title: Synchronization and resynchronization of inseminations in lactating dairy cows with the CIDR insert and the Ovsynch protocol.
abstract: Pregnancy per artificial insemination (AI) was evaluated in dairy cows (Bos taurus) subjected to synchronization and resynchronization for timed AI (TAI). Cows (n=718) received prostaglandin F(2alpha) (PGF) on Days -38 and -24 (Days 39 and 53 postpartum), gonadotropin-releasing hormone (GnRH) on Day -10, PGF on Day -3, and GnRH and TAI on Day 0. Between Days -10 and -3, cows received a progesterone intravaginal insert (CIDR group) or no CIDR (Control group). Between Days 14 and 23, cows received a CIDR (Resynch CIDR group) or no CIDR (Resynch control group), GnRH on Day 23, with pregnancy diagnosis on Day 30. Cows in estrus (between Days 0 and 30) were re-inseminated at detected estrus (RIDE). Nonpregnant cows received PGF on Day 30 and GnRH and TAI on Day 33. Plasma progesterone was determined to be low or high on Days -24 and -10. Pregnancy rates were evaluated 30 and 55 d after AI. The CIDR insert included in the Presynch-Ovsynch protocol did not increase overall pregnancy per AI for first service (36.1% and 33.6% for CIDR; 34.1% and 28.8% for Control) but did decrease pregnancy loss (7.0% for CIDR and 15.6% for Control). The CIDR insert increased pregnancy per AI in cows with high progesterone at the time the CIDR insert was applied. Administration of a CIDR insert between Days 14 and 23 of the estrous cycle after first service did not increase overall pregnancy per AI to second service (24.7% and 22.7% for Resynch CIDR; 28.6% and 25.3% for Resynch control). For second service, RIDE cows had lower pregnancy rates in the Resynch CIDR group than in the Resynch control group. Cows with a CL (corpus luteum) at Day 30 had higher pregnancy rates in the Resynch CIDR group than those in the Resynch control group.
authors: Facultad de Ciencias Veterinarias, Universidad Nacional de La Pampa, La Pampa, Argentina. bartolomejulian@yahoo.com.ar
authors: J A
authors: JA
authors: Bartolome
authors: J J J
authors: JJ
authors: van Leeuwen
authors: M
authors: M
authors: Thieme
authors: O G
authors: OG
authors: Sa'filho
authors: P
authors: P
authors: Melendez
authors: L F
authors: LF
authors: Archbald
authors: W W
authors: WW
authors: Thatcher
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D030762:Estrous Cycle; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007315:Insemination, Artificial / Q000379:methods*; D007774:Lactation; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D011453:Prostaglandins / Q000494:pharmacology
chemical_list: D011453:Prostaglandins; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone