Induction of cleft palate in newborn pigs by maternal ingestion of poison hemlock (Conium maculatum).

Cleft palates were induced in newborn pigs of gilts fed Conium maculatum seed or plant during gestation days 30 through 45. Twelve of 23 newborn pigs born to 3 gilts given Utah-grown C maculatum seed and 9 of 12 newborn pigs born to a single gilt given the fresh Utah spring-growth C maculatum plant had cleft palates. The cleft palates ranged from a unilateral cleft, involving only 1 side of the palate, to a full bilateral cleft. Brachygnathia was also observed in some of these newborn pigs with cleft palate. Other malformations were not observed. Chemical analysis of seed and plant samples indicated that gamma-coniceine was the responsible teratogenic alkaloid. A daily dose of plant or seed that provided greater than or equal to 1.07 mg of gamma-coniceine/kg of body weight fed to gilts during the 30th through the 45th day of pregnancy resulted in teratogenic effects.