INFLUENCE OF THE COLLECTION TECHNIQUE OF PREPUBERTAL GOAT OOCYTES ON IN-VITRO MATURATION AND FERTILIZATION

Prepubertal goat ovaries obtained from a slaughterhouse were used to s tudy the influence of the oocyte collection technique (dissection, asp iration and slicing) on the number of oocytes recovered and their capa city for maturation and fertilization in vitro. The oocytes were recov ered using 3 techniques, were selected for culture and were classified according to the number of cumulus cell layers. The numbers of oocyte s selected per ovary were 1.71, 1.27 and 6.05 for dissection, aspirati on and slicing, respectively. The percentages of maturation obtained f or slicing (56.9%) were lower than those obtained for dissection and a spiration (69.3 and 72.0%, respectively). The proportion of oocytes wi th the most cumulus cell layers (complete cumulus) was greatest for oo cytes recovered by dissection, but this had no influence on their capa city for nuclear maturation. The total percentage of fertilization was similar for oocytes obtained by dissection and by slicing, but the la tter yielded a lower percentage of normal fertilization (29.1 vs 18.2% ). Of the oocytes obtained by slicing, no difference was observed in t he fertilization rate between oocytes with a partial cumulus and a com plete cumulus. The decrease in maturation time from 27 to 25.5 and 24 h did not improve the results for fertilization but caused a decrease in the percentage of nuclear maturation. In conclusion, the recovery o f oocytes using the slicing technique yielded more oocytes per ovary t han dissection or aspiration, although the in vitro fertilization capa city of oocytes obtained by the slicing method was lower than for oocy tes obtained by dissection.