The general objective of this study was to perform follow-up studies including selected peri- and postnatal characteristics on calves born after transfer of in vitro produced (IVP) em- bryos vitrified by the ’Open Pulled Straw’ (OPS) method. An overall pregnancy rate of 16% after transfer of the OPS-vitrified IVP embryos was achieved and resulted in birth of 9 calves, with 11 AI calves serving as controls. There were no immediate or long- term effects on these calves with respect to birth weight, gestation length, perinatal mor- tality, growth rate, disease susceptibility and reproductive performance.
IVP