In Vitro Embryo Production and Transfer of Bubaline Embryos Using Oocytes Derived from Transvaginal Ultrasound-GuideFollicular Aspiration (TUFA)

Two separate studies sought to assess the effects of age (Study 1) on quantity and quality of cumulus oocyte complexes (COCs) and to assess the in vitro embryo production (Study II) using the Transvaginal Ultrasound-guided Follicular Aspiration (TUFA) technology. Ten (n=10) multiparous Bulgarian Murrah buffaloes were classified into two age groups consisted of 8-12 years old (Group1) and 13-17 years old, (Group2). Five cows were used in each age group where each cow serves as oocyte donor cow. The collection of oocytes was done weekly for seven months. The collected COCs were subjected to in vitro maturation, fertilization and embryos culture where bubaline embryos produced were transferred to surrogate cows. Results in study I showed that there were more COCs (71) collected in Group I than in Group 2 cows with 29 COCs. The collected COCs from Group I were classified into rank A, 5.63% (n=4) with intact 3 layers cumulus cells, rank B, 2.82% (n=2) with uneven dark ooplasm but had 3 layers intact cumulus cells, rank C, 32.39% (n=23) homogenously dark granulation of ooplasm and with intact/compact, 1 to 2 layers cumulus cells and rank D, 59.15% (n=42) without cumulus cells. In the older donor cows, the COCs derived were classified to rank A, 6.90% (n=2), rank B, 6.90% (n=2), rank C, 31.03% (n=9) and rank D, 55.17% (n=16). Results showed that younger buffalo donor cows gave significantly higher (P<0.05) number of oocytes collected (71) as against only 29 for older donor cows In study II, the pooled TUFA derived COCs gave an in vitro fertilization rate of 40.00%. Out of this, 32.50% developed into morulae and 32.5% developed to the blastocyst stage. All the blastocysts produced were transferred to surrogate cows where an embryo developed to full term resulting to a live birth of a male calf. The TUFA-IVEP using oocytes from the donor cows gave a success rate of 10%.