title: Early pregnancy associated thrombocytopenia as an initial response to pregnancy in cattle.
abstract: This study was conducted to determine if early pregnancy-associated thrombocytopenia exists in cattle as has been demonstrated in mice and in humans. Three experiments were designed to compare peripheral platelet counts in pregnant versus nonpregnant animals. In Experiment 1 heifers (n = 25) were artificially inseminated 12 h after the onset of estrus. Peripheral platelet counts in 19 pregnant versus 6 nonpregnant heifers did not reveal any significant differences between groups after insemination. In Experiment 2 embryos were collected nonsurgically from superovulated cows (n =18) on Days 6 to 7 after estrus. Platelet counts were monitored every 12 h after the first insemination until 60 h after the second insemination. Platelet counts and the number of embryos collected nonsurgically from these superovulated donors did not show any significant correlations (P>0.05). Ten recipient heifers synchronized to donor animals received either an unfertilized ovum or a good quality embryo via nonsurgical transfer into the uterus. There were no significant reductions in platelet counts after transfer. In Experiment 3 platelet counts were monitored daily in four pregnant and five nonpregnant recipient heifers between Day 0 and Day 30 after embryo transfer on Day 8 of the cycle. The platelet counts did not reveal any significant differences between the pregnant and nonpregnant groups throughout Days 0 to 30. These results indicate that early pregnancy-associated thrombocytopenia cannot be demonstrated in cattle. Peripheral platelet counts cannot be used as an indicator of early pregnancy in cattle.
authors.affiliation: Department of Dairy Science, LAES, LSU Agricultural Center Louisiana State University, Baton Rouge, Louisiana 70803 USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Thibodeaux
authors.forename: A E
authors.initials: AE
authors.lastname: Stock
authors.forename: J D
authors.initials: JD
authors.lastname: Roussel
authors.forename: R W
authors.initials: RW
authors.lastname: Adkinson
authors.forename: L L
authors.initials: LL
authors.lastname: Goodeaux