metabolism of ruminants Flashcards
ruminal microbes:
bacteria, protozoa, fungi; change in diet results in change of microbes - change must be done gradually!
how does microbes settle in the rumen
enter via feed at young age, where they start to colonize and settle.
absorption in rumen
ruminal papillae, incr. surface area
VFA production from
from pyruvate
VFA’s
acetate, butyrate, propionate
VFA function
acidosis of rumen: 5.8-6.8pH
- absorption give energy for the host
what are the 4 steps of nitrogen metabolism
- protein degradation
- ammonia production
- protein synthesis
- ammonia synthesis
rumen Undigestible proteins and non-protein urea
improving digestion and to help lactation, reproduction, and weight gain
NH3 toxicosis - how to prevent
ammonia from non-protein N-sources
- 0.5g/body mass max
- if urea supplementation, step by step to avoid stress and liver disease
NH3 toxicosis
accumilation of NH3 in circulation can enter the brain as it can pass the blood brain barrier, and react with alpha keto glutarate, which disrupts the glucose metabolism of the brain (inhibit TCA, not enough AKG)
treatment: starch addition, 5% acetate to decr. the pH of rumen fluid (incr. absorption),
NPN consist of
urea + ammonium acetate
how is ammonia produced in rumen
degr. og NPN and ox. deamination of aa.
RUP
bypass proteins, valuble proteins protected by encapsulation (denat. by formic/tannic acid): animal or plant-based protein source that resists degradation in the cow’s rumen in order to pass into the lower gastrointestinal tract and provide essential amino acids to the cow.
ruminohepatic circulation
ammonium is transformed to urea in liver and tp back to rumen through ruminohepatic circulation, to produce NH3, or as NPU to salivary gland to go back to rumen.
important in N- low diets (urea is broken down and the cycle repeats)
v. portae damaged
ruminohepatic circulation: no ammonia detoxification!
