Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: April 23, 1999
Publication Date: December 19, 1999
Citation: Vallet, J.L., Rohrer, G.A., Klemcke, H.G., Christenson, R.K. 1999. Factors affecting fetal hematocrit (HC) and fetal plasma iron (PI) at 105 days of gestation in swine [abstract]. Journal of Animal Science. 77(Supplement 1):219. Technical Abstract: Neonatal iron deficiency may be worsened in large litters where uterine crowding occurs. To test this idea, 98 half White crossbred, half Meishan gilts were unilaterally hysterectomized-ovariectomized at 100 d of age and then were mated after at least one estrous cycle. At 105 d gestation, gilts were slaughtered, the uterus was recovered and umbilical arterial blood samples were obtained from each fetus and measured for HC and PI. Each placenta, fetus and fetal liver was weighed. HC and PI were correlated(r = .3, P < .01). Also, fetal weight was positively correlated with HC and PI indicating that HC and PI are lower in small fetuses. The greatest source of variation in HC and PI was maternal gilt (47 and 53%, respectively). A genome scan to identify regions of the maternal genome controlling HC and PI indicated that a quantitative trait locus (qtl) was present on chromosome 12 for PI. The average Meishan allele increased PI .34 ug/mL and explained 9.3% of the variation in PI and 2.8% of the variation in HC. These results suggest that (1) blood cell synthesis and iron transport are decreased by uterine crowding, (2) a qtl for fetal PI is located on chromosome 12. This qtl could be used to improve fetal PI, possibly resulting in improved piglet survival.