Effects of fetal number on acute phase proteins, cortisol, and hematological parameters in ewes during the periparturient period

Many subclinical diseases associated with inflammation occur in sheep during the periparturient period. Clinical symptoms are usually detected at an advanced stage of the disease; therefore, there are considerable risks of permanent health disorders in fetuses or dams. Determination of acute phase proteins (APPs) as markers of inflammation may allow for an earlier diagnosis and effective treatment. Furthermore, multi-fetus pregnancies are often associated with hematological disturbances. The study objective was to compare plasma concentrations of serum amyloid A (SAA), haptoglobin (Hp), fibrinogen (Fb), and cortisol in ewes bearing one and two fetuses in the period from 2 weeks before to 2 weeks after parturition as well as to determine hematological parameters in peripheral blood. There was an important effect of fetal number on APP and cortisol concentrations in periparturient ewes. There was a greater concentration of SAA, Hp, Fb, and cortisol in ewes bearing two fetuses compared with those bearing one fetus. Profiles for APP and cortisol concentrations and hematological parameters were similar for ewes bearing one and two fetuses, and trends were within normal reference ranges for the periparturient period. Furthermore, there were no differences in values for hematological variables between ewes bearing one and two fetuses. with there being no ewes with anemia. In summary, separate determination of the previously undefined physiological ranges of APPs and cortisol for ewes bearing one and two fetuses may facilitate diagnosis of subclinical disorders and enable comparison of laboratory test results with different reference values for ewes bearing different numbers of fetuses.