우 수정란의 형태 및 발육단계가 수태율에 미치는 영향에 관한 연구 = The Studies on the Effects of Embryo Morphology and Assessment of Embryo Quality on Pregnancy Rates in Holstein Cows

다국어 초록 (Multilingual Abstract)

The studies was conducted to investigate the effects of embryo morphology and assessment of embryo quality on pregnancy rates in Holstein cows. Embryo were non-surgically recovered from superovulated donors 6 to 8 days after estrus (estrus = day 0). The donor and recipient cows were Holstein cows and heifers. All embryos were individually examined at 200 X magnification for cell stage of development and embryo quality. Embryos were surgical and nonsurgically transferred to recipients that with a ± 1 day of estrous cycle synchrony with donors. The pregnancy rates conduced on 60 days rectal palpation. 1. Embryos of excellent, good, fair and poor categories by surgical transfer were resulted in 71.4%., 66.7%, 50.0% and 0% pregnancy rate, respectively. The mean pregnancy rate of various of embryo quality was resulted in 62.1%. 2. Embryos of excellent, good, fair and poor categories by transcervical transfer were resulted in 5 3.8 io, 50.0%, 40.0% and 20.0% pregnancy rates, respectively. The mean pregnancy rates of various embryo quality was resulted in 46.2%. 3. The mean pregnancy rates of embryo quality by surgical and transcervical transfer were resulted in 51.1%. Embryos of excellent and good quality yiehied the highest pregnancy rates. 4. Embryos of morula, compacted morula, early blastocyst, blastocyst, expanded blastocyst and hatched blastocyst by surgical transfer were resulted in 33.3%, 66.7%, 80.0%, 80.0%, 66.7% and 0% pregnancy rates, respectively. The mean pregnancy rate of various stages of embryonic development was resulted in 68.2%. 5. Embryos of morula, compacted morula, early blastocyst, blastocyst, expanded blastocyst and hatched blastocyst by transcervical transfer were resulted in 28.6%, 35.7%, 63.6%, 83.3%, 75.0% and 33.3.% pregnancy rates, respectively. The mean pregnancy rate of various stages of embryonic development was resulted in 51.5%. 6. The mean pregnancy rates of embryonic developmental stage by surgical and transcervical transfer was resulted in 56.7%. Embryos of early blastocyst, blastocyst and expanded blastocyst yielded the highest pregnancy rates.