The objectives of this dissertation research were to determine the developmental competence of oocytes recovered from postpartum cows and to assess the effect of repeated follicular aspiration on ovarian follicle population and on the endocrine profiles of postpartum cows. Two papers are presented. In the first paper, multiparous Holstein dairy cows were selected on the basis of adjacent calving dates and were randomly assigned to one of two experimental groups in each of two experiments. In experiment 1, five cows were assigned to ultrasound-guided follicular aspiration (UGFA) twice per week for a total of four weeks beginning approximately 30 days after calving. The second group of cows (n = 5) served as a non-aspirated control. In experiment 2, all cows (n = 10) were subjected to UGFA twice per week for a total of four weeks beginning approximately 30 days after calving. Five cows received intramuscular injections of porcine follicle stimulating hormone (FSH) twice daily for three days beginning immediately after the first and fifth UGFA, while the remaining cows (n = 5) were injected with saline. In experiment 1, oocytes possessing excellent/good morphology which were recovered from postpartum dairy cows did not differ in blastocyst formation rate from oocytes obtained from slaughterhouse ovaries. A similar result was found in experiment 2. In experiment 2, FSH treatment did not affect the size or total number of ovarian follicles of postpartum dairy cows. Similarly, treatment of cows with FSH had no effect on the percentage of blastocysts that formed compared with saline-treated cows. In the second paper, eight postpartum beef cows were randomly assigned to one of two treatment groups. Four cows were subjected to weekly UGFA for three weeks beginning approximately 30 days after calving. The remaining cows (n = 4) served as a non-aspirated control group. No effect of UGFA was found on the total number or size of follicles in the ovaries of postpartum beef cows. Round echogenic structures were observed in the follicles of cows after UGFA was performed in all experiments, and analysis of blood samples taken three times per week revealed elevated progesterone levels in cows possessing these echogenic structures.