The ability to induce ovulation with an injection of GnRH facilitated the development of fixed-
time artificial insemination (AI) protocols. However, animals that exhibit estrus prior to fixed …

Three experiments evaluated the effects of expression of estrus and gonadotropin releasing
hormone (GnRH) treatment on pregnancies per AI (P/AI) in beef cattle that were treated with …

Two experiments evaluated timing of GnRH administration in beef heifers and cows on the
basis of estrous status during split-time artificial insemination (AI) after controlled internal …

Cows that exhibit estrus within 24 h of fixed-time AI have elevated concentrations of estradiol
and greater pregnancy rates compared with cows not in estrus. Our objective was to …

Animals that exhibited estrus had greater pregnancy success compared to animals that did
not exhibit estrus before fixed-time AI (FTAI). Estradiol is synthesized in bovine ovarian …

This experiment was designed to compare pregnancy rates in postpartum beef cows
following split-time (STAI) or fixed-time (FTAI) artificial insemination. Estrus was …

We have previously shown that expression of oestrus significantly influences the time of
ovulation and pregnancy rates to timed-AI (P/TAI) in beef cattle synchronized with …

It has been hypothesized that circulating concentrations of estradiol during the preovulatory
period, can impact subsequent progesterone concentrations. Ovulation was synchronized in …

Early estrus-synchronization protocols focused on regressing the corpus luteum (CL) with an
injection of PGF2α followed by detection of estrus or involved the use of exogenous …

The objective of the experiment was to compare pregnancy rates resulting from fixed-time AI
after administration of either 1 of 2 controlled internal drug release (CIDR)-based protocols …