Article

Effects of selenium supply and dietary restriction on maternal and fetal body weight, visceral organ mass and cellularity estimates, and jejunal vascularity in pregnant ewe lambs

Department of Animal Sciences, North Dakota State University, Fargo, North Dakota, United States
Journal of Animal Science (Impact Factor: 2.11). 10/2007; 85(10):2721-33. DOI: 10.2527/jas.2006-785
Source: PubMed

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 1 of 4 treatments in a 2 x 2 factorial arrangement. Treatments were plane of nutrition [control, 100% of requirements vs. restricted, 60% of controls] and dietary Se [adequate Se, ASe (6 microg/kg of BW) vs. high Se, HSe (80 microg/kg of BW)] from Se-enriched yeast. Selenium treatments were initiated 21 d before breeding and dietary restriction began on d 64 of gestation. Diets contained 16% CP and 2.12 Mcal/kg of ME (DM basis) and differing amounts were fed to control and restricted groups. On d 135 +/- 5 (mean +/- range) of gestation, ewes were slaughtered and visceral tissues were harvested. There was a nutrition x Se interaction (P = 0.02) for maternal jejunal RNA:DNA; no other interactions were detected for maternal measurements. Maternal BW, stomach complex, small intestine, large intestine, liver, and kidney mass were less (P < or = 0.01) in restricted than control ewes. Lung mass (g/kg of empty BW) was greater (P = 0.09) in restricted than control ewes and for HSe compared with ASe ewes. Maternal jejunal protein content and protein:DNA were less (P < or = 0.002) in restricted than control ewes. Maternal jejunal DNA and RNA concentrations and total proliferating jejunal cells were not affected (P > or = 0.11) by treatment. Total jejunal and mucosal vascularity (mL) were less (P < or = 0.01) in restricted than control ewes. Fetuses from restricted ewes had less BW (P = 0.06), empty carcass weight (P = 0.06), crown-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 controls. Fetuses from HSe ewes had heavier (P < or = 0.09) BW, and empty carcass, heart, lung, spleen, total viscera, and large intestine weights compared with ASe ewes. Nutrient restriction resulted in less protein content (mg, P = 0.01) and protein:DNA (P = 0.06) in fetal jejunum. Fetal muscle DNA (nutrition by Se interaction, P = 0.04) concentration was greater (P < 0.05) in restricted ewes fed HSe compared with other treatments. Fetal muscle RNA concentration (P = 0.01) and heart RNA content (P = 0.04) were greater in HSe vs. ASe ewes. These data indicate that maternal dietary Se may alter fetal responses, as noted by greater fetal heart, lung, spleen, and BW.

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    • "The ethanol was allowed to evaporate overnight at room temperature in complete darkness before feeding (Lemley et al., 2012). The amount of feed offered to individual ewes was adjusted weekly based on BW and change in BW to ensure the desired average daily gains were achieved (Reed et al., 2007). Ewes were maintained on their given dietary treatments until 130 days of gestation. "
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    • "Although diet type has previously affected organ masses in ruminants, this has often been confounded with DMI, nutrient intake, or both (Sainz and Bentley, 1997;McLeod and Baldwin, 2000;McCurdy et al., 2010). Because lambs fed the FOR diet had greater DMI than CONC-fed lambs, increased GIT masses of FOR-fed lambs may have been due to DMI (Rompala and Hoagland, 1987;Burrin et al., 1990;Reed et al., 2007) or dietary bulk (Rompala et al., 1988). In addition to fiber, protein intake was considerably greater for FOR-fed lambs, which may have also affected organ growth and final mass. "
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    • "(For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) size, and RNA:DNA ratio used as an index of transcriptional activity (Reed et al., 2007). "
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