found plasma
beta-carotene to be positively related to progesterone
production by corpus luteum cells. Cows that ovulated
during the first follicular wave postpartum had
a higher mean plasma beta-carotene concentration
than anovulatory cows (2.97 ± 0.24 μg/mL vs. 1.53 ±
0.14 μg/mL) three weeks prepartum