Abstract
The use of shearing during pregnancy has been described as a tool for improving productivity in sheep and for minimizing perinatal mortality in lambs through the increase of fetal development. This study assessed the effect of shearing around 74 days of gestation on the productive performance of ewes and lambs during the first month of life. Forty Corriedale ewes were inseminated in autumn in Southern Brazil. All ewes were kept together at the same pasture under extensive husbandry conditions. The ewes were randomly separated into two treatment groups: twenty animals were completely sheared at 74 ± 6 days of pregnancy, and twenty were kept without sheared during pregnancy, composing the control group. Ewes and their lambs were evaluated at three different times during the experiment: at birth, between 15 and 21 days post-partum and between 22 and 45 days post-partum. Ewes had their body condition score, body weight, placental weight, milk production and serum concentrations of beta-hydroxybutyrate measured, while lambs had hematocrit, hemoglobin, and plasma lactate and glucose, as well as body weight at birth and until wean determined. Values of hematocrit and hemoglobin were lower and body weight at birth and at wean was higher in the group of lambs born from sheared ewes. Placenta weight was higher in sheared ewes. Body condition score and beta-hydroxybutyrate showed no differences between groups. Milk production of sheared ewes (1.26 L/day) was higher than in control group (0.93 L/day). Shearing ewes at 74 days of pregnancy was efficient for the better development of lambs at post-birth, reducing perinatal mortality rates.
Highlights
Perinatal death in lambs, occurring immediately before, during or up to 28 days after birth, is one of the main causes of limited productivity in flocks from southern Brazil[1, 2]
Mellor & Murray[19] and Mellor[12] justified the higher hematocrit in newborn lambs from non-sheared sheep as a compensatory effect to the diminished blood contribution to the fetus and the resulting chronic hypoxia, which may lead to a lesser growth of the placenta
The hematological parameters of the lambs in this experiment had values within the reference for the species, which makes it difficult to state that the lambs suffered chronic hypoxia or even low placental growth
Summary
Perinatal death in lambs, occurring immediately before, during or up to 28 days after birth, is one of the main causes of limited productivity in flocks from southern Brazil[1, 2]. Some strategies can be adopted in order to diminish perinatal death in lambs, such as improving weight at birth[4], which involves enhancing fetal development[5], especially in periods of scarce grass or in winter. For this purpose, shearing during gestation has been used as an alternative, because it alters the metabolism and the placenta of ewes[6]. Morris and McCutcheon[10] and Ribeiro et al[11] verified a mean increase of body weight at birth of 700 and 710 g in lambs from ewes that were sheared between 70 and 74 days of pregnancy, respectively
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
