U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


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Date of this Version



Published in J. Reprod. Fert. (1982) 66, 513-518


Catheters were placed in the carotid artery via a facial artery (n = 12) and in the ovarian vein (n = 12), and, in conjunction, electromagnetic flow meters were placed around the ovarian artery (n = 6) in cyclic beef cows. Androstenedione was quantitatively the highest and dehydroepiandrosterone the lowest of the ovarian androgens measured. Ovarian androgens were correlated positively with each other (P < 0·05)but not with ovarian blood flow or day of the cycle. There was a trend for spikes of androgen release (ovarian vein concentration × ovarian blood flow) from the ovary to be greatest during the period of decreasing progesterone and CL regression. However, only with testosterone were spikes of release different (Days -13 to -9 < Days -8 to -4;P < 0·05;Day 0 = oestrus). The dynamic changes in ovarian androgens noted in this study were compatible with the concept of continuous follicular development and atresia throughout the oestrous cycle.