[Teratogenicity of zinc-metallibur]

Suisynchron-Prämix, 5 g/100 mg active principle, was administered daily to pregnant brood sows over 20 days, beginning from the 15th, 25th, 35th, 45th, and 55th days of pregnancy. The effects of Suisynchron on pregnancy were assessed by slaughter results immediately after administration as well as by farrowing results and slaughter of the newborn piglets. Suisynchron administration between the 15th and 55th day of pregnancy killed the embryos, while teratogenic effects were primarily recorded from administration in more advanced phases, say, between the 45th and 75th days of pregnancy. Teratogenicity was attributable to damage to metabolism which, in turn, had been caused by deviations in the activity of endocrine glands.