• Clinical and Experimental Reproductive Medicine
• /
• v.18 no.2
• /
• pp.233-235
• /
• 1991

A total of 167 patients underwent mascroscopic vasovasostomy by a modified double layer reanastomosis to correct postvasectomy sterility during a 5-year period between 1986 and 1991. We obtained the anatomical patency and pregnancy rates from 61 patients whose follow-ups were completed. There by, we report the following results. 1. Of the 167 patients, the mean age and the average duration of vasobstruction were 34.0 and 4. 4 years respectively. The reasons for ecanalization were desire for more baby in 71.9%. death of children, 24.5% and remarriage in 3.6%. 2. Of the 61 patients with complete follow-up. the anatomical patency and pregnancy rates were 83.6%(51 patients) and 50.8%(31 patients) respectively. 3. For the 36 out of 61 patients whose duration of vasobstruction was less than 5 years, the anatomical patency and pregnancy rates were 88.9%(32 patients) and 58.3%(21 patients) respectively. The rates for the remaining 25 patients whose duration was greater than 5 years were 80.0%(20 patients) and 40.0%(10 patients). 4. Of the 61 patients, 51 exhibited sperms from the proximal vas on microscope during the operation. Their anatomical patency and pregnancy rates were 88.2%(45) and 54.9%(28) respectively. The rates for the remaining 10 patients without any sperms were 60.0%(6) and 30.0%(3). From the above results, we can conclude that macroscopic reanastomoses by modified double layer technique has appreciable success rates that could possibly be compared to the microscopic results.

• Journal of Embryo Transfer
• /
• v.20 no.2
• /
• pp.89-95
• /
• 2005

In this study, we investigated the effects of number, grade, stage and day of embryos on pregnancy and abortion rates of Holstein heifer recipients after transfer of in-vitro produced Korean Native Cattle (Hanwoo) embryos. When one, two or three blastocysts were transferred to recipients, pregnancy (32.0, 44.0 and $32.0\%$) and abortion (12.5, 13.6 and $6.3\%$) rates did not differ among treatments. The pregnancy and abortion rates of different grades of blastocysts were $40.8\~44.2\%\;and\;9.4\~16.3\%$, respectively. However, they were not significantly different. According to the stage of blastocyst, the pregnancy rates were similar between $39.1\%\;and\;45.3\%$. However, the abortion rate in hatched blastocyst stage $(20.8\%)$ was significantly higher than that in late blastocyst stage $(9.0\%)$. The pregnancy rates in day $7\cdot7$ and day $7\cdot8$ blastocyst (47.1 and $53.9\%$, respectively) was significantly higher than that in the day $9\cdot9\;and\;8\cdot9$ blastocyst (29.8 and $27.7\%$, respectively). The abortion rate was the highest in the day $9\cdot9$ blastocyst $(30.8\%)$ among treatments, and it was significantly different compared to that in the day $7\cdot7$ blastocyst $(10.1\%)$. Therefore, this study suggested that the pregnancy rate was affected by only day of embryos, while the abortion rate was affected by stage and day of embryos.

• Korean Journal of Veterinary Research
• /
• v.36 no.4
• /
• pp.919-927
• /
• 1996

In the last few years, methods for in vitro culture of early embryo stages from oocytes matured and fertilized in vitro using suitable cell culture systems have been established. But the factors affecting pregnancy rates following transfer of bovine embryos produced in vitro were not evaluated enough. So this study was performed to investigate the effects of quality and stage of embryos, parity and Corpus Luteum quality of recipients on pregnancy rates following non-surgical transfer of bovine embryos produced in vitro. Oocytes aspirated from small antral follicles of ovaries obtained at a local slaughter house were matured, fertilized with frozen-thawed semen and co-cultured for 6-7 days by utilizing co-culture system with bovine oviduct epithelial cell in vitro. After co-culture, embryos were transfered to recipients on day 7 (estrus=day 0). Recipients were monitored by ultrasonic scanning method or observation for estrus and rectal palpation after 50 days from transfer. The results of this study are follows. 1. Of the 70 recipients, 70%(49 of 70) had not showed estrus sign between day 0 and day 50, but 22.9%(16 of 70) was diagnosed not pregnant. Therefore the overall pregnancy rate of this study was 47.1%(33 of 70). 2. The pregnancy rate of recipients transfered with excellent(66.7%) and good(54.5%) embryos were higher than that of recipients transfered with fair embryos(15.8%) (p<0.05). 3. The pregnancy rate of recipients transfered with morula, compacted morula, blastocyst and expanded blastocysts were 46.2, 55.0, 62.5 and 50.0%, respectively. 4. The pregnancy rates of recipients transfered to heifer and cow were 54.5 and 55.2%, respectively. 5. The pregnancy rates of recipients with CL score I, II(66.7, 63.6%) were higher than those of recipients with CL score III (10%), (p<0.05). Success of transfer of embryos produced in vitro depends on many variables. The important factors identified in this study were the quality of embryos and the CL score of recipient animals after non-surgical transfer of embryos matured, fertilized and cultured in vitro.

• Asian-Australasian Journal of Animal Sciences
• /
• v.9 no.3
• /
• pp.299-302
• /
• 1996

Milk samples(n = 78) were taken 19d, 20d, 21d, 22d after artificial insemination(AI) for early pregnancy diagnosis by using the Enzyme immunoassay(EIA) kit. The progesterone ($P_4$) concentration in the whole milk was measured on the same day of pregnancy diagnosis. Rectal palpation(RP) was accomplished between 60d and 70d after AI to estimate the ovary condition and pregnancy status. Milk progesterone concentrations measured by Radio-immunoassay(RIA) method, in the pregnant cows at 17d, 19d, 21d after insemination were $17.10{\pm}0.91$, $17.60{\pm}0.46$, and $18.43{\pm}0.79nmol/l$, whereas those in the not-pregnant cows were $6.57{\pm}1.03$, $2.63{\pm}0.29$, and $0.67{\pm}0.08nmol/l$, respectively. When the progesterone concentration was less than 7 nmol/l, the color of the EIA kit was lighter and when the progesterone concentration was ${\geq}16nmol/l$, the color of the EIA kit was darker compared to the standard color. The detection rates of error by judging the color differences were 5.1% and 20.7%, respectively. In the early pregnancy diagnosis by the EIA kit and RIA method, the accuracy rates in the pregnancy of cows were 82% and 87%, and those in not-pregnant cows were 86% and 91%, respectively. For ovarian status estimated by the RIA method and certified by RP, the accuracy rates of the ovarian atrophy, follicular cyst and luteal cyst were 80, 91 and 83% and the progesterone concentrations were 2.51, 2.03, and 26.7 nmol/l, respectively.

• Journal of Embryo Transfer
• /
• v.26 no.1
• /
• pp.33-36
• /
• 2011

The objective of this work was to determine the effect of corpus luteum (CL) grade on pregnancy rate after embryo transfer in Korean cattle and we found that CL development was linked to pregnancy rate. The in vivo derived blastocyst-stage embryos were transferred to 15 recipients synchronized in the estrus cycles. Based on size and palpable characteristics, CLs were categorized into three grade. The grade three CL is not to be identified by rectal palpation. The pregnancy rates tended to increase with the increase in CL size of recipients. In grade one, two, and three, the pregnancy rates were 62.5%, 50.0%, and 0%, respectively. This result suggests that pregnancy rates after embryo transfer might be affected by the CL status of recipients.

• Journal of Animal Reproduction and Biotechnology
• /
• v.39 no.1
• /
• pp.40-47
• /
• 2024

Background: Sperm quality and the number of sperm introduced into the uterus during artificial insemination (AI) are pivotal factors influencing pregnancy outcomes. However, there have been no reports on the relationship between sperm concentration at AI and sperm quality in Hanwoo cattle. In this study, we examined sperm quality and pregnancy rates after AI using sperm inseminated at different concentrations. Methods: We evaluated the motility, viability, and acrosomal membrane integrity of sperm at different concentrations (10, 15, 18, and 20 million sperm/straw) in 0.5-mL straws. Subsequently, we compared the pregnancy rates after AI with different sperm concentrations. Results: After freeze-thawing, sperm at the assessed concentrations showed similar viability and acrosomal membrane integrity. After AI, cattle in the 10 million group had significantly lower pregnancy rates compared to those in the 18 and 20 million groups. Conversely, there were no statistically significant variances observed between cattle in the 10 and 15 million groups. Conclusions: Sperm at concentrations of 10, 15, 18 and 20 million per straw exhibited comparable motility, viability, and acrosomal membrane integrity. However, a concentration of at least 18 million sperm per straw is required to achieve a consistent rate of pregnancy rate in Hanwoo cattle after AI.

• Korean Journal of Animal Reproduction
• /
• v.27 no.1
• /
• pp.35-44
• /
• 2003

The present study was performed to investigate the first polar body(PB) extrusion during in-vitro maturation(IVM) and to examine the effect of different maturation time on the embryo development of Korean Native Cows(KNC) with regard to blastocyst(BL) cell numbers and pregnancy rates. PB extrusion did not take place for the first 12 hours(hr) of IVM, and most of KNC oocytes extruded PB from 14 to 20 hr after the onset of maturation. There was no significant difference in cleavage and 8-cell stage rates among the treatment groups, but BL and BL/8-cell rates were significantly higher(P<0.05) in 18 hr maturation group(31.0$\pm$5.7 and 82.0$\pm$5.1%) than 22 and 24 hr maturation group. The proportion of BL formed on day 7 and 8 was significantly higher(P<0.05) in 18 hr maturation group(85%) than in 24 hr maturation group(55%). There was a significant difference(P<0.05) in inner cell mass, trophectoderm and total cell number between day 7 BL produced by in-vivo and IVM 18 hr and day 8 BL produced by IVM 18 hr and 24 hr. Pregnancy rates are also significantly higher(P<0.05) in in-vivo(56.3%) and IVM 18 hr day 7(50.0%) group than day 8 treatment groups(18 hr: 16.7%, 24 hr: 10.5%). These results suggest that KNC oocytes achieve developmental competency within 20 hr of IVM, and "short" IVM (18 hr) is more effective than "long" IVM(24 hr) in embryo development rates, BL cell numbers and pregnancy rates.

• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2002.11a
• /
• pp.85-85
• /
• 2002

Pregnancy block by male pheromones in mice differs in incidence depending on the combination of strains. Female mice of BALB/cA strain mated with BALB/cA males show a 100% pregnancy block when exposed to males of inbred strain DDK shortly after copulation (Chung et al., Biol Reprod 1997). In the present study, BALB/cA females mated with the males of other strains (CBA/J, C3H/HeN, C57BL/6Cr, and IXBL) showed higher pregnancy rates (66.6-87.5%) even when they were exposed to DDK males. In the pharmacological induction of pregnancy block with dopamine agonist (Bromocriptine, 4mg/kg BW), BALB/cA females mated with BALB/cA males showed a 100% pregnancy block. In contrast, BALB/cA females mated with CBA/J, C3H/HeN, and C57BL/6Cr males showed higher pregnancy rates (40-70%). These results suggest that the better pregnancy rate of BALB/cA females mated with alien males may be due to the stronger viability of F 1 embryos. This interpretation was confirmed by an embryo transfer experiment in which a higher implantation rate was observed when BALB/cA embryos grown in BALB/cA females exposed to BALB/cA males were transferred into recipient BALB/cA females exposed to DDK males. These results suggest that the embryonic genotype or viability of the embryo is one factor contributing to the occurrence of pregnancy block by male pheromones in mice.

• Journal of Embryo Transfer
• /
• v.32 no.3
• /
• pp.153-157
• /
• 2017

This study was conducted to investigate the optimal artificial insemination (AI) time with diagnostic kit at ovulation time. We already applied the patent about the protein in the cow heat mucose in external reproductive tract. And we would examine the accuracy for detection of cow heat by the kit produced with the protein. Evaluation of optimal heat detection was tried two time at 12 hrs and 24 hrs after the heat. And then, AI service also performed two times with no relation to the results of heat diagnosis by heat detection kit and pregnancy rates were checked with rectal palpation on $60^{th}$ day after AI. Heat diagnostic results by kit in natural heat after 12 hrs in Hanwoo cows were showed 31.3~75.0% on positive in first heat detection and 33.3~100.0% on positve in second heat detection. In the $1^{st}$ positive results were significant different (p<0.05), but $2^{nd}$ positive were not. The results of heat detection showed different result on regional influence and individual cow effects. The pregnancy rates of first trial of heat detection were showed 34.4~78.7% on positive and 21.3~68.8% on negative after the diagnosis by heat detection kit. And the pregnancy rates of next trial of heat detection were showed 33.3~85.7% on positive and 14.3~66.6% on negative after the heat diagnosis. Both positive results of first trial and next trial also were showed significant different (p<0.05), but negative results were not. In positive result, first trial of total pregnancy rates was higher than the next trial of pregnancy, but there showed opposite results on negative results. In conclusion, the optimal heat detection kit is suitable to ordinary Hanwoo cows and it suggested that we have to improve the kit's accuracy by detecting the materials like proteins related optimal AI time.

• Reproductive and Developmental Biology
• /
• v.28 no.3
• /
• pp.155-159
• /
• 2004

This study was carried out to investigate the general characteristics and viability of sperm after freezing and thawing and the pregnancy rates after artificial insemination with thawed semen. The rates of viable sperm after slow and rapid freezing were 87.4±3.85% and 70.8±4.45%, respectively which were significantly lower than that of fresh semen control (91.7±3.45%). The mean concentration of epididymal sperm after dilution in 1.0 ml saline and. 3.0 ml extender in a various concentrations of cryoprotectants was 124.5±48.3 x 10/sup 6/ (range of 45 x 10/sup 6/ to 280 X 10/sup 6/ /ml). There was a significant difference not in the percentage of acrosome-reacted sperm, but in the percentage of capacitated sperm, between fresh and frozen-thawed epididymal semen. When frozen-thawed after diluting with tris-buffer extender containing glycerol, DMSO and ethylene glycol with concentration of 2 to 6%, the rates of epididymal sperm exposed to different cryoprotectants ranged from 14.4±4.7% to 20.7±5.8%, 17.8±5.2% to 36.5±4.9%, and 14.4±4.6% to 18.5±5.3%, respectively which were lower compare to fresh semen control. The pregnancy rate after artificial insemination with frozen semen was 70.6%, whereas that with fresh semen was 90.0% in dogs with naturally induced estrus.