Publikationsdatenbank

Do we need estrus?
Influences of estrous intensity on fertility in dairy cattle (2021)

Art

Vortrag

Autoren

Cerri, R. L. A.

Burnett, T. A.

Madureira, A. M. L.

Moore, A. L.

Denis-Robichaud, J.

Vasconcelos, J. L. M.

Heuwieser, W. (WE 19)

Borchardt, S. (WE 19)

Kongress

ADSA 2021 Annual Meeting

Virtuell, 11. – 14.07.2021

Quelle

Journal of dairy science : JDS

Bandzählung: 104

Heftzählung: Suppl. 1

Seiten: 363

ISSN: 0022-0302

Sprache

Englisch

Verweise

URL (Volltext): https://www.adsa.org/Portals/0/SiteContent/Docs/Meetings/2021ADSA/ADSA2021_Abstracts.pdf

Kontakt

Tierklinik für Fortpflanzung

Königsweg 65
Haus 27
14163 Berlin
+49 30 838 62618
fortpflanzungsklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Recent studies have demonstrated how estrus events and intensity are associated with ovulation, ovarian and uterine function, and fertility. Data sets that included spontaneous and induced estrus have shown that greater relative increase and longer duration of estrus, captured by different activity monitors, significantly improve pregnancy per AI (P/AI; around 15% units across different studies) and decrease pregnancy losses (13.9 vs. 21.7%). Intensity and duration of estrus were weakly associated with follicle diameter and concentration of estradiol at estrus, but the odds of ovulation failure was reduced by 3-fold in cows displaying estrus with high relative increase in physical activity. Data from 2 studies in beef cows showed that estrus behavior near AI also modified transcripts related to the immune system, adhesion molecules and prostaglandin synthesis in the endometrium, as well as apoptosis, progesterone synthesis and prostaglandin receptor in the corpus luteum. Most recently, studies from the USA and Canada demonstrated that reproductive programs using activity monitors and emphasizing detection of estrus can be successful and comparable to intensive timed AI protocol-based programs. One last study from our laboratory also concluded that the inclusion of GnRH at AI greatly improved P/AI from cows displaying low intensity estrus, demonstrating the potential use of activity monitors as a tool in targeted protocols. Quantitative information from estrus events could be used to improve estrous detection quality and develop decision-making strategies at the farm level. Further studies in this field should aim to (1) better understand ovarian, embryo and endometrium mechanisms associated with either the expression or intensity of estrus, and (2) refine the collection of phenotypes related to estrus (i.e., relative increase, absolute increase, baseline levels, duration, and repeatability within cow) to improve estrous detection and possibly genetic selection.