In vitro culture of buffalo (Bubalus bubalis) embryos in the presence or absence of glucose.

The aim of this study was to evaluate whether the presence or absence of glucose during in vitro embryo culture, would affect embryo development in buffalo. Cumulus-oocytes complexes (n=1114, over 8 replicates), recovered from slaughtered animals, were matured and fertilized in vitro according to our standard procedures (1). On day 1 (Day 0 = fertilization), zygotes were cultured in: group A) Glucose-containing SOF throughout culture; group B) Glucose-containing SOF for early culture (Day 1 to Day 4) and glucose-free SOF for late culture (Day 4 to Day 7); group C) glucose-free SOF throughout culture and group D) glucose-free SOF for early culture and glucose-containing SOF for subsequent culture. In vitro culture was carried out at 38.5°C under 5% CO2, 7% O2, and 88% N2. Cleavage rate was evaluated on Day 4 and blastocyst yield, in relation to cleaved embryos, was recorded on Day 7. Differences among groups in blastocyst rate were analyzed by Chi Square test. The presence or absence of glucose did not affect cleavage rate (54.2 % vs 55.7 % respectively). By contrast, significantly higher blastocyst yields were found in Group A and B compared to Groups C and D (32.7 %, 30.7 %, 2.4 % and 9.6 % respectively; P<0.01). It is concluded that in buffalo, unlike sheep and cattle, glucose is more critical for early embryo development than for post-compaction development, as indicated by the poor embryo yield obtained in both groups lacking glucose during early culture. 1) Gasparrini B., 2002, Theriogenology, 57 (1), 237-256.