Reproduction Abstracts

Introduction: In general, the maternal age affects the quality of the oocytes as well as that of embryos. This study aims to examine whether changes in the follicular fluid (FF) can affect oocyte quality in aged cows.

Materials and methods: Oocytes were collected from ovaries of young (<120 months) or aged cows (≥120 months), and oocytes from animals in these two age groups were cultured in a maturation medium that contained 10% FF derived from young or aged cows (young-FF and aged-FF). In experiment 1, we compared progression of nuclear maturation, the fertilization outcome, and the developmental competence between the two groups. In experiment 2, we measured the levels of estradiol, progesterone, and advanced glycation endproducts (AGEs), and the antioxidant capacity of young-FF or aged-FF.

Results and discussion: Experiment 1: In oocytes from both the younger or older animals, nuclear maturation progressed faster when culture was carried out in the medium containing aged-FF compared to that in the medium containing young-FF. Moreover, for both groups, compared to the young-FF-cultured oocytes, the aged-FF-cultured oocytes showed a lower rate of normal fertilization and development to the blastocyst stage.

Experiment 2: The estradiol and progesterone levels were significantly lower while the AGE level was significantly higher in the aged-FF. In addition, antioxidant capacity in aged-FF was lower than that in young-FF, which resulted in higher ROS levels in these oocytes cultured with aged-FF.

These results suggest that age-associated deterioration in the FF induces a decline in oocyte quality.