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Objective I: Pine Needles<BR>
1.1 Determine if isocupressic acid (ICA; the abortifacient compound in pine needles)
concentration in pine needles is modulated by the environment.<BR>
1.2 Identify the matabolites of isocupressic acid in pine needles that cause
abortions in cattle. Determine the biological mechanism, develop diagnostic
techniques, and therapeutic procedures.<BR>
1.3 Determine factors that influence cattle consumption of pine needles and develop
management practices to prevent abortion.<BR><BR>
Objective II: Broom Snakeweed<BR>
2.1 Identify the toxic and abortifacient compounds in broom snakeweed.<BR>
2.2 Describe the ecology of broom snakeweed, develop management and control
guidelines to reduce incidence of poisoning and abortion in livestock.<BR><BR>
Objective III: Lupine<BR>
3.1 Isolate, identify, and evaluate toxicity and teratogenicity of lupine alkaloids
which cause birth defects in calves born to cows that graze these plants.<BR>
3.2 Evaluate the role of genotype and environment on lupine alkaloids, and thus the
relative toxicity of various species and populations of lupine.<BR>
3.3 Determine the physiological mechanism of lupine-induced birth defects and
evaluate the maternal and fetal toxicokinetics of alkaloids.<BR>
3.4 Evaluate the influence of climate on population cycles of lupine.<BR>
3.5 Determine the importance of lupines as nutritional components for cattle during
critical times of the year.<BR>
3.6 Identify conditions under which cattle graze various lupine species.<BR><BR>
Objective IV: Veratrum<BR>
4.1 Develop models to study the toxicokinetics, including clearance times, and
toxicity of steroidal alkaloids in Veratrum californicum.
Approach: <BR>
1.1 Data on environmental conditions will be collected at each site using local
weather stations. ICA levels and environmental conditions will be correlated to
determine if any patterns emerge. Soil samples will be collected at each site for
future evaluation.<BR>
1.2 Samples of maternal and fetal tissues will be collected for histologic analysis
and determination of ICA concentrations using existing ELISA’s and GC/MS methods.
Proteomic analyses via LC/MS/MS techniques will be done.<BR>
1.3 Pen and field studies using cattle in high, medium and low body condition will
be done to determine effects on needle consumption and grazing times. Nutrient
supplements will be offered to determine if pine needle consumption will be altered.<BR><BR>
2.1 The diterpene acid “fingerprint” of broom snakeweed from various populations in
Arizona, New Mexico and Utah will be determined by chemical analysis. Subsequent in
vitro and in vivo studies will be done to determine abortifacient activity.<BR>
2.2 A grazing study will be conducted to determine if various management practices
can be implemented to force cattle to graze snakeweed as a biological control. A
clipping study will be conducted to further describe the effects of defoliation on snakeweed and the surrounding plant community.<BR><BR>
3.1 Alkaloids will be isolated by chemical methods and identified by chromatography,
NMR, mass spectrometry, and elemental analysis. Toxicology will be evaluated using a
mouse bioassay and cell lines that express nicotinic acetylcholine receptors.<BR>
3.2 A chemical fingerprint of Lupinus sulphureus collected from different locations
will be generated using chemical methods. Fingerprints will be analyzed via cluster
analysis and phylogenetic analysis will be performed using AFLPs (Amplified Fragment
Length Polymorphisms) to determine the genetic relationship of the populations.<BR>
3.3 Pregnant goats in late gestation will be used to determine the rate of
absorption, distribution and elimination of the teratogenic alkaloids. The
pharmacokinetic profiles of the alkaloids will be compared between maternal and fetal
systems.<BR>
3.4 Established transects will be monitored over the next 5 years to determine the
influence of weather patterns on lupine density. Correlations of lupine age, class,
density, and trends will be made with seasonal precipitation and temperature.<BR>
3.5 Consumption of lupines by cattle on rangelands dominated by low quality forages
may be related to nutrient content. Twelve yearling heifers in a field study will be
supplemented with different levels of protein to compare lupine ingestion.<BR>
3.6 Short-duration and high intensity grazing studies in early, mid, and late
summer will be used to determine what role grazing pressure has on lupine intake
during different seasons of the year.<BR><BR>
4.1 A monogastric model (swine) will be used to determine the kinetics (clearance and
metabolism) of a well known teratogenic alkaloid from Veratrum. This pilot project
will be a model for testing the clearance of other plant toxins from animal tissues
to evaluate food safety of animal products. Clearance rates between the monogastric
model and small ruminant model will be compared.