Ruminants 3 Flashcards
What should we typically think about the relationship between protein and nitrogen?
-think of protein as the nitrogen containing portion of the diet
-contrast to carbohydrates and lipids
What are the types of proteins?
-true protein
-non-protein nitrogen
What do protein contain?
-amino acids
-amino acids contain nitrogen
What type of protein is in the rumen?
-dietary protein
-microbial protein
-non-protein hydrogen
Ammonia N in the rumen
dietary NPN or protein degradation
Where does Urea N in the rumen originate? and where does it come from?
-Originating from the blood
-from the saliva or absorbed through the rumen wall
How are dietary proteins classified?
-according to its degradability in the rumen
What are the classifications of dietary proteins?
-Rumen degradable protein (RDP)
-Rumen undegradable (RUP)
What does degradability determine?
-how microbes interact with proteins
-whether they modify them: Deaminate
What does rumen proteolysis by microbes do?
-Proportion of protein is degraded to ammonia N with residual reaching the small intestine intact
What are some feeds with high feed protein degradability?
-Soybean meal: 84%
-Cottonseed meal: 60%
-Alfalfa: 83%
What are some feeds with low feed protein degradability?
-Blood meal: 31%
-Fish meal: 32%
-Meat meal: 35%
What can influence the degradability of protein by microbes in the rumen?
-processing feeds or modifying them
-Heat treating
-Coating or encapsulation
What does heat treating do?
Forming crosslinks to limit accessibility
What does coating or encapsulation do?
-blockage of access
What does reverse modification do?
-limit microbial access in the rumen
-but allow access and digestion in the small intestine
Where does reverse modification take place?
-acid reversal happens in the abomasum
-proteolysis by pancreatic enzymes
What can overprocessing (overprotection) do?
-limit degradability too much
-not degraded in the rumen or the small intestine
What are the two forms protein enter the small intestine?
-feed protein unmodified in the rumen
-microbial protein produced in the rumen
Characteristics of microbial protein?
-high quality: good amino acid profile)
-insufficient to support highest levels of production
How much of rumen protein do bacteria make up? protozoa?
-bacteria about 50%
-Protozoa vary, but average 40%
How much true protein entering the small intestine is microbial protein?
-40%
Is microbial protein a significant source of protein for ruminants?
Yes
What can many rumen bacteria use to synthesis amino acids?
-Ammonia N
When does the ammonia N that rumen bacteria use to make amino acids come from?
-NPN in diet
-Hydrolysis of urea entering the rumen from the animal (nitrogen recycling)
-from protein degradation (deamination)
What is Nitrogen recycling?
-Urea converted to Ammonia in rumen
-Urea is from the blood, saliva, or diet
How is the nitrogen from nitrogen recycling used?
-excreted in the urine
-some reenters the rumen
How is the ammonia that reenters the rumen returned? and used?
-plasma urea crosses the rumen wall or is returned in the saliva
-bacterial urease activity liberates ammonia
-bacteria can use ammonia to produce amino acids and microbial protein
When bacteria use ammonia to produce amino acids and microbial protein an energy dependent process?
Yes
Is it possible for the flow of protein into the small intestine to exceed the amount of dietary protein fed?
-Yes because you can feed urea and that animal can make protein from it.
-Basically, feed ruminant what it needs to make protein and you get more protein out then was put in
What type of protein do ruminants make?
-High quailty
Where does NPN come from?
-diet
-from the animal
What is the overall process of protein going through a ruminant?
-Protein and NPN enter the rumen
-Some protein degraded to ammonia (RDP): some protein exits the rumen unchanged (RUP)
-Some protein is produced in the rumen from NPN
-Protein entering the small intestine consists of dietary RUP and microbial protein from the rumen
What process in the rumen is use to produced amino acids?
-Nitrogen recycling
-use of dietary NPN
What are Ionophores?
-modifiers of rumen fermentation
What are ionophores originally described as products of?
Streptomyces species
What do ionophores do?
-transport cations across membranes
-inhibit the gram positive bacteria in the rumen
-modify the bacteria populations fermentation
What is the major function of ionophores?
Improves fermentation products to support greater efficiency
-improved nutrient availability
How do ionophores inhibit gram positive bacteria?
-incorporate into cell membrane
-allow flux of ions (loss of gradients)
How does ionophores modify the bacteria population fermentation?
-increasing propionate (important to glucose)
-decreasing methane production
-inhibition proteolysis and deamination
