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United States Department of Agriculture

Agricultural Research Service

Title: Effects of selenium supply and dietary restriction on maternal and fetal body weight, visceral organ mass, cellularity estimates, and jejeunal vascularity in pregnant ewe lambs.)

item Reed, Jake
item Ward, Marcy
item Vonnahme, Kimberly
item Neville, Tammi
item Julius, S
item Borowicz, P
item Taylor, Joshua - Bret
item Redmer, Dale
item Reynold, Lawrence
item Caton, Joel

Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2007
Publication Date: 7/8/2007
Citation: Reed, J.J., Ward, M.A., Vonnahme, K.A., Neville, T.L., Julius, S.L., Borowicz, P.P., Taylor, J.B., Redmer, D.A., Reynold, L.P., Caton, J.S. 2007. Effects of selenium supply and dietary restriction on maternal and fetal body weight, visceral organ mass, cellularity estimates, and jejeunal vascularity in pregnant ewe lambs.. Journal of Animal Science. doi:10.2527/jas.2006-785

Interpretive Summary: We investigated the effects of maternal nutrient restriction and supranutritional-dietary selenium, from a high selenomethionine source, on fetal growth. Restricting daily-nutrient intake of pregnant ewe lambs resulted in reduced body and organ growth of their fetuses. Feeding supranutritional selenium to pregnant ewe lambs seemed to result in heavier fetal-spleen, -heart, and -lung weights, but lighter fetal-adrenal weight. There is some (but limited) evidence that the supranutritional-selenium effects seemed to be altered when daily-nutrient intake of the pregnant ewe is restricted.

Technical Abstract: To examine effects of nutrient restriction and dietary Se on maternal and fetal visceral tissues, 36 pregnant Targhee-cross ewe lambs were allotted randomly to one of four treatments in a 2 x 2 factorial design. Factors were nutrition [control nutrition (CON, 100% of requirements) vs. restricted nutrition (RES, 60% of controls] and dietary Se [Adequate Se (ASe, 7.4 'g/kg BW) vs. High Se (HSe, 81.5 'g/kg BW]. Selenium treatments were initiated 21 d prior to breeding and restriction treatments on d 64 of gestation. Diets were 16% CP and 2.12 Mcal/kg metabolizable energy (DM basis). On d 135 ± 5 of gestation, ewes were slaughtered and tissues harvested. There was (P = 0.02) a nutrition x Se interaction for maternal jejunal RNA:DNA; there were no other interactions for maternal measurements. Maternal BW (P = 0.001), stomach complex (P = 0.001), small intestine (P = 0.001), large intestine (P = 0.001), liver (P = 0.001), and kidney (P = 0.01) mass were decreased in RES vs. CON ewes. Lung mass (g/kg empty BW) was greater (P = 0.09) in RES vs. CON ewes and for HSe compared with ASe ewes. Maternal jejunal protein content and protein:DNA were decreased (P = 0.001 and 0.002, respectively) in RES vs. CON ewes. Maternal jejunal DNA and RNA concentrations and total proliferating cells were not affected (P = 0.35, 0.11, and 0.34, respectively) by treatment. Total jejunal and mucosal vascularity (mL) decreased (P = 0.001 and 0.01) in RES vs. CON ewes. Fetuses from RES ewes had decreased BW (P = 0.06), empty carcass weight (P = 0.06) and decreased crown to rump length (P = 0.03), liver (P = 0.01), pancreas (P = 0.07), perirenal fat (P = 0.02), small intestine (P = 0.007), and spleen weights (P = 0.03) compared with fetuses from CON ewes. Fetuses from HSe ewes had heavier BW (P = 0.08), empty carcass (P = 0.09), heart (P = 0.09), lung (P = 0.06), spleen (P = 0.05) total viscera (P = 0.03), and large intestine (P = 0.01) weights compared with ASe ewes. Nutrient restriction resulted in decreased protein content (mg, P = 0.01) and protein:DNA (P = 0.06) in fetal jejunum. Protein concentrations (mg/g) decreased in fetal heart (P = 0.07) and muscle (P = 0.02) due to nutrient restriction. Fetal heart RNA content (P = 0.04) and muscle RNA concentration (P = 0.01) were greater in HSe vs. ASe ewes. These data indicated dietary Se may provide a sparing effect on the fetus when maternal nutrition is limiting.

Last Modified: 8/24/2016
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