EFFECT OF ALTRENOGEST TREATMENT TO EARLY POSTPARTUM MARES ON REPRODUCTIVE-PERFORMANCE OF THE MERE AND HEALTH, GROWTH AND DEVELOPMENT OF THEFOAL

Fourteen mares were included in a study to determine the effect of alt renogest treatment to early postpartum mares on the reproductive perfo rmance of the mares and health, growth and development of the foals. M ares were assigned to one of three groups :group 1- no treatment (cont rol group), group 2- orally administered altrenogest for the first 7 d ays postpartum and group 3- orally administered altrenogest for the fi rst 15 days postpartum. On days 1-30 postpartum, mares were tested dai ly with a stallion to determine estrus. Foals were monitored daily for general health and weighed and bled for serum chemistry concentration s on days 1, 5 10, 15, 20 25 and 30 of age. Foals nursing mares orally administered altrenogest grew as rapidly as foals suckling untreated mares (P>.20). Furthermore, serum chemistry of foals nursing mares ora lly administered altrenogest were not adversely affected and none of t he foals became ill during the first 30 days of age. As anticipated, t he foal heats were delayed (P<0.05) in the mares orally administered a ltrenogest for the first 15 days postpartum. No adverse effects on the reproductive performance of the mares were detected. In summary, admi nistration of altrenogest to early postpartum mares had no adverse eff ects on the reproductive performance of the mares and on the health, g rowth and development of the suckling foals.