Effects of prepartum shearing on metabolic and placental parameters of ewes: Impact on productive parameters of their lambs

Prepartum shearing has been associated with increased lamb survival under pastoral conditions. This research aimed to evaluate the effects of early and late prepartum shearing in gestating Corriedale ewes on the metabolic profile and placental parameters of the ewes and how these changes affect the productive parameters of their lambs. On day 70 of gestation, 37 ewes carrying a single foetus were randomly divided into three groups: ewes sheared at day 70 of gestation (early, PS70, n = 12), sheared at day 110 of gestation (late, PS110, n = 12), and ewes unsheared at prepartum (US, n = 13, control group). Energy metabolism (glycaemia, insulin, NEFA, and BHB) and placental parameters (placental weight, number, and characteristics of cotyledons, and placental efficiency) were evaluated in the ewes. Live weight, morphometric measurements, and body composition were determined in the lambs. Prepartum shearing performed on different days (early and late) caused changes in energy metabolism, leading to a decrease in serum insulin and an increase in NEFA and BHB blood values. Early prepartum shearing increased placental weight and the number and weight of the 2–3 cm-cotyledons, while late prepartum shearing increased placental weight and placental efficiency and only changed the weight of the 2–3 cm-cotyledons. Prepartum shearing on both days caused an increase in lamb birth weight. Therefore, prepartum shearing caused changes in the metabolic profile and placenta of the ewes, which resulted in increased weight and development of lambs at birth.