02914naa a2200277 a 450000100080000000500110000800800410001902400430006010000150010324501580011826000090027650001490028552019180043465000290235265000110238165000180239265000200241065300280243065300080245865300180246665300210248465300330250570000170253870000240255577300570257910547952019-08-08       2016    bl uuuu     u00u1 u    #d7 a10.1016/j.anireprosci.2016.02.0092DOI1 aFIERRO, S.  aConcentrations of steroid hormones, estrous, ovarian andreproductive responses in sheep estrous synchronized withdifferent prostaglandin-based protocols.  c2016  aArticle history: Received 14 August 2015; Received in revised form 7 February 2016; Accepted 8 February 2016; Available online 10 February 2016.  aTo determine estrous, ovarian and reproductive responses after different prostaglandin(PG)-based protocols, ewes were assigned to groups PG10, PG12, PG14 or PG16 (two PGinjections administered 10, 12, 14 or 16 days apart; respectively). Experiment I (n = 132) wasconducted to evaluate the estrous response, ovulation rate (OR), conception and fertility.Experiment II (n = 24) was conducted to evaluate ovarian follicle growth, steroid concen-trations and the interval from the second PG injection to estrus (PG-estrus) and ovulation(PG-ovulation). Estrous response was less with the PG16 (P < 0.05) treatment, and the extentof estrous synchrony was greater with the PG10 and PG12 treatments. Ovarian folliclegrowth and the intervals for the variables PG-estrus, PG-ovulation and OR were similaramong groups (P > 0.05). From 8 to 4 days before estrus, progesterone (P4) concentrationswere greater for the PG14 and PG16 than for the PG10 and PG12 (P < 0.05) groups. Therewere more days where concentrations of P4 were above 3.18 nmol/L with the PG14 andPG16 than PG10 and PG12 (P < 0.05) treatments. Use of the PG14 and PG16 treatmentsresulted in greater estradiol (E2) at estrus and 12 h later than use of the PG10 and PG12treatments. A positive correlation was observed between the duration of the luteal phaseand maximum E2 concentrations, and between duration of the luteal phase and days withE2 concentrations above 10 pmol/L. Conception and fertility were greater with use of thePG14 compared with PG10 and PG12 (P < 0.05) treatments. The administration of two PGinjections 10, 12, 14 or 16 days apart resulted in different durations of the luteal phasethat were positively associated with E2 concentrations and the reproductive outcome. Theshorter luteal phases were associated with greater synchrony in time of estrus. The intervalsfor the variables PG-estrus, PG-ovulation and OR were similar among groups.  aINSEMINACIÓN ARTIFICIAL  aOVINOS  aREPRODUCCIÓN  aTASA OVULATORIA  aESTROUS SYNCHRONIZATION  aEWE  aPROSTAGLANDIN  aSTEROID HORMONES  aTIMED ARTIFICIAL INEMINATION1 aVIÑOLES, C.1 aOLIVERA-MUZANTE, J.  tAnimal Reproduction Science, 2016gv. 167, p. 74-82.