The study aims to assess viability, acrosomal menbrane, integrity and mitochondria membrane potential of sperm separated using a percoll density gradient(45% and 90%) and swim-up methods using Hanwoo epididymal sperm frozen semen. Briefy, motile sperm separated using a percoll gradient and swim-up. 25 μl of sperm dilution from droplets were transferred to 1.5 mL tube and incubated with fluorescent probes at 39°C in dark as follows. After incubation, 75 μl of 5,5',6,6'-tetrachloro-1,1',3,3'- -JC-1; Mitochondrial Membrane Potential Detection kit, Cell Technology Inc., USA) working solution was mixed with sperm dilution and incubated for 30 min. One μl of Hoechst 33342 (H1339; Molecular Probe, Eugene, OR, USA) stock solution was mixed with sperm dilution and incubated for 10 min. And then, 0.5 μl of propidium iodide (PI) stock solution and 0.5 μl of fluorescein peanut agglutinin FITC conjugate (FITC-PNA; Vector Laboratories, FL-1071) were mixed with sperm dilution and incubated for 8 min. After mixing with fluorescent probes and sperm dilution, 5 μl of stained sperm dilution was mounted on a slide glass and covered with cover glass. More than 200 sperms in a slide glass were counted with × 400 magnification by fluorescent microscope (Eclipse Ci_L, Nikon, JAPAN) and evaluated viability, acrosomal membrane integrity, and mitochondrial membrane potential of sperm with triple band filter (DAPI/FITC/TRITC; Nikon, Tokyo, Japan). Live sperm were stained with Hoechst 33342(blue) and dead sperm were stained with PI (red). Damaged acrosomal membrane of sperm was stained with FITC-PNA (green) and intact acrosomal membrane of sperm was not stained. Both of sperm swim-up method with or without BSA separated to Live intact mitochondria (15.39±4.31 vs, 12.58±3.74, and) without significant difference. and percoll density gradient method also similar (7.29±6.54), swim-up method of sperm preparation appeared to be more efficacious in percentage recovery of motile sperm concentration compared to Density gradient method.

Sperm recovery from epididymis in animals considered as important tools to preserve high-value or endangered species. However, there are no appropriate castrating indicators of timing for recovery of sperm which can be available to artificial reproduction technologies such as artificial insemination (AI) and in vitro fertilization (IVF), particularly in young Hanwoo bull. Therefore, this study aimed to investigate semen volume, morphology and motility of sperm in epididymis of young Hanwoo bulls at 8, 13, 14, and 15 months of age. About 2 cm of the epididymal tail only was cut and minced using blades. Minced epididymal tail tissues were mixed with semen extender (OptixCell, France, IMV technologies) and sperm were recovered with a cell strainer (100 μm nylon mesh). The number of sperm at 8 months of age was lower than that at 13, 14, 15 months of age in bulls after collection (33.6±27.2 vs. 352.4±39.2, 320.4±113.6 and 422.8±252.4×107cells respectively; P<0.05). After the frozen-thawed sperm the the percentage of abnormal head, tail and dead damaged acrosome did not differ between the ages 13, 14 and 15 months of age in bulls (P>0.05), however, the dead sperm with intact acrosome (DIA), the numbers showed that more than 15 months in 8, 13, 14 months (8.7±4.1 vs. 47.3±12.2, 34.8±14.0, 28.8±8.5, P<0.05). In addition, frozen-thawed sperm at 8 months of age showed low total motile sperm compared to those at 13, 14 and 15 months of age (26.4±8.2 vs. 45.7±29.5, 62.3±41.0, 70.4±15.9%, respectively; P<0.05). In conclusion, sperm derived from epididymal tail at 8 months of age in Hanwoo bulls showed high abnormal morphology and poor motility, which is not adequate for artificial insemination(AI) and in vitro fertilization(IVF). On the other hand, sperm derived from epididymal tail at 13, 14, 15 months of age in bull showed high normal morphology and motility, which may be available for AI and IVF. Epididymal sperm collected from bulls over 13 months is needed for further study whether to use the actual in vitro fertilization.

The present study was conducted to investigate the effect of caffeine and theophilline on sperm motility during in vitro fertilization (IVF). Briefly, commercial boar semen was centrifuged and resuspended (5x107 sperms/ml) with fertilization medium (mTBM) supplemented with 2 mM caffeine (Caf), 5 mM theophylline (The), 2 mM caffeine + 5mM theophylline (Caf + The), and not supplemented control. The semen parameters of the four groups were analyzed by computer-assisted semen analysis (CASA, Medical Supply Co. Ltd) system at 6 h as time for IVF at 38.5 C under 5 % CO2 in air. The groups were examined 11 semen parameters such as total motility (TM), curvilinier velocity (VCL), straight-line velocity (VSL), average-path velocity (VAP), and hyperactivated (HYP), etc. A total motility of control group (41.3 %) at 6 h showed significantly (P<0.05) higher than those of other groups (Caf, 37.2; The, 35.2; Caf + The, 30.1 %). Results from many other sperm parameters indicated that the theophylline and caffeine negatively affected on sperm motility during IVF. These results suggested that the supplementation of caffeine and/or theophylline was not essential for IVF in pigs. To prove this suggestion, further studies are needed to analyze fertility and embryonic development after IVF with or without the supplementation of caffeine and/or theophylline.

Bisphenol‒A (BPA) is a known endocrine‒disrupting chemical used extensively to manufacture plastic bottles, canned food linings, thermal receipts, and other commonly used items. BPA is capable of inducing chromosomal alterations in germ cell line, thereby produced transgenerational effects on brain function, social recognition, reproductive diseases, sperm quality, gene expression, and obesity. Here, we aimed to investigate the transgenerational effects of BPA on murine male fertility. Six-week-old male mice (F0) were gavaged with corn oil (control), two different doses of BPA (5 mg, and 50 mg·kg bw-1·day-1),andethinylestradiol(EE,0.4mg·kg bw-1·day-1), dailyfor6weeks. Treated male mice were mated with wild‒type female and sibling pairs were bred up to the third generation (F3) in a similar manner with no further BPA exposure. Testes and spermatozoa were collected from 14-week-old males of all generation (F0 to F3) to evaluate testis weight, sperm function, and fertility. We found that high concentration of BPA significantly increased testicular weight in F2. Although the sperm viability, capacitation status, and intracellular ROS levels were not affected by BPA, however, sperm count, motility, hyperactivated motility, and intracellular ATP levels were significantly altered by BPA, dose dependently. In majority of the cases the effects were prominent in F2 followed by F1 and F0, whereas the effects were diminished in F3 generation. Simultaneously, high concentration of BPA significantly decreased cleavage and blastocyst formation rate in both F1 and F2. Similar inhibitory effects on cleavage and blastocyst were also noted in F1 by low dose of BPA. Depending on these findings we conclude that BPA decreases the fertility potential of exposed males and has an adverse impact on sperm function and fertility in subsequent generations.

Sperm adhesion molecule 1 (SPAM1) and Hyaluronidase 5 (HYAL5) has been well-known as assistants for sperm penetrate through the cumulus mass surrounding the ovulated eggs. However, so far their role in mammalian fertilization remain elusive, because mouse sperm lacking SPAM1 or HYAL5 were still capable of penetrating the cumulus mass despite a delayed dispersal of cumulus mass. Those data collectively demonstrated that SPAM1 or HYAL5 deficiency alone was not sufficient to cause male infertility in mice. In the present study, SPAM1 and HYAL5-simultaneous deficient male mice model was generated. Because of inhibition in sperm hyaluronidases, SPAM1 and HYAL5-deficient male mice produced significantly smaller numbers of offspring than hetero type and wild type mice. Hyaluronic acid degradation assay and cumulus oocyte complex dispersal assay as well as sperm motility assay using double knock out sperm and extracts had severe adverse effects on the dispersal of cumulus oocyte complex, which was the main reason for the impaired fertility of double knock out male sperm. Moreover, hyaluronic acid degradation assay using human sperm extracts revealed that sperm hyaluronidase has a principal role in sperm penetration through the cumulus oocyte complex. In conclusion, our results suggest that sperm hyaluronidase deficiency may be sufficient to cause male sterility in mammal because SPAM1 and HYAL5 deficiency sperm not impaired the sperm motility in hyaluronic acid but also cumulus oocyte complex penetration.

Our objective was to evaluate the function of treahlose and erythritol in reducing ROS concentrations, which is associated with a general improvement in the quality of frozen-thawing miniature pig sperm. Semen was mixed in modified Modena B extender, added to cooling media and freezing media, followed by the supplement of 100 mM trehalose and/or 100 mM erythritol with spermatozoa (1000x 109cells/straw). The trehalose plus erythritol (TE) added group had less intracellular H2O2 than did control and trehalose (36.6±1.6 vs. 49.0±5.8 and 48.8±7.9; P<0.05). The percentage of viable acrosome-intact sperm (FITC-PNA-/PI-) was higher in erythritol and TE than controls (57.0±5.5% and 62.5±4.3% vs. 45.4±5.4%; P<0.05 and P<0.001). The percentage of sperm with high fragmented DNA was observed in control group when compared with erythritol and TE also trehalose (65.5±1.3% vs 59.3±0.7% and 59.0±0.3% vs 62.2± 0.8%; P<0.001). The percentage of sperm LPO was higher in control and trehalose than erythritol (4.4±0.5% and 5.0±0.5% vs. 3.5±0.2; P<0.01 and P<0.001), and was lowest in the TE (control and trehalose vs. TE: P<0.001, erythritol vs. TE: P<0.05). Also, we performed that surgical insemination based on above data to evaluate the function of new cryoprotectant such as trehalose plus erythritol in vivo. Finally, 1 pregnant gilt showed natural estrus was allowed to go to term and 8 live piglets were born. In conclusion, miniature pig sperm was successfully cryopreserved with trehalose plus erythritol provided the increasing the sperm quality and reducing the ROS.

Jeju Black Cattle (JBC) is an indigenous species of Korea and their mass production and industrialization are required for this high quality indigenous species. For production of elite JBC zygotes, selection of high quality sperm is necessary for in vitro fertilizatioin. In this study, we compared the sperm fertility and developmental capacity of IVF embryos using various JBC sperm (Bull A, B and C). The frozen semen was thawed and confirmed sperm viability and motility. In addition, frozen-thawed sperm was used for a chlorotetracycline(CTC) staining assay and in vitro fertilization. Sperm were classified into three staining patterns. The F pattern is indicative of uncapacitated sperm, the B pattern is indicative of capacitating and capacitated sperm and the AR pattern is indicative of acrosome-reacting sperm or acrosome-reacted sperm, respectively. Several kinds of JBC sperm was inseminated in 44 ㎕ IVF drop contained 10 oocytes with sperm concentration of 1 × 106 cells/ml, and then 2 ㎕ heparin and 2 ㎕ PHE (20 μM penicillamine, 10 μM hypotaurine, 2 μM epinephrine) were added. The sperm viability and motility were higher in sperm 3 species (n=8). When we confirmed sperm capacitation, F pattern and B pattern rate were higher than AR pattern in sperm A group. After IVF, the rates of cleavage and blastocyst development were higher in sperm C group compared to other sperm group. However, the cell number of blastocyst was higher in sperm E group. These results demonstrate that the use of sperm C was effective in production of elite JBC IVF embryos. Additional experimental data are required for more accurate analysis.

For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Phospholipase C zeta (PLCz) is important enzyme in spermatogenesis, but their effect has not been confirmed in pigs yet. Therefore, this study was aimed to analyze their association with sperm motility and kinematic characteristics. DNA samples from 124 Duroc pigs with records of sperm motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity (VCL), Straight-line velocity (VSL), the ratio between VSL and VCL (LIN), Amplitude of Lateral Head displacement (ALH)] were subjected. A SNP in non-coding region of PLCz g.158 A > C was associated with MOT (p < 0.05), VCL (p < 0.01), LIN (p < 0.01) and ALH (p < 0.05) in Duroc population. Therefore, we suggest that the intron region of the porcine PLCz gene may be used as a molecular marker for Duroc boar semen quality, although its functional effect was not defined yet. Whether the association is due to the candidate gene or not require further verification. Thus, it will be of interest to continue association studies in the regions surrounding those genes.

For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Estrogen receptors 2(ESR2) is involved in estrogen related apoptosis in cell cycle spermatogenesis, but their functions have not been confirmed in pig until now. Therefore, this study was conducted to analyze their association with sperm motility and kinematic characteristics. DNA samples from 105 Duroc pigs with records of semen motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity(VCL), Straight-line velocity(VSL), the ratio between VSL and VCL(LIN), Amplitude of Lateral Head displacement(ALH)] were analyzed. A SNP in coding region of ESR2 g.35547A > G in exon 5 was associated with MOT (p < 0.05) in Duroc population. Therefore, we suggest that the porcine ESR2 gene may be used as a molecular marker for Duroc boar semen quality, although its functional effects were not defined yet. These results might shed new light on the roles of ESR2 in spermatogenesis as candidate gene for boar fertility, but still the lack of association across populations should be considered.

Cluster-of-differentiation antigen 9 (CD9) gene expressed in the male germ line stem cells is crucial for sperm–egg fusion, and was therefore selected as candidate gene for boar semen motility and kinematic characteristics. This study was performed to investigatetheir association with semen motility and kinematic characteristics. DNA samples from 96 Duroc pigs with records of sperm motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity(VCL), Straight-line velocity(VSL), the ratio between VSL and VCL(LIN), Amplitude of Lateral Head displacement(ALH)] were used in present study. A single nucleotide polymorphism (g.358A>T) in intron 6 was associated with MOT, VCL, VAP and ALH in Duroc population (p < 0.05). Therefore, we suggest that the porcine CD9 may be used as a molecular marker for Duroc boar semen quality, although its functional effect was not clear yet. These results will improve the understanding of the functions of the CD9 in spermatogenesis within the reproductive tracts, and will shed light on CD9 as a candidate gene in the selection of good sperm quality boars.

Processes of cryopreservation consists of three steps: dilution with the extender/cooling (Step 1), addition of cryoprotectant (Step 2), and freezing/thawing (Step 3) and spermatozoa are exposed different kind of environment and stress in each step. We categorized sperm samples as good freezablitiy (GF), damaged by cryoprotectant (DCP), and damaged by freezing (DF) and identified characteristics of each group in different step of cryopreservation. In Step 2, DCP was significantly decreased in motility, rapid speed and increased in slow speed. DF was significantly decreased in only motility whereas there were no significant difference between GF and DF and significantly higher than DCP in Step 2. Motility, rapid, medium speed of all group were significantly decreased in Step 3 and GF was significantly higer than other groups. AR pattern of all groups were significantly increased in Step 3 whereas GF was significantly lower than other groups. Additionally AR pattern of DF was significantly increased in Step 2. F pattern of DF and DCP were significantly decreased in Step 3. There no difference of B pattern in whole process. Mitochondrial activity of DCP was significantly decreased in Step 2 and mtichondrial activity of all groups were significantly decreased in Step 3. However mtichondrial activity of GF was higher than other groups. Viability result shows same significant difference with mitochondrial pattern. The present study compared with various sperm parameters in different groups which has different freezability. We defined different two types of group that damaged from different step of cryopreservation. DF and DCP is mainly damaged in Step 3 and Step 2 respectively. The results of current study suggest that various sperm parameters can be used as physical markers in freezability.

Cryopreservation of miniature pig sperm is essential because of high demand of organ transplant in mass production. However, miniature pig sperm are vulnerable to oxidative stress more than other mammals. Erythritol is a naturally occurring sugar alcohol with powerful antioxidant property. Thus, the aim of our study is to verify if erythritol could reduce lipid peroxide and enhance viability of frozen thawed miniature pig sperm. Ejaculated semen samples were frozen with cryoprotectant subjected to erythritol treatment (0, 10, 100, 500 mM). After frozen thawed, spematozoa viability were examined using the computer assisted sperm analysis (CASA) system. The product of lipid peroxidation, malondialdehyde (MDA) were quantified using spectrophotometer with DPPH and ABTS assays as ROS scavenger markers. Our result showed that erythritol enhanced sperm viability (p<0.05), reduced lipid peroxides significantly (p<0.05), proving the concentration of 100 mM erythritol to be an effective for lowing oxidative damage. Data from our study suggest that erythritol exhibits significant lipid peroxidation scavenging characteristics which may prevent oxidative damage, enhance viability of frozen thawed sperm and thus could be a effective additive as cryoprotectant.

Although cryopreservation of sperm is routinely used for clinical requirement, it has some problems, such as high generation of reactive oxygen species (ROS) and cold-shock. To reduce the detrimental damage in sperm, anti-oxidants were added to cryoprotectant for sperm. Curcumin is one of anti-oxidants, which are added in cryoprotectants. However, recent studies have demonstrated that curcumin decreases sperm viability and motility. This study was performed to identify the effect of curcumin on hydrogen peroxide (H2O2)-exposed bovine sperm, which were cryopreserved-thawed. In H2O2-exposed bovine sperm, reactive oxygen species (ROS) were significantly reduced by treatment with curcumin in a dose-dependent manner (p < 0.05). Among tested concentrations of curcumin (1 to 50 μM), 30 and 50 μM curcumin showed anti-oxidant effect on H2O2-induced ROS generation. On the other hand, combination of 30 or 50 μM curcumin with anti-oxidant H2O2 increased the percentage of apoptotic sperm compared to only H2O2 treatment. Sperm viability was also decreased in the combination of 30 or 50 μM curcumin with H2O2 as judged by FDA/PI staining. H2O2–induced decrease in sperm progressive motility was recovered by treatment with 1 μM curcumin. These results show that high concentration of curcumin has anti-oxidant effect, but it has also cytotoxic effect on bovine sperm. Sperm viability and motility might be more affected by cytotoxic signals of curcumin compared to antioxidant signals.

For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Estrogen receptors 2(ESR2) is involved in estrogen related apoptosis in cell cycle spermatogenesis, but their functions have not been confirmed in pig until now. Therefore, this study was conducted to analyze their association with sperm motility and kinematic characteristics. DNA samples from 105 Duroc pigs with records of semen motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity(VCL), Straight-line velocity(VSL), the ratio between VSL and VCL(LIN), Amplitude of Lateral Head displacement(ALH)] were analyzed. A SNP in coding region of ESR2 g.35547A > G in exon 5 was associated with MOT (p < 0.05) in Duroc population. Therefore, we suggest that the porcine ESR2 gene may be used as a molecular marker for Duroc boar semen quality, although its functional effects were not defined yet. These results might shed new light on the roles of ESR2 in spermatogenesis as candidate gene for boar fertility, but still the lack of association across populations should be considered.

Cluster-of-differentiation antigen 9 (CD9) gene expressed in the male germ line stem cells is crucial for sperm–egg fusion, and was therefore selected as a candidate gene to investigate Duroc boar semen motility and kinematic characteristics. This study was performed to investigatetheir association with semen motility and kinematic characteristics. DNA samples from 96 Duroc pigs with records of sperm motility and kinematic characteristics [Total motile spermatozoa (MOT, 82.27±5.58), Curvilinear velocity(VCL, 68.37±14.58), Straight-line velocity(VSL, 29.06±6.58), the ratio between VSL and VCL(LIN, 47.36±8.42), Amplitude of Lateral Head displacement(ALH, 2.88±0.70)] were used in present study. A single nucleotide polymorphism (g.358A>T) in intron 6 was associated with MOT, VCL, VAP and ALH in Duroc population (p<0.05). Therefore, we suggest that the porcine CD9 may be used as a molecular marker for Duroc boar semen quality, although its functional effect was not clear yet. These results will improve the understanding of the functions of the CD9 in spermatogenesis within the reproductive tracts, and will shed light on CD9 as a candidate gene in the selection of good sperm quality boars.

The recovery of epididymal sperm in animals is considered as one of the important tools to preserve high value or endangered species. However, there are no appropriate castrating indicators such as months of age in bull, sperm morphology, and motility, particularly in young Korean native bull (Hanwoo). Therefore, this study aimed to investigate sperm number, morphology, and motility of sperm in the epididymis tail of young Hanwoo bulls at 8 and 15 months of age. After castration, epididymal tails were collected and minced with blades to recover sperm. In experiments 1 and 2, sperm number, morphology, and motility were examined. Total number of sperm and percentage of normal sperm from bulls at 8 months of age was lower than that of bulls at 15 months of age after collection (P<0.05). Percentage of abnormal head, tail, proximal cytoplasmic droplet, dead and damaged acrosome of sperm from bulls at 8 months of age were higher than those of bulls at 15 months of age (P<0.05). In experiment 3, sperm motility from bulls at 8 and 15 months of age were examined before freezing and after thawing. Frozen-thawed sperm at 8 months of age showed low total motility and motile sperm with ≥ 25 μm/sec compared to those at 15 months of age and commercially-used sperm (P<0.05). In conclusion, sperm derived from the epididymal tail of bulls at 8 months of age showed high abnormal morphology and poor motility, which are not adequate for AI and IVF. On the other hand, sperm derived from the epididymal tail of bulls at 15 months of age showed high normal morphology and motility.

The purpose of this study was to examine the effects of taurine and vitamin E on sperm characteristics damaged by bromopropane (BP) in pig. We evaluated toxicity of BP on viability, membrane integrity and mitochondrial activity of spermatozoa. 1-BP (0, 2.5, 5.0, 10, and 50 μM), 2-BP (0, 2.5, 5.0, 10, and 50 μM), taurine (0, 5.0, 10, and 25 μM) and vitamin E (0, 50, 100, and 200 μM) were treated in fresh boar semen for 6 h. 10 and 50 μM of 1-BP and 2-BP inhibited sperm viability, membrane integrity and mitochondrial activity in fresh boar semen (P<0.05). 25 μM of taurine increased sperm viability and membrane integrity (P<0.05), 100 μM of vitamin E enhanced viability and mitochondrial activity of sperm (P<0.05). Finally, 10 μM of 1-BP and 2-BP was co-treated with taurine (25 μM) and vitamin E (100 μM) in the fresh boar semen. The co-treated samples did affected viability, membrane integrity and mitochondrial activity of sperm. In conclusion, taurine and vitamin E can improve and maintain sperm quality in fresh boar semen.

This study investigated the effects of L-carnitine (LC) and nicotinic acid (NA) on sperm viability during liquid storage at 18℃ in miniature pigs. 10 μM LC and 30 mM NA, combined LC and NA (LN) were treated in fresh semen for 3, 7, and 10 days. In results, sperm survival increased in NA- and LN-treated semen on 7 and 10 days (p<0.05), mitochondrial integrity of live sperm increased in LN-treated semen on 7 days (p<0.05), but not NA-treated semen. In addition, we examined the acrosome reaction of sperm in miniature pigs. LC and NA did not influence on acrosome reaction of boar sperm. In conclusion, LC and NA effectively maintained the viability and quality of sperm during long-term storage in miniature pigs, suggesting that the combined LN may be useful for improving the semen extender for long-term liquid storage in pigs.

The objective of this study was to investigate the result of in vivo embryo collection and pregnancy rate after embryo transfer using sex-sorted sperm of Korean brindle cattle. Donor Korean brindle cattle superovulation treated by decreasing dose of FSH injection. Embryos were recovered on 7 days after the third artificial insemination. Control group semen straw used artificial insemination contained 20 million sperm. Sex-sorted semen straws contained 4 million sperm or 10 million sperm. As for the result of the recovery of the in vivo embryos derived from sex-sorted sperm, the number of transferable embryos was significantly highly recovered to be 6.20±2.28/donor from the control group and was significantly lowly recovered to be 1.57±1.72/donor from the group treated at a sperm concentration of 10×106 (p<0.05). The number of unfertilized embryo was 0.8±1.30/donor in control group which was significantly lower than the group treated at a sperm concentration of 4×106 (p<0.05). However, there was no significant difference in the number of undeveloped ova between control and treatment groups. Pregnancy rate after embryo transfer was shown to be 35.00% in control group and 12.50% in treatment group. The karyotype analysis of the calf derived from sex-sorted sperm resulted in a similar chromosomal distribution pattern (2n=60, XX) compared to those of common Korean native cattle.

The objective of this study was to investigate the efficiency of nicotinic acid during in vitro fertilization (IVF) in frozen-thawed bull sperm . The ejaculated semen was diluted with Triladyl containing 20% egg-yolk and cryopreserved in liquid notrigen. The frozen sperm was thawed for 45 seconds in the 38℃ water bath. Sperm was diluted with IVF medium (Bovine-Oviduct medium; BO) containing 0, 15, 30 and 60 mM nicotinic acid (NA), which were incubated at 39℃, 5% CO2 for 0, 0.5, 1, 2 and 4h. The characteristics of frozen-thawed sperm were estimated with SYBR14/PI double staining for viability, FITC-PNA/PI for outer acrosomal membrane damage and Rhodamine123/PI for mitochondrial integrity using flow cytometry. And the sperm ability was analysed by Coomassie brilliant blue (CBB) staining for acrosome reaction state and Rose bengal staining for abnormality. Acrosome reaction and abnormality were analyzed using a microscope. In results, sperm viability was significantly higer in 30 mM group than 0 and 15 mM groups at 1 and 2 h (p<0.05). Outer acrosomal membrane damage was significantly lower in 30 mM group than 0 and 15 mM groups at 1, 2 and 4 h (p<0.05). And mitochondrial integrity was significantly higher in 30 mM group than 0 and 15 mM groups at 2 and 4 h (p<0.05). Also, acrosome reaction was significantly lower in 30 mM than 0 and 15 mM groups at 1 and 2 h (p<0.05) and abnormality was lower NA groups than 0 group at 1 h (p<0.05). In couclusion, we suggest that using the thawing medium containing NA for sperm dilution can be benefical for IVF in bulls