Location: Poisonous Plant ResearchTitle: A study on embryonic death in goats due to Nicotiana glauca ingestion
Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2014
Publication Date: 8/7/2014
Publication URL: http://handle.nal.usda.gov/10113/59647
Citation: Welch, K.D., Lee, S.T., Panter, K.E., Gardner, D.R. 2014. A study on embryonic death in goats due to Nicotiana glauca ingestion. Toxicon. 90:64-69.
Interpretive Summary: Substantial research has demonstrated that numerous poisonous plants contain compounds that are teratogenic to livestock species. In addition to teratogenesis, research and field observations suggest that ingestion of some of the “teratogenic plants” may result in early embryonic loss. Lupines are responsible for a condition in cattle referred to as “crooked calf syndrome” that occurs when pregnant cattle graze lupines containing the quinolizidine alkaloid anagyrine or the piperidine alkaloids ammodendrine, N-methyl-ammodendrine or N-acetyl hystrine. Similar malformations are also seen in animals poisoned by Conium, containing the alkaloids coniine and N-methylconiine, and Nicotiana species, containing the alkaloid anabasine, with a similar mechanism of action. It has been suspected for many years by livestock producers, clinical veterinarians, extension agents, and scientists that early embryonic loss may be associated with lupine ingestion in the first trimester of pregnancy. However, it is not known if lupines, poison hemlock, or tobaccos (these plants induce terata by the same biological mechanism) affect the viability of the embryo, causing embryonic losses. Therefore, the objective of this study was to compare the incidence of embryonic death in goats fed N. glauca (wild tree tobacco) at varying time points during the embryonic period of gestation. Overall, there was no evidence from this study that N. glauca, or anabasine, at the dose used in this study, will cause embryonic death in goats.
Technical Abstract: Numerous plants are known to be teratogenic in livestock. In addition to causing malformations, several plants can also cause embryonic death. These losses decrease the reproductive efficiency of animals exposed to these plants. The aim of this study was to determine if teratogenic plants such as lupines or tobaccos cause embryonic losses. A goat model using the plant Nicotiana glauca was used in this study, as this model has been used to characterize the mechanism of Lupinus, Conium, and Nicotiana-induced terata. Four groups of goats were dosed from gestational day 1-10, 11-20, 21-30, and 31-40. Goats were evaluated via ultrasound imaging for pregnancy after completion of the dosing regimen and kids were evaluated for malformations at the time of parturition. Overall, there was no evidence from this study that N. glauca (anabasine) at this dose would cause embryonic losses in goats. However, the dose of N. glauca used in this study was at the lower threshold that would be expected to produce terata. Therefore it is possible that higher doses of anabasine could cause embryonic loss. Further work is also needed to characterize the kinetic profile of anabasine, and other teratogenic alkaloids, in the fetal compartments.