ARS | Publication request: Fetal liver glycogen production and glycogenic transcript expression during prenatal development from pig breeds differing in preweaning survivability

Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: December 19, 2012
Publication Date: March 1, 2013
Citation: Miles, J.R., Noel, J.A., Rempel, L.A., Vallet, J.L., Freking, B.A. 2013. Fetal liver glycogen production and glycogenic transcript expression during prenatal development from pig breeds differing in preweaning survivability [abstract]. Journal of Animal Science. 91 (Supplement 2):124 (Abstract #P105).

Technical Abstract: Sow productivity is influenced by a number of factors including preweaning piglet mortality. In commercial pigs, low birth weight piglets exhibit the greatest susceptibility to preweaning mortality. In contrast, Meishan (MS) piglets have naturally occurring lower birth weight and also improved preweaning survival. Furthermore, we have demonstrated that MS piglets have enhanced glycogen metabolism during early neonatal life. The objective of this study was to characterize the expression of glycogenic transcripts along with glycogen levels in livers of MS and White crossbred (WC) fetal piglets to identify breed differences in glycogen metabolism during prenatal development. Eighteen gilts from each breed (MS and WC) were bred at estrus (designed d 0) to boars from their respective breeds. At d 70, 90 and 110 of gestation, gilts were harvested (n=6 breed**1d**1) and fetal livers were collected from the smallest and largest littermates. Liver glycogen was determined using an anthrone method. Expression for key glycogenic anabolic (UDP-glucose pyrophosporylase 2 [UGP2] and glycogen synthase 2 [GSY2]) and glycogenic (phosphorylase, glycogen liver [PYGL] and amylo-alpha-1,6-glucosidase [AGL]) transcripts were determined using real-time PCR. All data were analyzed by MIXED procedures for ANOVA. Fetal weight was greater (P<0.05) for WC fetuses compared to MS fetuses at d 90 and 110 of gestation. Fetal liver glycogen was greater (P=0.04) in MS fetuses compared to WC fetuses, irrespective of fetal size, at d 110 of gestation. However, no apparent breed differences (P>0.10) in glycogenic transcripts were observed between MS and WC piglets. These results demonstrate increased glycogen production in MS fetuses during late gestation without a decisive increase in expression of key glycogenic transcripts. USDA is an equal opportunity provider and employer.