Abstract
Pregnancy rate from 970 imported frozen-thawed bovine embryos was 63.4%. Pregnancy rate (number of recipients) of USA, Canada and Netherlands embryos was 66.2 (524), 59.9 (409) and 62.1% (37), respectively. Pregnancy rate (number of recipients) using cryoprotectants of 1.4 M glycerol (Gly), 1.4 M Gly + 0.1 M sucrose (Suc), 1.5 M ethylene glycol (EG) and 1.7 M EG was 67.5 (570), 52.5 (61), 59.2 (306) and 51.5% (33), respectively. Pregnancy rate with deep point or shallow point transfer position of uterine horn using 1.5 M EG (32.6 or 63.7%) and 1.7 M EG (15.4 or 75.0%) was significantly different (p< 0.05). Deep point of uterine horn was about 10-14 cm apart (deep intrauterine) and shallow point was about 2-4 cm apart (close to uterine body) from the uterine body bifurcation, respectively. Pregnancy rate of poor quality embryos (61 embryos) after dilution with 1.4M Gly was significantly different (p< 0.05) with deep point (48.3%) or shallow point (25.0%) uterine horn transfer. Abortion occurred in 39 head, and abortion rate was 6.3% of total pregnant recipients. Abortion rate of embryos after dilution with 1.4M Gly was significantly different (p< 0.05) with good quality embryos (5.9%) or poor quality embryos (18.2%).
