Elecko, J [Levels of thyroxine, beta carotene and vitamin A during successful and unsuccessful insemination of heifers]. [electronic resource] - Veterinarni medicina Dec 1986 - 705-12 p. digital Publication Type: English Abstract; Journal Article ISSN: 0375-8427 Subjects--Topical Terms: AnimalsCarotenoids--bloodCattle--bloodFemaleInsemination, Artificial--veterinaryPregnancyThyroxine--bloodVitamin A--bloodbeta Carotene