Influence of 7,8-methylenedioxylycoctonine-type alkaloids on the toxic effects associated with ingestion of tall larkspur (Delphinium spp) in cattle.
OBJECTIVE
To determine the contribution of 7,8-methylenedioxylycoctonine (MDL)-type alkaloids to the toxic effects of tall larkspur (Delphinium spp) consumption in cattle.


METHODS
Sixteen 2-year-old Angus steers.


METHODS
Plant material from 3 populations of tall larkspur that contained different concentration ratios of MDL-type-to-N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids was collected, dried, and finely ground. For each plant population, a dose of ground plant material that would elicit similar clinical signs of toxicosis in cattle after oral administration was determined on the basis of the plants' MSAL-type alkaloid concentration. Cattle were treated via oral gavage with single doses of ground plant material from each of the 3 populations of tall larkspur; each animal underwent 1 to 3 single-dose treatments (> or = 21-day interval between treatments). Heart rate was recorded immediately before (baseline) and 24 hours after each larkspur treatment.


RESULTS
Tall larkspur populations with a lower MDL-type-to-MSAL-type alkaloid concentration ratio required a greater amount of MSAL-type alkaloids to cause the expected clinical signs of toxicosis (including increased heart rate) in cattle.


CONCLUSIONS
Results indicated that the typically less toxic MDL-type alkaloids contributed in a significant manner to the toxic effects of tall larkspur in steers. Consequently, both the concentration of MSAL-type alkaloids and the total concentration of MSAL- and MDL-type alkaloids should be determined when assessing the relative toxicity of tall larkspur populations. These results provide valuable information to determine the risk of toxicosis in cattle grazing on tall larkspur-infested rangelands.
Welch
Kevin D
KD
USDA Agricultural Research Service, Poisonous Plant Research Laboratory, 1150 E 1400 N, Logan, UT 84341, USA. kevin.welch@ars.usda.gov
Green
Benedict T
BT
Gardner
Dale R
DR
Cook
Daniel
D
Pfister
James A
JA
Stegelmeier
Bryan L
BL
Panter
Kip E
KE
Davis
T Zane
TZ
D000470:Alkaloids / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000209:etiology*; D031882:Delphinium / Q000737:chemistry* / Q000633:toxicity; D006339:Heart Rate; D008297:Male; D010939:Plant Poisoning / Q000209:etiology / Q000662:veterinary*; D010947:Plants, Toxic / Q000737:chemistry* / Q000633:toxicity; D021241:Spectrometry, Mass, Electrospray Ionization
D000470:Alkaloids