Transcript Monkey-faced lambs are born in a flock of sheep in Spanish

“Monkey-faced lambs are
born in a flock of sheep in
Spanish Forks, Utah”
Scenario #2 Lab 12
Due: November 29, 2006
Melissa Hayden
Erich Roush
Laura Statz
Harpreet Singh
Scenario #2
• We have been asked to consult with a
sheep rancher, Larry Spikes, in Spanish
Forks, Utah.
• Lambs are being born with birth defects,
as well as motor nerve paralysis
What we know from Mr. Spikes
• Because of the drought, the sheep herds
had been left on mountain pastures (75009500 ft) later into the fall breeding season
than usual.
Problem
• Mr. Spikes is complaining
of "monkey-faced" lambs.
The lambs have a
distorted upper jaw, cleft
palate, cyclopia or
pronounced proboscis
above the eyes. The
rancher also relates that
some of the lamb crop
had motor nerve
paralysis.
Problem
• Many of the surviving lambs have shortened
legs
Plants found in pasture area
Corn Lily
Lupine
Teratogen-Corn Lily
“Corn Lily” Veratrum californicum
• The highest concentration of toxins are in the
roots.
• Originally used medicinally by Native Americans
for external use as a local anesthetic.
• Veratrum induces various craniofacial defects,
specifically induced in lambs after pregnant
ewes graze on the plant on the 14th day of
gestation.
Corn Lily Toxicity
• Poisoning may occur in 2 to 3 hours after the animal eats the plant.
• Signs of Poisoning:
* Excessive salivation with frothing
* General body weakness - animal may be unable to stand
* Irregular gait
* Fast, irregular heartbeat
* Slow, shallow breathing
* Convulsions
• Ewes carrying monkey-faced lambs may fail to lamb at the end of
gestation. The fetus may grow to an abnormal size and it could kill
the ewe unless the lamb is delivered by surgery.
Corn Lily: Inhibitor mechanism
• Steroidal alkaloids cyclopamine and jervine
isolated from Veratrum: primarily responsible for
the malformations.
• Cyclopamine and jervine are potent teratogens
that inhibit Sonic hedgehog (Shh) signaling
during gastrulation-stage of embryonic
development
• Shh normally encodes a signal vital for
patterning the early embryo.
Teratogen-Lupine
• All parts of the lupine plant are toxic
• Cows and goats that eat lupines can pass toxins
through their milk
• Toxicity can cause bone abnormalities in the
forelimbs, spine and skull (scoliosis and cleft
palate)
• Livestock that eat lupine in great quantities may
die.
• Mothers that graze on lupine during days 40–70
of gestation may have affected lambs.
Lupine Toxicity
• Quinolizidine alkaloids cause neurologic problems in sheep and
acute death.
• The teratogenic alkaloid, anagyrine, was identified and was shown
to inhibit fetal movement, causing the limbs and spine to develop in
abnormal positions.
• Signs of Poisoning
* Excessive salivation; frothing at the mouth
* Difficulty in breathing
* Loss of all muscular control
* Convulsions
* Cleft palate and skeletal defects in fetus when grazed 40-70 days
gestation
Management (Corn Lily)
• Avoid grazing Veratrum for 30 days after
breeding
• Reverse the grazing pattern so that the pregnant
ewes are not in the Veratrum patches during
early pregnancy.
• Herbicidal application of amine salts of 2,4-D at
the rate of 1 kg per acre of acid equivalent after
the last leaves have expanded and before bud
stage. A second treatment may be required the
following year.
Management (Lupine)
• Prevent grazing of lupine patches in the early growth
stage and in late summer when the plant is in the highly
toxic seed stage, and from dense plant stands at all
times. Supplemental feeding is beneficial.
• Lupine can be controlled with 2,4-D (1 kg ae/Ac), 2,4-D +
dicamba (0.5 + 0.25 kg ai/Ac), or trichlopyr (0.25 to 0.75
kg ae/Ac).
•
Spray actively growing plants after they are 10 cm high
but before they bloom. Reinvasion is rapid and
retreatment may be necessary every 4 to 5 years.
References
• Important poisonous plants on Rangelands
vol. 27 Issue 5 Oct.2005 pg 3-9 BioOne Journal
• Reproductive toxicology in livestock. J.Anim Sci 1990;68:403-4
James L.F.
• Development of an Enzyme-Linked Immunosorbent Assay for
the Veratrum Plant Teratogens: Cyclopamine and Jervine J.
Agric. Food Chem., 51 (3), 582 -586, 2003. 10.1021/jf020961s
S0021-8561(02)00961-5
References
• http://extoxnet.orst.edu/newsletters/n23_81.htm
• http://sis.nlm.nih.gov/enviro/especiallypublic.html
• http://extension.usu.edu/conference/events/isop
p7/plants.cfm
• http://pubs.acs.org/cgibin/abstract.cgi/jafcau/2003/51/i03/abs/jf020961
s.html
• http://www.cybergoat.com/cyclopia/cyclopia.htm