growth and found further additional genes (MYOCD, ARHGAP44, ELAC2, MAP2K4, FBXO4, FBLL1, RARS1, SLIT3, and RANK3) that are presumed to have an effect on LMA. Conclusion: This study contributes to the identification of the mutation that underlies quantitative trait loci associated with LMA and to future pig breeding programs based on marker-assisted selection. Further studies are needed to elucidate the role of the identified candidate genes in the physiological processes involved in LMA regulation.

• Animal Bioscience
• /
• v.35 no.10
• /
• pp.1479-1488
• /
• 2022

Objective: This work was to determine coat inheritance and evaluate production performance for crossbred pigs from Berkshire×Chenghua (BC) compared with Chinese indigenous Chenghua (CH) pigs. Methods: The coat color phenotypes were recorded for more than 16,000 pigs, and the genotypes of melanocortin 1 receptor (MCIR) gene were identified by sequencing. The reproductive performance of 927 crossbred BC F4 gilts and 320 purebred CH gilts was recorded. Sixty pigs of each breed were randomly selected at approximately 60 days of age to determine growth performance during fattening period, which lasted for 150 days for BC pigs and 240 days for CH pigs. At the end of the fattening period, 30 pigs of each breed were slaughtered to determine carcass composition and meat quality. Results: The coat color of BC pigs exhibits a "dominant black" hereditary pattern, and all piglets derived from boars or sows genotyped E^D1 E^D1 homozygous for MC1R gene showed a uniform black coat phenotype. The BC F4 gilts displayed a good reproductive performance, showing a higher litter and tear size and were heavier at farrowing litter and at weaning litter than the CH gilts, but they reached puberty later than the CH gilts. BC F4 pigs exhibited improved growth and carcass characteristics with a higher average daily live weight gain, lower feed-to-gain ratio, and higher carcass lean meat rate than CH pigs. Like CH pigs, BC F4 pigs produced superior meat-quality characteristics, showing ideal pH and meat-color values, high intramuscular fat content and water-holding capacity, and acceptable muscle-fiber parameters. C18:1, C16:0, C18:0, and C18:2 were the main fatty acids in M. longissimus lumborum in the two breeds, and a remarkably high polyunsaturated/saturated fatty acid ratio of ~0.39 was observed in the BC F4 pigs. Conclusion: The BC F4 pigs exhibit a uniform black coat pattern and acceptable total production performance.