title: Maternal metabolizable protein restriction during late gestation on uterine and umbilical blood flows and maternal and fetal amino acid concentrations near term in sheep.
abstract: To examine the effects of maternal metabolizable protein (MP) restriction during late gestation on uterine and umbilical blood flows, conceptus size, and amino acid concentrations in the uterine and umbilical vessels, 11 ewes with singleton pregnancies were assigned to one of three isocaloric diets formulated to provide 60% of MP (MP60), 80% of MP (MP80), or 100% of MP (MP100) requirements from days 100 to 130 of gestation. On day 130 of gestation, intraoperative uterine and umbilical blood flows were obtained as well as serum samples from the uterine artery, uterine vein, umbilical artery, and umbilical vein. Ewes on the MP60 diet had lighter (P=0.04) and smaller (P≤0.05) fetuses, but increased (P=0.02) uterine blood flow relative to fetal weight compared with MP100 ewes, with MP80 being intermediate. Umbilical blood flow was similar (P=0.70) across treatments. Glutamine, glycine, isoleucine, leucine, ornithine, serine, and valine concentrations were impacted (P≤0.02) by maternal treatment. While uterine flux of total serum nitrites was greater (P=0.03) in MP60 and MP80 ewes compared with MP100 ewes, fetal flux did not differ. Decreased maternal protein intake resulted in less (P<0.01) maternal cytochrome P450 1A enzyme activity. There were minimal impacts of maternal diet on steroid concentrations. Maternal dietary protein may alter fetal growth by impacting placental vasculature function and nutrient absorptive capabilities.
authors.affiliation: Department of Animal Sciences, North Dakota State University, Fargo 58108, United States.
authors.forename: L A
authors.initials: LA
authors.lastname: Lekatz
authors.affiliation: Department of Animal Sciences, North Dakota State University, Fargo 58108, United States.
authors.forename: T J
authors.initials: TJ
authors.lastname: Swanson
authors.affiliation: Department of Animal Sciences, North Dakota State University, Fargo 58108, United States.
authors.forename: L E
authors.initials: LE
authors.lastname: Camacho
authors.affiliation: Hettinger Research Extension Center, North Dakota State University, Hettinger 58639, United States.
authors.forename: M L
authors.initials: ML
authors.lastname: Van Emon
authors.affiliation: Hettinger Research Extension Center, North Dakota State University, Hettinger 58639, United States.
authors.forename: C S
authors.initials: CS
authors.lastname: Schauer
authors.affiliation: Department of Animal Sciences, North Dakota State University, Fargo 58108, United States.
authors.forename: K R
authors.initials: KR
authors.lastname: Maddock Carlin
authors.affiliation: Department of Animal Sciences, North Dakota State University, Fargo 58108, United States.
authors.forename: C J
authors.initials: CJ
authors.lastname: Hammer
authors.affiliation: Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762, United States.
authors.forename: C O
authors.initials: CO
authors.lastname: Lemley
authors.affiliation: Department of Animal Sciences, North Dakota State University, Fargo 58108, United States. Electronic address: Kim.Vonnahme@ndsu.edu.
authors.forename: K A
authors.initials: KA
authors.lastname: Vonnahme
mesh_terms: D000596:Amino Acids / Q000097:blood; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001783:Blood Flow Velocity; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005317:Fetal Growth Retardation; D039382:Maternal Nutritional Physiological Phenomena; D011247:Pregnancy; D012756:Sheep / Q000502:physiology*; D014470:Umbilical Cord / Q000098:blood supply* / Q000502:physiology; D014599:Uterus / Q000098:blood supply*
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins
keywords: Amino acids; Metabolizable protein; Sheep; Umbilical blood flow; Uterine blood flow