| dc.description.abstract | This study was conducted to test the hypothesis that dietary supplementation with
0.4% L-arginine between days 14 and 30 of gestation would enhance survival and
development of conceptuses (embryo and its extra-embryonic membranes) in gilts. Gilts
were bred at the onset of second estrus and fed twice daily 1 kg of a corn- and soybean
meal-based diet containing 12% crude protein beginning on day 0 of gestation (the day
of breeding). Either 0.4% L-arginine or an isonitrogenous amount of L-alanine (control)
was supplemented to the basal diet from days 14 to 30 of gestation. At day 30 of
gestation, gilts were hysterectomized and euthanized to obtain uteri, conceptuses and
fetal fluids. Placental water transport was determined by using Ussing chambers.
Concentrations of AAs in fetal fluids and maternal plasma were determined by HPLC.
Total RNA and protein were extracted from the frozen tissues. Quantitative RT-PCR and
western blotting were performed to determine the changes in gene expression at mRNA
and protein levels. Porcine trophectoderm (PTr2) cells were cultured in medium with
different concentrations of arginine to determine water transport and cGMP production.
Compared to the control group, arginine supplementation increased (P < 0.05)
embryonic survival from 87.3% in the control group to 96.5% in the arginine group.
Allantoic fluid volume was increased by 25% and amniotic fluid volume was increased
by 48% in the arginine group. The placentae of arginine-supplemented gilts were more
vascularized in terms of the number and size of blood vessels. Compared to the control
group, arginine supplementation increased (P < 0.05) the number of placental blood
vessels; placental expression of angiogenic factors VEGFA120, VEGFR1, VEGFR2,
eNOS, PlGF, GTP-CH and FGF-2; and placental transport of water. We conclude that
dietary arginine supplementation to pigs between days 14 and 30 of gestation improves
survival and development of the conceptuses through stimulating placental water
transport and angiogenesis. | en |
