Test 4: 56 feed toxicosis Flashcards
— are toxins made by fungus
mycotoxins
made by mushrooms, molds and yeast
major mycotoxins
- Aflatoxins
- Deoxynivalenol (DON/Vomatoxin)
- T2 toxin
- Fumonisin(s)
- Zearalenone
- Ergot
AT FEDZ
alfatoxin is made by — and causes
aspergillus mold growing on grains
liver damage
Fusarium molds make — toxins that attack —
Deoxynivalenol (DON): diarrhea
T2 toxin (tricothecenes): vomit
Fumonisin: equine leuko encephalomalacia
Zearalenone: estrogenic
pigs very sensitive
Claviceps molds make — toxin that cause
ergot
gangrene
organs affected by mycotoxins
GI, liver, kidney, heart, brain, lungs and repro tract
clinical signs of mycotoxin
- None
- Reduced feed intake
- Compromised production and growth
- Impaired immune function
- Reproductive dysfunction
- Organ disease
- Carcinogenic and teratogenic
- Death
preharvest myoctoxin exposure
stress(drought) or insects damage the seed, spores enter and grow. humidity, temp and season influence type of mold grown
post harvest mold growth is controlled by what three factors
moisture >30%
temp > 35%
oxygen needed to grow
how to control mycotoxins
Preharvest
* Tillage
* Reduce plant stress & insect infestation
* Fungicide application
* Drying grain at harvest
Reduce toxin load in grain
* Do not mix dry and wet grains
* Destroy toxins prior to feeding
Prevent absorption of toxins
* Yeasts, Enzymes
* Yeast-microbial cell wall polysaccharides
* Activated charcoal
* Clay based binders
FDA monitors which mycotoxins
alfatoxin
vomitoxin
fumonisin
advisory level
action level
regulatory level
advisory: provide a margin of safety
active level: believed to be harmful
regulatory level: limits level in saleable grains
— is a toxin made by cotton seeds
gossypol toxin
gossypol toxin can cause
myocardial degeneration and heart failure, liver toxicity
cotton seed
can feed small amount to pugs and ruminats
clinical signs of cow with gossypol toxicity
abomasitis, hemoglobinuria, respiratory distress
nitrites or nitrates are more toxic?
nitrities are 10x more toxic
* Nitrite easily enters erythrocytes in exchange for Cl ions
* Hypoxia and chocolate brown blood
* Treatment with Methylene Blue
what plants have high nitrates
plants: pigweed, lam’s quarter, jimson weed, fireweed, johnson grass
clinical signs of nitrate toxicity
hypoxia when 20-30% of hemoglobin is converted to methemoglobin and chocolate brown blood
treatment: methylene blue
treatment for nitrate toxicity
methylene blue
— nitrate-N concentration in water are toxic for cattle and sheep
↑15,000 ppm
10ppm is toxic for human infant
syndromes associated with excess non protein Nitrogen
- Sudden death from ammonia toxicity
- Subclinical toxicosis – impaired fertility (high BUN,MUN)
- Bovine Bonkers – ammonization of forage
- Environmental contamination
- Nitrate in ground water
- Ammonia and air particulates
Ruminants can utilize up to — of crude protein as NPN
40%
CP = N x 6.25
* Urea is 45% N
* CP of urea is 281% CP
rumen metabolism of non protein nitrogen
rumen: NPN → ammonia
NPN Toxicity Risk
* Amount of NPN in diet
* Rate of release exceed rate of capture as microbial protein
if there is too musch ammonia in the rumen what will happen
microbial protein capture
* ammonia will be absorbed into poral circulartion and converted into urea by the liver
