title: Synchronization of estrus in beef cows and heifers with prostaglandin F(2alpha) and estradiol benzoate.
abstract: An experiment was conducted to study an estrous synchronization regimen that involved the use of prostaglandin F(2alpha) (PGF(2alpha)) alone or in combination with estradiol benzoate (EB) and appointment breeding. Fifty-three registered Angus yearling heifers and 167 registered Angus cows (3 to 9 yr of age) were given two injections of PGF(2alpha) 11 d apart. Forty-eight hours after the second injection of PGF(2alpha') a random sample consisting of 117 cows and heifers was injected with EB in sesame seed oil. All females in the herd were artificially inseminated 80 h after the second injection of PGF(2alpha). Nearly equal percentages (25.1 vs 25.6%; P = 0.93) of treated (EB) and control (no EB) females conceived at the appointment breeding. Use of EB tended to reduce (P = 0.06) natural service conception rate (83.4 vs 93.1% for EB and control groups, respectively). Estrous synchronization treatment did not affect interval from Day 1 of the breeding season to calving.
authors.affiliation: Animal Science Department The Ohio State University, Columbus, OH 43210 USA; Ohio Agricultural Research and Development Center, Wooster, OH 44691 USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Davis
authors.forename: T B
authors.initials: TB
authors.lastname: Turner
authors.forename: J T
authors.initials: JT
authors.lastname: Forry
authors.forename: S L
authors.initials: SL
authors.lastname: Boyles
authors.forename: G R
authors.initials: GR
authors.lastname: Wilson