Lupines, poison-hemlock and Nicotiana spp: toxicity and teratogenicity in livestock.

Many species of lupines contain quinolizidine or piperidine alkaloids known to be toxic or teratogenic to livestock. Poison-hemlock (Conium maculatum) and Nicotiana spp. including N. tabacum and N. glauca contain toxic and teratogenic piperidine alkaloids. The toxic and teratogenic effects from these plant species have distinct similarities including maternal muscular weakness and ataxia and fetal contracture-type skeletal defects and cleft palate. It is believed that the mechanism of action of the piperidine and quinolizidine alkaloid-induced teratogenesis is the same; however, there are some differences in incidence, susceptible gestational periods, and severity between livestock species. Wildlife species have also been poisoned after eating poison-hemlock but no terata have been reported. The most widespread problem for livestock producers in recent times has been lupine-induced "crooked calf disease." Crooked calf disease is characterized as skeletal contracture-type malformations and occasional cleft palate in calves after maternal ingestion of lupines containing the quinolizidine alkaloid anagyrine during gestation days 40-100. Similar malformations have been induced in cattle and goats with lupines containing the piperidine alkaloids ammodendrine, N-methyl ammodendrine, and N-acetyl hystrine and in cattle, sheep, goats, and pigs with poison-hemlock containing predominantly coniine or gamma-coniceine and N. glauca containing anabasine. Toxic and teratogenic effects have been linked to structural aspects of these alkaloids, and the mechanism of action is believed to be associated with an alkaloid-induced inhibition of fetal movement during specific gestational periods. This review presents a historical perspective, description and distribution of lupines, poison-hemlock and Nicotiana spp., toxic and teratogenic effects and management information to reduce losses.