title: Estrous cycle synchronization in dairy heifers with the prostaglandin analog alfaprostol (I).
abstract: The prostaglandin F(2alpha) analog (PGFA) alfaprostol was used in 277 cyclic dairy heifers for the purpose of estrous cycle synchronization. A dose of 5 mg was used in all the trials during spring 1979 and 1.5 mg 100 kg body weight were used during winter 1979/80. Animals were treated according to 3 schedules: two doses 11 days apart without prior examination (Schedule I), one dose without prior observation and a second dose 11 days later only for those animals that failed to show estrus after the first treatment (Schedule II) and one dose for animals not showing estrus after a 5-day observation period (Schedule III). Estrus synchronization was achieved with peak estrus activity occurring form 32 to 72 h after treatment in 95% of the responding animals. Of the animals treated according to schedules I, II and III, 93%, 100% and 100% showed synchronized estrus activities respectively. Conception rates in all trials, from insemination at observed heat (Schedules I, II and III) or from fixed time insemination at 48 and 72 h after the first or second treatments in schedules III and I, respectively, compared well with that of untreated contemporary controls with a range of 34.2 to 66.7% for animals in these trials, and an overall conception rate of 49.48% for treated and of 48.30% for control animals. This observation, together with the pregnancy rate at 60 days after breeding (78.30% for all treated animals and 73.50% for all untreated controls), indicates that alfaprostol had no adverse effects on fertility.
authors.affiliation: Wolfgang Jöchle Associates, Inc. 10 Old Boonton Road, Denville, NJ 07834, USA.
authors.forename: W
authors.initials: W
authors.lastname: Jöchle
authors.forename: D
authors.initials: D
authors.lastname: Kuzmanov
authors.forename: J
authors.initials: J
authors.lastname: Vujosevic