Supplementation with Polyphenols (Olive and Grape Extracts) Improves Pregnancy Outcomes in Underfed Sheep

Our study aimed to test the hypothesis that supplementation with a combination of dry grape extracts (DGS) and olive-originated hydroxityrosol (HxT) polyphenols during ovine gestation under moderate nutritional restriction allows for the improvement of the birth weight and size of newborn lambs, especially in more demanding pregnancies such as twins. Twenty-six pregnant ewes (fourteen ewes with singleton pregnancies and twelve ewes with twin pregnancies) were divided in two equal groups, treated or not with the polyphenols, and involved in the study. The results indicate that supplementation with the combination of polyphenols, without modifying maternal body weight and body condition score, increased the maternal total antioxidant capacity (<i>p</i> < 0.05) and, interacting with pregnancy rank, improved maternal metabolic status by reducing β-hydroxybutyrate and non-esterified fatty acids (<i>p</i> < 0.05). Afterwards, supplementation improved birth weight and size of newborns in the most compromised pregnancies (i.e., twin pregnancies; twins lambs born to supplemented ewes were significantly heavier than those born to control ewes (3.3 ± 0.13 vs. 2.8 ± 0.23 kg, respectively; <i>p</i> < 0.05).