HEMATOLOGICAL FINDINGS IN PREGNANT, POSTPARTURIENT AND NURSING MARES

Venous blood samples were collected from 16 Thoroughbred and Quarter H orse mares during late pregnancy (approximately one month before partu rition), approximately 6 h after parturition, one month after parturit ion and 4 months after parturition when the foals were weaned. There w ere no significant differences over time for haematocrit, mean cell vo lume, mean cell haemoglobin concentration, platelet count or mean plat elet volume. The icterus index was significantly higher, and the total plasma protein concentration was slightly lower, during late pregnanc y than when nursing. Plasma fibrinogen concentration and total leucocy te counts were highest shortly after birth. Results from differential leucocyte counts revealed that the increased total leucocyte count mea sured shortly after birth was the result of increased numbers of neutr ophils. There were no significant differences in absolute lymphocyte, monocyte or basophil counts, but the number of eosinophils was signifi cantly lower shortly after birth. Total serum iron concentration and p ercentage saturation of transferrin with iron were highest shortly aft er birth. There was no significant difference in iron binding capacity over time. Serum ferritin and cortisol concentrations were lowest dur ing late pregnancy, but the mean ferritin value was not significantly different from other time periods. The addition of iron and other mine ral supplements to the basic concentrate fed at the University of Flor ida Horse Research Unit did not have a measurable effect on any haemat ological parameter evaluated in mares.