Plasma concentrations of essential trace microminerals and thyroid hormones during single or twin pregnancies in fat-tailed ewes

The aim of this study was to monitor changes in plasma concentrations of essential trace microminerals including: Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), Selenium (Se), Iodine (I) and thyroid hormones in single and twin fat-tailed pregnant ewes. Estrus of 150 fat-tailed Afshari ewes was synchronized using CIDR, inserted for 14 days and ewes given 400 IU eCG im on the day of CIDR removal. A total number of 40 apparently healthy pregnant sheep (20 single and 20 twin pregnancies), 4-5 years old, weighing 60.19 +/- 1.65 kg, were randomly selected using sonography. The ewes were assigned in 2 groups: group 1 (ewes carrying single fetus) and group 2 (ewes carrying twin fetuses). The blood samples were collected at days 30, 60, 90, 120 and 150 of gestation and analyzed for plasma Cu, Zn, Fe, Mn, Se, I, T-3 and T-4 concentrations. Data were analyzed using a restricted maximum likelihood-based, mixed-effects model, and repeat measures analysis. A t-test was used to evaluate the differences between single and twin pregnancy of plasma micromineral levels, T-3 and T-4 hormones. Results indicated that the concentrations of Mn, Se, I, T-3 and T-4 were decreased (P < 0.05) in plasma from day 90 in single and twin pregnant ewes. However, the level of Cu, Zn and Fe were decreased (P < 0.05) during late gestation period. The Plasma Cu, Se and T-3 concentrations in single were higher (P < 0.05) than twin pregnant ewes on day 150 of pregnancy. Plasma Zn, Mn, I and T-4 measured in twin were lower (P < 0.05) than single pregnant ewes on all period of gestation. In conclusion, the twin had lower essential trace microminerals and thyroid hormones than single pregnant ewes during pregnancy (Zn, Mn, I, and T-4) or late period of gestation (Cu, Se and T-3). (C) 2013 Elsevier B.V. All rights reserved.