• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.305-310
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• 2019

Embryos produced with serum show the alterations in their ultrastructure, impaired compaction, abnormal blastulation, aberrant mRNA expression profiles and large calf syndrome with greater incidences of stillbirths and deaths after birth. The aim of the present study was to describe in vitro embryo production by analyzing embryo production, fetal production and pregnancy rate in free-serum medium. The OPU-IVP data used in this study from 2016. Approximately, sixteen cows (Hanwoo), which belonged to the Institute of Gyeongsang National University, were used. Two experimental group is used in this study. Serum groups were conducted in March to July and free-serum group was conducted in September to December. The recovered cumulus-oocyte complexes were morphologically classified to four grades based on the compaction of cumulus cells layers and homogeneity of the cytoplasm. The number of oocyte was significantly greater in serum groups than that in free-serum groups (29.61 ± 0.63 vs. 15.6 ± 0.62; p < 0.05). Between serum and free-serum groups indicate that average of 1st and 2nd grade oocytes were no difference (2.38 ± 1.67 vs. 2.38 ± 1.48; p > 0.05), but number of 3rd and 4th grade oocytes were greater in serum groups than that in free-serum groups (7.31 ± 7.64 vs. 5.60 ± 6.29; p < 0.05). Embryo cleaved competence was higher in rate in free-serum groups than that in serum groups (62.1% vs. 58.3; p < 0.05). However, blastocyst developmental rate was no difference between serum and free-serum groups (33.1% vs. 43.5%; p < 0.05). 986 recipients were used for embryo transfer. Pregnancy rate was indicated that between serum and free-serum group was no difference (54.6% vs. 56.3%; p < 0.05). In conclusion, we developed the free-serum system for production of in vitro bovine embryos in order to meet the developmental and qualitative requirements for large scale commercial use.

• Journal of Embryo Transfer
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• v.9 no.2
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• pp.145-152
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• 1994

The suitable electric stimulation is essential for activation and fusion of oocytes before or after nuclear transplantation The present study was undertaken to determine the optirnal condition for the parthenogenetic activation of in vitro rnatured(IVM) bovine oocytes by electric stimulation. Different direct current(DC) electric voltage of 1.0, 1.5 and 2.0 kV/cm and pulse duration of 30, 60 and 120 $\mu$sec were applied to the JVM nocytes in 0.3 M mannitol solution containing each 100 $\mu$M CaCl$_2$ and MgCl$_2$. IVM occytes at 24, 28 and 32 hours Post-maturation(hpm) were also electrically stimulated at 1.5 kV /cm, for 60 $\mu$ sec. The stimulated nocytes were then co-cultured in TCM-199 solution containing 10% fetal calf serum with bovine oviductal epithelial cells for 7~9 days in a 5% $CO_2$ incubator at 39$^{\circ}C$ ~ Their activation and in vitro development to morula and blastocyst were assessed under an inverted microscope. The higher activation rates 62.8 and 63.4% and in vitro de- velopment rates to morula and blastocyst 5.1 and 10.9% were shown in the oocytes stimulated at the voltage of 1.0 and 1.5 kV/cm than 2.0 kV/cm, respectively. No signifi- cantly(P<0.05) different activation rate was shown in JVM oocytes stimulated for 30, 60 and 120 $\mu$sec, but developmental rates to morula and blastocyst was significantly(P<0.05) higher in the oocytes stimulated for 30 $\mu$sec(6~3%) and 60 $\mu$sec(10~0%) than 120 $\mu$sec(0~ 0%). The aged oocytes at 28 and 30 hpm showed significantly(P<0.05) higher activation rates(72~7 and 79.7%) than the oocytes at 24 hpm(50~9%)~ Also, their developmental rates to morula and blastocyst were significantly(P<0.05) higher in the nocytes at 28(14.3%) and 32 hpm(15.9%) than 24 hpm(3.6%). From these results, it can be suggested that the optimal electric stimulation for IVM bovine occytes is a DC voltage between 1.0 and 1.5 kV/cm, pulse duration of 30 or 60 $\mu$sec, and the optimal age of IVM oocytes for electric activation is at 32 hpm.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.667-672
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• 2011

This study was carried out to increase the breeding rate using sustained recombinant bovine somatotropin (bST) and examine the reproductive disorder and disease prevalencies of cow and calf, respectively. Sixty cows were allotted randomly to three groups in randomized complete block design; (1) No treatment, (2) 500 mg bST two times + 250 mg bST SC injection five times from 3 weeks before to 9 weeks after parturition every two weeks, (3) 500 mg bST two times before 3 weeks parturition + 250 mg bST SC injection three times from five to 9 weeks after parturition every two weeks. Developmental data of birth weight, weaning weight, total gain and average daily gain in control was $22.9{\mu}0.45$ kg, $88.0{\mu}1.13$ kg, $65.1{\mu}0.74$ kg and $0.54{\mu}0.08$ kg, respectively. There is no significant difference between Group 1 and 3 in the examined factors. However, there is significant difference between Group 1 and 2 in the birth weight ($24.4{\mu}0.88$ kg), weaning weight ($101.0{\mu}1.77$ kg), total gain ($76.7{\mu}0.9$ kg) and average daily gain ($76.7{\mu}0.9$ kg). Total gain was showed higher in Group 2 and 3 than Group 1 in the >2nd parity, and in Group 2 than Group 1 and 3 in the 1st parity. There is no significant difference in the BCS, no return days and disease occurrence of cow and calf by bST treatment. Number of service per conception was slightly increased in the Group 3 compared to Group 1 and 2. To increase the breeding ability of Hanwoo, it is recommended that 500 mg bST two times + 250 mg bST injection five times from 3 weeks before to 9 weeks after parturition every two weeks.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.27-36
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• 1997

The studies were carried out to investigate the effects of co-culture with cumulus cells and oviduct epithelial cells on the in vitro fertilization and cleavage rate of bovine follicular cocytes and to determine the optimum thawing temperature and equilibration time on in vitro developmental rate of frozen bovine embryos. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TGM-199 medium containing 10 IU /ml의 PM SG, 10 IU /ml의 hCG, ip g/ml의 $\beta$-estradiol and 10% FCS for 24~48 hrs in incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$. The bovine embryos following dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquld nitrogen and thawed in 3$0^{\circ}C$ water. Survival rate was defined as developmental rate on in vitro culture or FDA-test. The results are sunanarized as followes :1. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with cumulus cells in TCM499 medium were 75.0~76.8% and 17.3~27.6%, respect-ively. And in-vitro fertilization rates of cumulus-enclosed oocytes(55.4%)were significantly(p<0.05) higher than cumulus-denuded oocytes (23.1%). 2. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with l$\times$ l04cells /ml, 1 x l06cells /ml, lx l08cells /ml and 1 x l015cells /ml oviduct epithelial cells in TCM-199 medium were 74.5~77.8% and 15.7~21.20 respectively.3. The in-vitro fertilization and in vitro developmental rates of bovine oocytes cocultured in '1CM-199 media containing PMSG, hCG, PMSG+hCG. PMSG+$\beta$-estradiol, hCG+$\beta$-estradiol 0 to 40 hrs after insemination were 74.0~77.4% and l8.9~23.l%, re-spectiv ely.4.The survival rates of bovine embryos thawed after rapid freezing in the freezing medium containing a various concentration of sucrose added 1.5M and 2.OM glycerol,DMSO and propanediol were 23.5~31.4% and 20.6~34.l%, respectively. 5. The temperature thawed at 3$0^{\circ}C$ after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 2$0^{\circ}C$ and 35$^{\circ}C$.6. The equilibration time on the survival rates of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (10~20min.). (Key words : bovine embryos, co-culture, freezing, in vitro development)

• Journal of Embryo Transfer
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• v.29 no.3
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• pp.283-287
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• 2014

Sexed semen is commonly used for the production of calves of the desired gender. Gender selection is important in animal production industries. For example, female cattle are required for the dairy industry while males are preferred in the beef cattle industry. The present study was to assess the in vivo embryo production efficiency using the semen separated according to sex during superovulation in Hanwoo. Seventy Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with embryo collection medium. KPN semen straws used artificial insemination contained 20 million sperm (total number 60 million per donor). Sex-sorted semen straws contained 4 million sperm (total number 12 million per donor). The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on KPN semen 87%, and sexed semen 100%, respectively. The mean numbers of total embryos are each $12.58{\pm}8.31$ and $13.25{\pm}7.86$. The mean numbers of transferable embryos, sexed semen were significantly lower than KPN semen ($3.75{\pm}1.98$ vs. $8.23{\pm}6.07$, P<0.05). The rates of unfertilized embryos from superovulation using sexed semen were significantly higher than KPN semen (50% vs. 15%, P<0.05). The rate of degenerated 2-cell embryos from sexed and KPN semen was 60.87% and 11.11%, respectively (p<0.05). In conclusion, these results indicate that superovulation using sexed semen was useful, but efficient embryo production was important to reducing the damage caused by the Flowcytometer-based sperm sorting procedure.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1202-1208
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• 2020

Objective: The aim of this study was to identify a distribution pattern of meat quality grade (MQG) as a function of carcass yield index (CYI) and the gender of Hanwoo (bull, cow, and steer) to determine the optimum point between both yield and quality. We also attempted to identify how pre- and post-deboning variables affect the gender-specific beef quality of Hanwoo. Methods: A total of 31 deboning variables, consisting of 7 pre-deboning and 24 post-deboning variables from bulls (n = 139), cows (n = 69), and steers (n = 153), were obtained from the National Institute of Animal Science (NIAS) in South Korea. The database was reconstructed to be suitable for a statistical significance test between the CYI and the MQG as well as classification of meat quality. Discriminant function analysis was used for classifying MQG using the deboning parameters of Hanwoo by gender. Results: The means of CYI according to 1+, 1, 2, and 3 of MQG were 68.64±2.02, 68.85±1.94, 68.62±5.88, and 70.99±3.32, respectively. High carcass yield correlated with low-quality grade, while high-quality meat most frequently was obtained from steers. The classification ability of pre-deboning parameters was higher than that of post-deboning parameters. Moisture and the shear force were the common significant parameters in all discriminant functions having a classification accuracy of 80.6%, 71%, and 56.9% for the bull, cow, and steer, respectively. Conclusion: This study provides basic information for predicting the meat quality by gender using pre-deboning variables consistent with the actual grading index.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.216-224
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• 1998

This study was performed to offer the basic and applicable data for improvement of Korean cattle and dairy cattle, according to finding the genetic construction obtained from analysis of genetic polymorphisms of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci related Korean cattle and Holstein cows using PCR-RFLP. Genomic DNA used in this study was prepared from the blood of 253 individuals of Korean cattle in Korean Native Cattle Improvement Center, NLCF, and the blood of 113 individuals of Holstein cows in National Livestock Research Institute. The results obtained are summarized as follows : 1. This study confirmed amplified products of 530bp and 262bp fragments obtained from the amplification of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci in Korean cattle and Holstein breed by PCR. 2. The ${\beta}$-lactoglobulin AA genotype showed 153bp and 109bp fragments, and ${\beta}$-lactoglobulin AB genotype showed 153bp, 109bp, 79bp and 74bp fragments, and BB genotype showed 109bp, 79bp and 74bp fragments in amplified products of ${\beta}$-lactoglobulin loci with the restricted enzyme digestion of Hae III. 3. The ${\kappa}$-casein AA genotype showed a 530bp fragment, and ${\kappa}$-casein AB genotype showed 530bp, 344bp and 186bp fragments, and BB genotype showed 344bp and 186bp fragments in amplified products of ${\kappa}$-casein loci with the restricted enzyme digestion of Taq I. 4. On ${\beta}$-lactoglobulin genotypes and gene frequencies, Korean cattle were 6.72%, 26.09% and 67.19% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.197 and 0.803, and Holstein were 35.40%, 56.64% and 7.96% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.637 and 0.363, respectively. 5. On ${\kappa}$-casein genotypes and gene frequencies, Korean cattle were 46.25%, 39.13% and 14.62% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.658 and 0.342, and Holstein were 60.18% and 38.94% and 0.88% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.796 and 0.204, respectively. 6. As a consequence, the gene frequency was 0.197 and 0.803 for ${\beta}$-lactoglobulin A and B alleles, and 0.658 and 0.342 for ${\kappa}$-casein A and B alleles in Korea cattle, but was 0.637 and 0.363 for ${\beta}$-lactoglobulin A and B alleles, and 0.796 and 0.204 for ${\kappa}$-casein A and B alleles in Holstein, respectively.

• Korean Journal of Veterinary Research
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• v.31 no.2
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• pp.179-187
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• 1991

These studies were carried out to investigate the effects of the size of follicles, semen types, capacitation methods, and additions of hormones, estrous cow serum(ECS), fetal calf serum(FCS), bovine follicular fluid(BFF) and matured cumulus cell(MCC) to the medium on in vitro maturation and fertilization of bovine follicular oocytes. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluid from the visible follicles of diameter 3~5mm. The follicular oocytes were cultured in TCM-199 medium containing hormones, FCS, ECS, BFF and MCC for 24~48hrs. in an incubator with 5% $CO_2$ in air at $38.5^{\circ}C$ and then matured oocytes were again cultured for 18~20 hrs. with motile capacitated spermatozoas the TCF (Tyrode calcium free) solution containing $100{\mu}g/ml$ of heparin. The results obtained in these experiments were summarized as follows: 1. The oocytes classified as "A,B,C,D and Degenerative" depending morphological integrity and those 61.4%, 12.1%, 19.2%, 4.2% and 3.0% of the total oocytes recovered, respectively. The maturation and fertilization rate of the A, B, C class follicular oocytes, cultured in the TCM-199 medium supplemented with 10% FCS were 89.1%, 78.0%, 52.6% and 78.1%, 66.1, 33.3%, respectively. 2. The average number of the follicular oocytes recovered from follicles size, 1~2mm, 3~5mm and above 5mm in diameter were 67, 98 and 63, respectively. The maturation and fertilization rate of the follicular oocytes, cultured in the TCM-199 medium were 56.7%, 82.5%, 46.0% and 44.8%, 71.4%, 28.6%, respectively. 3. The fertilization and cleavage rate of the follicular oocytes, inseminated with spermatozoas of epididymal cauda, neat and frozen semen were 63.3%, 73.3%, 70.0% and 32.7%, 37.8% 38.3%, respectively. 4. The fertilization and cleavage rate of follicular oocytes, fertilized with capacitated spermatozoas by heparin, BFF and HIS methods were 70.0%, 53.8%, 34.2% and 38.3%, 23.1%. 17.1%, respectively. And the fertilization and cleavage rate were higher method of heparin. 5. The maturation and fertilization rate of follicular oocytes, cultured in the TCM-199 medium supplemented with 5%, 10%, 15%, 20% and FSH, HCG, 17, $\beta$-estradiol were 76.0~82.3% and 26.2~70.0%, and those values were higher the supplementation than non-supplementation. 6. The maturation and fertilization rate of the follicular oocytes cultured in TCM-199 medium supplemented with 5~20% ECS and FCS were 74.0~80.6%, 26.2~30.0% and 71.7~76.9%, 51.9~58.0%, and the values were higher the supplement of ECS than FCS. 7. The maturation rate (68.0~64.6%) and fertilization rate(59.6~60.4%) of follicular oocytes cultured in TCM-199 medium supplemented with 10% FCS and 20~30% BFF were higher than those of follicular oocytes cultured TCM-199 medium supplemented with 10% FCS and 10% and 50% BFF. 8. The maturation rate(76.5%) and fertilization rate (61.7%) of follicular oocytes cultured in TCM-199 medium supplemented with 10% FCS and $1{\times}10^6/ml$ MCC were higher than those of follicular oocytes cultured in TCM-199 medium supplemented with 10% FCS and $1{\times}10^{{4}{\sim}{5}}/ml$ and $1{\times}10^8/ml$ cumulus cells.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.147-156
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• 1997

Ultrasound-guided follicular aspiration was performed in Holstein heifers once weekly with or without pretreatment of single or multiple decreasing doses using a total of 400 mg FSH. Oocytes were aspirated with a 6.5 MHz convex-array ultrasound trasducer designed for intravaginal use. All the visible follicles larger than 4 mm in diameter were punctured with a 17 gauge, 55 cm needle at each aspiration session and the follicular fluids containing oocytes were obtained by vacuum suction. The results obtained were as follows: As a preliminary experiment, the recovery rates of folicular oocytes by ultrasound-guided aspiration from the isolated ovaries of Korean native cows were compared between suction methods using manual syringe or vacuum pump. The recovery rate of oocytes using vacuum pump (80.7%) was significantly (P<0.05) higher than that using manual syringe (47.1%). The follicles were counted by their size in diameter with ultrasound image, and recovery rates and grades of follicular oocytes collected by ultrasound-guided aspiration were investigated in Holstein heifers pretreated with or without FSH. A group of heifiers were injected with multiple decreasing doses (twice a day for 3 days) of a total of 400 mg FSH. The other 2 groups were injected with a single dose of 400 mg FSH mixed with 25% PVP. Ultrasound observation of follicle population and/or ultrasound-guided transvaginal oocyte aspiration were performed 12 hrs following the last FSH injection in the multiple dose group, and 48 or 60 hrs after FSH injection in the single dose groups. Most of the visible follicles had small size of less than 3 mm in diameter in unstimulated heifers (71.0%), but medium size in all the heifers treated with FSH. (70.5 to 92.8%). The number of OPU follicles per session (4.6$\pm$1.9) were much less, compared to the vilsible follicle counts (9.7$\pm$2.2), in the nustimulated heifers due to the small dominant follicles. Among 4 goups of heifers the most visible as well as OPU follicles were observed in the heifers at 60 hrs following treatment of a single dose of 400 mg FSH (21.2$\pm$2.3 and 21.0$\pm$2.0), and the differences in both the follicle counts between the groups was found significant (P<0.05) The rates of oocyte recovery from the follicles by ultrasound-guilded aspiration were varied 46.3 to 75.0% in the heifers unstimulated and treated with a single dose of 400 mg FSH, but the group difference was not significant. The number of recovered oocytes per session a, pp.ared to be highest at aspiration at 60 hrs following single FSH (10.6$\pm$2.2) than at aspiration at 48 hrs after single FSH (7.8$\pm$2.7) or in the unstimulated heifers (3.4$\pm$3.0). The proportion of grade I and II oocytes to all oocytes collected was varied 31.8 to 64.0% between the groups. However, there was found no significant difference in both the number of oocytes recovered per session and the percentage and the percentage of grade I and II oocytes. From the above results it was concluded that the more oocytes of superior quality might be recovered economically by ultrasound-guided aspiration at 60 hrs following the pretreatment of a single dose of 400 mg FSH and by suction using a vacuum pump system of about negative pressure of 75 to 85 mmHg.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.307-318
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• 2005

This study was conducted to examine effects of brewery meal-based fermented feedstuff supplemented with Aspergillus oryzae(AO) or Saccharomyces cerevisiae(SC) on luminal micro-organism of Korean native cattle. Two cows equipped with luminal cannulas were used as experimental animals. Experiment was done with three treatment groups: $71.5\%$ of commercial feed and $28.5\%$ of com silage(control): $45.0\%$ of commercial feed, $26.5\%$ of fermented feedstuff supplemented with AO and $28.5\%$ of corn silage(TAO): $45.0\%$ of commercial feed, $26.5\%$ of fermented ffedstuff supplemented with SC and $28.5\%$ of corn silage(TSC). The number of total viable bacteria (p<0.05), anaerobic fungi and protozoa(p<0.05) was higher in TAO and TSC than in control. The number of proteolytic bacteria(p<0.05), cellulolytic bacteria and xylan fermenters tended to be higher in TAO and TSC than in control. The dry matter recovery (DMR) of protozoa was higher in TAO and TSC than in control(p<0.05). The crude protein (CP) content of total microbes and protozoa was higher in TSC than in control and TAO (p<0.05). The CP content of bacteria was higher in TAO and TSC than in control(p<0.05). The ether extract(EE) content of the total microbes was higher in TAO than in control and TSC(p<0.05), and the EE of protozoa and bacteria were higher in TSC than in control and TAO(p<0.05). The ratio of essential amino acids of total microbe was higher in control than in TAO and TSC(p<0.05). The ratio of methionine and alanine of bacteria was higher in TAO and TSC than in control(p<0.05). The results suggested that the feeding of fermented feedstuff supplemented with AO or SC had an influence on the numbers of ruminal microorganism and the changes of microbial body composition.