title: Luteal function after intrauterine infusion of recombinant bovine interferon-alpha I1 into postpartum beef cows expected to have short or normal luteal phases.
abstract: This study was conducted to determine whether intrauterine infusion of recombinant bovine interferon-alpha I1 (rboIFN-alpha I1), which has 70% sequence identity to bovine trophoblast protein-1, will prevent regression of corpora lutea anticipated to have a short lifespan. Twenty-six beef cows in good body condition were allotted to four treatment groups at parturition in a 2 x 2 factorial design. Treatments were: group 1, saline; group 2, rboIFN-alpha I1; group 3, norgestomet-saline; and group 4, norgestomet-rboIFN-alpha I1. Norgestomet implants were inserted on days 21-24 postpartum and removed 9 days later (before injection of human chorionic gonadotrophin (hCG)). Ovulation was induced 30 to 33 days postpartum with 5000 or 10,000 iu hCG. Groups 1 (n = 7) and 3 (n = 5) were given intrauterine infusions (rectocervical approach) twice daily with saline on days 1-12 or 13-24 after hCG injection, respectively. Cows allotted to groups 2 (n = 8) and 4 (n = 6) were given intrauterine infusions (rectocervical approach) of 2 mg rboIFN-alpha I1 twice daily on days 1-12 or 13-24 after hCG injection, respectively. Treatment with both norgestomet and rboIFN-alpha I1 delayed (P less than 0.01) luteolysis. Lengths of luteal phases (days; mean +/- SEM) were 8.4 +/- 0.7 (group 1, saline), 14.1 +/- 1.0 (group 2, rboIFN-alpha I1), 18.6 +/- 1.3 (group 3, norgestomet-saline) and 20.8 +/- 1.2 (group 4, norgestomet-rboIFN-alpha I1). Concentration of progesterone in serum was similar among all groups the first 6 days following hCG-induced ovulation, but differed (P less than 0.01) thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal Sciences, University of Missouri, Columbia 65211.
authors.forename: H A
authors.initials: HA
authors.lastname: Garverick
authors.forename: M T
authors.initials: MT
authors.lastname: Moser
authors.forename: D H
authors.initials: DH
authors.lastname: Keisler
authors.forename: S A
authors.initials: SA
authors.lastname: Hamilton
authors.forename: R M
authors.initials: RM
authors.lastname: Roberts
authors.forename: M F
authors.initials: MF
authors.lastname: Smith
mesh_terms: D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000187:drug effects*; D005260:Female; D007370:Interferon Type I / Q000494:pharmacology*; D008183:Luteal Phase / Q000187:drug effects; D003341:Luteolysis / Q000187:drug effects*; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D011282:Pregnenediones / Q000494:pharmacology; D011374:Progesterone / Q000097:blood; D045167:Progesterone Congeners / Q000494:pharmacology; D011994:Recombinant Proteins
chemical_list: D007370:Interferon Type I; D011282:Pregnenediones; D045167:Progesterone Congeners; D011994:Recombinant Proteins; C100284:norgestomet; D011374:Progesterone