• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.111-117
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• 2002

This study was carried out to investigate the effects of frozen boar semen on reproductive performance in swine artificial insemination (AI). Many factors, which were breeds, time of insemination, sperm concentration per dose, farm and year were investigated to improve reproductive performance efficiency. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. This experiment was carried out from 1995 to 2000. There were no differences in swine AI with frozen boar semen using 5$m\ell$ maxi-straw among 3 breeds (Landrace, Yorkshire, Duroc), 2 or 3 times insemination per estrus, and 3 different sperm numbers of 3.0, 4.0, and 5.0$\times$10$^{9}$ per dose of insemination. However, non-return rate and litter size of sows inseminated with frozen boar semen of commercial farms were different according to farm management system and inseminator's skill. Conception rate, farrowing rate and number of pigs born alive per litter by artificial insemination with frozen boar semen (5$m\ell$ maxi-straw) from 1995 to 1999 was 68.3~74.6%, 61.7~67.6% and 8.1~8.7 heads.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.106-110
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• 2019

Sexed sperm can contribute to increase the profitability of the cow industry through the production of offspring of the craved sex, such as males for meat or females for dairy production. Therefore, the utilization of sexed sperms plays a very important role in the production of offspring of superior cattle. In this study, we examined the pregnancy rates and calves sexing proportion of male and female calves produced using AI, both performed using sexed and conventional sperm. In the result, the conception rates after ET were 73.3% (33/45) sexed semen and 52% (55/104) conventional semen. Thus, the sex ratio for sexed-semen inseminations was 70% (21/30) females for singleton births within a 272 to 292 day gestation interval. The sex ratio for conventional semen was 61% (34/56) females for births. As a result, it is suggested that the use of sex classification sperm will play a very important role in the offspring production of Korean bovine.

• Korean Journal of Animal Reproduction
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• v.4 no.1
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• pp.20-27
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• 1980

This experiment was to study semen properties of Charolais for the a, pp.ication ot artificial insemination. The result obtained were summarized as follows: 1. In the preservation of liquid semen for 6 days, the survival rates of Charolais semen averaged 57.14% in skim milk solution and 58.17% in tris buffer solution. There were not differences. 2. Recovery of semen after thawing was vigorous in the semen that was diluted and frozen in 48 hrs. 3. The real rates of survival sperm for Charolais averaged 83% after living sperm was diluted and stained for 6 days. 4. Methylene blue reduction test diluted semen was fresh when it was diluted within 48 hrs. 5. If the diluted semen was preserved below 5$^{\circ}C$ in Charolais, the pH decreased by 0.2 in a day. 6. Diluted semen was more resistant to the cold shock than fresh semen. 7. In resistance against hot shock, sperm was almost dead in 20 minutes in 46.5$^{\circ}C$ in diluted semen, while it was dead in 30 minutes in 42.5$^{\circ}C$ in diluted semen. 8. In examination of morphological changes of sperm acrosome for 6 days, normal sperm in skim milk solution and tris buffer solution was 80% and 76.97% respectively, swelling sperm 12.8% and 15.27%, deficient sperm 0.6% and 0.97% abnormal staining 3.07% and 5.25%, immature sperm 0.28%, and 0.23%, whereas other abnormal sperm was 1.28% and 1.42%.

• Korean Journal of Animal Reproduction
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• v.4 no.1
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• pp.75-82
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• 1980

This experiment was carried out to improve a simple and effective procedure of egg transfer which is considered to be the most useful technique for the improvementand proliferation of domestic animals. Several experiment procedures such as superovulation, surgical recovery of ovulated egg, in vitro capacitation of ejaculated spermatozoa, in vitro fertilization and culture of embryo were conducted. The results obtained in this experiment were summarized as follows: 1. In rabbits treated with PMS in combination with estradiol and HCG, 10 to 43 eggs were obtained in one rabbit and the average ovulation number of 20 rabbits was 21 eggs. 2. Six to 24 eggs (average 13 eggs) were recovered from the removed oviducts by the methods of flushing technique and the average recovery rate of 20 rabbits was 61.9 percent. 3. Most rabbit spermatozoa ejaculated by artificial vagina were capacitated in vitro by the culture of the spermatozoa with PBI medium at 37$^{\circ}C$ for 4 hours after removal of seminal plasma. 4. Normal fetilization following in vitro fetilization was observed in 88 (42.7%) of 206 eggs. 5. The number of eggs developed to 2-, 4-, and 8-cell stage following in vitro culture with PBI medium at 37$^{\circ}C$ was 26 (70.3%), 20 (54.1%) and 17 (45.9%) of 37 eggs used for in vitro culture.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.231-237
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• 1992

The effects to the corticosteroid dexamethasone(DEX) and(or) estradiol-benzoate(E-B) treated to induction of parturition and birth weights of the young was conducted in 48 pregnant Korean native goats. The animals were divided into 4 goats per each treatment by the time(142, 145 and 148 day of pregnancy) and dosage(DEX 15, 20mg, DEX 8mg＋E-B 10mg and DEX 13mg＋E-B 7.5mg per goat). The results obtained were summarized as follows: 1 The time for induction of parturtion after DEX(15, 20mg) treatment on day 148 of pregnancy was significantly(P<0.01) shorter than 142 and 145 days. There was no significant difference each dosage of DEX on same day of pregnancy. 2. The addition of E-B to DEX treatment compared with DEX alone group at day 142 and 145 of pregnancy were significantly(P<0.01) shorter the time for induction of parturition. However, treatment with DEX along or with E-B on 148 day of pregnancy did not affect the time to induction(about 27 hrs) of parturition between each treatment. 3. The birth weight of kids after parturition was heaviest(P<0.01) on day 148 of pregnancy. However, development and vigor of kids were not significant different between DEX alone treatment and with E-B.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.923-928
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• 1993

Genetic algorithms are powerful optimization methods based on the mechanism of natural genetics and natural selection. Genetic algorithms reduce chance of searching local optima unlike most conventional search algorithms and especially show good performances in complex nonlinear optimization problems because they do not require any information except objective function value. This paper presents a new model based on sexual reproduction in nature. In the proposed Sexual Reproduction model(SR model), individuals consist of the diploid of chromosomes, which are artificially coded as binary string in computer program. The meiosis is modeled to produce the sexual cell(gamete). In the artificial meiosis, crossover between homologous chromosomes plays an essential role for exchanging genetic informations. We apply proposed SR model to optimization of the design parameters of Single-sided Linear Induction Motor(SLIM). Sequential Unconstrained Minimization Technique(SUMT) is used to transform the nonlinear optimization problem with many constraints of SLIM to a simple unconstrained problem, We perform optimal design of SLIM available to FA conveyer systems and discuss its results.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.3
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• pp.137-144
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• 2021

In this study, to analyze whether artificial regulation of apoptosis in the development of somatic cells can affect the stable growth and development of cells, 20 alpha-hydroxysteroid dehydrogenase (20α-HSD) and rapamycin were treated to induce apoptosis and autophagy in the both skin and muscle cells. Respectively, and 3-methyladenine was supplemented to inhibit cell death. Our results show that stimulation with rapamycin activated autophagy in both types of cells, but increased apoptosis more than autophagy in the case of skin cells. These results indicate that there was a difference in the expression of survival factors and cell development depending on the type of cell. In particular, in the expression of autophagy-related gene (MAP1LC3A) was higher than that of Casp-3, an apoptosis factor. Furthermore, cell development was the highest in all cell groups cultured by artificially inducing autophagy, however the lowest in the apoptosis-inhibited group. Especially, the noteworthy result of this study was that when apoptosis was induced using 20α-HSD, it was possible to induce apoptosis in both skin and muscle cells. Therefore, the main point of this study is that apoptosis induced during cell culture plays a pivotal role in cell remodeling.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.45-50
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• 2021

In recent years, various methods of measuring body temperature have been developed using wireless biosensors to facilitate an early detection of pregnancy and parturition in cows. However, there are no studies on real-time monitoring of cattle body temperature throughout pregnancy. Therefore, we investigated the daily mean ruminal temperature in pregnant cows throughout pregnancy using a ruminal bio-capsule sensor and then evaluated the temperature variation between pregnant and non-pregnant cows. In pregnant cows, the mean and standard deviation of ruminal temperature was 38.86 ± 0.17℃. Ruminal temperature in pregnant cows slowly decreased until 180 to 190 days after artificial insemination and after that, the temperature increased dramatically until just before parturition. Furthermore, the means ruminal temperature was significantly different between pregnant and nonpregnant cows. The mean and standard deviation of ruminal temperature were as follows: 38.68 ± 0.01℃ from days 80 to 100, 38.78 ± 0.02℃ from days 145 to 165, 38.99 ± 0.45℃ from days 200 to 220, 39.14 ± 0.38℃ from days 250 to 270 before parturition. Therefore, our results could provide useful data for early detection of pregnancy and parturition in Korean cows.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.209-216
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• 2000

This study was carried out to investigate the effects of breed, age of boar, season, parity and mating system on boar semen characteristics and fertilizing capacity. A total of 4181 sows and 199 boars of Durocs (D), Landraces (L), and Yorkshires (Y) were used for this experiment at Darby Artificicial Insemination Center from 1996 through 1999. Semen volume per ejaculate was largest in Landrace (266.8 $m\ell$), followed by Yorkshire, and was smallest in Duroc. Sperm motility did not show significant differences among the above breeds. Sperm concentration was lowest in Landrace (4.7$\times$10$^{9}$ sperm/$m\ell$) and was highest in Duroc (5.7$\times$10$^{9}$ sperm/$m\ell$). Semen volume per ejaculate according to the age of boars was largest at the age of 2 years, followed by the age of 4 and 3 years, and was smallest at the age of I year. Semen volume per ejaculate according to the season in boars was largest in winter (228.6 $m\ell$), followed by autumn and summer, and was smallest in spring. Sperm concentration was highest in spring (5.9$\times$10$^{9}$ sperm/$m\ell$), followed by summer and winter, and was lowest in autumn. The average litter weight at birth did not show any differences according to the mating type. But the number of pigs born alive per litter was largest (9.5 pigs) in the natural mating ＋ artificial insemination group, followed by the artificial insemination group (9.2 pigs), and was smallest (8.9 pigs) in the natural mating group (P＜0.01). The average litter weight at birth and number of pigs born alive per litter did not show any differences between the natural mating and artificial insemination. The L (♀)$\times$Y (♂) and L (♀)$\times$L (♂) matings show $\varepsilon$ d higher average litter weight at birth and number of pigs born alive per litter than the Y (♀) $\times$ Y (♂) and Y (♀) $\times$ L (♂) matings. The pigs in the 2~6th parities had higher average litter weight at birth and number of pigs born alive per litter than those in the 1 st and 7~9th parities.

• Animal Bioscience
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• v.34 no.2
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• pp.198-204
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• 2021

Objective: The aim of this study was to ascertain the effects of adding green tea extract (GTE) to skim milk-egg yolk (SM-EY) extender on both the quality of post-thawed bull semen and the pregnancy rates of the recipient cows. Methods: Twelve ejaculates from four Simmental bulls, aged 3 to 5 years and weighing 900 to 950 kg, were diluted SM-EY extender, added with 0, 0.05, 0.1, and 0.15 mg GTE/100 mL extender and then frozen. After four weeks storage in liquid nitrogen, the sperm were thawed and evaluated for viability, motility, intact plasma membrane (IPM), and DNA fragmentation. Meanwhile, the estrus cycles of 48 recipient cows were synchronized by intramuscular administration of a single injection of 5 mg prostaglandin F2α. Estrus cows were divided into four equal groups and inseminated artificially 18 to 20 h after the onset of estrus by using semen from each extender group. Pregnancy was diagnosed by measuring serum progesterone levels at 21 days, followed by transrectal palpation 90 days after insemination. Results: The findings revealed that adding 0.1 mg of GTE/100 mL extender produced the highest percentages of sperm viability (70.67%±1.75%), motility (69.17%±1.47%), and IPM (69.23%±1.21%) and the lowest percentage of DNA fragmentation (3.00%±0.50%). The pregnancy diagnosis revealed that all cows (36/36) inseminated using frozen semen in GTE addition extender were pregnant (pregnancy rate 100%), whereas the pregnancy rate of the control group was 83.33% (10/12). Conclusion: It may be concluded that 0.1 mg GTE/100 mL extender yields the best quality of spermatozoa and that all variants doses of GTE in extender produce a higher pregnancy rate among recipient cows.