• 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.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.111-117
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• 2002

This study was carried out to investigate the effects of frozen boar semen on reproductive performance in swine artificial insemination (AI). Many factors, which were breeds, time of insemination, sperm concentration per dose, farm and year were investigated to improve reproductive performance efficiency. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. This experiment was carried out from 1995 to 2000. There were no differences in swine AI with frozen boar semen using 5$m\ell$ maxi-straw among 3 breeds (Landrace, Yorkshire, Duroc), 2 or 3 times insemination per estrus, and 3 different sperm numbers of 3.0, 4.0, and 5.0$\times$10$^{9}$ per dose of insemination. However, non-return rate and litter size of sows inseminated with frozen boar semen of commercial farms were different according to farm management system and inseminator's skill. Conception rate, farrowing rate and number of pigs born alive per litter by artificial insemination with frozen boar semen (5$m\ell$ maxi-straw) from 1995 to 1999 was 68.3~74.6%, 61.7~67.6% and 8.1~8.7 heads.

• Korean Journal of Animal Reproduction
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• v.3 no.1
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• pp.26-29
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• 1979

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.111-116
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• 2011

Artificial insemination (AI) of swine is a very useful reproductive tool and that offers convenience in the Korean swine industry. Since many viruses have been reported to be excreted through boar semen, we investigated the presence of antibodies and antigens against viruses causing reproductive failure in semen of boar in 349 semen samples collected from six Korean AI centers. Viral antigens were detected by polymerase chain reaction (PCR) or reverse transcription-PCR predominantly. The results was as follows. The major reproductive failure causing factor was porcine circovirus type 2 (PCV2), followed by porcine reproductive and respiratory syndrome virus (PRRSV) ($X^2$=166.64, P<0.001). PCV2 and PRRSV, Japanese encephalitis virus (JEV), encephalomyocarditis virus (EMCV) was detected in 73 samples (20.9%), 44 samples (12.6%), 4 samples (1.1%), 3 samples (0.9%), respectively and porcine parvovirus in one sample (0.3%) Classical swine fever virus (CSFV), bovine viral diarrhea virus and Aujeszky's disease virus (ADV) were not detected. Enzyme-linked immunosorbent assay was carried out in 111 serum samples from three AI centers. In most pigs, antibodies response was showed prominently in CSFV (105 sera, 94.6%) ($X^2$=82.580, P<0.001), followed by, in PRRSV (100 sera, 90.1%), PCV2 (92 sera, 90.1%), and PPV (8 sera, 82.9%). ADV antibody was not detected. Thus, the experimental results will be used for the base data, with respect to the state of viral stillbirth in general pig farms, as well as AI centers and breeding farms in Korea.

• Korean Journal of Agricultural Science
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• v.28 no.2
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• pp.85-91
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• 2001

This study was carried out to investigate the effects of liquid boar semen on reproductive performance in swine artificial insemination. Many factors, which were breeds, time of insemination, breeding season, sperm per dose etc, have been tried to improve reproductive efficiency. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. This experiment was carried out from 1995 to 2000. There were no differences in the fertility results compared with 3 breeds (Landrace, Yorkshire and Duroc), frequencies of artificial insemination (double and triple) per estrus cycle and different seasons by using liquid boar semen. There were no significant differences in conception rate, farrowing rate and litter size using 4 trials of 3.0, 2.5, 2.0 and $1.5{\times}10^9/80ml$ in liquid boar semen with 70% of motile sperm cells. We confirmed that the sperm number per dose of $1.5{\times}10^9/80ml$ could be used for commercial artificial insemination.

• Reproductive and Developmental Biology
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• v.38 no.4
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• pp.159-163
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• 2014

The objective of this study was to determine the effects of E. coli on boar sperm quality and reproductive performance in sows after artificial insemination. Three different levels of E. coli were artificially inoculated to semen with following concentrations; Control, 500, 5,000 and 50,000 colony forming unit (cfu)/ml. Semen samples were preserved at $17^{\circ}C$ for 5 days. Sperm motility was significantly decreased (p<0.05) on day 3 in the group inoculated with 5,000 cfu/ml compared to control groups. In all treatment groups, sperm motility was gradually decreased as storage time increased, but the decline pattern was more drastic in the groups inoculated with 5,000 and 50,000 cfu/ml groups from day 3 (p<0.05) compared to control group. After 3 day of storage at $17^{\circ}C$, sperm viability in sample inoculated with the highest concentration (50,000 cfu/ml) of bacteria was less (p<0.05) than that of control group. The pH of semen sample pH was maintained 7.2~7.5 in all groups during the experimental period. No differences (p>0.05) were found for both storage time and bacterial concentration. The pregnancy rate and live born piglets tend to decrease by increasing the concentration of E. coli in semen. In particular, the rate of pregnancy was lower in the group inoculated with 50,000 cfu/ml (58.3%) compare to the other groups (81.8, 75.0, 76.5%). These results suggest that the contamination of E. coli in boar semen negatively affects fertilizing ability of boar sperm and the reproductive performance obtained from sows after artificial insemination.

• Reproductive and Developmental Biology
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• v.37 no.4
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• pp.263-267
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• 2013

Pig producers have been shown keen interest of the number of spermatozoa in a semen dose since pig artificial insemination introduce. However, determining the minimal number of spermatozoa need per AI without detrimental effect on overall reproductive performances is not an easy question to answer. To increase the efficiency of semen utilization in pig AI, optimum number of spermatozoa per dose needed to determine. The objective of this study was to determine the reproductive performance and factors that affect on-farm application of low-dose semen insemination in sows. Data were collected from Darby Genetics AI studs from 4th of June to 7th of July, 2012 (n=401). The numbers of parturition were 84, 234 and 83 in sows inseminated with doses of $1.5{\times}10^9$, $2.0{\times}10^9$ and $2.5{\times}10^9$ spermatozoa in 100ml extender, respectively. There were no significant differences on reproductive performances such as gestation period, total born, total born alive, stillbirth and mummy in sows inseminated with different semen doses. The average number of born alive was 10.5, 11.0 and 10.4 from sows inseminated with $1.5{\times}10^9$, $2.0{\times}10^9$ and $2.5{\times}10^9$ sperms, respectively. Also, number of spermatozoa per dose did not affect litter size (p>0.10). There were no significant differences of maternal genetic line difference on gestation period, total number born, number born alive, born dead and mummy. The estimated correlation coefficients of the different semen doses with total number born, number born alive, born dead and mummy were r=-0.00, -0.01, 0.02 and 0.02, respectively. Taken together, the result of this study suggested that when semen was appropriately inseminated after induced ovulation, insemination with low-dose ($1.5{\sim}2.0{\times}10^9$) semen dose not adversely affect sow's fertility.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.979-985
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• 2020

A wide range of techniques have been developed to separate X or Y- chromosome-bearing sperm. In particular, bovine semen sex-sorted by using flow cytometry based on differences in the amount of DNA between X and Y chromosome bearing sperm is used in dairy farms. The first piglets were produced using sex-sorted sperm 30 years ago. However, sexed sperm have not been commercially available in pigs because the flow cytometry technique is not capable of sorting the high number of sperm required for porcine artificial insemination (AI), and the prolonged exposure to an electrical filed might damage to the DNA in sperm. The purpose of this study was to evaluate a boar sperm sorting method based on magnetic nanoparticles. A flow cytometer assay verified the efficacy of the magnetic nanoparticles (> 90% of sex-sorted sperm). In addition, a duplex polymerase chain reaction (PCR) assay using sex chromosome specific genes including SRY (sex-determining region Y; male), ZFY (zinc finger protein Y-linked; male), and ZFX (zinc finger protein X-linked; female) showed that in vitro fertilized porcine embryos by X and Y-chromosome bearing sperm were 100% female (40/40) and 72% female (35/48), respectively, at 8-cell or morula stages, suggesting that the sex-sorted sperm were fertile. In conclusion, our findings suggest that the sex-sorted method based on magnetic nanoparticles can be utilized for porcine sex-sorted AI.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.129-135
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• 2015

The aim of this study is to examine current status of swine AI and boar stud in South Korea using survey and data analysis. This survey included 48 boar studs registered as 'semen processing business'. The survey data were collected by direct visitation, FAX and/or telephone conversation for 7 months from June through December in 2013. 48 boar studs owned a total of 3,537 boars and the Duroc breed accounted for the highest rate (75.3%) of all boar breeds. In case of ownership, agricultural management corporations was the highest (50.0%) and followed by individual ownership (33.3%). Large-scale boar studs in terms of own over 151 boar were surveyed as 4.2% and most boar studs owned less than 100 boars (77.1%). The amount of liquid semen provided by 48 boar studs were 1,889,000 doses and each boar stud provided average of 39,000 does, which is represented for 90% consumption by sows in South Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.789-792
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• 2006

Two separate trials were conducted to determine the effects of uterine priming prior to first breeding and quantify any changes in the reproductive efficiency of gilts. In trial I twelve (12) gilts were randomly assigned to 3 treatments:T1:infusion of distilled water (control), T2: single infusion of killed semen (KS1), and T3: double infusion of killed semen (KS2). Each treatment had 4 breeding gilts which were bred by natural insemination (NI). In trial II, another set of 12 breeding gilts were randomly allotted to the same treatments and were subsequently bred by artificial insemination (AI). Infusions, through the use of AI catheters, were done during the $2^{nd}$ estrous cycle for T1 and T2, whereas infusions for T3 were made during the $1^{st}$ and $2^{nd}$ cycles. Regular breeding was subsequently made during the $3^{rd}$ estrous cycle. All gilts that returned to cycle were rebred within the 30-day period. In trial I (natural breeding), total piglets born was higher (p<0.05) in T2 (12.75 piglets) and T3 (11.75 piglets) than in the control (10.5 piglets). T3 obtained the highest (p<0.05) litter size (10.25 piglets) and heaviest litter weight (74.12 kg) at 28 days weaning, followed by T2 (9.80 piglets and 65.0 kg, respectively). The control yielded the lowest (p<0.05) litter size (7.50) and the lightest litter weight (47.00 kg) at weaning. For Trial II gilts (artificially inseminated), T3 gave higher (p<0.05) litter size born alive (10.88 piglets), total piglets born (11.72 piglets) and live litter weight at birth (15.30 kg) than those of T2 and the control. These results indicate that prebreeding intrauterine infusion of killed boar semen, either single or double, improved the reproductive performance of gilts.