The Effect of Culture Methods and Serum Supplementation on Developmental Competence of Bovine Embryos Cultured In vitro

The objective of this study, was to compare the developmental competence of bovine in vitro fertilized embryos in three different culture methods; microdrop method (50 mu L of medium under mineral oil in petri dishes) compared to tube methods (1 mL of medium in tubes) with or without oil overlay and to examine the influence of Fetal Bovine Serum (FBS) in culture methods. They were randomly allocated to one of following culture conditions: (Group 1) microdrop method supplemented with 10% (v:v) FBS at day 5 post-insemination (pi); (Group 2) microdrop method without FBS; (Group 3) tube method with oil overlay and FBS added at day 5 pi; (Group 4) tube method with oil overlay; (Group 5) tube method without oil overlay but FBS added at day 5 pi; (Group 6) tube method without oil overlay and FBS. There were no differences (p>0.05) in cleavage rates among the culture methods (78.3, 75.6 and 74.9% for microdrop, tube with oil overlay and tube method without overlay, respectively). However, regardless of serum addition, blastocyst rates in the microdrop method (30.5%) were significantly higher (p<0.05) than those in the tube method without oil overlay (9.8%). There was no difference (p>0.05) between with or without serum in blastocyst rate regardless culture methods. Numerically, the highest blastocyst rate was observed in the microdrop method with the FBS supplementation (Group 1; 36.6%). Overall, the microdrop method was the optimum culture method among the culture methods; however, serum supplementation did not significantly affect the blatocyst rate.