This study was focused on improvement of milk production in Mongolia dairy industry by artificial insemination (AI) technology, of which was supported from ODA project of KOICA in Republic of Korea. The study was started from January 2009 to present and 3rd years in this year. So, all data, especially synchronization and pregnancy of dairy cows (Holstein) will be summarized in final result in this year. For synchronization, total 81 dairy cows selected from 4 private farms that were 38, 30, 8 and 5 in Undarmal milk, Onjin (Enkhbayer), Jargalant, and BRM School, respectively. All the dairy cows were injected intramuscular (IM) of 5 ml PGF2α in the vulva and detected estrus 2 to 3 days after PGF2α injection. Total 78 out of 81 dairy cows (96.3%) were detected estrus by only 1 time injection of PGF2α. The dairy cows that were induced estrus, inseminated with 0.5 ml dairy frozen semen by conventional AI techniques. The pregnancy diagnosis of the AI dairy cows was detected by uterus palpation after 60 days of insemination. Total 75 from 78 inseminated dairy cows (90.1%) were diagnosis pregnant. The estrus induction and pregnant rate were very effective using PGF2α injection and conventional AI techniques in Mongolia dairy cow. The results indicated that AI after estrus induction in Mongolia dairy cows could be applied to dairy breeding technology to improve the breeding efficiency and milk production.

The present research was carried out to evaluate the possibility of female offspring production using artificial insemination buffer (AIB) before artificial insemination (AI). To do it, we carried out the optimization of AIB, making of AIB gun and analysis of affecting AI rate after AIB treatment. AIB made with the base of Tris‐buffer supplemented with L‐arginine and several materials that could be reduced the motility of male sperm compared with female one. This mean that female sperm could be increased the possibility of fertilization with ovum compared with male one. AIB must be deposited into 2nd to 4th cervix by the guide of AIB gun. After 15 min of AIB insertion, frozen semen was deposited into same place after. Total 352 cattle were inseminated with AIB insemination and was not significant difference between AIB and traditional AI rate (56.8 vs. 55.7%). However, AIB AI rate was significantly differs among 12 different farms. The parturition number of cows did not effect on AIB AI rate among 1st to 7th parturition number of cows. The proportion of AIB AI success rates in hanwoo cows was significantly higher than in dairy cows (61.0% vs. 48.7%), but the average AI success rate was not different between AIB and conventional AI (56.8% vs. 55.7%). The female offspring production rate in 2nd to 4th cervix deposition place was significantly higher than in uterus body (77.7% vs. 59.6%, p<0.05). The injection volume of AIB in 5 and 10 ml was significantly higher than in 2 ml (77.7, 78.7 vs. 51.8%, p<0.05), but not different between 5 and 10 ml ABI volume. The best exposure time of AIB in the cervix was 10 and 15 min rather than that of 5 min (79.2%, 77.2% vs. 63.2%, p< 0.05), and so AIB have to expose at least 10 min to get higher female offspring. In conclusion, AIB could be used in AI industry to produce female offspring and also AIB AI can be increased the AI success rate compared with traditional AI rate.

The objective of this study was to evaluate the comparison of production efficiency of oocytes and OPU (ovum pick‐up) derived embryos of Hanwoo with Holstein. The OPU session of each species (6 cows) was carried out from the Hanwoo (106 sessions) and Holstein (114 sessions) at intervals of 3 4 days (2 times per week) for 3 months. Cumulus‐oocyte‐complexes (COCs) retrieved were classified into 4 grades by the status of oocyte cytoplasm and cumulus cells. The COCs collected were matured in vitro in TCM‐199 supplemented with 10% FBS, 10 mg/ml FSH and 1 mg/ml estradiol‐ 17β in 5% CO2 and over 99% humidity for 24 h. After 24 h co‐incubation with post‐thaw sperm, the presumed zygotes were cultured in CR1aa medium with 4 mg/ml BSA for 3 days and then changed CR1aa medium with 10% of FBS for another 3 4 days. The Mean number of aspirated follicles and collected oocytes were not significantly different between Hanwoo and Holstein spacies (10.4±0.42 vs. 11.4±0.41 and 7.5±0.38 vs. 6.1±0.37 per session). But the collection rate of oocytes from aspirated follicles were significantly higher in Hanwoo (72.8%) than that in Holstein (53.6%) (p< 0.05). Furthermore, the average number of good quality oocytes (Grade I and II) was 5.9±0.28 and 4.1±0.27 (Mean±SD), and the cleavage rate and the development rate to blastocysts was significantly (p<0.05) higher in Hanwoo (40.0%) than Holstein (21.6%). The OPU derived embryos of Hanwoo were transferred 83 times into 52 recipients and then 42 calves were produced from 44 pregnancy recipients. In conclusion, the efficiency of OPU derived embryo was significantly different between Hanwoo and Holstein species. In vitro culture system for OPU derived embryo production should be optimized for industrialization and the improvement of livestock.