p. 241 - 250 INFLUENCE OF SEWEED MEAL ON THE THYROID FUNCTION AND MILK PRODUCTION OF DAIRY COWS Teodoru Vitalie Central Institute for Technical Documentation, Bucharest Maria Stadniciuc Institut Roumain de Recherches Marines Constanta Alexandru Lungu and Graziella Nicolau Institut of Endrocrinology, Bucharest Dumitru Petcu Palas Experimental Station, Constanta Vasilica Manciu Agricultural Production Cooperative, Leresti-Arges Abstract Study of the effect of seaweed in rations for dairy cows on thyroid function and milk production. Testings were carried out in two diferent regions: an iodine-providing (non-goitrogenic) zone (Palas-Constantza) and an iodine-deficient (goitrogenic) zone (Leresi-Arges). The estimation of thyroid activity was carried out by dosage of protein bound iodine (P.B.I.)in blood and milk. There was established that in the iodine deficient area, seaweed added to food determines an averange increase in P.B.I.: with 88.37 p.c. in milk and 75.26 p.c. in blood. The daily milk production of cows which received seaweed meal in their rations rose with 8.63 p.c.