[Megestrolacetat applied for oestrusinduction and oestrussynchronization in heifers (author's transl)]

Forty-seven heifers with the diagnosis anoestrus were treated with 15 mg to 60 mg megestrolacetat (Niagestin "NOVO") per os for 10 days. Thirty heifers showed oestrus within 10 days after treatment and 56% of these conceived after first insemination. There was no significant difference in fertility after different doses of megestrolacetat. Ten cycling heifers were synchronized with 50 mg megestrolacetat per os for 14 days. On the first day of treatment 5 mg oestradiolvalerat was given intramuscularily. All heifers came into heat and were inseminated 2--4 days after treatment. Fifty per cent were pregnant 55 days after insemination. Dosage of megestrolacetat for cows and heifers are discussed.