Effect of Glucocorticoid Treatment on Biochemical and Hormonal Blood Parameters in Early Pregnant Gilts

Twenty Polish Landrace gilts were grouped immediately after mating as follows: Experiment I–Group 1 (5 gilts), control animals and Group 2 (5 gilts), injected i.m. with dexamethasone (30 mg/kg) at 12-h intervals from day 13 to day 22 of pregnancy; Experiment II–Group 3 (5 gilts), injected i.m. with corn oil from day 13 to day 22 of pregnancy and Group 4 (5 gilts), injected i.m. with hydrocortisone acetate (250 mg) at 12-h intervals from day 11 to day 20 of pregnancy. Gilts were placed in metabolic cages on day 7. On days 34–36 of pregnancy gilts were slaughtered and blood samples were collected. Serum was used for analysis of aspartate aminotransferase (S-ASAT), alanine aminotransferase (S-ALAT), alkaline phosphatase (S-ALP), S-cholesterol, S-triglycerides, S-fructosa-mine, S-urea, S-total protein, and for electrophoretic fractionation of serum proteins, corticosteroid-binding globulin (CBG), Cortisol, progesterone, thyroxine (T₄) and free T₄. There were no significant differences between groups in embryonic survival or in number of viable fetuses after treatment with glucocorticoids. The activity of S-ALP was lower (p<0.05) in Group 4 than in Group 3 (0.5 vs 1.2 μkat/1). Group 4 had higher (p<0.05) levels of S-triglycerides (1.17 vs 0.73 mmol/1), S-cholesterol (5.4 vs 2.7 mmol/1), S-total protein (110.5 vs 93.3 g/1), S-albumin (56.3 vs 43.3 g/1) and α₂-globulin concentrations (18.0 vs 14.3 g/1) than Group 3. The hydrocortisone-treated gilts had lower (p<0.05) CBG (6.8 vs 21.3 nmol/1) and β₁ globulin (3.25 vs 5.0 g/1) concentrations than the oil-treated ones. Concentrations of T₄ were lower (p<0.05) in Groups 2 (61.3 nmo/1) and 4 (49.0 nmol/1) compared with control Groups 1 and 3 (88.2 and 97.0 nmol/1, respectively). Overall, the treatment of early pregnant gilts with hydrocortisone acetate resulted in decreased levels of S-ALP, CBG,β₁ -globulin and T₄, and in increased levels of S-cholesterol, S-triglycerides, S-total protein, S-albumin and α₂-globulin. The only effect of dexamethasone was a lowering of T₄. There were no differences in free T₄, S-fructosamine or S-urea between controls and treatments. Furthermore a negative correlation between triglycerides concentrations and the number of embryos (r =–0.76, p<0.05) was found in control untreated and oil-treated pregnant gilts.