Chapter 7- Proteins and Amino Acids (Oct 20 Lec) Flashcards
what is considered ideal to be compared to for chemical score? (determining nutritive value of proteins)
egg protein is the golden standard
biological value (nutritive value of proteins)=
How can we increase BV?
- % of N absorbed which is available for body functions
- can increase BV of an ingredient by feeding with a complementary protein
what does nutritive value depend on? (3)
- dietary level
- absorbability
- metabolic usefulness
Maillard products are formed when:
- maillard products can be absorbed from the gut, but not _____by the animal
specific amino acids reacts with a reducing sugar molecule (often lysine and glucose)
metabolized
For heat-treated ingredients (ie maillard products), what is the issue?
- digestibility vs metabolic availability can be an issue
- lysine digestibility not = to lysine availability
Is each sentence T/F
- AA have a carbon skeleton
- C skeletons cannot be used for other purposes
- AA synthesis involves adding amino groups to the C skeleton
- AA have a carbon skeleton - T
- C skeletons cannot be used for other purposes - F
- AA synthesis involves adding amino groups to the C skeleton - T
crude protein contains ___ ___ and __-__ ____
true protein
and
non-protein nitrogen (NPN)
Rumen microbes require ____.
A deficiency decreases microbial growth
nitrogen
bypass protein=
protein which escapes rumen digestion (40% of true protein escapes digestion in rumen!)
where is bypass protein broken down?
abomasum
degraded by the animal through digestion in stomach/ small intestine
degradability=
rate and extent to which is a feed protein is broken down in the rumen
NPN is converted to ___ in the rumen (regardless of its original form)
NH3
true protein=
protein contains only protein and amino acids (no NPN)
is bypass protein more or less important for high-producing ruminants?
more!
- most ruminants can meet protein requirements from microbial synthesis + normal bypass protein
- high producing/ growing need more bypass protein
