Effect of post-thaw cell rehydration at 4 degrees C on survival of frozen and vitrified IVP-derived bovine embryos.
In vitro-produced bovine embryos (IVP) were either frozen in 10% glycerol in a phosphate-buffered saline solution (PBS) using conventional slow freezing or vitrified in 25% glycerol and 25% ethylene glycol in PBS. The results of viability and hatching rates were compared between frozen and vitrified embryos after thawing and dilution using one of three different protocols: (A) a three-step dilution procedure, (B) a one-step dilution procedure or (C) a procedure in which embryos were kept in situ inside the straw at 4 degrees C for 10 min during a one-step dilution procedure. No significant differences in embryo survival were found among protocols A, B and C for frozen embryos and between protocols A and B for vitrified embryos. Viability and hatching rates of vitrified embryos thawed and diluted by protocol C (73 and 62%) were significantly enhanced (P < 0.05) in comparison to those obtained with protocol A (55 and 41.6%) or protocol B (54.5 and 35.3%). These results indicate that for vitrified IVP bovine embryos, direct in-straw rehydration at 4 degrees C for 10 min improves embryo survival and it could be a practical procedure for use under field conditions where there is sometimes a longer interval between thawing and transfer.
Gutiérrez-Adán
A
A
Departamento de Reprodución Animal y Conservación de Recursos Zoogenéticos, INIA, Madrid, Spain. agutierr@inia.es
Granados
J
J
De La Fuente
J
J
D000818:Animals; D002021:Buffers; D002417:Cattle / Q000196:embryology*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D004622:Embryo, Mammalian / Q000502:physiology*; D019855:Ethylene Glycol; D005260:Female; D005307:Fertilization in Vitro; D005990:Glycerol; D006358:Hot Temperature; D010710:Phosphates; D012996:Solutions; D013395:Sucrose
D002021:Buffers; D003451:Cryoprotective Agents; D010710:Phosphates; D012996:Solutions; D013395:Sucrose; D019855:Ethylene Glycol; D005990:Glycerol