Male factor infertility or sub-fertility contributed half of all cases of infertility while the semen abnormality is the current topic of argument. Conventional analysis of semen showed poor correlation with fertility. Therefore, evaluation of current semen analysis method is necessary to improve standards of semen assessment. The goal of this study was to investigate that correlation between motion kinematic before and after capacitation and litter size in porcine. Sperm motility and kinematics were measure by computer-assisted sperm analysis (CASA). The motility of spermatozoa was positively correlated with curvilinear velocity (VCL), average path velocity (VAP), and mean amplitude of head lateral displacement (ALH) (p<0.05). Where as VCL positively correlated with VSL, VAP and ALH (p<0.01). Straight-line velocity (VSL) was positively correlated with VAP and ALH (p<0.01). VAP was significantly positively correlated with ALH (p<0.01). Also, we found significant positive correlation among variation of VSL, VAP and ALH (p<0.05). No motility and kinematic parameter are correlated with litter size. However, litter size was significantly correlated with breed (p<0.05). Our results suggested that analysis of sperm motility and kinematics using CASA is questionable for prediction of litter size. However, it has some practical importance to evaluate semen commercially.

The objective of this study was to determine the effects of E. coli isolated from porcine semen on sperm viability, motility, and semen pH. Semen samples were prepared using commercial extender, SeminarkPro (Noahbio Tech, Korea) that did not contain antibiotics. And 4 different levels of E. coli were artificially innoculated to semen with following concentrations; 4,000 of sperms with 1 of E. coli (T1), 400 with 1 (T2), 40 with 1 (T3), and 4 with 1 (T4). Semen samples were preserved at 17℃ for 5 days in semen storage box until analyzed by flowcytometer. Aliquots were subjected to measure the sperm viability (Live/Dead® stain), motility (mitochondrial function), and semen acidity (pH) from day 0 (day of semen collection) to day 5. Sperm motility and viability were significantly decreased (p<0.05) on day 0 (4 hrs after preservation at 17℃) in T3 and T4 compared to control groups and were significantly decreased (p<0.05) in all groups from day 3. Sample pH was acidic in T3 (6.90～6.86) and T4 (6.86～6.65) from day 3 to day 5 (p<0.05). On the other hand, sample pH was maintained 7.0～7.1 in control, T1, and T2 during the experimental period. Sperm motility and viability were significantly decreased from day 0 to day 5 compared to control in samples contaminated with E. coli above a value of 40:1 (20×106 sperm cells/ml : 5×105 cfu/ml). Even on day 1 in T4 and on day 3 in T3, semen pH was acidic probably due to the acidification of dead spermatozoa. These results suggest that E. coli contamination has a concentration-dependent detrimental effect on extended porcine semen quality.

The objective of this study was to find out candidate genes associated with litter size trait in pigs of inbred Large Yorkshire and Landrace populations. 86 sows were screened for candidate genotypes along with litter size data recordings. Association of litter size with genotypes of candidate genes were investigated to verify the usefulness of each gene's genotypes as markers for the trait. For the lines of Large Yorkshire, PRLR3 and RBP4 genes were genotyped. Frequency distribution of PRLR3 with genotypes AA, AB and BB were each 0.14, 0.44 and 0.42. And the average litter size by PRLR3 genotypes were 8.83, 10.81 and 10.70 piglets per litter, the average estimated breeding values of which were 0.243, 0.332, 0.365, respectively for AA, AB and BB genotypes. Genotypic frequencies of RBP4 by AA, AB and BB genotypes were 0.10, 0.44 and 0.46. The average litter size by genotypes of RBP4 were 10.40, 10.57 and 10.35 piglets per litter and their corresponding average estimated breeding values were 0.451, 0.353 and 0.261, respectively for genotypes AA, AB and BB. Significance in differences among genotypes were not observed, but B allele of RBP4 seems to be associated with litter size. In Landrace lines, frequencies of RBP4 genotypes, AA, AB and BB were 0.29, 0.55 and 0.16. And the average litter size of these genotypes were 10.50, 11.08 and 11.00 piglets per litter. The corresponding averages of estimated breeding values of each genotypes were 0.172, 0.135 and 0.104. In Landrace lines, allele A was more likely to be associated with litter size, even if differences among average litter size were not significant. We conclude that genotyping of two candidate genes is a helpful tool to identify genetic potentials of litter size in pigs.

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.

This study was undertaken to evaluate the relationship between in vitro maturation and plasminogen activators (PAs) activity on porcine cumulus-oocytes complexes (COCs) exposed to oxidative stress. When COCs were cultured in maturation medium with hydrogen peroxide (H2O2), the proportion of the germinal vesicle breakdown (GVBD) and oocytes maturation were decreased with addition of H2O2, and were significantly (p<0.05) lower in medium with 0.1 mM H2O2 than control group. Also, the rate of degenerated oocytes was increased in as H2O2 concentration increased. When COCs were cultured for 48 h, three plasminogen-dependent lytic bands were observed: tissue-type PA (tPA); urokinase-type PA (uPA); and tPA-PA inhibitor (tPA-PAI). PA activity was quantified using SDS-PAGE and zymography. When H2O2 concentration was increased, tPA and tPA-PAI activities also increased in porcine oocytes cultured for 48 h, but not uPA. In other experiment, embryos were divided into three groups and cultured in (1) control medium, (2) control medium with 1.0 mM H2O2 and (3) control medium with 1.0 mM H2O2 along with catalase in concentrations of 0.01, 0.1, and 1.0 mg/ml, respectively. H2O2 decreased the rate of GVBD and maturation in porcine COCs but catalase revealed protective activity against oxidative stress caused by H2O2. In this experiment, tPA and tPA-PAI activities were higher in media with 1.0 mM H2O2 alone. Increasing concentration of catalase decreased tPA and tPA-PAI activities in porcine oocytes. These results indicate that the exposure of porcine follicular oocytes to ROS inhibits oocytes maturation to metaphase-II stage and increase the oocytes degeneration. Also, we speculated that increased ROS level may trigger tPA and tPA-PAI activities in porcine oocytes matured in vitro.

The objective of this study was to determine the effect of semen extenders on the motility, viability and fertility in vitro of spermatozoa during storage of fresh boar semen diluted in different commercial extenders used for pig artificial insemination (AI). In this experiment, semen were diluted in Androhep plus, Beltsville Thawing Solution (BTS), Modena, Seminark and Vitasem LD. Five ejaculates were collected from three Duroc boars and sub-samples were diluted (30×106 spermatozoa/ml) in different extenders. Semen was stored at 17℃ for 10 days. Sperm motility and viability was assessed using Computer-Assisted Semen Analysis (CASA) and flow-cytometry on 1, 3, 5 and 10 day post collection. The motility of spermatozoa stored in different extenders was gradually decreased by increasing the duration of storage of semen. However, there was not significantly different in the sperm motility and viability among other extenders. On the other hand, the in vitro-matured oocytes were fertilized and cultured in vitro to assess the fertility of boar spermatozoa stored for 3 and 10 days in different extenders. The percentage of morula and blastocyst were taken as indicators of fertility in vitro of spermatozoa. Therefore, there were no differences in the rate of embryos developed to the molular and blastocyst stage. There were no differences in the motility and fertility in vitro among 5 kinds of commercial boar semen extenders.

The objective of this study was two folds: to investigate the relationship between paternal identification rate and sperm quality parameters such as motility and sperm chromatin structure assay after heterospermic insemination; to see if mutual complement between tests and development of useful technique to enhance the fertility in artificial insemination. In individual boar's fertilizing ability, 3 high fertility boars showed significantly high fertility (p<0.05) compared to 3 low fertility boars, but there was no difference in litter size between two groups. Sperm motility test in pooled and individual semen using computer assisted sperm analysis (CASA) revealed that no significant difference among boars. The high fertile boar showed tendency of low %Red (High red fluorescence/green+red fluorescence) in sperm chromatin structure assay (SCSA) but paternal identification rate from piglets did not differ after heterospermic insemination. The correlation coefficient between individual or pooled semen function test and farrowing rates were well correlated as follows: %Red with litter size (r= - 0.53, p=0.03); %Red with paternal identification rates (r=-0.51, p=0.03); paternal identification rates with litter size (r=0.57, p=0.02). These results indicate that sperm chromatin structure assay and sperm quality parameter test in pooled semen are useful method to predict and evaluate the fertilizing capacity after heterospermic insemination in boars.

The objective of this study was to determine the potential hazardous effects of sorting process by flowcytometry on the quality of boar spermatozoa by flowcytometer. Freshly collected boar semen was diluted and divided into two groups; control none sorted and sorted. Sperms in sorted group were processed with flowcytometer for cell sorting with 100 uM nozzle under the 20 psi pressure. Measurements on each parameter were made at two time points, 0hr (right after sorting) and 24 hr post sorting. Although there was a tendency of lower viability in sorted group than none sorted control group, the percentage of live cells in control(75.83+-6.92 & 59.53+-10.34) was not significantly different from sorted (59.7+-7.34 & 43.97+-3.76) at both 0 and 24 hr post sorting. However, sorted sperm showed significantly lower mitochondrial function compared to the control at both 0 h (79.37+-3.22 vs. 63.50+-10.05) and 24hr(67.27+-3.22 vs. 46.97+-5.37) time points (p<0.007). Sperm DNA fragmentation rate was significantly lower in control (22.0+-7.04) than that of sorted (32.27+-7.49) at 24 hr time point (p<0.0002). Taken together, these data suggested thatsorting process by flowcytometer may have influenced sperm motility rather than viability. Also high speed sperm sorting by flowcytometer has significant effects on DNA fragmentation on elapsed time after sorting.

The objective of this study was to determine the effect of administration of Prostaglandin F2α (PGF2α) on semen collection training and semen characteristics in sexually inexperienced boars. Boars were moved individually to a semen collection pen and were trained to mount dummy sow. During the first and second semen collection secessions, 4 out of 17 boars and 4 out of remaining 13 boars allowed collection of semen. The 9 boars that failed semen collection from first 2 attempts received immediately 15 mg of PGF2α i.m. (intramuscular injection) upon entering the collection pen for semen collection resulted in successful semen collection from all 9 boars. Total numbers of spermatozoa were higher in PGF2α treated boars but there was no significant difference in % motility kinematics characteristics between control and PGF2α treated groups during 72 hr period. Overall, administration of PGF2α in sexually inexperienced boars increased the sex drive and facilitated the mounting activity to the dummy sow for semen collection.

Molecular genetic markers have wide applicability for a various genetic analyses, and genetic mapping with PCR-based markers has identified many loci in the rice genome. This study was conducted to develop a genetic map of rice based on SSR and MITE-AFLP