English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Low doses of progestogens in regimens for synchronization of estrus result in persistent follicles (PF) and reduced conception rates in cattle. The effects of PF on recovery of oocytes/embryos, fertilization, and embryonic development were examined in beef cows. To produce PF, cows received a used Controlled Internal Drug Releasing device on Days 4 through 13 after pretreatment estrus (Day 0) and two injections of 20 mg prostaglandin (PG) F2 alpha, i.m., 12 h apart on Day 6 (PF; n = 20). Control cows received only PGF2 alpha on Day 6 so they would ovulate growing follicles (GF; n = 22). With this model, the largest (dominant) follicle from the first wave of follicular development was being ovulated in cows in each group. Cows were observed for estrus twice daily and were then mated to highly fertile bulls. Follicular development was monitored by ultrasonography on alternate days from Day 2 until estrus and then daily until apparent ovulation. Jugular blood samples were collected every other day from Day 2 through 6 days after mating at posttreatment estrus, when uteri were flushed nonsurgically. The ovulatory follicle, which was followed retrospectively and had been observed longer (14 +/- 1 vs. 8 +/- 1 days), was larger in PF (17.2 +/- 0.5 mm) than in GF (14.5 +/- 0.6 mm; p &lt; 0.01). Mean estradiol-17 beta (E2) in jugular plasma during the 6 days before estrus was higher in PF than in GF (5.7 +/- 0.4 vs. 2.6 +/- 0.4 pg/ml; p &lt; 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Persistent Follicles on Early Embryonic Losses in Beef Cows1