Gestational nutrition 1: alterations to gestational nutrition can increase indicators of fertility in sheep

The aim of this study was to examine the effects of alterations to gestational nutrition on fetal development and aspects of fertility in female offspring in sheep. Sheep were fed either a maintenance diet or 0.6 of maintenance for the first 55 days of gestation and thereafter fed ad lib. Fetuses were collected for analysis at days 55 and 75 of gestation. Female offspring were monitored from birth until 19 months of age. Significant effects of restricted nutrition were observed on maternal concentrations of albumin, creatinine, Ca2+, and progesterone. Concentrations of metabolic factors and steroid hormones in day 75 fetal plasma were not affected by alterations to gestational nutrition. Fetal ovarian germ cell numbers, rates of apoptosis, proliferation and autophagy were not affected by nutrition restriction at day 55 of gestation. At day 75 of gestation fetal ovaries exposed to altered gestational nutrition contained more germ cells but had lower germ cell proliferation rates than controls. In female offspring at 8 months of age, the onset of puberty and indicators of fertility (OR and AFC) were not significantly different between ewes from control dams and dams exposed to altered gestational nutrition. At 19 months of age ewes from dams exposed to altered gestational nutrition had significantly higher OR, AFC, and progesterone concentrations while concentrations of FSH were significantly lower. In conclusion the data shows that alterations to gestational nutrition can improve indicators of fertility in female offspring. Further, it is proposed that factors important in establishing this phenotype include the change from restricted to ad libitum nutrition, the timing of this change as well as alterations to fetal germ cell development