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Full-Text Articles in Toxicology

Conditioned Feed Aversion As A Means Of Conditioning Livestock To Avoid Consuming Toxic Plants Growing In South Africa : An Overview, Leendert D. Snyman, Frederick D. Provenza Feb 2026

Conditioned Feed Aversion As A Means Of Conditioning Livestock To Avoid Consuming Toxic Plants Growing In South Africa : An Overview, Leendert D. Snyman, Frederick D. Provenza

Poisonous Plant Research (PPR)

Significant economic losses to the livestock industry are caused by the ingestion of toxic plants in South Africa, among which the most dangerous ones are Moraea pallida (geeltulp), Urginea/Drimea sanguinea (rooislangkop), Senecio latifolius (Staggers Ragwort), and Geigeria ornativa (vermeerbos). Conditioned feed aversion is a potential means to address this issue. Treating animals with an aversive substance along with an extract of the sensory characteristics of a specific plant conditions animals to avoid the plant. Geigeria ornativa, unlike the other three plants, is non-aversive. Following treatment for aversion, the induced aversion fades with time and eventually breaks down. Continuous exposure …


Continuous Exposure To An Aversive Mixture: A Means Of Maintaining Aversion In Sheep Averted To Geigeria Ornativa O. Hoffm. (Vermeerbos) - An Assessment, Leendert D. Snyman Mar 2025

Continuous Exposure To An Aversive Mixture: A Means Of Maintaining Aversion In Sheep Averted To Geigeria Ornativa O. Hoffm. (Vermeerbos) - An Assessment, Leendert D. Snyman

Poisonous Plant Research (PPR)

Establishing aversion to Geigeria ornativa only lasts for some time, after which the induced aversion disappears and sheep start eating G. ornativa again. This behavior is aggravated by the social influence of non-averted sheep in mixed grazing situations. Exposing sheep continuously to a so-called “aversive mixture”, containing an aversive substance (lithium chloride) and the sensory characteristics of the plant (hexane extract of G. ornativa) mixed with a tasty meal (maize meal), following an initial aversion treatment, resulted in sustained aversion to G. ornativa in the field. This method proved to be applicable to mixed grazing situations with averted and …


Toxicosis From Range Lupine Ingestion In A Research Herd Of Rafter 7 Merino Sheep, Benjamin J. Weigler, Walter F. Mandeville Iii, Scott Huber, Gary Mccuin, Fabrizio Caragena, Daniel D. Cook, Stephen T. Lee, Chris A. Pritsos Jun 2024

Toxicosis From Range Lupine Ingestion In A Research Herd Of Rafter 7 Merino Sheep, Benjamin J. Weigler, Walter F. Mandeville Iii, Scott Huber, Gary Mccuin, Fabrizio Caragena, Daniel D. Cook, Stephen T. Lee, Chris A. Pritsos

Poisonous Plant Research (PPR)

An outbreak of lupine alkaloid neurotoxicosis and death occurred in sheep grazed on rangeland areas of the Nevada Great Basin during the summer of 2023. Overall, 97 sheep died despite veterinary supportive care. Lupinus argenteus var. utahensis was implicated as the causative plant with high levels of lupanine (11.5 µg/mg) and spartiene (13.7 µg/mg) in collected and archived samples. Previous reports of sheep deaths due to lupine ingestion have not been recorded in this region. An increased abundance of the number plants producing seed pods having a high alkaloid content may have been associated with abnormally elevated levels of precipitation …


Aversion Properties Of Retrorsine, Retrorsine Nitrogen Oxide And Frosted Senecio Latifolius, Leendert D. Snyman Dec 2023

Aversion Properties Of Retrorsine, Retrorsine Nitrogen Oxide And Frosted Senecio Latifolius, Leendert D. Snyman

Poisonous Plant Research (PPR)

Two pilot trials, investigating the aversive properties of retrorsine and retrorsine nitrogen oxide and that of frosted Senecio latifolius, were executed. Retrorsine and retrorsine-NO (the toxic principles of Senecio retrorsus), unlke sceleratine-NO (the toxic principle of another hepatotoxic pyrrolizidine alkaloid containing plant, namely S. latifolius), were not capable of establishing aversion when given to a sheep. Frosted S. latifolius given to a sheep also did not induce aversion. However, a sheep averted to S. latifolius (non-frosted) refused eating frosted S. latifolius.


Sceleratin Nitrogen Oxide As Aversive Agent In Conditioning Livestock To Avoid Senecio Latifolius, Leendert D. Snyman Dec 2023

Sceleratin Nitrogen Oxide As Aversive Agent In Conditioning Livestock To Avoid Senecio Latifolius, Leendert D. Snyman

Poisonous Plant Research (PPR)

Sceleratine nitrogen oxide, when administered together with a dichloromethane extract of Senecio latifolius, successfully conditioned cattle and sheep to avoid milled freeze dried S. latifolius mixed with maize meal. This treatment was effectively applied in conditioning steers to refuse eating S. latifolius grown in pots.


Isolation Of The Toxic Principle Of Senecio Latifolius By Means Of The Sensory Receptors Of Sheep, Leendert D. Snyman Dec 2023

Isolation Of The Toxic Principle Of Senecio Latifolius By Means Of The Sensory Receptors Of Sheep, Leendert D. Snyman

Poisonous Plant Research (PPR)

The aversive substance of Senecio latifolius was isolated by means of the sensory receptors of sheep averted to S. latifolius. Chemical fractions refused due to the presence of the aversive substance sensed by the sheep were fractionated until a purified substance had been isolated. Nuclear magnetic resonance (NMR) analysis of the purified substance showed it to be sceleratine nitrogen oxide, the toxic principle of S. latifolius.


Fruits Of Nandina Domestica Are (Sometimes) Cyanogenic And (Sometimes) Hazardous To Birds, Scott Zona Apr 2022

Fruits Of Nandina Domestica Are (Sometimes) Cyanogenic And (Sometimes) Hazardous To Birds, Scott Zona

Poisonous Plant Research (PPR)

A 12-month survey of cyanogenesis in the fruits and leaves of Nandina domestica (Berberidaceae) revealed that the leaves are strongly cyanogenic throughout the year, as measured by the Feigl-Anger test. Fruits vary in their cyanogenic potential depending on the degree of ripeness and clone. Green fruits are strongly and rapidly cyanogenic, but most ripe fruits are weakly and slowly cyanogenic. Some fruits tested negative for cyanide. Fruits tend to become less cyanogenic the longer they remain on the plant, so birds feeding on older fruits are at a lower risk of poisoning. More than other frugivores, cedar waxwings (Bombycilla …


An Evaluation Of The Susceptibility Of Goats To Larkspur Toxicosis, Kevin D. Welch, Clint A. Stonecipher, Dale R. Gardner, Benedict T. Green, Daniel Cook Apr 2020

An Evaluation Of The Susceptibility Of Goats To Larkspur Toxicosis, Kevin D. Welch, Clint A. Stonecipher, Dale R. Gardner, Benedict T. Green, Daniel Cook

Poisonous Plant Research (PPR)

Larkspurs (Delphinium spp.) are a major cause of cattle losses in western North America, whereas sheep have been shown to be resistant to larkspur toxicosis. Goats are often used as a small ruminant model to study poisonous plants, even though they can be more resistant to some poisonous plants. It is not known how susceptible goats are to the adverse effects of larkspurs. In this study, we evaluated the susceptibility of goats to larkspur toxicosis by performing a dose-response study. We dosed goats with D. barbeyi collected near Cedar City, Utah at 3.3, 4.4, 6.6, 8.8 and 10.0 g …


Neurobehavioral Evaluation Of Mice Dosed With Water Hemlock Green Seeds And Tubers, Camila F. P. Orlando-Goulart, Kevin D. Welch, James A. Pfister, Daniel S. Goulart, Adilson D. Damasceno, Stephen T. Lee Oct 2018

Neurobehavioral Evaluation Of Mice Dosed With Water Hemlock Green Seeds And Tubers, Camila F. P. Orlando-Goulart, Kevin D. Welch, James A. Pfister, Daniel S. Goulart, Adilson D. Damasceno, Stephen T. Lee

Poisonous Plant Research (PPR)

Water hemlock are plants of the genus Cicuta and are toxic to animals and humans. The primary toxin is cicutoxin, which is abundant in the tubers, but less abundant in other parts of the plant. Other cicutoxin-like compounds, such as cicutols, which may also contribute to the toxicity of water hemlock, are more abundant in non-tuber plant parts. The objective of this study was to determine the toxicity of different parts of water hemlock and characterize their effects on motor function/coordination in mice. An aqueous extract of green seeds, dry seeds, tubers, flowers and stems of water hemlock was dosed …