• Journal of Embryo Transfer
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• v.21 no.3
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• pp.177-182
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• 2006

This study was conducted to investigate the effects of melengesterol acetate (MGA) and $PGF_{2{\alpha}}$ administrations on serum progesterone level, synchrony of estrus and conception rates in Han-woo. Firstly, ten heifers and one freematin were fed 0.5 mg MGA/day for 14 days in a grain carrier, and after 19 days of MGA feeding, a single injection of 25 mg $PGF_{2{\alpha}}$ were treated. Blood samples were collected to evaluate serum progesterone concentrations from the start of feeding of MGA until the end of feeding and subsequent estrous detection and artificial insemination (AI) at 3 days intervals, and on days of $PGF_{2{\alpha}}$ injection, estrous detection, AI, and 15th and 60th days after AI. The level of progesterone in the blood began to increase from 7 days after MGA feeding, and 9 days after feeding it became 5.4 ng/ml and maintained that level thereafter. On the 33th day when the $PGF_{2{\alpha}}$ was injected, it reached the peak level of 7.6 ng/ml. However, 2-3 days after $PGF_{2{\alpha}}$ injection, it dropped to 1.4 ng/ml drastically (p<0.05). Secondly, one hundred and ninety four Hanwoo heifers or cows were divided into two groups to compare estrous induction and conception rates: the one treated with MGA and $PGF_{2{\alpha}}$, (n=104) and the other with $PGF_{2{\alpha}}$ treatment (two injections at 11 days interval, n=90). The heifers or cows treated with MGA and $PGF_{2{\alpha}}$ were identical to those used as above. The percentages of heifers or cows showed estrus were higher in the $MGA+PGF_{2{\alpha}}$ treatment (91.3%) than in the $PGF_{2{\alpha}}$ treatment (72.2%, p<0.05). Conception rates were also higher in the $MGA+PGF_{2{\alpha}}$ treatment (94.2%) than in the $PGF_{2{\alpha}}$ treatment (88.9%, p<0.05). The results of this experiment indicate that estrus synchronization using $MGA+PGF_{2{\alpha}}$ is more effective than that using $PGF_{2{\alpha}}$ (two injections) in Hanwoo.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.263-271
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• 2006

The purpose of this study was undertaken to compare ability of frozen-thawed sperm characteristics between two strains (miniature pig and Duroc). The semen was collected by gloved-hand method into a pre-warmed ($37^{\circ}C$) thermos bottle. The semen was diluted with same volume extender and added to LEY solution for freezing. The diluted semen was placed in 0.5 ml straws, and freezing was initiated by exposing the straws to liquid nitrogen ($LN_2$) vapours for 10 min before placing them into $LN_2$ for cryopreservation. The frozen-semen straw were thawed at 20, 37 and $50^{\circ}C$ for 1 min, 45 sec and 10 sec within water-bath. The semen sample were evaluated at 0, 3, 6, 9, and 12 h after incubation at $37^{\circ}C$ for analysis of sperm ability. Abnormality of spermatozoa in miniature pig was significantly (p<0.05) higher than that in Duroc at 0, 9 and 12 h of post-thawing incubation after frozen-thawing. The percentage of F-patterned spermatozoa in miniature pig was significantly (p<0.05) lower, while the percentage of AR (acrosome reacted spermatozoa) pattern was higher in the miniature than in the Duroc. On the other hand, there was no significant difference in the viability of spermatozoa thawed at different temperature ($20^{\circ}C\;and\;37^{\circ}C$) between two species, but the viability in miniature pig was higher (p<0.05) than in Duroc when sperm was thawed at $50^{\circ}C$. In conclusion, this study suggest that suitable freezing method for miniature pig semen is required for increasing post-thawing viability and fertilization capacity.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.207-216
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• 2006

Vaginal cytology was examined in 12 Shih-tzu bitches to establish the accurate basic data for estimate to the optimal mating time and ovulation time. The mean duration of proestrus and estrus were $9.09{\pm}0.83\;(mean{\pm}SD)$ days and $7.36{\pm}0.47$ days in pregnant bitches. The gestational length in the 12 pregnant bitches was $65.2{\pm}0.5$ days in pregnant bitches when Day 0 was timed from the first day of male acceptance. Characteristic features of vaginal cytology during the estrous cycle were the high proportion of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell, anuclear cell and erythrocyte in estrus, and parabasal cell, small and large intermediate cell and leukocyte in diestrus, respectively. Cornification index (CI) was the high proportion in proestrus and estrus, then it decreased in diestrus and anestrus. When Day 0 was timed from the day of the first male acceptance, the CI peak was Day 2 and maintained above 80% between Day -4 and Day 6 during 11 days, and above 90% between Day -1 and Day 5 during 7 days. In relationship between CI and reproductive hormones, CI showed peak at the first day after plasma estradiol-$17{\beta}$ concentration peak and plasma progesterone concentration was first increased above 4.0 ng/ml at Day 0 which was the first day after CI peak. In conclusion, ovulation in Shih-tzu bitches occurred at the first day after CI peak. Vaginal cytology is the simple and reliable method for estimating estrous cycle, optimal breeding time and ovulation time in Shih-tzu bitches.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.217-223
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• 2006

This study was carried out principally to obtain the basic data for the improvement of the reproductive performance and production using plasma progesterone assay and ultrasonography in dairy cow. The results obtained from this studies were as follows. The results of reproductive examination in 85,983 cows were ovarian diseases 40,399 (47.0%), uterine diseases 11,912 (13.9%), pregnancy or pregnant failures 26,587 (30.9%), adhesion of reproductive tracts 172 (0.2%), freemartin 8 (0.01%), and others 6,905 (8.3%), respectively. The treatment status of reproductive dysfunction in 30,241 cows were silent heat or error of estrus detection 14,909 (49.3%), follicular cysts 3,750 (12.4%), luteal cysts 907 (3.0%), inactive ovaries 665 (2.2%), granulosa cell tumor of ovary 3 (0.01%) and endometritis 6,986 (23.1%), respectively. The indices of reproductive efficiency after the periodical examination of reproductive status were as follows; the mean intercalving inteual was reduced from 475 days at the first examination to 381 days at the last examination of reproductive status, the mean interval calving to conception was reduced from 186 to 98 days, the mean interval calving to first service was reduced from 106 to 66 days, the cows showing heat by 60 days postpartum were increased from 32 to 90%, the mean conception rate to first service was increased from 42 to 64%, and the mean service per conception was reduced from 2.6 to 1.8 times, respectively.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.233-239
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• 2006

This study was carried out to investigate the effect of intra-uterine infusion of lipopolysaccharides (LPS) on uterine involution in dairy cows with retained placenta. The LPS isolated from Bacteroides helcogenes and Fusobaoterium varium was infused at the rate of 100 ug (n=11) and 200 ug (n=11) with 30 ml of phosphate buffer saline in each cow at 20 days post-partum. The cows in conrol group (n=11) with retained placenta were infused with 30 ml phosphate buffer saline in each cow at 20 days postpartum. Cross-sectional ultrasonography was performed at days 40 postpartum to examine uterine involution and exudate in the all dairy cows in study. The cows in control group have shown 45.5, 27.3 and 27.3% gravid horn with less than 30 mm (normal), $31{\sim}50mm$ (medium) and more than 51 mm (large) in diameter. Respective average values of gravid horn diameter in cows treated with LPS 200 ug were noticed 72.7, 18.2 and 9.1%. However, the gravid horn diameter in all the cows treated with 100 ug of LPS was less than 30 mm. The 18.2, 63.6 and 54.6% cows in the control, LPS 100 ug and LPS 200 ug, respectively, have shown no exudate in uterine cavity. However, the respective rates of small amount of exudate retention in uterine cavity were 45.5, 0.0, and 9.1%. Approximately 36.4% cows in all 3 treated groups have shown minute quantity of exudate. In conclusion, the LPS intra-uterine infusion promoted postpartum uterine involution in dairy cows with retained placenta.

• Journal of Embryo Transfer
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• v.24 no.1
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• pp.57-64
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• 2009

This study was carried out to investigate expression of apoptosis-related differentially expressed gene (DEG) in ovaries of Korean cattle with follicular and luteal cysts and to identify the relationship between cyst and apoptosis using microarray, real-time PCR, TUNEL staining, and Western blot analysis. Microarray data showed that PIK3R2 and AKT1 were significantly up-regulated in follicular cyst, and TNF-RAF2, PRLR, FOXL2, STK4, and COL4A3 were up-regulated whereas INHA, CIDEB, BCL10, and FASLG were down-regulated in luteal cyst. Real-time PCR was performed to validate DEGs altered in luteal cyst. Of nine DEGs, four DEGs down-regulated in luteal cyst showed a positive corelation between microarray data and real-time PCR data. In this study, we focused on INHA, among many DEGs, which was highly down-regulated in both follicular and luteal cysts. Real-time PCR and micro array data showed that INHA was down-regulated by 12.3-fold and by 1.4-fold, respectively, in the bovine follicular cyst. TUNEL assay and Western blot analysis for ERK, JNK, p38, PI3K, and Akt, which were used to detect whether apoptosis is occurred, showed no significant changes in cystic ovaries (p>0.05). In the expression and activity of caspase-3, Bax, Bel-2, and Bel-xL, there was no significant changes between follicular cystic ovary and normal ovary. Rather, the expression levels of PI3K and p-Akt were decreased in follicular cystic ovary. These results suggest that deficiency of apoptosis in cystic ovary is associated with decreased expression of apoptotic effectors.

• Journal of Embryo Transfer
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• v.33 no.1
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• pp.17-22
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• 2018

This study was conducted to determine the effect of pentoxifylline levels on sperm motility, survival rate, sperm membrane integrity of frozen semen and fresh-extended equine semen in Jeju cross-bred horses. As a result of sperm characteristic comparison depending on pentoxifylline levles at 30 minutes post-thaw, the progressive motilities were $53.25{\pm}2.87$ (4mM pentoxifylline) and $50.28{\pm}2.14$ (8mM pentoxifylline) and significantly higher compared to the control group($40.09{\pm}5.15$) and other treatment group (16mM pentoxifylline, $41.27{\pm}2.82$). The progressive fast motility were $22.44{\pm}1.62$ (4mM pentoxifylline,) and $22.74{\pm}3.07$ (8mM pentoxifylline) and significantly higher compared to the control group ($13.47{\pm}1.48$) and other treatment group (16mM pentoxifylline, $14.66{\pm}3.68$) (p<0.05). As a result of sperm characteristic comparison depending on pentoxifylline levles at 30 minutes post-thaw were $68.96{\pm}1.64$ (4mM pentoxifylline) and $67.90{\pm}6.72$ (8mM pentoxifylline) and significantly higher compared to the control group ($53.48{\pm}4.84$) and other treatment group (16mM pentoxifylline, $58.14{\pm}2.65$) (p<0.05). In conclusion, these results suggest that treatment groups with 4mM and 8mM pentoxifylline were higher compare to equine seperm mobility and the control group and treatment groups with more than 16mM pentoxifylline has a negative effect on sperm characteristics. After thawing, the total motility in post-thawed equine sperm has increased by 10 percent for 1 hour. these results suggest that pentoxifylline contributes to the improvement of the equine sperm motility and characteristics in post-thawed semen.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.43-50
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• 2003

The objective of this study was to investigate the effect of cryopreservation by slow and rapid freezing on the sperm motility index, viability and morphology of post-thaw human spermatozoa. After rapid freezing and thawing, sperm motility index was significantly higher (MOT:47.40$\pm$20.06%, VCL : 38.12$\pm$15.58 $\mu$m/s, VSL : 28.19$\pm$14.10 $\mu$m/s, VAP:33.64$\pm$15.15 $\mu$m/s, and HYP 2.77$\pm$2.71%) than slow freezing and thawing(MOT : 43.39$\pm$ 18.79%, VCL .33.91 $\pm$ 13.50 Um/s, VSL . 19.98$\pm$0.88 $\mu$m/s, VAP : 24.60$\pm$11.72 $\mu$m/s, and HYP . 1.33$\pm$1.57% ; P<0.05). But sperm Linearity(LIN) was significantly lower(28.83 $\pm$ 10.35) comparing to the slow freezing method(34.64 $\pm$ 11.36 ; P<0.05). On the other hand, significant difference were not observed MAD, WOB, DNC and DNM by slow and rapid frozen-thawed methods. After rapid freezing and thawing, sperm viability was lower(60 $\pm$ 2.2%) than slow freezing method(62 $\pm$2.1%) and sperm morphology was higher(46$\pm$7.7%) than that(44: 8.3). But there was no significantly These results indicate that rapid freezing method was positive effect of sperm cryopreservation in human.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.61-68
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• 2003

Considerable attention has been focused on the cryopreservation of semen and estrus induction in dog, as consequence of poor productivity caused by long anestrus period, in order to enhance the productivity of youngs and to preserve the breeds. The objectives of this study were to improve reproductive efficiency of artificial insemination with fresh- and frozen-semen following estrus induction in dog. Fifty infertilie dogs (age 2~3 years) were selected fur the study and divided into three different estrus induction treatment groups. Group 1 : dogs (n=15) were given clomifene (0.1 mg/kg) orally f3r five days at 12 hr intervals. Croup 2: dogs (n=15) were given bromocriptine (50 $\mu$g/kg) orally for five days at 12 hr intervals, followed by single injection intravenously of 500 IU GnRH (Croup 3, n=20) when pro-estrus occurred. After being treated, the dogs were evaluated fur the rates of estrus induction and time interval lapses from treatment to beginning of the pro-estrus. The rates of pregnancy in estrus inducted dogs mated naturally compared to those inseminated artificially with ejaculated fresh semen and frozen-thawed semen. Estrus detection was performed using the method of vaginal smear and confirmed by the plasma progesterone assay. Pregnancy was confirmed by ultrasonograpy on day 25, 35 and 55 post insemination. The ejaculated semen was exposed to a mixture of Tris extender with cryoprotectant (Trisma, 81 mM; TES, 209 mM; citric acid, 6 mM; glucose, 5 mM; glycerol, 8%) and cryopreserved gradually by slow-cooling at 17 co above the surface of liquid nitrogen (L$N_2$) for 23 min. The use of fresh semen, the pregnancy rates were observed 66.6, 66.6, 75.0 and 83.3% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. The use of frozen-thawed semen, the pregnancy rates were observed 66.6, 33.3, 50.0 and 60.0% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. No difference was observed in the number of offspring produced among natural estrus and treated groups inseminated with fresh or frozen-thawed semen. In conclusion, there was no significant differences in the pregnancy rate of dogs between group treated with a combination of GnRH and bromocriptine and group treated clomifene or bromocriptine only. However, frozen-thawed semen can be used successfully fur artificial insemination in dog.

• Journal of Embryo Transfer
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• v.18 no.3
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• pp.195-201
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• 2003

This study was carried out to establish most suitable freezing condition, to evaluate the different condition of freezing and thawing rates on the viability and motility of frozen canine spermatozoa. The ejaculated semen was added to obtained 200∼400 ${\times}$ 10$^{6}$ /$m\ell$ with extender I and was cooled to 4$^{\circ}C$ over 30, 60 and 120 minutes. And then, semen was diluted with extender II containing 4, 6 and 8％(v/v) glycerol for 60 min, respectively and packaged in 0.5$m\ell$ straw, equilibrated far 30, 60 and 120 min at 4$^{\circ}C$ and cryopreserved in liquid nitrogen vapor at different distance(3, 5, 7 and 9 cm, respectively), plunged into nitrogen tank. Samples were thawed by placing straws into 27, 37, 47, 57$^{\circ}C$ water bath for 120, 20 and 12 sec, respectively. The results were as follows; 1. The survival and motility rate immediately post-thawing was significantly higher in samples frozen in 4％ glycerol than 6 or 8％ glycerol(P< 0.05). 2. According to equilibration time at 4$^{\circ}C$, the survival and motility rate immediately post-thawing was significantly higher in samples frozen after 60 min equilibration than 30 or 120 min equilibration(P<0.05). 3. Freezing in distance of 5 cm from liquid nitrogen yield better survival and motility rate than the others(3, 7 or 9 cm)(P<0.05). 4. The effect of thawing rate on sperm survival were higher when the thawing was done at 37$^{\circ}C$ for 120 sec(P<0.05).