Mineral-salt supplementation to ameliorate larkspur poisoning in cattle.

Larkspurs (Delphinium spp.) are native forbs that are poisonous to cattle and cost livestock producers millions of dollars in losses each year. Macro and micro minerals are required for normal functioning of essentially all metabolic processes in ruminants. The role that mineral status may play in larkspur poisoning in cattle is not clear. In this study, we seek to determine the effects a mineral-salt supplement, commonly used by cattle producers, to potentially reduce cattle losses to larkspur. The ability of mineral-salt supplementation to alter susceptibility to larkspur toxicosis was evaluated in a pen study. Animals supplemented with mineral-salt were found to be less susceptible to larkspur poisoning than the non-supplemented animals. A separate group of animals were then grazed on larkspur infested rangelands. One group was supplemented with a mineral-salt mix and the other group did not receive any mineral-salt. Supplementing cattle with the mineral-salt mix did not alter larkspur consumption (P > 0.05). However, overall larkspur consumption was low and averaged 3 ± 1.0% and 2 ± 1.1% for cattle supplemented with mineral and non-supplemented, respectively. Serum was collected from animals once a week during the grazing study. Average and maximum serum concentrations of toxic larkspur alkaloids were numerically higher in mineral-salt supplemented cattle compared with the non-supplemented animals. Results from the pen study suggest that a good mineral supplementation program will provide a protective effect for animals grazing in larkspur-infested ranges. The mineral-salt supplemented steers, in the grazing study, were not observed to consume less larkspur than the non-supplemented animals; however, the mineral-salt supplemented animals had higher concentrations of larkspur alkaloids in their serum indicating they may be able to tolerate higher larkspur consumption. The data also indicate that mineral-salt supplementation must be continuous throughout the time the animals are grazing these rangelands as the positive effects can be lost within 30 d post supplementation.

Larkspurs (Delphinium spp.) are native forbs poisonous to cattle and cost livestock producers millions of dollars in losses each year. The role mineral status may play in larkspur poisoning in cattle is unclear. The ability of mineral-salt supplementation to alter susceptibility to larkspur toxicosis was evaluated in a pen and grazing study. In the pen study, animals supplemented with mineral-salt were found to be less susceptible to larkspur poisoning than non-supplemented animals. A separate group of animals grazed on larkspur infested rangelands. One group was supplemented with a mineral-salt mix and the other group did not receive any mineral-salt. Supplementing cattle with the mineral-salt mix did not alter larkspur consumption of grazing cattle. However, overall larkspur consumption was low. Results from the pen study suggest that a good mineral supplementation program will provide a protective effect for animals grazing in larkspur-infested ranges. The mineral-salt supplemented steers, in the grazing study, had higher concentrations of larkspur alkaloids in their blood serum indicating they may be able to tolerate higher larkspur consumption. The data also indicate that mineral-salt supplementation must be continuous throughout the time the animals are grazing as the positive effects can be lost within 30 days after supplementation.

Evaluation of diazepam as a drug treatment for water hemlock (Cicuta species) poisoning in Spanish goats.

Water hemlocks (Cicuta spp.) are toxic members of the Apiaceae plant family. The best drug treatment for the convulsions associated with acute water hemlock poisoning in livestock and humans has not been determined experimentally. This work compared the therapeutic actions of benzodiazepines (diazepam) and barbiturates (phenobarbital) on water hemlock poisoning in a goat model. C. maculata tubers were orally dosed to goats. Experimental groups consisted of; control saline; 20 mg/kg phenobarbital; 1.0 mg/kg diazepam; 10 mg/kg diazepam; and 1.0 mg/kg diazepam administered as needed to moderate convulsions by intravenous (i.v.) infusion. Diazepam provided nearly instant control of convulsions. Clinical signs of poisoning were completely controlled for the duration of the experiment in the goats that received the 10 mg/kg diazepam dose. These results suggest that diazepam is effective at managing the clinical signs of water hemlock poisoning in goats. We speculate that diazepam can be used as a potential treatment for water hemlock poisoning in other livestock species and humans.

Hepatotoxicity in Cattle Associated with Salvia reflexa Diterpenes, including 7-Hydroxyrhyacophiline, a New Seco-Clerodane Diterpene.

A case of baled alfalfa hay contaminated with multiple weeds induced hepatotoxicity and death in cattle. The hepatotoxic compounds were isolated by bioassay-guided fractionation using a mouse model and identified as salviarin, salvianduline D, rhyacophiline, and 7-hydroxyrhyacophiline. The structure of 7-hydroxyrhyacophiline has not been previously reported. All compounds were found to induce severe acute hepatic necrosis within 24-48 h after a single oral dosage (260-280 mg/kg). The identified diterpenes are known to be found among different Salvia species which led to finding dried plant parts of Salvia reflexa within bales of weedy hay and subsequently a population of S. reflexa was found along the field edges and irrigation ditch banks of the alfalfa hay field. It was thus determined that S. reflexa was responsible for the hepatotoxicity observed in cattle fed the contaminated hay.

Genetic Relationships among Different Chemotypes of Lupinus sulphureus.

Lupines (Lupinus spp.) are a common plant legume species found on western U.S. rangelands. Lupinus spp. may contain quinolizidine and/or piperidine alkaloids that can be toxic and/or teratogenic to grazing livestock. Alkaloid profiles may vary between and within a species. The objectives of this study were to (1) further explore the characteristic alkaloid profiles of Lupinus sulphureus using field collections and (2) explore the phylogenetic relationship of the different populations and chemotypes of L. sulphureus using the amplified fragment length polymorphism method of DNA fingerprinting, thus providing possible explanations to the phenomena of multiple chemotypes within a species. A total of 49 accessions of L. sulphureus were classified into seven chemotypes. The DNA profiles showed that one L. sulphureus chemotype, chemotype A, is genetically divergent from the other chemotypes of L. sulphureus, suggesting that it represents an unresolved lupine taxon, possibly a new lupine species. Additionally, the different chemotypes of L. sulphureus represented different genetic groups, as shown by Bayesian cluster analysis and principle component analysis.

The relative toxicity of Delphinium stachydeum in mice and cattle.

Larkspurs (Delphinium spp.) are poisonous plants on rangelands throughout the Western United States and Canada. Larkspur-induced poisoning in cattle is due to norditerpene alkaloids that are represented by two main structural groups of norditerpene alkaloids, the N-(methylsuccinimido) anthranoyllycoctonine type (MSAL-type) and the non-MSAL type. Information on the alkaloid composition and resulting toxicity in mice and cattle is lacking for a number of Delphinium species, including Delphinium stachydeum. The objective of this study was to determine the alkaloid composition of D. stachydeum and to characterize its relative toxicity in mice and cattle compared to two reference species Delphinium barbeyi and Delphinium occidentale. D. stachydeum contains the non-MSAL-type alkaloids but not the MSAL-type alkaloids. D. stachydeum was less toxic than D. barbeyi and D. occidentale in the mouse model. D. stachydeum was less toxic than the MSAL-containing D. barbeyi but much more toxic than the non-MSAL-containing D. occidentale in cattle as measured by heart rate and time of exercise. These results indicate that predictions of Delphinium toxicity can't be accurately made based solely on results from the mouse model or the absence of the MSAL-type alkaloids in the plant.