title: Reproductive performance of lactating dairy cattle after intrauterine administration of a prostaglandin F2α receptor antagonist 4 days after insemination.
abstract: Previous research has determined that PGF2α detrimentally affects pregnancy via direct effects on early embryonic development. Because early embryonic loss is relatively prevalent in lactating dairy cows, we hypothesized that pregnancy retention (and resulting conception rates) would be improved by administering a PGF2α receptor antagonist (AL-8810) shortly after insemination. Multiparous, lactating Holstein dairy cows were randomly assigned to receive one of four intrauterine treatments: (1) control group-untreated cohort (CON; n = 93); (2) control group-vehicle infusion (CON-V; n = 90); (3) 2000 nM AL-8810 infusion (AL-2000; n = 96); or (4) 10,000 nM AL-8810 infusion (AL-10,000; n = 93). Treatments were administered transcervically 4 days after insemination in the horn ipsilateral to the CL. There was no effect of treatment on conception rate (36.6%, 38.9%, 25.0%, and 35.5% for CON, CON-V, AL-2000, and AL-10,000, respectively) or calving rate (24.7%, 24.4%, 16.7%, and 28.0% for CON, CON-V, AL-2000, and AL-10,000, respectively). There was a significant effect of treatment on return to estrus with CON-V (23.6 ± 0.6) and AL-10,000 (23.3 ± 0.6) groups having a longer interval to next estrus over the CON group (21.5 ± 0.6; P < 0.05). Prior treatment did not affect conception to the subsequent insemination. It is important to note that although the addition of AL-8810 into the uterus on Day 4 after insemination did not increase conception rates in the present experiment, it also did not have a negative impact. Furthermore, the treatment procedure itself did not impair the establishment of pregnancy (CON vs. CON-V, AL-2000, and AL-10,000). These results demonstrate that a therapeutic agent can be administered directly into the uterus on Day 4 after insemination without detrimentally affecting conception rates.
authors.affiliation: Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Deaver
authors.affiliation: Department of Animal Sciences, University of Arizona, Tucson, Arizona, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Felix
authors.affiliation: Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA. Electronic address: rhoadsm@vt.edu.
authors.forename: M L
authors.initials: ML
authors.lastname: Rhoads
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D015237:Dinoprost / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004333:Drug Administration Routes; D005260:Female; D007315:Insemination, Artificial / Q000662:veterinary*; D007774:Lactation; D011247:Pregnancy; D011982:Receptors, Prostaglandin / Q000037:antagonists & inhibitors*
chemical_list: D011982:Receptors, Prostaglandin; C034671:prostaglandin F2alpha receptor; C121227:AL 8810; D015237:Dinoprost
keywords: Cow; Embryo; Pregnancy rate; Prostaglandin