Effect of short-term prepartum supplementation with propylene glycol and calcium propionate on metabolic parameters and lamb performance in multiparous ewes with a low body condition score

This study evaluated the effect of short-term prepartum supplementation of ewes with two gluconeogenic precursors propylene glycol (PG) and calcium propionate (CP) in the Chilean drylands with a Mediterranean climate. We started with 22 adult Romanov ewes with a low body condition score and synchronized in estrus. After pregnancy diagnosis, we selected 18 ewes with two or three gestations and randomly assigned them to three groups: the control group (CG; n = 6), the PG group (n = 6), and the CP group (n = 6). We supplemented the PG and CP groups for 10 days before the estimated lambing date. We measured the β-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), and glucose plasma levels as well as the body condition score (BCS) at 3 timepoints: 10 days before lambing, right after lambing, and day 10 postpartum. In addition, we weighed the lambs at birth and on day 10 postpartum. The BHB level right after lambing decreased in the PG and CP groups compared with the CG (P < 0.05). The NEFA level did not vary between the groups at the different timepoints. The glucose level increased approximately 2–3-fold (P < 0.05) in all ewes after lambing and decreased on day 10 postpartum, but there were no significant differences between the PG and CP groups (p > 0.05). In addition, the BCS did not differ between the groups at any time point (P > 0.05). The weight of the lambs on day 10 postpartum increased significantly (P < 0.05) in the PG and CP groups compared with the CG. In addition, the mean daily weight gain was approximately 50% higher in the PG and CP groups compared with the CG (P < 0.05). Based on these findings, short-term prepartum supplementation with PG or CP reduced the BHB level in ewes with a low BCS and multifetal gestations during lambing and improved the lamb weight on day 10 postpartum. Therefore, the administration of these additives could be a useful strategy in sheep under feed restrictions in the Chilean drylands with a Mediterranean climate at times of high nutritional requirements.