title: Relationship between variation in conceptus development and differences in estrous cycle duration in ewes.
abstract: The objective of this study was to examine conceptus development on Day 13 in ewes with estrous cycles of different durations. Ewes (n = 80) were screened according to the length of their estrous cycles. Subsequently, ewes that had either SHORT or LONG cycles were utilized (15.9 +/- 0.1 or 18.6 +/- 0.4 days; mean +/- SEM, p less than 0.01; 10 ewes per group). Jugular blood samples were collected twice daily from Days 0-6 after mating and then once a day until slaughter on Day 13. Concentrations of progesterone in plasma and amounts of ovine trophoblast protein-1 (oTP-1), protein, and prostaglandins (PG) E2 and F2 alpha (PGF2 alpha) in uterine flushings were determined. Concentrations of progesterone were greater (Day by treatment interaction, p less than 0.01) on Days 2-4 for ewes in the SHORT group. On Day 5 and thereafter, progesterone concentrations were not different between groups. More (p less than 0.05) oTP-1 and protein (8.1 +/- 1.3 micrograms and 1.8 +/- 0.3 micrograms versus 2.4 +/- 1.3 micrograms and 0.8 +/- 0.3 mg) were recovered from uterine flushings from ewes in the SHORT versus LONG groups, respectively. The ratio of PGE2:PGF2 alpha was higher (p less than 0.06) in flushings from ewes in the SHORT versus LONG group (1.4 +/- 0.2 versus 0.9 +/- 0.2, respectively). Conceptuses were classified by stage of morphological development. Conceptus development was accelerated (p less than 0.01) in ewes of the SHORT group, as shown by filamentous conceptuses recovered from 78% versus 0% of SHORT versus LONG ewes, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal Science, Ohio State University, Columbus 43210.
authors.forename: K P
authors.initials: KP
authors.lastname: Nephew
authors.forename: K E
authors.initials: KE
authors.lastname: McClure
authors.forename: T L
authors.initials: TL
authors.lastname: Ott
authors.forename: D H
authors.initials: DH
authors.lastname: Dubois
authors.forename: F W
authors.initials: FW
authors.lastname: Bazer
authors.forename: W F
authors.initials: WF
authors.lastname: Pope
mesh_terms: D000818:Animals; D015237:Dinoprost / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D005314:Embryonic and Fetal Development / Q000502:physiology*; D004971:Estrus / Q000502:physiology*; D005260:Female; D007370:Interferon Type I; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism; D011374:Progesterone / Q000097:blood; D012756:Sheep; D013997:Time Factors
chemical_list: D007370:Interferon Type I; D011257:Pregnancy Proteins; C020947:interferon tau; D011374:Progesterone; D015237:Dinoprost; D015232:Dinoprostone