anti nutritive factors Flashcards
What things can make diagnosing exposure to mycotoxins difficult
Suspect feed may already have been consumed
* Large variations in concentrations of antinutritional factors or
mycotoxins – get a feed test if available
* Multiple concurrent factors
* Tempting to blame mycotoxins for poor
livestock growth performance
what are anti-nutritional factors
“Any dietary compound that reduces voluntary feed intake of
animals or impairs digestive function or partitioning and
utilization of absorbed nutrients.”
What are mycotoxins
secondary metabolites of fungi with the capacity to induce distinct toxic effects in animals and humans
what are the general characteristics of antinutritional factors
usually prodcuts of secondary metabolism
present in virtually all plants to some degree
defensive role- protection from herbivores
what are the two classifications of antinutritional factors
heat stable
heat labile
what happens to the protease (trypsin) inhibitors in raw soybeans when heat is added
heat treatment of soybeans inactivates the inhibitor
What are lectins found in
soybeans and pulses
what do lectins do
prevent absorption of nutrients in SI
impair growth and cause diarrhea
affects mostly monogastrics
what does moist heat treatment do to lectins
it destroys much of the lectin in grain legumes
Gossypol causes what two syndromes in preruminants
- sudden death syndrome (resembles heart attack)
- chronic labored breathing (resembles pneumonia)
What affect does gossypol have on bulls
reduced fertility
why can mature cattle tolerate higher levels of gossypol
because gossypol binds to soluble proteins in the rumen
what are tannins
polyphenolic compounds with the ability to bind and precipitate proteins
Some herbivores also have evolved to produce_______ in their
saliva which bind to tannins during ingestion and reduce biological activity
(deer > goat > sheep > cattle)
proline-rich proteins
what affect do tannins have on ruminants
reduces RDP and increases RUP
What beneficial affect do tannins have
provides protection against bloat
what affect do tannins have non monogastrics
reduces DM and protein digestion, voluntary intake and growth
Saponins
form stable soap-like forms, impair digestion of protein and uptake of vit and min in gut
what affect does saponins have on ruminants
increases bloat
Saponins ____ bloat while tannins _____ decrease bloat
saponins increase, tannins decrease
mimosine
has metabolic derivative 3,4-DHP, and comes from legume plant Leucaena leucocephala. causes anorexia, reduced growth, goiter, etc
cyanogenic glycosides
found in clover, high concentrates associated with N fertilization, immaturity, and frost damage, may cause neurological symptoms
phytoestrogens
reduce fertility through competitive inhibition of estrogen.
the main source of phytoestrogen is
clover
Plant breeders have developed ______ of subterranean
clover, greatly reducing animal losses due to phytoestrogens
low-estrogen cultivars
oxalate
promotes formation of kidney stones.
what causes secondary nutritional hyperparathyroidism
oxalate
what are two sources of oxalate
rhubarb leaves, or kochia
what does oxalate posioning resemble
antifreeze poisoning
glucosinolates
contain toxin s-methylcysteine sulfoxide (SMCSO)
what is SMCSO also known as
“brassica anemia factor”
how do mycotoxins exert their effects
Reduced intake or feed refusal
* Reduced nutrient absorption and
impaired metabolism
* Altered endocrine or exocrine systems
* Suppressed immune function
* Altered rumen microbial growth
what are the most prevalent mycotoxins in canada
Most prevalent in Canada are Fusarium toxins and ergot alkaloids
what are the three primary infleunces of mold growth
mositure, temperature, oxygen level
aflatoxin
carcinogenic. corn, peanuts, peanut meal. causes liver damage and accumulates in liver
what clinical signs does aflatoxin have in cattle
diarrhea, severe tenesmus, pale enlargd fatty livers
what clinical signs does aflatoxin have in pigs
anorexia, weight loss, tremours, hemorrhagic diarrhea
fumonisin B1 and B2 cause what in horses
equine leukoencephalomalacia
fumonisin B1 and B2 cause what in pigs
porcine pulmonary edema (PPE) and abortion
vomitoxins are particularly dangerous to what species
swine
zearlaenone is a ____ mycotoxin
estrogen-like
T/F zearalenone affects feed intake
false
what species is particularly sensitive to zearalenone
swine
what problems does zearalenone cause
reproductive problems
T2 toxin in cattle
Gastroenteritis, intestinal hemorrhage, abomasal
and ruminal ulcers, death
T2 toxin in pigs
potent immunosuppressive agent
ochratoxin A is a ____ toxin that causes ____
renal, PUPD
Ergot affects which two grains the most
rye and triticale
what is ergotism
Caused by ingestion of infected pasture, hayor
cereal kernels
* Disease-causing agents are alkaloids within the
ergot bodies
* Cattle, sheep, pigs, horses,dogs and birds can be
affected;
* Toxic component is preserved during ensiling
what are ergot alkaloids
stable version of ergot, hard to break down
ergotism in cattle
Gangrene of the extremities due to vasoconstriction, agalactia, low conception rates,abortion
what hormone does Ergotism mess with
prolactin
ergotism in pigs
agalactia due to lack of prolactin, neonatal mortality, gangrene on ear and tail
