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 lambs1

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.

Influence of nutrient restriction and melatonin supplementation of pregnant ewes on maternal and fetal pancreatic digestive enzymes and insulin-containing clusters

“…However, fetal pancreatic mass was not influenced by nutrient restriction, contradicting past research (Reed et al, 2007), which reported that fetal pancreatic mass from undernourished ewes was decreased compared with those from ewes adequately fed. Moreover, the melatonin supplementation strategy did not rescue fetal growth restriction brought about by maternal nutrient restriction from mid-to late-pregnancy (Lemley et al, 2012).…”

“…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.…”

Neonatal hormone changes and growth in lambs born to dams receiving differing nutritional intakes and selenium supplementation during gestation

“…Previous work from our laboratory has demonstrated that maternal Se supplementation much above the requirements may help to offset some of the negative impacts of maternal dietary restriction, which in our model leads to IUGR (Reed et al 2007. In this study, our focus was how neonatal growth, T 3 , T 4 , and cortisol concentrations would be impacted by maternal diet, as There was no effect of maternal Se by offspring sex (PR0.17), maternal nutritional intake by offspring sex (PO0.14), or maternal Se!maternal nutritional intake!offspring sex (PO0.15) interactions for the measures presented in the table, except for A pancreas wt (g and g/g brain) and adrenal wt (mg/g brain), see Table 5; and liver (g/g EBW), see Table 4.…”

“…Our laboratory has reported that maternal nutrient restriction during mid-to-late gestation in ewes decreased fetal body weight (BW; Reed et al 2007) as well as birth weight . However, ewes given supranutritional selenium (Se) levels had greater fetal BW compared with ewes receiving adequate Se (ASe) levels (Reed et al 2007).…”

<b>Efeito da suplementação proteica no terço final da gestação de vacas Nelore associada a suplementação das crias em <i>creep-feeding</i> e o subseqüente desempenho produtivo e reprodutivo das bezerras e/ou novilhas</b>

“…A formação do tecido muscular é uma função de baixa prioridade na partição dos nutrientes, quando comparado a orgãos como cérebro, coração e fígado (DU et al, 2010), pois o comprometimento do crescimento dos órgãos internos é geralmente mais severo quando a restrição nutricional materna ocorre no início e meados da gestação em relação a restrição durante o final da gestação (REED et al, 2007;CARLSON et al, 2009;CATON et al, 2009). Entretanto, a restrição nutricional do segundo ao sétimo mês de gestação da vaca pode ter conseqüências irreversíveis na formação das miofibras secundárias e, conseqüentemente, no crescimento muscular pós-natal, pois o processo de hiperplasia muscular é restrito à gestação (DU et al, 2010), e, após o nascimento, o crescimento muscular ocorre por meio da hipertrofia das células musculares pré-existentes, o que é dependente das células satélites.…”