• Journal of Animal Science and Technology
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• v.55 no.5
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• pp.389-398
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• 2013

This study was conducted to investigate the genetic relationships among four reproductive traits. Data for this study were 7616 records from 1910 Landrace (L) and 10,454 records from 2283 Yorkshire (Y) in a closed nucleus swine herd. Traits considered on this study were gestation length (GL), total number of piglets born (TNB), wean to first service (WFS), and number of stillborn per litter (NSB). Heritabilities and genetic correlations were estimated by using the Bayesian inferences via Gibbs sampling in a four trait linear-threshold repeatability animal mixed model by designating NSB as a categorical trait in the L and Y purebred populations. Effects on the statistical model were considered for parity, contemporary group as fixed and service sire, permanent environmental, animal additive genetic effects as random. Estimates of heritability were 0.21, 0.23, 0.16, and 0.09 for GL, WFS, TNB, and NSB in the L population and 0.35, 0.16, 0.14 and 0.10 for corresponding traits in the Y population, respectively. Genetic correlation for GL was -0.59 and -0.28 with TNB and -0.58 and -0.17 with NSB in the L and Y populations, respectively. The NSB was positively correlated with TNB in the L and Y populations in genetic and environmental aspects. Therefore, the NSB should be taken into account in selecting sows for improving prolificacy of dam line breeding swine stock.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.29 no.4
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• pp.158-165
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• 2018

The present study was undertaken to investigate the reproductive performance of the female breeding pigs after artificial insemination (AI) using the frozen boar semen imported from Canada, thereby finding insights into improving the efficiency of AI using the frozen semen (FSAI). Analyzed in the present study were the records of a total of 626 FSAI in a great grandparent (GGP) farm beginning from May through November of the year of 2016 (Farm A) and 2,024 FSAI beginning from 2015 through 2017 from a second GGP farm (Farm B). Both the total number of piglets born (TNB) and the number born alive (NBA) were greater during May than during September within FSAI (p<0.05) in Farm A (p<0.01 for the effect of the month). In Farm B, no difference was detected between the years in any of the farrowing rate, TNB, and NBA. When the records from Farm A and Farm B were pooled, the farrowing rate was greater for Farm A vs. Farm B (p<0.01), with no difference between the two farms in TNB and NBA. Moreover, TNB and NBA were less for FSAI than for AI using the liquid semen (LSAI; $10.9{\pm}0.3$ vs. $13.4{\pm}0.1$ and $10.0{\pm}0.3$ vs. $12.0{\pm}0.1$ piglets, respectively, for FSAI vs. LSAI in TNB and NBA, respectively; p<0.01). In conclusion, these results suggest that the reproduction efficiency for FSAI, which is lower than that for LSAI, could be improved by selecting an optimal period of the year for the use of the former.

• The Korea Swine Journal
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• v.27 no.7 s.311
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• pp.166-169
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• 2005

• The Korea Swine Journal
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• v.25 no.6 s.286
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• pp.180-184
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• 2003

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.251-257
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• 2001

This study was carried out to investigate the effect of breed, parity, litter size, lactating period, and estrus interval on sow productivity traits in swine. Data from 492 heads of Landrace, Yorkshire or crossbred sow which were raised at Yonam College of Agriculture from March, 1998 to July, 2000 were analyzed for this study. The total number of pigs born (TN), the number of pigs born alive (NB), and the number of pigs suckled (NS) were greater in the crossbred sows than in the purebred. In TN and NB, the 3rd to 7th parities were greater than other parities, and the 8th parity was the lowest. The number of pigs stillbirthed (NSB) and the number of runt per litter tended to increase with the increase of TN. In addition, statistical analysis showed that parity had significant effect on most of traits. The current TN had highly significant effect on TN, NB and NS of the next parity As current TN increased, TN, NB, and NS of the next parity increased. The current lactating period also affected significantly for TN, NB, and NS of the next parity The sows which had the lactating period of 20∼21 days produced the greatest TN and NB in the next parity. Weaning to estrus interval(WEI) had significant effect on TN, NB, and NSB. Among WEI groups, the WEI group of 7∼13 days was the lowest in TN, NB and NSB.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.61-67
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• 2003

This study was conducted to investigate the effect of infusion of sterile boar and their semen as pregnancy antigen factor for improvement of production in gilts. We observed 160 gilts between 7 to 8 months of age that were divided into 4 treatment groups vie. A group-epidimetomized boar, B group-no sperm semen infusion, C group-vasectomized boar, and D group-control in a completely randomized design. The number of total pigs born(NT) of A, B, C, and D groups were 10.05, 10.44, 11.63, and 9.97 pigs, respectively(P<0.05). And the NT of C g.cup was the highest among treatment. The number of live pigs born(NB) was similar to NT The NB of C group (10.70) was higher than that of A(9.12) and control(9.11)(P<0.05). However, there was not significant between B and C groups. The progesterone concentration of C group was the highest compare to other group at the 6th day after breeding. However, the progesterone concentration of C was lower than other groups after 8th day. There were not significant among cortisol of A, B, C and D groups. According of the results of this study, the infusion with vasectomized boar and semen at estrus before gestation can be improved reproductive efficiency because of more litter size in gilts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.514-520
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• 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 Animal Science and Technology
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• v.44 no.4
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• pp.377-382
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• 2002

This study was carried out for the simultaneous genetic evaluation of swine breeds from the seedstock farms in Korea. The performance tested production records of 96,842 heads and the litter records of 90,396 litters from 1995 to 2001 were analyzed to estimate the breeding values and the breed effects of days to 90kg, daily gain, back fat thickness, loin muscle area, lean meat percent, total litter size and number born alive from Landrace, Yorkshire and Duroc. Estimated breed effects of traits had shown the characteristics of the breeds. Landrace was superior in back fat thickness and lean meat percent to other breeds. Yorkshire had shown good performance in lean meat percent, loin muscle area, total litter size and number born alive. Duroc was superior to the other breeds in days to 90kg and daily gain. Conclusively, the multi-breed genetic evaluation would result in higher connectedness and provide convenience for the routine genetic evaluation process of swine performance and reproduction test.

• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.33-44
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• 2008

The purpose of this study was to estimate the genetic parameters and trend of Landrace and Yorkshire pigs, which were raised on private farms from 1999 to 2005 and tested for their reproductive performance by the Korea Animal Improvement Association. Prior to analysis, records without pedigree or having value with larger than±3×standard deviation for the Total number of born were excluded. The effects of breed and environmental factors were estimated with least square method(Harvey, 1979), and estimation of breeding values and genetic parameters were performed on the data of 1’st litter only with GIBBSF90(Misztal, 2001) which was programmed according to Gibbs Sampling method based on Bayesian Inference by Gianola and Fernando(1986), Jensen(1994) and others. Gibbs sampling was performed 50,000 times for each parameter, and the first 5000 samples were regarded as those in burn-in period and thus, excluded for post hoc analysis. Total number of born and total number of accident were statistically significant(p<0.01) for the breed, farrowing year, farrowing season and parity effects, and the number born alive at birth was statistically significantp<(0.01) for the breed, farrowing year, farrowing season and parity effects. No particular trend was observed in the genetic and phenotypic improvement of the total number of born and number born alive at birth before 2001, when the piglet registration system started, but the tendencies of increasing for the total number of born and number born alive and decreasing for the total number of accident were observed since 2001. Somewhat higher heritability estimates of our study seems to be attributed to the situations that first parity records with poor farrowing performances were used in the analyses and it was impossible to obtain accurate reproductive performance due to the absence of criteria for record keeping at the level of individual farms.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.523-528
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• 2003

This study was performed to investigate a possible association of the porcine estrogen receptor(ER) locus with the total number of born(TNB) and number of born alive(NBA) in Yorkshire pigs. Using DNAs extracted from 242 Yorkshire pigs, the ER genotype was determined by PvuII PCR-RFLP. The ER allele frequencies of two types of A and B were 0.39 and 0.61, respectively. The least squares means of the litter size by ER genotype was evaluated. The TNB and NBA were found to be associated with an specific ER allele. The genotype at the porcine ER locus has an application potential for marker-assisted selection for litter size in pigs.