Deep freezing of cattle embryos in glass ampules or French straws.
Ninety four cow embryos recovered on day 7-8 after onset of oestrus were frozen by the "Two Step" freezing procedure: 49 in pyrex glass ampules and 45 in .25 ml French semen straws. The overall survival rate was 33.7% (36.2% for embryos frozen in glass ampules; 31.1% for embryos frozen in plastic straws). 45.2% of transferred embryos resulted in pregnancies (35.7% after freezing in glass ampules v.s 52.9% after freezing in plastic straws).
Massip
A
A
Department of Obstetrics and Animal Reproduction, Faculty of Veterinary Medicine, 45 rue des Vétérinaires, 1070, Brussels, Belgium.
Van der Zwalmen
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P
Ectors
F
F
De Coster
R
R
D'Ieteren
G
G
Hanzen
C
C