We hypothesize rumen-protected arginine supplementation during gestation will mitigate deleterious offspring effects caused by undernutrition. Experiment 1: non-pregnant ewes were supplemented with rumen-protected arginine at varying doses to assess effects on circulating amino acids and carotid hemodynamics. Arginine concentrations post-supplementation were greater in ewes supplemented with 180 vs. 90 mg/kg BW, and vascular resistance indices were lesser with 180 mg/kg BW; therefore, 180 mg/kg BW was used in experiment 2. Experiment 2: nutrient-restricted pregnant ewes were supplemented with rumen-protected arginine and maternal and offspring growth and physiological responses were measured. Arginine supplementation to nutrient restricted ewes improved offspring development compared to restricted ewes without supplementation. Circulating amino acids in offspring were efficiently metabolized, which may contribute to improved growth and development. There was no change in carotid hemodynamics in supplemented pregnant ewes. Further research should determine how arginine improves development, as this dietary supplement could rescue at-risk pregnancies.