title: Progesterone enhances in vitro development of bovine embryos.
abstract: Increased pregnancy rates in cattle given progesterone (P4) prior to 5 d after breeding have recently been reported. The objective was to determine if this increase in pregnancy rate could be attributed to a direct positive effect of P4 on the developing embryo. In Experiment 1, 280 bovine oocytes were inseminated in vitro and at Day 3 (insemination=Day 0), good quality 8 cell embryos (n=206) were randomly allocated to be cultured in either CR1aa+serum with 0 or ∼15 ng/mL (n=102 and n=104, respectively). In Experiment 2, 881 bovine oocytes were used; on Day 3, good quality 8 cell embryos (n=511) were randomly allocated to either the control (CR1aa+FCS, n=168), vehicle (CR1aa+FCS+ethanol, n=170), or P4 treatment (CR1aa+FCS+∼15 ng/mL P4 in ethanol, n=173). On Day 7, in both experiments, there were increased numbers of blastocysts developing in the P4 group (Experiment 1, 59% and Experiment 2, 71%) compared to the vehicle (Experiment 2, 53%) or control (40 and 62% in Experiments 1 and 2, respectively). The addition of P4 (8%) stimulated the rate of embryo development (early blastocysts or more advanced stages on Day 6) compared to vehicle (3%) and control (0%) and the P4 group had more hatched or hatching blastocysts (33%) on Day 9 compared to the control or vehicle group (21 or 22%). Additionally, the P4 group had greater embryo diameter and significantly more Grade 1 blastocysts on Day 7. In conclusion, P4 had a direct, positive effect on developing bovine embryos cultured in vitro.
authors.affiliation: Department of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA. ferguson@mcneese.edu
authors.forename: C E
authors.initials: CE
authors.lastname: Ferguson
authors.forename: D J
authors.initials: DJ
authors.lastname: Kesler
authors.forename: R A
authors.initials: RA
authors.lastname: Godke
mesh_terms: D000818:Animals; D002417:Cattle / Q000196:embryology*; D046149:Embryo Culture Techniques / Q000662:veterinary; D004622:Embryo, Mammalian / Q000187:drug effects*; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000494:pharmacology*
chemical_list: D011374:Progesterone