산양의 수정란 이식 및 조작기법 개발에 관한 연구 2 . 산양의 분만 및 유산 후의 단발정주기

박충생(C . S . Park),최상용(S . Y . Choe),이효종(H . J . Lee),이지삼(J . S . Lee) 한국축산학회 1991 한국축산학회지 Vol.33 No.4

This experiment was conducted to investigate the incidence of short estrous cycle and control of short cycle in Korean native goats. Abortion was induced by a single i.m. injection of 3 ㎎ PGF₂α at late stage of gestation. Does after parturition or abortion were teased twice daily with vasectornized bucks and behavioral estrus was recorded. Serum progesterone concentration was analysed by RIA. Mean post-partum or post-abortion interval to first estrus was shortest as 11.9 days in PGF₂α-aborted does compared to 22.1 days in does isolated from their kids within 7 days after parturition and 26.8 days in suckling does. Duration of this first standing estrus was not significantly different among groups. Four limes daily injections of 25 ㎍ Gn RH to does for Day 3 to 5 of the first estrous cycle following parturition or abortion ruduced significantly(p$lt;0.0l) the incidence of short estrous cycle to 38.5% compared to 80.0% in control group of does. Mean concentration of serum progesterone in does showing short estrous cycle was found to be basal level at estrual phase but considerably high level up to 1.06 ㎎/㎖ on Day 3 to 4 of the cycle. These results indicate that the short estrous. cycle may he resulted from the premature luteal regression and GnRH treatment during early luteal phase of the estrous cycle can partly prolong the short lifespan of corpora lutea.

산양의 수정란 이식 및 조작기법 개발에 관한 연구 3 . PMSG 와 FSH 를 이용한 산양의 과배란 유기

박충생(C . S . Park),최상용(S . Y . Choe),이효종(H . J . Lee),이지삼(J . S . Lee) 한국축산학회 1991 한국축산학회지 Vol.33 No.4

This study was conducted to investigate the effects of PMSG or FSH treatment with PGF₂α to induce superovulation in Korean native goats. Does were treated with a single s.c. injection of 1,000 IU PMSG on Day 12 or twice daily s.c. injections of a total of 20 ㎎ FSH in decreasing doses over 4 days beginning on Day 12 of the estrous cycle, Estrus was induced by a single i.m. injection of 10 ㎎ PGF₂α 48 hours after the first gonadotropins injection. The does in estrus were mated with intact bucks twice daily 12 hours apart. Ovarian responses and embryo development were observed by laparotomv 72 hours after mating. Mean interval from PGF₂α injection to onset of estrus was significantly(p$lt;0.01) shorter (45.2±7.5 hours) in FSH group than ill PMSG group(64.8±9.6 hours). Duration of estrus, length of estrous cycle and the incidence of short estrous cycle following superovulation were not significantly different between the 2 treatment groups. The mean number of corpora lutea(P$lt;0.01) and ma recovered(P$lt;0.05) were significantly greater for FSH group(13.2 and 9.2) than for PMSG group(5.1 and 3.5). The mean number of trans-ferable embryos kva, 5.9 and 1.9 in FSH-treated and PMSG-treated group. respectively. These results indicate that FSH treatment with PGF₂α could be superior to PMSG treatment with PGF₂α for the induction of superovulation in Korean native goats.

산양의 수정란 이식 및 조작기법 개발에 관한 연구 Ⅰ. 산양의 발정유기 및 동기화에 관하여

박충생(C . S . Park),최상용(S . Y . Choe),이효종(H . J . Lee),이지삼(J . S . Lee) 한국축산학회 1989 한국축산학회지 Vol.31 No.1

This experiment was conducted to find out an efficient method for estrus induction and synchronization in goats. Sixty of 83 pluriparous Korean native goats received a single i.m. injection of 3㎎ PGF2α on Days 3 to 12 of the estrous cycle. Remained 23 goats received twice daily i.m. injection of 5㎎ progesterone for 6 or 7 days and a single i. m. injection of 3㎎ PGF2α 1 day before the last injection of progesterone. Serum progesterone concentrations were analyzed by RIA. A single intramuscular injection of 3㎎ prostaglandin F2α(PGE2α) on Days 5 to 12 of the estrous cycle induced estrus in 96% of 50 goats treated, but this treatment on Day 3 to 4 was not effective. Estrus was induced in all of 23 goats injected 3㎎ PGF 2αi.m. 24 hours before the last one of successive injections of 5mg progesterone for 6 or 7 days. The onset of estrus was significantly(P$lt;0.01) earlier in PGF 2α treated goats during Days 5 to 6 of the estrous cycle than those treated on Days 7 to 12. PGF 2α treatment with progesterone delayed significantly (P$lt;0.01) the onset of returning to estrus, compared with the PGF2α injection only during mid-luteal phase of the cycle. Serum progesterone concentration was decreased to a nadir at 24 hours following PGF2α administration on Days 5 to 8 of the cycle, but increased to 2.39±0.66 to 2.69±0.56ng / ml at 48 hours after PGF2α injection on Days 3 to 4. Incidence of short estrous cycle following estrus synchronization by PGF2α with or without progesterone was 26.1 % and 26.0 %, respectively. More effective synchronization of estrus was feasible by progesterone treatment for 6 or 7 days plus PGF2α injection 24 hours prior to the last progesterone administration, compared with a single intramuscular injection of 3㎎ PGF2α alone.

산양의 수정란 이식 및 조작기법 개발에 관한 연구 4 . 생쥐 및 산양 수정란의 분할조작에 의한 일란성 쌍태유기

박충생(C . S . Park),최상용(S . Y . Choe),이효종(H . J . Lee),이지삼(J . S . Lee),박희성(H . S . Park) 한국축산학회 1991 한국축산학회지 Vol.33 No.4

This experiment was conducted to establish a simple technique for bisecting mouse and goat embryos of morula to blastocyst stage and to develop a better culture and transfer system of demi-embryos for the production of identical twins. Mouse morulae or blastocysts and goat blastocysts were easily bisected without pronase treatment, using a microblade fixed to a micromanipulator. Bisected mouse embryos developing normally during culture were 71.4% of a total of 319 morulae and blastocysts. Survival rate of demi-embryos(29.0%) after culture and surgical transfer to recipient mice was comparable to result of intact embryos(26.0%). More transferable embryos (3.5±0.8/donor) were recovered in 7 to 8 days after mating when the does were induced to superovulate by injection of FSH-p in decreasing doses and progesterone priming for 10 days. and this superovulation regimen resulted in very low incidence of short estrous cycle(6.7%). Three kids were produced from 2 of 6 does received intact embryos. Fourteen pairs and one-half of demi-embryos were transferred to 15 recipients. of which one recipient delivered a single female kid.

산양의 수정란 이식 및 조작기법 개발에 관한 연구 5 . 생쥐 및 산양 분할 수정란의 생존성 및 이식 후 수태율의 향상

박충생(C . S . Park),최상용(S . Y . Choe),이효종(H . J . Lee),이지삼(J . S . Lee),박희성(H . S . Park) 한국축산학회 1991 한국축산학회지 Vol.33 No.5

This experiment was conducted to compare different procedures for improvement of viability of embryos after bisection and to investigate some factors affecting development of the bisected embryos. Demi-embryos were successfully produced by micromanipulation of mouse and goat embryos at stages from morula to blastocyst. In mouse, a superior viability(90%) of demi-embryos was achieved by culturing expanded blastocysts after bisection. The highest pregnancy rate(57.1%) and implantation rate(28.2%), which were almost same as the rates of intact embryos. were also achieved by transferring the demi-embryos at this stage after culture for 24 h in vitro. Twenty -eight 3%) of 30 embryos collected from superovulated Korean native goats were successfully bisected, of them 23 demi-pairs were transferred to recipients. Six and 3 does of them were diagnosed pregnant on 21 and 60 days of gestation, respectively. The present result indicates that in goat, hatched blastocysts might be more suitable for successful bisection to produce monozygotic twins than morulae or earlier blastocysts.

Rat H - Y 항체에 의한 생쥐 Embryo 의 성 조절에 관한 연구 Ⅲ. H - Y 항혈청에 의한 BALB c 생쥐 상실배의 성 판별

정장용(J . Y . Jeung),박충생(C . S . Park),박희성(H . S . Park) 한국축산학회 1989 한국축산학회지 Vol.31 No.10

This experiment was carried out to develop a new technique by identifying XX-bearing embryos prior to implantation by immunological method. H-Y antiserum was prepared in inbred Wistar female rats by repeated immunization with spleen cells from males of the same strain. The reactivity of H-Y antibody was confirmed by culturing mouse embryos in the medium containing H-Y antiserum and complement obtained from the guinea pig. The optimal condition for the activity of H-Y antibody was also investigated by culturing embryos under the various conditions of equilibration times, complement concentrations and various media. The results obtained in this experiment are as follows: When the embryos were cultured in the medium of H-Y antiserum and complement which was given the equilibration time of less than 30 minutes in CO₂ incubator, the lysis-rate of embryo was 89.3%. The embryo lysis-rates in the equilibration time of 1-1.5, 3-3.5, or 24-26 hours were 48.1, 47.7 and 48.2%, respectively. When the concentration rate of complement to H-Y antiserum varied from 0.25 - 4.0, the lysis-rate of embryo was 43.2 to 52.7%. The concentration rate of complement did not influence the lysis-rate of embryos. The meda of D-PBS + 0.3% BSA, D-PBS + 20% FCS, Ham`s F-10 + 0.3% BSA and Ham`s F-10 + 20% FCS showed the embryo lysis-rate of 46.4, 57.4, 49.3 and 49.1%, respectively. The culture media used in this experiment did not show any significant difference in the embryo lysis-rate. After the embryos were cultured to the late blastocyst in the media of D-PBS + NGPS + H-Y antiserum or D-PBS + NGPS + normal female rat serum the normally developed embryos were selected and transferred to the pseudo pregnant recipients. The percentages of their female offspring were 82.3%(14/17) in H-Y antiserum treatment and 53.6%(15/28) in normal serum treatment and showed a significant difference between the two treatments(p $lt;0.001).

생쥐 초기배의 분리할구와 분할배의 체외배양

윤창현(C . H . Yun),강대진(D . J . Kang),박충생(C . S . Park),민관식(K . S . Min),오석두(S . D . Oh),이은봉(E . B . Lee) 한국축산학회 1990 한국축산학회지 Vol.32 No.12

This experiment was carried out to investigate the developmental potential of bisected morulae and blastocysts, and the isolated blastomeres from 4-and 8-cell embryos in mouse. The results obtained were summarized as follows: l. The rates of blastomeres survived manipulation were 83.4 and 76.7%, in 4-and 8-cell embryos, respectively. 2. The rates of half embryos survived bisection were 77.7 and 75.3%. in morulae and blastocysts, respectively. 3. The rates of development of isolated blastorneres from 4-and 8-cell embryos were 24.7 and 10,4% respectively. 4. The rates of development of the bisected morulae and blastocysts were 67.7 and 71.9% respectively.

재래산양의 단발정주기중 혈청 Progesterone 및 Estradiol - 17β 의 수준의 변화

송우준,박충생,최상용 ( D . J . Song,C . S . Park,S . Y . Choe ) 한국축산학회 1985 한국축산학회지 Vol.27 No.10

The peripheral blood was collected from 6 Korean native goats which showed a short estrous cycle from 5.5 to 7.0 days. The serum levels of progesterone and estradiol-17β were determined at the interval of 12 hours through the estrous cycle. Using a vasectomized buck the estrous behaviours of the goats were checked twice a day. The average levels of serum progesterone were found lower than 0.02ng/㎖ at Day 0 before and after the short cycle, and increased to 0.14ng/㎖ at Days 2 and 3, and 1.15ng/㎖ (0.57-1.64ng/㎖) at Days 4 and 5. The levels of serum estradiol-17β through the short estrous cycle was fluctuated in a similar pattern to normal estrous cycle. These data suggest that the short estrous cycle may be resulted from the early regression of the premature corpus lutea.

다배란과 수정란이식에 의한 젖소 산유능력의 유전적 변화에 관한 연구 1 . 선발방법에 따른 선발효과

김철욱(C . W . Kim),강대진(D . J . Kang),박충생(C . S . Park),이정규(J . K . Lee) 한국축산학회 1988 한국축산학회지 Vol.30 No.1

Thanks to the recent technical development of embryo transfer, it has become possible to produce many good offsprings from the genetically highly productive dairy cattle in a short period, With the help of this technical development this study aims to analysis genetic change by use of multiple evulation and embryo transfer (MOST), Under the condition that the heritability of milk yield is 0.25, the number of donors per male is 20, and the number of embryo transfers per donor is 20, comparing their respective selection effects of dam I, dam II, dam I + dam II, and the females and males selected according to the genetic selection index, 1 have found that the annual genetic change of the group selected by the genetic selection index is the highest. And the genetic change is the highest when one male per half-sib is selected.

Prostaglandin F2α 근주 ( 筋注 ) 에 의한 홀스타인 젖소의 발정동기화에 관한 연구

임경순,박충생 ( K . S . Im,C . S . Park ) 한국축산학회 1983 한국축산학회지 Vol.25 No.1

For induction of estrus from the respeat breeders and silent heat cows, 25 or 50 ㎎ of PGF₂α was intramuscularly injected and symptoms of estrus such as vaginal swollen, mucus state, existence of mounting and receptive standing conception rate and return intervals were observed. The results were as follows: 1. Eleven (78.5%) of 14 cows treated showed estrus and ten (90.9%) of the eleven observed estrus on day 3 after treatment. 2. Estrus was induced in five of the seven cows with silent heat and in six of the seven cows with repeat heat. 3. Ten cows in heat following the treatment showed the same vaginal redness and swollen cervix as those of natural heating cows. 4. A considerable amount of mucus in vigina was observed in the four cows. 5. Only three cows showed the sexual behavior of mounting and receptive standing during heat. 6. Three cows were conceived at the induced estrus and calved these after. 7. Four cows showed return intervals of 18-25 days. This investigation was supported by grant of PGF₂α from The Upjohn Company, Kalamz-zoo, Michican, U.S.A.. I sincerely thank Dr. S.H. Langford, Pacific region technical manager for his effort of granting PGF₂α and his deep consideration of this work.