Thyroid Hormones and Cortisol Concentrations in Offspring are Influenced by Maternal Supranutritional Selenium and Nutritional Plane in Sheep

To determine the effects of maternal supranutritional selenium (Se) supplementation and maternal nutritional plane on offspring growth potential, ewes were randomly assigned to 1 of 6 treatments in a 2 × 3 factorial arrangement [dietary Se (adequate Se; 9.5 μg/kg body weight vs. high Se; 81.8 μg/kg body weight initiated at breeding) and plane of nutrition [60%, 100%, or 140% of requirements; initiated on day 50 of gestation]]. Lambs were immediately removed from dams at birth and reared. Cortisol concentrations at birth were similar, but by 24 h, a relationship (P = 0.02) between maternal Se supplementation and nutritional plane on cortisol concentrations was observed in lambs. A sex of offspring × day of age interaction (P = 0.01) and a maternal Se supplementation × nutritional plane × day of age interaction (P = 0.04) was observed for thyroxine concentrations. Differences in growth may be influenced by thyroid hormone production early in neonatal life.