Reproductive Toxicants Flashcards
What reproductive toxicants are teratogens?
▪ Locoweed
▪ Poison Hemlock
▪ Lupines
▪ Tree tobacco
What reproductie toxicants cause abortions?
▪ Locoweed
▪ Nitrates
▪ Ponderosa Pine
▪ Broomweed
What reproductive toxicants cause infertility?
▪ Locoweed
▪ Fescue
▪ Insecticides (?)
What is the science name for poison hemlock?
Conium maculatum
When does poison hemlock spring up? hint hint
Spring time –> first green forage to appear
What problem does poison hemlock cause?
▪ Crooked Calf Syndrome
▪ Multiple congenital contractures
▪ Ingestion 50-75 days in gestation
What are some examples of lupines and what problems do they cause?
▪ Anagyrine (Lupinus caudatus) and ammodendrine (Lupinus formosus) ▪ Teratogenic ▪ Severe limb and spinal deformities ▪ Cleft palate ▪ Ingestion between 40-70 days ▪ Not teratogenic in small ruminants
What is the scientific name for tobacco and what problem does it cause?
▪ Nicotiana glauca
▪ Teratogenic
▪ Arthrogryposis of the forelimbs and curvature of the spine
▪ Ingestion between 50-75 days
What are some examples and problems with locoweed?
▪ Astragalus and Oxytropis spp.
▪ Swainsonine (toxin –> important part)
▪ Can cause:
▪ Neurologic signs
▪ Abortion
▪ Fetal abnormalities- hydrops/arthrogryposis
▪ Up to 40% of cattle grazing may abort
▪ Cattle get “hooked” and can’t quit
▪ Chronic condition; need ingestion for 4-6 weeks
▪ Diagnosis on circumstantial evidence
▪ Causes more economic losses than any other plant** Animals get hooked on it and can’t stop eating it
What is the main toxicant in ponderosa pine?
Isocupressic acid
What problem does ponderosa pine cause?
▪ Up to 50% abortion rate in cattle grazing pine needles
▪ Vasoconstriction at caruncles
▪ Hemorrhagic placentitis
▪ > 3 days of ingestion
▪ Diagnosis on history of ingestion and circumstantial
evidence
▪ Feeding corn silage reduces ingestion
What are the toxins in broomweed/snakeweed?
▪ Mono and di-terpenes, saponins, oxygentated flavonol
methyl esters
▪ Toxicity varies according to growing conditions, stage of growth,
and soil type
What problems occur due to broomweed/snakeweed?
▪ Abortion and retained fetal membranes
▪ Spring
▪ First to bloom
What is the toxin in fescue?
The fungus Neotyphodium coenophialum produces toxic alkaloid ERGOVALINE –> causes peripheral vasoconstriction
What is the problem with fescue toxicity?
▪ “Summer Slump” in cattle
▪ Decreased repro eff./infertility
▪ Decreased milk
How do you treat fescue toxicity?
▪ Rotate off of fescue in summer
▪ Re-plant pastures…
▪ Avoid seedhead grazing
▪ Mow or heavy graze
How do you get nitrate poisoning?
▪ Nitrate accumulating plants ▪ Johnson grass, Sudan grass, oats, wheat, corn ▪ Exposure to fertilizers ▪ Especially seen in drought periods ▪ Rumen microbes increase toxic nitrite ▪ Methemoglobinemia
What clinical signs does nitrate toxicity cause?
▪ Fetal hypoxia and death
▪ Late gestation abortions
How do you diagnose and treat nitrate poisoning?
▪ Diagnosis- test ocular fluid of aborted fetus
▪ Prevention- Test hay- > 1 % =toxic
What are some types of insecticides that cause toxicity?
• Pyrethroid insecticides used in beef cattle operations to combat pests (flies, ticks, lice) • Methods of application include • topical (pour ons) & ear tags • Back rubs • Sprays • Seasons for pest control coincide with breeding seasons in most beef operations
How do pyrethroid insecticides alter reproduction?
- Pyrethroids are metabolized by same group of enzymes that clear steroid hormones
- Potential for reproduction to be altered if sex steroid profiles are disrupted
Why would you want to cause abortion in cattle?
▪ Accidental breeding of young heifers ▪ Bull running with herd year round ▪ Pregnancy in feedlot heifer ▪ Fetal maceration ▪ Fetal mummification ▪ May also surgically remove ▪ Hydrops conditions
What is hydrallantois?
▪ Abnormal accumulation of allantoic fluid during 5-20 day period of last trimester ▪ More common ▪ Placental dysfunction ▪ Seen more commonly in IVF or transgenic fetus
What is hydramnios?
▪ Gradual accumulation of excessive amniotic fluid ▪ Fetal dysfunction ▪ Fetal abnormality that prevents swallowing or intestinal transport of amniotic fluids
What is dropsical condition abortion treatment?
▪ Induce abortion ▪ Slow drainage of fluid ▪ 24 hour period ▪ Constant monitoring ▪ Dam ▪ Vaginal exam for relaxation of cervix ▪ Delivery will most likely require assistance
