The concentrations of IGF-I, glucose and testosterone in 140-day-old male lambs born to ewes fed a nutritional supplement from day 70 of gestation to term.

Abstract

Maternal nutrition influences fetal development, leading to lasting effects on postnatal growth, health and performance in the offspring. In sheep, we have demonstrated the effects of maternal supplementation in the second half of pregnancy on reproductive development in adult male offspring. These effects could be mediated by alterations in the circulating concentrations of metabolic hormones and growth factors that are crucial for the development of reproductive function in both males and females. We therefore tested whether maternal nutritional supplementation from day 70 of gestation until parturition affected the concentrations of IGF-I and glucose in the male offspring when they were 140 days old. We also studied testosterone concentrations to test for long-term effects on gonadal function. Pregnant Corriedale × Hampshire Down ewes were randomly assigned to a Control group (n = 20) fed on natural pasture throughout gestation, or a Supplemented group (n = 20) fed on natural pasture plus 400 g/day of a maintenance ration starting on day 70 of gestation. After weaning, male lambs (n = 12 per group) remained with their dams on natural pasture until 140 days of age when blood was sampled. There were no differences (P > 0.05) between the treatments for IGF-I (Supplemented 82.1 ± 8.1; Control 68.6 ± 7.2 ng/ml), glucose (Supplemented 89.1 ± 2.6; Control 84.0 ± 1.8 mg/dl). We conclude that maternal dietary supplementation from mid-gestation to term has no long-term carryover effects on the secretion of IGF-I or glucose, although other aspects of metabolic homeostasis might be affected. Similarly, the lack of effect on testosterone concentration suggests no long-term effects on Leydig cell function.