title: Effects of time of progesterone supplementation on embryo development and interferon-tau production in the cow.
abstract: We have investigated the effects of the timing of progesterone supplementation on early embryo development in mature, non-lactating Holstein-Friesian cows. Animals were inseminated 72 h (day 1) and 96 h following prostaglandin injection and were either left as untreated controls (n=6) or received progesterone supplementation from either days 5 to 9 (early; n=6) or from days 12 to 16 (late; n=6). Daily plasma samples were collected until day 16, when cows were slaughtered and reproductive tracts recovered and flushed to collect embryos and to measure interferon-tau activity. Both early and later progesterone supplementation resulted in marked increases in plasma progesterone (P<0.01). Early, but not late, progesterone supplementation resulted in a fourfold increase in trophoblast length (P<0.01) and a sixfold increase in uterine concentration of interferon-tau (P<0.05). The results demonstrate that progesterone supplementation during the postovulatory rise, but not later in the luteal phase, increases embryo development and interferon-tau production.
authors.affiliation: Division of Animal Physiology, School of Biosciences, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, UK. george.mann@nottingham.ac.uk
authors.forename: G E
authors.initials: GE
authors.lastname: Mann
authors.forename: M D
authors.initials: MD
authors.lastname: Fray
authors.forename: G E
authors.initials: GE
authors.lastname: Lamming
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002417:Cattle / Q000196:embryology / Q000502:physiology*; D019587:Dietary Supplements; D047108:Embryonic Development / Q000187:drug effects*; D004973:Estrus Synchronization; D005260:Female; D007370:Interferon Type I / Q000096:biosynthesis*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis*; D011270:Pregnancy, Animal / Q000187:drug effects / Q000502:physiology*; D011374:Progesterone / Q000097:blood* / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D007370:Interferon Type I; D011257:Pregnancy Proteins; C020947:interferon tau; D011374:Progesterone