Maturational and developmental competence of immature oocytes retrieved from bovine ovaries at different phases of folliculogenesis.

Immature oocytes recovered from bovine ovaries were studied to determine if their maturational and developmental competence is affected by phase of folliculogenesis. Ovaries (a total of 39 pairs) were collected from a local abattoir. Following examination, each pair of ovaries was assigned to one of three groups, according to follicle size and with or without a corpus luteum: (i) early phase (n = 13 pairs): all follicles were or=15 mm in diameter; (iii) luteal phase (n = 13 pairs): all follicles were