Pregnancy maintenance following sequential induced prostaglandin pulses in beef cows

S T Reese; G A Franco; G D de Melo; R V Oliveira Filho; R F Cooke; K G Pohler

doi:10.1016/j.domaniend.2022.106724

Pregnancy maintenance following sequential induced prostaglandin pulses in beef cows

Domest Anim Endocrinol. 2022 Jul:80:106724. doi: 10.1016/j.domaniend.2022.106724. Epub 2022 Mar 4.

Authors

S T Reese¹, G A Franco¹, G D de Melo¹, R V Oliveira Filho¹, R F Cooke¹, K G Pohler²

Affiliations

¹ Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, 2471 TAMU, College Station, 77843, TX, USA.
² Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, 2471 TAMU, College Station, 77843, TX, USA. Electronic address: kpohler@tamu.edu.

PMID: 35398669
DOI: 10.1016/j.domaniend.2022.106724

Abstract

The relationship between the maternal endocrine environment and late embryonic mortality (> 28 d of gestation) in cattle is poorly defined. A definitive rise and alterations in secretion patterns of prostaglandin F_2α (PGF_2α) concentration without luteal regression is a trademark of this period. The objective was to evaluate whether consecutively induced PGF_2α pulses would alter steroid hormone production and luteal blood perfusion potentially influencing pregnancy success. Pregnant beef cows (n = 12) were selected to receive either an oxytocin injection (OT, n = 8) or saline injection (CON, n = 4) on d 30 and 31 of gestation to stimulate sequential prostaglandin releases 24 h apart. Blood samples were collected every 30 min for 1 h before and continuing for 4 h post oxytocin administration. Luteal blood perfusion was measured via Doppler ultrasound at the beginning and end of the OT challenge. Concentrations of prostaglandin F_2α metabolite (PGFM) were quantified to show effectiveness of the treatment while concentrations of progesterone, estradiol and pregnancy-associated glycoproteins (PAG) were measured to examine the effect of PGF_2α release. Control animals exhibited no changes in any quantified hormone and an expected numerical increase in circulating PAG concentrations. Peak concentrations of PGFM in OT cows were observed 2 h post OT administration and concentrations returned to basal levels by the end of the sampling period. Peak concentrations of PGFM were decreased on d 31 compared to d 30. Following OT administration, progesterone and estradiol concentrations did not change in response to PGF_2α release but were decreased on d 31 compared to d 30. There were no changes in luteal blood perfusion in response to PGF release on d 30 or d 31. Repeated PGF_2α release may alter steroid hormone production; however, it does not negatively affect pregnancy status during the transition between early and late embryonic development.

Keywords: Cattle; Pregnancy; pregnancy loss.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cattle
Dinoprost*
Estradiol
Female
Oxytocin / pharmacology
Pregnancy
Pregnancy Maintenance
Progesterone*
Prostaglandins

Substances

Prostaglandins
Progesterone
Estradiol
Oxytocin
Dinoprost