Comparison of hematological parameters between single and twin pregnancies in Dorper ewes during gestation, lambing, and postpartum

Bianca Paola Santarosa,Soraya Regina Sacco Surian,Henrique Barbosa Hooper,Andreza Amaral Da Silva,Silvia Maria França Carvalho Garcia,Danilo Otávio Laurenti Ferreira,Ana Carolina Rusca Correa Porto,Roberto Calderon Gonçalves,Paula Adriane Piccolo Pieruzzi,Gabriela Nascimento Dantas

doi:10.1590/0103-8478cr20201065

Abstract

ABSTRACT: The hematopoietic system changes during the pregnancy to carry fetal development and maternal needs. This study compared the hematological parameters between ewes with single and twin pregnancies during gestation, delivery, and postpartum. The experiment was conducted on 60 healthy pregnant Dorper ewes that were divided into two experimental groups: Group 1 (G1), with single pregnancies (n=30), and Group 2 (G2), with twin pregnancies (n=30). Blood samples were collected from all ewes at different times: immediately before fixed-time artificial insemination (AI); on day 30, 90, 120, 130, and 140 of pregnancy; immediately after delivery; and at 24h and 48h postpartum. Statistical analysis compared the two groups at different times (P<0.05). Mild, normocytic, and hypochromic anemia was detected in all ewes from AI time and throughout pregnancy from both groups, but did not prove to be of clinical relevance. In the peripartum stage (from the 140th day of pregnancy to 48h postpartum), the ewes with twin pregnancies (G2) exhibited higher erythrogram values and neutrophil:lymphocyte ratio than did ewes with single pregnancies (G1). This indicated a greater hematopoietic adaptation in the body during the development of two fetuses. Except for the eosinophil numbers, all leukogram parameters were influenced by pregnancy in a similar way in both groups, and was characterized mainly by leukocytosis with neutrophilia during peripartum due to the high presence of endogenous cortisol at delivery. Thus, these findings showed that pregnancy was a stressful physiological event that increased the leukocyte count with a slight alteration in the erythrogram of Dorper ewes.

Highlights

Important physiological changes during pregnancy determine the birth weight and neonatal viability of the fetus and lead to changes in the maternal hematopoietic system in different animal species including sheep
The mean erythrogram values in the Group 1 (G1) and Group 2 (G2) groups under different stages have been presented in table 1
The mean erythrogram values in both G1 and G2 groups (Table 1) only differed (P

Summary

Introduction

Important physiological changes during pregnancy determine the birth weight and neonatal viability of the fetus and lead to changes in the maternal hematopoietic system in different animal species including sheep. In addition to an ewe’s nutritional requirements during pregnancy, high nutrient intake is required during delivery and the peripartum and lactation periods for both the dam and the newborn lambs (PEREIRA et al, 2015). Research has been carried out in Brazil to study the influence of pregnancy, parturition, and peripartum on the blood count in cattle (OLIVEIRA et al, 2019), goats (VIANA et al, 2002; VIANA et al, 2003), and sheep (PEREIRA et al, 2015; BEZERRA et al, 2017). Pereira et al (2015) reported blood count data of Santa Inês ewes on pasture from the 75th day of pregnancy until the 75th day of lactation. Bezerra et al (2017) described the hematological profile of the Santa Inês and Morada Nova sheep in all their reproductive stages, from non-pregnant to 60 d postpartum

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