The boar sperm has more lipid droplets and specialty of seminal plasma compared with other species, causing difficulties of freezing sperm and decreases for the utilization of frozen semen into the artificial insemination. However, several studies reported significant results for the recovery of sperm motility and reproductive by addition of cryoprotectants and seminal plasma after thawing. This study was designed to investigate the effects of supplementation of trehalose or glycerol in the LEY (lactose and egg yolk in BTS) solution for the conventional freezing and vitrification process. Two boars aged 16 months were used to collect semen for 2 times in a week. The samples were allotted to 3 freezing solutions (LEY + glycerol 10.5% + OEP 1.5%, LEY + trehalose 1M + OEP 1.5%, and sucrose 1.5M + trehalose 1 M + OEP 1.5%) after centrifugation at 800 g for 10 minutes. Semen was equilibrated in freezing solutions for 10 minutes and injected into plastic straws with 2∼3 air bubbles to minimize freezing damages. Vitrification was performed to locate sperm in 5 cm above LN2 for 5 minutes, and the conventional freezing was conducted with an automatic freezer. Motility and survival rates were measured by CASA (Computer assisted sperm an alyzing system) and FITC (Fluorescein isothiocyanate), respectively after thawing semen at 50℃ for 12 seconds. The results were analyzed by ANOVA with STATVIEW statistical program. The vitrificatioin solution (LEY + 10.5% glycerol + 1.5% OEP) presented higher motility (20.9%) than other solutions while the solution (LEY + 1M trehalose + 1.5% OEP) showed the lowest (motility : 5.2%). However, survival rates of vitrified sperms detected by FITC showed 1~4% live sperms in almost of dead sperms at all vitrification solutions’ groups, but survival rate of freezing solution of LEY + 1M trehalose + 1.5% OEP LEY and LEY + 10.5% glycerol + 1.5% OEP were showed 49%, and 79%, respectively. There were differences (P<0.05) survival rate of conventional freezing in LEY + 10.5% glycerol + 1.5% OEP and LEY + 1M trehalose + 1.5% OEP and the remaining showed no differences. The results suggested that vitrified boar semen was not enough to be utilized for the artificial insemination, but it showed possibility to utilize for ICSI and conventional freezing with glycerol would be useful method for artificial insemination in pig while we choose the outstanding semen against tolerance to freezing damages.

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.