Plasma glycosaminoglycans, cortisol, iron and haemoglobin in term and nursing mares

The purpose of this study was to evaluate the contribution of the total content of glycosaminoglycans (GAGs), cortisol, iron, and hemoglobin (Hb) in term and nursing mares. Twenty-four healthy mares, aged 7 ± 1.5 years, were examined. Eighteen pregnant mares were considered the observational group, and six nonpregnant mares were considered the control group, by random selection. Blood samples were taken at the 10 and 11 months of gestation and at 15 and 30 postpartum days for the observational group and in baseline condition for the control group. Two-way analysis of variance showed a significant interaction between peripartum, postpartum, and time points for GAGs (F = 34.75; P < .0001) and Hb (F = 8.77; P = .007) changes. A significant effect of peripartum (F = 64.96; P < .0001) on the Hb changes was observed, with higher concentrations at 15 days of postpartum (P < .01) than 11 months of pregnancy. Compared with control group, observational group showed lower Hb values along peripartum (P < .01) and at 30 days of postpartum (P < .01). A significant and positive correlation between GAGs and cortisol concentrations (r = 0.99; P = .008) was also shown. The present study contributes to a deeper knowledge on the dynamic endocrine–metabolic profile of mare throughout the transition from one to another physiological stage.