Circulating concentration of progesterone (P4) is determined by a balance between P4
production, primarily by corpus luteum (CL), and P4 metabolism, primarily by liver. The …

This manuscript reviews the effect of progesterone (P4) during timed AI protocols in lactating
dairy cows. Circulating P4 is determined by a balance between P4 production, primarily by …

The discovery of progesterone (P4) and elucidation of the mechanisms of P4 action have an
important place in the history of endocrinology and reproduction. Circulating P4 …

This report summarizes three studies conducted with lactating dairy cows aiming to increase
pregnancy rates to fixed time artificial insemination (TAI) protocols. Experiment 1 was …

Adequate circulating progesterone (P4) is important for pregnancy. Lactating dairy cattle
have lower circulating P4, particularly when smaller follicles are ovulated during timed AI …

The objective of this experiment was to determine the effect of high versus low progesterone
(P4) during the pre-dominance or dominance phase (or both) of ovulatory follicle …

Our objective was to examine the role of progestin type on serum concentrations of
progesterone (P4) and estradiol-17 β (E2), ovarian follicular dynamics, and fertility in cattle …

The role of progesterone in maintaining pregnancy is well known in the bovine. Subtle
differences exist between dairy and beef cows because of differing concentrations of …

Lactating dairy cows have low fertility marked by normal fertilization but subsequent
degeneration of the early embryo (about 50% degenerate prior to Day 7). Our hypothesis …

To investigate the influence of low plasma progesterone (P4) concentrations on luteal and
ovarian follicular development as well as endometrial gene expression in the concomitant …