title: Effect of prostaglandin F2 alpha administered before estrus synchronization with norgestomet and estradiol valerate on calving rates of beef cows.
abstract: Three experiments were conducted to evaluate the effects of prostaglandin F2 alpha treatments 5, 9, and 14 d before Syncro-Mate B on calving rates of 1,072 beef cows from inseminations at a pre-set time. The administration of prostaglandin F2 alpha 5 d before Syncro-Mate B decreased (P < .01) calving rates. This reduction was associated with lower (P < .05) calving rates in cows administered Syncro-Mate B in the first half of the estrous cycle. Calving rates were unaffected n cows administered prostaglandin F2 alpha 9 d before Syncro-Mate B. The administration of prostaglandin F2 alpha 14 d before Syncro-Mate B reduced (P < .05) calving rates in previously anestrous cows. In summary, prostaglandin F2 alpha should not be administered to postpartum cows 5 to 14 d before Syncro-Mate B synchronization.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kesler
authors.forename: D B
authors.initials: DB
authors.lastname: Faulkner
authors.forename: R
authors.initials: R
authors.lastname: Machado
authors.forename: F A
authors.initials: FA
authors.lastname: Ireland
authors.forename: K E
authors.initials: KE
authors.lastname: Tjardes
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D015237:Dinoprost / Q000494:pharmacology*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004973:Estrus Synchronization / Q000502:physiology*; D005260:Female; D011247:Pregnancy; D018873:Pregnancy Rate; D011270:Pregnancy, Animal / Q000502:physiology*; D011282:Pregnenediones / Q000494:pharmacology*; D045167:Progesterone Congeners / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D011282:Pregnenediones; D045167:Progesterone Congeners; C100284:norgestomet; D004958:Estradiol; D015237:Dinoprost