IN-VITRO MATURATION AND FERTILIZATION OF PREPUBERTAL GOAT OOCYTES

The aim of this work was to study the IVM-IVF of prepubertal goat oocy tes collected from a slaughterhouse as an alternative source of oocyte s to those of FSH-primed adult goats. In Experiment 1, IVM of prepuber tal goat oocytes in co-culture with granulosa cells were compared with IVM in 50 mu l microdrops of medium. There was no significant differe nce in the percentage of maturation (72.0 vs 76.9%) between the 2 grou ps. In Experiment 2, a low percentage of normal fertilization (24.4%) was observed for prepubertal goat oocytes matured with granulosa cells from prepubertal goats. This result was significantly lower than that obtained for ovulated (62.2%) or in vitro-matured (48.7%) oocytes fro m adult goats. There were no significant differences with respect to t he oocytes from adult goats matured in vitro when prepubertal goat ooc ytes were cultured with adult goat granulosa cells (33.3%) or in micro drops (29.7%). No differences were observed among the treatments in th e percentage of oocytes showing evidence of fertilization (normal fert ilization + abnormal fertilization + polyspermy). In Experiment 3, it was shown that there were no differences in the percentage of normally fertilized oocytes after in vitro maturation in microdrops containing oocytes with 1 to 2 and 3 or more complete layers of cumulus cells (3 2.1 and 33.3% respectively). La conclusion, the ovaries of prepubertal slaughterhouse goats were found to be an economical alternative for a n abundant source of oocytes for IVM-IVF research. In vitro maturation of oocytes in microdrops yielded maturation and fertilization ratesco mparable to those obtained with oocytes from FSH-primed adult goats. M oreover, similar maturation and fertilization rates were obtained usin g oocytes with 1 to 2 layers or 3 or more layers of cumulus cells.