Serum concentration of thyroid hormones in crioula lanada serrana ewes in gestation and lactation

Abstract

The effects of gestation and lactation on the dynamics of the thyroid hormones triiodothyronine (T-3) and thyroxine (T-4) were evaluated in Crioula Lanada Serrana ewes from the plateau region in Santa Catarina Brazil To evaluate the effects of gestation twenty four ewes were randomly divided into groups I and II Group I was composed of 12 pregnant ewes and the control group (II) was composed of 12 non pregnant ewes The effects of lactation were evaluated in the same ewes of group I after parturition (LE) and in the control group (NL) Blood samples were taken in the first second and third periods of gestation at parturition and at 30 60 and 90 days of lactation T-3 and T-4 concentrations were determined by radio immunoassay (RIA) Pregnant ewes showed lower serum concentrations of T-3 and T-4 than those of non pregnant ewes At parturition there was no significant difference in T-3 concentrations between groups land II (p>0 05) During lactation serum T-3 concentrations were lower (p 0 05) from those of NL ewes During lactation T-4 concentrations of LE were lower (p