title: Estrus synchronization and conception rate after a progesterone releasing intravaginal device (PRID) treatment from the early luteal phase in heifers.
abstract: The objective of the present study was to evaluate estrus synchronization and conception rate after progesterone releasing intravaginal device (PRID) treatment from the early luteal phase in the presence or absence of estradiol benzoate (EB) in heifers. Heifers (n=11) were assigned randomly to two treatments; insertion of a PRID containing 1.55 g progesterone with a capsule attached including 10 mg EB (P+EB; n=6) and the PRID withdrawn the EB capsule (P-EB; n=5). The PRID was inserted into the vagina on Day 2 of the estrous cycle (Day 0 was the day of ovulation) and was left for 12 days. The proportion of heifers exhibiting standing estrus within 3 days after PRID removal was 83.3% (5/6) for the P+EB group, and 80.0% (4/5) for the P-EB group, respectively. Conception rate by artificial insemination on synchronized estrus was 80.0% (4/5) in the P+EB group, and 100% (4/4) in the P-EB treatment group, respectively. These results suggest that a PRID treatment from 2 days after ovulation for 12 days in the presence or absence of EB has an effect on the synchronization of estrus and produces a beneficial conception rate in heifers.
authors.affiliation: Laboratory of Veterinary Reproduction, Tokyo University of Agriculture and Technology, Japan.
authors.forename: Takenobu
authors.initials: T
authors.lastname: Kuroiwa
authors.forename: Ai
authors.initials: A
authors.lastname: Ishibashi
authors.forename: Masaharu
authors.initials: M
authors.lastname: Fukuda
authors.forename: Seungjoon
authors.initials: S
authors.lastname: Kim
authors.forename: Tomomi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Hideo
authors.initials: H
authors.lastname: Kamomae
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D004971:Estrus / Q000187:drug effects* / Q000502:physiology; D004973:Estrus Synchronization / Q000379:methods*; D005260:Female; D005306:Fertilization / Q000502:physiology; D007315:Insemination, Artificial / Q000662:veterinary; D008183:Luteal Phase / Q000187:drug effects* / Q000502:physiology; D008297:Male; D011247:Pregnancy; D011374:Progesterone / Q000008:administration & dosage* / Q000097:blood
chemical_list: C074283:estradiol 3-benzoate; D011374:Progesterone; D004958:Estradiol