Abstract

The bovine conceptus induces an array of physiological and biochemical responses that lead to the establishment of pregnancy. Among the most studied of these is secretion of prostaglandin (PG) F2alpha (F) from the uterine endometrium. Pregnancy appears to be associated with laterations in many of the regulatory systems that cause PGF secretion leading to luteolysis in cyclic animals. The conceptus secretes an antiluteolytic protein (bovine trophoblast protein-1 complex [bTP-1] that appears to induce an inhibitor of prostaglandin synthesis. The bTP-1 antiluteolytic protein is an alphaII interferon. The secondary effects associated with interferon-like activities (antiviral, antiproliferative, altered gene expression, immunosuppressive) may complement development and sustenance of the conceptus. Both ovarian CL function and follicular activity are altered in early pregnancy. Changes in follicular activity may reinforce the antiluteolytic signals from the conceptus leading to maintenance of the CL. Potential management systems to improve reproductive efficiency that are based on supplementation with bTP-1-like molecules, controlled ovarian follicular management, and progesterone therapy are discussed.

JJ, Bass, and PD Gluckman

Proceedings of the New Zealand Society of Animal Production, Volume 50, , 73-79, 1990