title: In vivo and in vitro survival of goat embryos after freezing with ethylene glycol or glycerol.
abstract: The aim of the present study was to compare the survival rates of goat morulae and blastocysts after different freezing procedures. The viability of frozen-thawed embryos was assessed both in vivo and in vitro. Two cryoprotectants, ethylene glycol and glycerol, were used and three cryoprotectant removal procedures were compared: progressive dilution in 1.0, 0.5, 0.3 and 0 M of cryoprotectant in PBS; a similar progressive dilution with cryoprotectant in PBS plus 0.25 M of sucrose; or one-step transfer in PBS containing 0.25 M of sucrose. In vitro development of frozen-thawed blastocysts was always higher than that of frozen morulae irrespective of the cryoprotectant (52 129 = 40.3% vs 23 161 = 14.3% ; P< 0.001). In vivo, however, frozen-thawed morulae developed equally as well as blastocysts after an identical freezing-thawing protocol. Development both in vivo and in vitro showed ethylene glycol to be a better cryoprotectant than glycerol for goat embryos at both developmental stages (23 vs 0%, 45 vs 35% in vitro; 34.5 vs 21%, 35 vs 23% in vivo for morulae and blastocysts, respectively).
authors.affiliation: Unité de Biologie de la Fécondation-Station de Physiologie animale I.N.R.A. 78352 Jouy-en-Josas Cédex, France.
authors.forename: F
authors.initials: F
authors.lastname: Le Gal
authors.forename: G
authors.initials: G
authors.lastname: Baril
authors.forename: J C
authors.initials: JC
authors.lastname: Vallet
authors.forename: B
authors.initials: B
authors.lastname: Leboeuf