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.

Amphiregulin (AREG), a glycoprotein that is a member of the epidermal growth factor (EGF) family, is expressed by the porcine conceptus and endometrium. AREG genotypes were determined based on an SNP in the intron 3 of the gene. Contradictory effects of AREG genotypes on reproductive traits in different pig breeds were reported previously. G allele had undesirable effect on reproductive trait in Meishan breed, while it had favorable effects in Polish Landrace and Large White. We determined AREG genotypes of 179 pigs including the Duroc, Landrace, Yorkshire, Korean native pig (KNP), and Meishan breeds. Two new SNPs were identified near the previously reported SNP in the intron 3 of AREG. Frequencies of AREG alleles among the Duroc, Landrace, Yorkshire, and KNP sows were significantly different (p<0.001), indicating association between AREG genotypes and pig breeds. The first parity litter size was significantly affected by the breeds (p=0.014), but not by AREG genotypes (p=0.148). However, there were breed and AREG genotype associated trends in the first parity litter size. The first parity litter size appeared to be higher in Duroc and KNP sows with G allele, while it appeared to be lower in Landrace sows with G allele. Significant variability of AREG alleles among pig breeds, for the first time in Duroc and KNP sows, was identified. AREG genotypes may influence reproductive traits differentially for each breed and thus, AREG genotypes may need to be considered when sows are bred to increase litter size.

The objective of this study was to compare the effect of semen extenders on the sperm motility, viability, acrosome integrity and functional integrity of plasma membrane (HOST: hypo-osmotic swelling test) during liquid preservation of Korean Native boar semen. In this experiment, semen was diluted in Androhep plus, Beltsville Thawing Solution (BTS), ModenaTM, Seminark and Vitasem LD. Sperm-rich fractions were collected from three Korean Native boars and sub-samples were diluted (30×106 spermatozoa/ml) in different semen extenders. Semen samples were stored at 17℃ for 96 hours. On everyday (0, 24, 48, 72, 96 h) after storage, the sperm characteristics relevant for fertility, such as sperm motility, viability, acrosome integrity and HOST positive were evaluated. The motility of spermatozoa stored in different extenders was no significantly different among other extenders (P>0.05). Also, no difference was observed among samples processed with different extenders in the percentage of sperm viability, acrosome integrity and HOST positive. All extenders maintained a high percentage (70%) of sperm motility, viability and acrosome integrity through 96 h of storage. The result of this study show that there was no significant differences among extenders in their capacity to preserve motility, viability and membrane integrity of spermatozoa from normal, fertile Korean Native boars for 96 h of liquid preservation at 17℃.

This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-17 β (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L × Y) (respectively n=3) with excellent ability, and to provide a baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or more were used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushing feed before estrus. Each pig’s blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analyses of P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-17β were measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels were significantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen between the L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, the tendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a little higher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similar to the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swine production, these results proved the fact of the methods. And these results suggested that more studies about hormonal changes in sows according to seasonal and nutritional factors should be needed.