RUMINANT DIGESTION AND METABOLSIM

what do herbivores rely on in order to digest cellulose

micro organisms via fermentation

what are two types of fermentation

hindgut and foregut

why is the food passage in fermentation slower compared to enzymatic digestion

because fermentation takes time

what are the 3 phases involved in the digestion of cellulose

complex sugars are broken down into simple sugars by extra cellular microbial enzymes

simple sugars are converted into pyruvate by intra cellular microbial enzymes

pyruvate is converted to volatile fatty acids

what are 3 types of fatty acids that ruminants use

acetate

propionate

butyrate

What are acetate and butyrate used for?

they are converted into Acetyl CoA where they are used in the Kreb's cycle to form ATP (energy)

what is propinoate converted into and what is it used to form

OAA where it forms glucose 6- P and it then it can forms blood glucose

why do metabolic diseases arise in intensive production

due to the high glucose demands which cannot be met by the ruminants as they cannot absorb as much glucose

what are two types of ketosis

primary and secondary

what is primary ketosis

nutritionally caused as cows cannot take in enough input to meet the metabolic demands (likely to affect multiple cows)

what is secondary ketosis

due to another disease, which decreases food intake by the cow (likely to affect 1 cow)

what happens during twin lamb disease

high glucose demand due to multiple fetuses' will lead to high ketone bodies in the blood leading to ketoacidosis which can lead to death

how can ketosis diseases be prevented

by increasing propionate and microbial amino acids

what two ways are proteins digested in the ruminant

1) moves straight into the abomasum and Si

2)digested in the rumen

what happens to the protein digested in the rumen

reincorporated into microbes

deaminated, generating volatile FA and ammonia

the ammonia produced by the protein digested in the rumen can be reused to form what

reused by microflora to make new aa and for more microbial proteins

what can the addtion of a non proteinaceous N such as urea be used for

microflora to manufacture aa

what happens when these microbes pass into the rest of the GIT

they are enzymatically digested and these aa can be absorbed into the body

why are ruminants able to thrive on low protein diets

as they are able to produce their own protein

why are they less well designed to meet high production demands for glucose

they cannot absorb glucose

what else can microbes in the rumen also produce which are absorbed in the SI

vitamins

how is foregut and hindgut fermentation different

foregut - involves material being fermented and then absorbed and digested in the intestines

hindgut - digestion occurs first and then there is an addition of fermentation

what fermentation products can hind gut fermenters obtain

VFA