anti nutritive factors Flashcards
(54 cards)
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
