• Korean Journal of Animal Reproduction
• /
• v.16 no.1
• /
• pp.55-62
• /
• 1992

Bovine oocytes obtained from ovarian(2 to 5mm in diameter) of slaughtered cows were cultured in TCM 199 with 10~20% estrous-cow-serum(ECS) for 24~25hr at 39$^{\circ}C$ in 5% CO2-95% air. After culture, some oocytes were examined their maturation. The remainder were used to assess the fertilizability with frozen-thawed spermatozoa in a medium containing caffeine and heparin, and subsequent development in media with bovien cumulus cells(BCC) or bovine oviduct epithelial cells(BOEC). The results obtained were summarized as follows ; 1. The maturation rate of the oocytes in TCM199 with 15% ECS group(76.5%) was higher than that of 10% ECS(69.2%) or 20% ECS group(64.8%). 2. The proportions of the oocytes penetrated and the pronuclear oocytes in the presence of caffeine and heparin were 72.1%(62/86) and 93.5%(58/62), respectively. The rate of polyspermy in the fertilized oocytes was 8.1%. 3. When 73 oocytes recovered from fertilization drop were cultured in TC-199 medium with 10% fetal calf serum(FCS), 41 oocytes(56%) cleaved to 2-cell and further stages of embryos. Among these only one embryo developed upto morula stage. 4. The rate of the cleaved oocytes was higher in medium with BCC(80%:59/74) than BOEC(76%:58/76). However, the rate of developed morulae and blastocysts was higher in the medium with BOEC(40%;23/58) than with BCC(34;20/59).

• Korean Journal of Animal Reproduction
• /
• v.21 no.2
• /
• pp.111-116
• /
• 1997

We determined the effects of follicular fluid fractions in the maturation medium on bovine oocyte maturation, fertilization and subsequent development, as well as on number of cells in blastocysts following culture. Follicular fluid and oocytes from bovine follicles less than 5 mm in diameter were collected from the ovaries of slaughtered cows. Follicular fluid was separated into different molecular weight fractions by untrafiltration through a membrane using a centrifuge at 500$\times$g, for 2h. For the maturation medium, follicular fluid fractions (30%, v/v), whole fluid (30%) or PVP(3mg/ml) were added to TCM 199(0.1$\mu\textrm{g}$/ml estradiol-17$\beta$, 100IU hCG). After maturation for 24h, oocytes were fertilized in vitro with bull frozen-thawed spermatozoa and cultured on a monolayer of granulosa cells for 9 days after fertilization. There were no differences in maturation rates or fertilization rates among any maturation conditions. The rates of development to >2-cell stage of the oocytes were significantly decreased when fraction of follicular fluid below 10,000 MW were added into maturation medium, compared with control and fraction above 10,000 MW(26.0% vs 40.8% to 64.0%, respectveily. p<0.01). Likewise, the rates of development to blastocysts of fertilized oocytes were significantly decreased in maturation medium containing fraction of follicular fluid (<10,000 MW). The average cell number of blastocysts derived from oocytes that matured in the fraction(>10,000 MW) of follicular fluid was 154.7$\pm$13.7. These embryos contained more cells than those matured in whole follicular fluid, or the fraction(<10, 000 MW) of follicular fluid or control(107.0$\pm$8.4, 91.8$\pm$11.8 and 95.8$\pm$6.2, respectively). In conclusion, we found that fractions of follicular fluid contained factors stimulating or inhibiting oocyte cytoplasmic matruation. These suggest that a factor(s) inducing cytoplasmic maturation of oocytes may exist in >10,000 MW fraction of follicular fluid.

• Journal of Veterinary Clinics
• /
• v.9 no.1
• /
• pp.323-332
• /
• 1992

The present study was carried out to examine the effect of oviduct epithelium and its conditioned medium on e development of early bovine embryos in vitro. Oocytes obtained from ovarian follicles of slaughtered cows were cultured in TCM199 with 10% fetal calf serum for 22-24hrs and then fertillzed in vitro using frozen-thawed semen treated with BO-caffein, BO-BSA(20mM heparin added). Oviduct epithelium was collected in each stage of the estrus cycle and conditioned medium was the medium in which oviduct epithelium in early luteal stage was cultured. In vitro fertilized bovine embryos of 1～2 cell were co-cultured with oviduct epithelium from different estrus cycles, cultured in conditioned medium, and cultured in rabbit oviduct. The cleavage rates of in vitro fertilized early bovine embryos co-cultured with oviduct epithelial cell from early luteal, luteal and follicular phase of estrus cycle(67.2～70.8%) and cultured in conditioned medium(56.7%) were significantly(p<0.05) higher than that of the control(44.2%) The rate of development to morula or blastocyst stage in oviduct epithelial cell co-culture(15.3～32.5%) from three phase of estrus cycles and conditioned medium(14.5%) were significantly(p<0.05) higher than that of the control(5.2%). The oviduct epithelial cell from early luteal phase gave a significantly( p<0.05) higher rate of development to morula or blastocyst stage than both luteal and follicular phase. The results of in vivo culture in rabbit oviduct of early bovine embryos were 52.1% for the cleavage rate and 26.7% for the rate of development to morula or blastocyst stage.

• Journal of Environmental Health Sciences
• /
• v.37 no.2
• /
• pp.165-169
• /
• 2011

Between January 2010 and March 2011, there were three outbreaks of foot and mouth disease (FMD) in South Korea. Over 3.45 million animals (5,660 farms) were slaughtered, which was 33.3% of the existing pigs, 8.4% of dairy cows and 3.4% of cattle. FMD disaster costs were estimated at around three billion Korean won. Nine civil servants were killed, over 150 people were wounded and 4,788 landfills were confronted with a pollution problem. Vaccination and slaughter are the two basic alternatives for eradication of FMD. Altho ugh slaughter is more violent, risky and expensive than vaccination, the Korean government had chosen only slaughter eradication by the end of 2010. Even though over three million animals were killed, FMD spread out over most of the country. Finally, the government chose to begin vaccination. Following vaccination, outbreaks decreased dramatically. The purpose of this report is a cultural analysis of the related decision-making process, laws and systems. For the culture analysis, we utilize interviews, symposiums, laws, FMD manual, government reports and press releases. In conclusion, we found that the FMD massacre was influenced by cultural and organizational factors. The cultural factors were economism, cheapening of the value of life, biased perceptions and fears. The organizational factors were a closed process of decision-making, monopoly system, a small homogeneous group and group-think. Therefore, more studies will be needed for those factors of FMD disasters in national-scale cases.

• Korean Journal of Animal Reproduction
• /
• v.17 no.4
• /
• pp.271-278
• /
• 1994

The aim of this study was to compare the two culture systems 1) co-culture with cumulus cells and 2) chemically defined medium supplemented with amino acids (CR1aa) and fetal calf serum (FCS) of in vitro produced bovine embryos from follicular oocytes in vitro. Bovine follicular oocytes were collected from ovaries of slaughtered cows and matured in TCM199 supplemented with 10% FCS and hormones (1$\mu\textrm{g}$/ml FSH-P and 1$\mu\textrm{g}$/ml oestradiol-17$\beta$)24 hours at 39$^{\circ}C$ under 5% CO2 in air. The capacitation of spermatozoa from ejaculated or frozen bull semen was induced by centrifugation through Percoll density gradient (45%, 90%). Then capacitated spermatozoa (1$\times$106/ml) were inseminated into 50${mu}ell$ droplet containing matured follicular oocytes and incubated for 40~42 hours. Cleaved embryos of 2~4cell stage were transferred to the co-culture with cumulus cells and/or CR1aa medium supplemented with FCS. In semen source, the developmental rates to the blastocyst and the hatched blastocyst stages were higher in ejaculated semen(27.6% and 14.9%) than those of frozen-thawed semen(18.3% and 11.8%), respectively. In two culture systems, the proportions of embryonic development upto the blastocysts and the hatched blastocysts were higher of CR1aa medium (22.1% and 12.1%) than those of cumulus cell co-culture (16.8% and 5.1%), respectively. The number of cells in exapnded blastocysts was slightly higher in cumulus cells co-culture (122.6$\pm$8.5) than that in CR1aa medium (117.9$\pm$5.9). The present results indicated that the early development of in vitro produced bovine embryos can be maintained efficiently in CR1aa medium as well as in co-culture with cumulus cells.

• Korean Journal of Animal Reproduction
• /
• v.16 no.3
• /
• pp.239-246
• /
• 1992

Capacitated and acrosome~reacted spermatozoa were microinjected into the perivitelline space of bovine oocytes matured in vitro. Oocytes obtained from the ovaries of slaughtered heifers and cows were cultured in vitro in the TCM-199 supplemented with 20% FCS for 24 hr at 39$^{\circ}C$ under an atmosphere of 5% CO$_2$ 8% O$_2$. Fresh or frozen spermatozoa were incubated for 2 hr at 39°C under an atmos-phere of 5% CO$_2$, 8% O$_2$ in Ham's F-lO medium containing 0.75% BSA for capacitation, and kept for 30 min in culture medium containing 12 mM of dbcGMP and lOmM of immidazol for acrosome resction. One motile spermatozoon was injected into the perivitelline space of each oocyte. The 2nd polar body and the pronuclei were observed in 9.5% and 5.4% of oocytes, respectively. The rate of cleavage of oocyte over 2-cell stage was 4.1%(10 of 242), These results indicate that the microinjection may be a useful technique to study sperm-oocyte interaction.

• Korean Journal of Agricultural Science
• /
• v.44 no.3
• /
• pp.375-383
• /
• 2017

This study was conducted to investigate the effects of sex, environmental factors, and feeding system on the carcass traits of Hanwoo (Korean Native Cattle). Data were collected from 7,866 heads slaughtered in Chungnam province during one-year period. Using the collected carcass traits data which greatly influence a Hanwoo's carcass grade, the effects of sex class, slaughter season, and feeding system were estimated. Backfat thickness of steers was significantly higher than that of bulls (p < 0.05). Marbling score was also the highest in steers when compared with cows and bulls (p < 0.05). Live weight and carcass weight were significantly higher in winter than in summer (p < 0.05). However, backfat thickness was significantly lower in summer than in other seasons (p < 0.05). Marbling score was higher in spring and fall than in summer and winter (p < 0.05). In terms of feeding systems, TMR (Total mixed ration) and TMF (Total mixed fermentation feed) fed groups showed the highest carcass grade (p < 0.05). However, the group fed TMR and formula feed at the final fattening period showed the lowest performance (p < 0.05) and it is assumed that some stress was associated to the feed change. The results reconfirm that castration may be recommended in order to improve meat quality and marbling scores in bulls. There was no consistent trend of seasonal effects of slaughter on carcass traits although some traits were significantly affected. Regarding the feeding system, either TMR or TMF can be supplied to achieve high feed efficiency and good carcass characteristics in Hanwoo.

• Journal of Embryo Transfer
• /
• v.12 no.1
• /
• pp.21-27
• /
• 1997

The studies were carried out to investigate the effects of bisection method and with and without-zona pellucida of embryos on in vitro developmental rate bisected embryos by micromanipulator, micropipette and pipetting. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TCM-199 mediurn containing 10 IU /ml의 PMSG(Sigma, USA), 10 IU /ml의 hCG, 1$\mu$g /ml의 $\beta$-estradiol(Sigma, USA) and 10% FCS for 24~48 hrs in incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$ and then, matured oocytes were again cultured for 12~ 18 hrs with motile capacitated sperm by preincubation of heparin. Bisected embryos cultured for 1~5 days in 20% FCS + TCM-199 medium. Survival rate was defined as developmental rate on in vitro culture or FDA-test. The results are summarized as follows :1. The survival rates of bisected bovine embryos by micromanipulator and micropipett were 29.2% and 19.1%, respectively. The rates of non-bisection embryos(46.7%) were significantly higher than those of bisection embryos. 2. The in vitro developmental rates of bisected bovine embryos by micromanipulator, micropipett and pipetting method were 32.4%, 19.4% and 25.6%, respectively.3. The in vitro developmental rates of with and without-zona pellucida of bisected bovine embryos by raicromanipulator were 30.8% and 25.0%, respectively. The rates of nonbisection embryos(53.1%) were significantly higher than those of bisection embryos.

• Journal of Embryo Transfer
• /
• v.12 no.3
• /
• pp.283-291
• /
• 1997

In vitro development of bovine embryos is affected by many factors such as energy substrates, amino acids, and some growth factors. It has been reported that mRNA of insulin, PDGF and their receptors are detected in cow embryos, and that some chelating agents such as EDTA and transferrin have beneficial role on mouse and bovine embryos. The author hypothesized that insulin, transferrin arid PDGF added to a culture medium increase in vitro development of bovine embryos by chelating toxic substance(s) or increasing cell growth and metabolism. Immature oocytes from slaughtered ovaries of Holstein cows and heifers were matured for 24 hours in a TCM199 containing 10% fetal calf serum, FSH, LH and estradiol with granulosa cells in vitro. Matured oocytes were coincubated with sperm for 30 hours in a modified Tyrode's medium (IVF). Embryos cleaved to 2- to 4-cell at 30 hours after IVF were selected and cultured in a 30-$\mu$l drop of a synthetic oviduct fluid medium (SOFM) containing 0.8% BSA, Minimum Essential Medium essential and non-essential amino acids, and insulin, transferrin or PDGF for 9 days. Supplementation of a SOFM with insulin, and /or transferrin did not increase develop-mental rate to expanding and hatching blastocyst of 2- to 4-cell bovine embryos compared with control. The highest developmental rate to hatching blastocyst was shown when PDGF was added at the concentration of 10 ng /ml among the supplementing doses tested in the present study (p<0.05). Addition of PDGF without insulin to a SOFM could not increase embrye development, but combined addition of PDGF with insulin significantly increased (p<0.05) embryo development to hatching blastocyst (50%) compared with control (38%). In conclusion, insulin and PDGF supplemented to a SOFM may act synergistically and have beneficial effect on in vitro development of 2- to 4-cell bovine embryos matured and fertilized in vitro.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.9
• /
• pp.1260-1266
• /
• 2001

The effect of protein supplementation, $O_2$ concentration and co-culture on the development of embryos produced by nuclear transfer using cultured cumulus cell was investigated. Recipient oocytes and cumulus cells were obtained from the ovaries of the slaughtered Hanwoo cows. Donor cumulus cells were cultured in Dulbecco's modified Eagle medium containing 10% fetal bovine serum at 5% $CO_2$ in air at $38.5^{\circ}C$. The 1 to 6 passages of cumulus cells were isolated and used as donor cells. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. One $15{\mu}s$ pulse of 180 volts was applied to induce the fusion between karyoplast and cytoplast. The fused embryos were activated with $10{\mu}M$ calcium ionophore for 5 min and 2 mM 6-dimethylaminopurine for 3 h. To examine the effect of protein supplementation, nuclear transfer (NT) embryos were cultured in one of the following 4 treatments : 1) CR1aa + 3 mg/ml BSA for 7 days ; 2) CR1aa + 10% FBS for 7 days ; 3) CR1aa + 1.5 mg/ml BSA + 5% FBS for 7 days ; and 4) CR1aa + 3 mg/ml BSA for first 3 days and then CR1aa + 1.5 mg/ml BSA + 5% FBS for 4 days. Culture took place at 5% $CO_2$, 5% $O_2$ and 90% $N_2$ at $38.5^{\circ}C$. Although there were no significant differences in cleavage rate among different protein supplements, the rates of blastocyst formation were significantly different. When NT embryos were cultured in the medium supplemented with only BSA, they could develop to only morula not to blastocyst. However, when FBS was supplemented, NT embryos developed to blastocyst stage. In order to investigate the effect of $O_2$ concentration and co-culture, NT embryos were cultured in CR1aa + 1.5 mg/ml BSA + 5% FBS with or without cumulus cell co-culture at an atmosphere of 5% $CO_2$ in air (20% $O_2$) or 5% $CO_2$, 5% $O_2$, 90% $N_2$ (5% $O_2$) at $38.5^{\circ}C$ for 7 days. The percentage of blastocyst development was significantly higher when the NT embryos were cultured at an atmosphere of 5% $O_2$ than that of 20% $O_2$ (p<0.05). However, there was no significant difference between with and without cumulus cell co-culture at an atmosphere of 5% $O_2$ or 20% $O_2$. Fifty embryos were transferred to 25 recipients and 5 recipients were pregnant at 100 days. From 5 pregnant cows, only one cow was delivered of female twin. In conclusion, the embryos reconstructed by enucleation of metaphase II oocytes and introduction of the cycling and quiescent cumulus donor cells in Hanwoo had developmental potential to term after embryo transfer to recipient cows.