title: The Role of Progesterone in Maternal Recognition of Pregnancy in Domestic Ruminants.
abstract: Progesterone (P4) secretion by the corpus luteum is critical for the establishment and maintenance of pregnancy and plays a major role in regulating endometrial secretions essential for stimulating and mediating changes in conceptus growth and differentiation throughout early pregnancy. Numerous studies have demonstrated an association between elevated P4 and acceleration in conceptus elongation. Given that larger conceptuses produce more interferon tau, the pregnancy recognition signal in ruminants, it would be reasonable to hypothesize that treatments aimed at increasing peripheral concentrations of P4 should improve pregnancy rate. However, data on the impact of post-insemination supplementation of P4 on pregnancy rates are conflicting and, at best, indicate a modest positive response. Whether a P4-induced increase in conceptus size can improve fertility continues to be an active area of investigation. The aim of this chapter is to review recent data on the role of P4 in conceptus development in ruminants, particularly cattle, and to summarize results from attempts at manipulating endogenous P4 with the aim of improving conceptus survival and pregnancy rate.
authors.affiliation: Animal and Crops Sciences, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland. pat.lonergan@ucd.ie.
authors.forename: Pat
authors.initials: P
authors.lastname: Lonergan
authors.affiliation: Division of Reproduction and Early Development, Leeds Institute of Cardiovascular and Molecular Medicine, University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK. N.Forde@leeds.ac.uk.
authors.forename: Niamh
authors.initials: N
authors.lastname: Forde
mesh_terms: D000818:Animals; D005260:Female; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000502:physiology; D012418:Ruminants / Q000502:physiology*; D014599:Uterus / Q000502:physiology
chemical_list: D011374:Progesterone