Submitted to: Biology of Reproduction Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 23, 1999
Publication Date: December 19, 1999
Citation: Vallet, J.L., Klemcke, H.G., Pearson, P.L., Christenson, R.K. 1999. Effect of intrauterine crowding and breed on fetal erythropoiesis on day 35 of pregnancy in swine [abstract]. Biology of Reproduction. 60(Supplement 1):126-127. Technical Abstract: Intact white crossbred (WC) gilts (INT), unilaterally hysterectomized ovariectomized WC gilts (UHO) and intact Meishan gilts (ME; n=15/group) were mated after at least one estrous cycle. Gilts were slaughtered at d 35 of pregnancy and a blood sample was collected from each fetus. Fetuses and placentae were weighed. Blood samples were measured for hematocrit, cell number, hemoglobin, % nucleated cells, % reticulocytes and erythropoietin (largest and smallest fetuses only). Hematocrit was not affected by treatment (20, 20 and 19%, S.E.M.=1; ME, INT and UHO, respectively). Blood cell counts were greater (p<.01) in ME compared to INT and UHO (1.7, 1.1 and 1.2 million cells/ul, S.E.M.=.1). Hemoglobin was less (p<.01) in ME compared to INT and UHO (4.2, 5.2 and 4.7 g/dl, S.E.M.=.2). The % nucleated (immature) blood cells was less (p<.01) in ME and UHO compared to the INT group (17, 18 and 29%, S.E.M.=2). The % reticulocytes was lower (p<.01) in ME compared to the INT and UHO groups (33, 45 and 48%, S.E.M.= 2). Erythropoietin was also lower (p<.01) in ME compared to INT and UHO groups (17, 30 and 25 ng/ml, S.E.M.=2). A positive relationship (r=.28. p<.01) with fetal weight was found for hemoglobin. These data suggest that blood development in ME gilts is accelerated. Intrauterine crowding may accelerate blood development and interfere with hemoglobin synthesis. Improvements in blood cell development could be beneficial to fetal survival in swine.