Ewe nutrition in early and mid- to late pregnancy has few effects on fetal development

Abstract

Maternal nutrition affects fetal development, with potential lifelong consequences. The study reported here compared the anatomical development (dimensions and organs) of twin fetuses at Day 140 of gestation, from 58 twin-bearing ewes fed at one of three different nutritional treatments in early pregnancy [Day 21–50, Low (LD21–50) versus Medium (MD21–50) versus High (HD21–50)] and one of two different nutritional treatments in mid- to late pregnancy (Day 50–140, Medium (MD50–140) versus High (HD50–140)]. There were no effects (P > 0.05) of either early or mid- to late pregnancy nutrition on placental weight and fetal bodyweight or size measurements at Day 140. Semitendinosus muscles from LD21–50-HD50–140 fetuses were heavier (P < 0.05) than those from LD21–50-MD50–140 and HD21–50-HD50–140 fetuses, and fetuses from LD21–50 dams had lighter (P < 0.05) mammary glands compared with those from MD21–50 and HD21–50 dams, even after adjustment for fetal weight. Maternal nutrition also affected (P < 0.05) the weights of the fetal thyroid and brain. These results suggest that farmers can limit ewe nutrition in early pregnancy with only minor effects on the fetus. To investigate potential lifetime effects, a larger cohort of these animals is currently being monitored.