Dietary l-arginine supplementation enhances placental growth and reproductive performance in sows

Suboptimal embryonic/fetal survival and growth remains a significant problem in mammals. Using a swine model, we tested the hypothesis that dietary l -arginine supplementation during gestation may improve pregnancy outcomes through enhancing placental growth and modulating hormonal secretions. Gestating pigs (Yorkshire × Landrace, n = 108) were assigned randomly into two groups based on parity and body weight, representing dietary supplementation with 1.0% l -arginine–HCl or 1.7% l -alanine (isonitrogenous control) between days 22 and 114 of gestation. Blood samples were obtained from the ear vein on days 22, 40, 70 and 90 of gestation. On days 40, 70 and 90 of gestation, concentrations of estradiol in plasma were higher ( P