HomePhilippine Journal of Veterinary and Animal Sciencesvol. 27 no. 2 (2001)

Effect of Time on Maturation and Embryo Development Rates of Buffalo Oocytes In Vitro

Bernadette B. Hufana | Danilda H. Duran | Rogelio D. Hufana | Peregrino G. Duran | Ernesto P. Garillo | Libertado C. Cruz

Discipline: Veterinary Medicine, Animal Science



Two studies were conducted to examine the effect of time on buffalo oocytes in vitro maturation (IVM) and embryo development after in vitro fertilization (IVF). The general objective is to come up with a concrete basis for technical procedure on collection and length of preservation of ovaries and oocytes IVM for improved rate of in vitro embryo production. Study 1 examined the effects of short (3-4 hr) and long (5-6 hr) periods of ovary collection and preservation on the subsequent development potential of buffalo oocytes after IVF. A total of 132 oocytes were randomly distributed into two groups - long period and short period. Results revealed that cleavage and blastocyst development rates are higher in the short period than in the long period, 58.57% vs. 46.77% and 21.43% vs.12.9%, respectively (P<0.05). Study 2 assessed the optimum time for IVM to obtain higher percentage of oocytes at Metaphase II stage (MII, mature stage) and determine the best time for IVF in water buffalo. Immature oocytes were cultured in vitro for 16,19,22,25 and 28 hr after which the oocytes were fixed for nuclear examination. Results revealed that 15%, 20%, 30%, 85% and 64.71% of the oocytes at 16, 19, 22, 25 and 28 hr, respectively, are at MII stage, with 25 hr having the highest MII. However, signs of aging in 23.53% of the MII oocytes at 25 hr were observed. Further study is recommended to assess the timing of sequential events of oocyte nuclear maturation from 23-25 hr to determine the perfect timing for buffalo IVF. These results suggest that time element is an important factor for consideration in implementing in vitro manipulation procedures in order to obtain higher rates of in vitro embryo production.