Effects of Acetoacetate on in vitro Development of Bovine Embryos in Medium Containing Citrate and Myo-inositol

Abstract

This study investigated bovine embryo development in vitro in the presence of acetoacetate in serum-free medium. In vitro- matured and fertilized oocytes from ovaries of slaughtered cows were cultured in synthetic oviduct ¯uid (SOF) containing citrate, myo-inositol, lactate and pyruvate. In the medium with acetoacetate this compound replaced both lactate and pyru- vate as energy sources. Three experiments were carried out: (1) to test development in medium with acetoacetate and bovine serum albumin; (2) to analyse the e ects of acetoacetate that were dependent upon citrate and myo-inositol; and (3) to determine the e ects of acetoacetate in the presence of serum. Blastocyst development was recorded at day 8 and the number of cells of expanded blastocysts obtained were counted. Blastocysts development was reduced in medium with 1.8, 3.6 or 7.2 mM acetoacetate in comparison with the control with or without lactate and pyruvate. The detrimental e ect of acetoacetate was independent of the presence of citrate and myo-inositol, but serum added to culture medium protected against this e ect. Citrate and myo-inositol did not improve blastocyst formation. Morphological quality and cell number of blastocysts were similar between groups.