Fetal and organ development at gestational days 45, 90, 135 and at birth of lambs exposed to under- or over-nutrition during gestation1,2,3

Abstract

To determine the effects of poor maternal nutrition on offspring body and organ growth during gestation, pregnant Western White-faced ewes (n = 82) were randomly assigned into a 3 × 4 factorial treatment structure at d 30.2 ± 0.2 of gestation (n = 5 to 7 ewes per treatment). Ewes were individually fed 100% (control), 60% (restricted) or 140% (over) of NRC requirements for TDN. Ewes were euthanized at d 45, 90 or 135 of gestation or underwent parturition (birth) and tissues were collected from the offspring (n = 10 to 15 offspring per treatment). Offspring from control, restricted and overfed ewes are referred to as CON, RES and OVER, respectively. Ewe data were analyzed as a completely randomized design and offspring data were analyzed as a split-plot design using PROC MIXED. Ewe BW did not differ at d 30 (P ≥ 0.43), however restricted ewes weighed less than overfed and overfed were heavier than controls at d 45, and restricted weighed less and overfed were heavier than controls at d 90 and 135 and birth (P ≤ 0.05). Ewe BCS was similar at d 30, 45 and 90 (P ≤ 0.07), however restricted ewes scored lower than control at d 135 and birth (P ≤ 0.05) and over ewes scored higher than control at d 135 (P ≤ 0.05) but not at birth (P = 0.06). A maternal diet by day of gestation interaction indicated that at birth the body weight (BW) of RES offspring was less than CON and OVER (P ≤ 0.04) and heart girth of RES was smaller than CON and OVER (P ≤ 0.004). There was no interaction of maternal diet and day of gestation on crown-rump, fetal, or nose occipital length, or orbit or umbilical diam. (P ≥ 0.31). A main effect of maternal diet indicated that the RES crown-rump length was shorter than CON and OVER (P ≤ 0.05). An interaction was observed for liver, kidney and renal fat (P ≤ 0.02). At d 45 the liver of RES offspring was larger than CON and OVER (P ≤ 0.002), but no differences observed at d 90, 135 or birth (P ≥ 0.07). At d 45, the kidneys of OVER offspring were larger than CON and RES (P ≤ 0.04), but no differences observed at d 90, 135 or birth (P ≥ 0.60). At d 135, OVER had more perirenal fat than CON and RES (P ≤ 0.03), and at birth RES had more perirenal fat than CON and OVER (P ≤ 0.04). There was no interaction observed for offspring heart weight, length or width, kidney length, adrenal gland weight, loin eye area or rib width (P ≥ 0.09). In conclusion, poor maternal nutrition differentially alters offspring body size and organ growth depending on the stage of gestation.

CELL BIOLOGY SYMPOSIUM: METABOLIC RESPONSES TO STRESS: FROM ANIMAL TO CELL: Poor maternal nutrition during gestation: effects on offspring whole-body and tissue-specific metabolism in livestock species1,2

“…However, maternal nutrient restriction and realimentation did not affect offspring liver oxygen consumption (Prezotto et al, 2016). In sheep, nutrient restriction (60% of control) beginning at day 30 of gestation increased liver size in offspring at day 45 of gestation, but was similar mass to controls at birth (Pillai et al, 2017). It is well established that during postnatal growth and adulthood, obesity and metabolic disorders lead to increased lipid and collagen accumulation in the liver in multiple species, including sheep, humans, and rodents (Bringhenti et al, 2011;Hyatt et al, 2011;George et al, 2012).…”

“…The negative effects of maternal diet on offspring fat deposition can have multigenerational effects as demonstrated by Shasa et al (2015) in which granddaughters of obese ewes, even when F1 were fed a control diet, had increased adipose at birth and throughout life. Several studies using an over nutrition model in sheep did not observe an effect during fetal and early postnatal growth (Meyer et al, 2010;Hoffman et al, 2014Hoffman et al, , 2016aKleemann et al, 2015;Pillai et al, 2017), suggesting that there are potential metabolic changes in the offspring that make them more susceptible to fat deposition as an adult. This can have negative impacts on product quality, animal health, and animal reproduction.…”

“…Specifically, several laboratories have developed models of overfeeding and/or restricted-feeding (total energy or total nutrients) during different stages of gestation and demonstrated negative impacts on maternal health and reproductive organs, including placental development and fetal growth and development (Scheaffer et al, 2004;Vonnahme et al, 2007;Caton et al, 2009;Long et al, 2010). Our laboratory has used similar models of overfeeding (140% of control) and restricted-feeding (60% of control) from early gestation in the same experiments (Hoffman et al, 2014(Hoffman et al, , 2016aReed et al, 2014;Pillai et al, 2017). Using this model, we have demonstrated negative impacts of poor maternal nutrition on both prenatal and postnatal growth, and metabolism in offspring.…”

Influence of crossbreeding on meat goat doe fitness when comparing Boer F1 with base breeds in the Southeastern United States1

“…Litter traits at parturition represent both the end point for in utero conceptus development and the starting point for preweaning kid growth and development. As such, the litter traits at kidding can be used to assess if any differences in the uterine environment among maternal genotypes or litter types may exist that could affect postnatal offspring performance and warrant further inquiry (Rhind et al, 2001;Du et al, 2010;Pillai et al, 2017).…”

Ultrasound during mid‐gestation: Agreement with physical foetal and placental measurements and use in predicting gestational age in sheep

“…Rations were adjusted weekly for body weight changes (Reed, Raja, Hoffman, Zinn, & Govoni, 2014). A subset of ewes (n = 20-21 per time point) was euthanized at day 45 or 90 of gestation for offspring tissue collection (Pillai et al, 2017).…”