For a long time, Pantaneiro and Campeiro breeds were raised only within their places of origin. Consequently, there are few of these horses; therefore, establishing reproductive and clinical standards for these animals is necessary to implant new biotechnologies for reproduction to preserve their genetics. This study aimed to perform a descriptive evaluation of fetal age determination by fetus ocular orbit measurement in mares of the Campeiro and Pantaneiro breeds. We also evaluated sequential changes in hematology and biochemistry for foals from birth to six months of life by counting red blood cells, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin concentration, leukocytes, neutrophils, lymphocytes, eosinophils, monocytes, basophils, platelet count, fibrinogen, albumin, plasma protein, creatinine, aspartate aminotransferase, alkaline phosphatase, gammaglutamyl transferase, and globulins. There was no significant difference in relation to fetal gestational age and ocular orbit between the two breeds (P = 0.578). There was no significant difference in the hematological parameters between the Campeiro and Pantaneiro foals, but there were differences in the means and changes in the blood variables when compared to the literature. These hematological and biochemical variations provide useful information for clinical evaluations from Campeiro and Pantaneiro foals up to six months of age.

por toda orientação, paciência, confiança e humildade demonstrada durante esse período do mestrado. Ao Dr. Alexandre Floriani Ramos e à toda equipe da embrapa por todo suporte para realização do experimento desta dissertação.Aos amigos Aline Campeche Lopes e Andrei Antonioni Guedes Fidelis por todo auxílio na execução deste experimento.Aos professores e funcionários do programa de Pós-graduação em ciências animais da Faculdade de Agronomia e Medicina Veterinária da Universidade de Brasília (UnB).À CAPES pela concessão da bolsa de estudos.