204 Awardee Talk: Poor Maternal Nutrition Impacts Metabolic Factors and Glucose Tolerance in Sheep Offspring

Abstract

To evaluate the hypothesis that offspring born to restricted- and over-fed ewes would exhibit decreased glucose tolerance, total cholesterol (TC), and triglyceride (TG), and increased leptin, multiparous Dorset ewes (n = 46) pregnant with twins were fed 100%, 60% or 140% of National Research Council (NRC) requirements from d30±0.02 of gestation until parturition. Offspring are referred to as CON (n=10 ewes; 12 rams), RES (n=13 ewes; 21 rams), and OVER (n =16 ewes; 15 rams), respectively. Blood samples were collected from offspring at d0, 7, 14, 58, 210, and 252 of age and plasma TC, plasma TG, and serum leptin were analyzed with commercial kits. Concentrations of TG were greater in rams than ewes (P=0.029). Leptin was greater (P< 0.0001) in ewes than rams at d30 and 36, and greater in CON than RES and OVER at d252 (P=0.058). At d133±0.25 an intravenous glucose tolerance test was performed, and blood samples collected at -30, -15, 0, 2, 5, 10, 15, 30, 60, and 120 min relative to glucose infusion (0.25 g/kg body weight of a 50% dextrose solution). Glucose and insulin concentrations were determined using commercial kits. Glucose concentrations were greater at 5 and 15 min in ewes than rams (P≤0.04) and at 2 min, OVER were greater than CON and RES (P=0.03). Insulin concentrations were greater in rams than ewes between 5 and 15 min (P=0.0251). Insulin in RES rams tended to be greater than OVER and RES ewes between 5 and 10 min (P=0.06) and continued to be greater than RES ewes at 15 min (P=0.05). First-phase response of insulin tended to be greater in RES compared with CON and OVER (P=0.092). There were no differences detected in insulin:glucose (P=0.312). In conclusion, poor maternal nutrition negatively impacts key metabolic hormones in offspring thereby contributing to altered growth and metabolism.