rum nutrition Flashcards
what is the major contribution of ruminant livestock to global systems ?
to convert human inedible feed sources to human edible feed sources
what percentage of habitable land is Agriculture ?
50%
of the agriculture land what % is livestock and what % is crops ?
livestock = 75%
crops = 23%
what does reducing the pre-grazing herbage mass do in terms of carb digestion ?
increases carb digestion in the rumen
what type of loss is methane in ruminant animals ?
source of energy loss
what is the VFA ratio
70:20:10
70% acetate
20% propionate
10% butyrate
where does carb fermentation take place ?
Rumen
what are the 3 types of ruminants ?
concentrate selectors
intermediate types
grass/roughage eaters
do ruminants need to consume amino acids ?
no ruminants synthesise amino acids through non-protein nitrogen.
what is pH of rumen
6.3 - 6.4
Omasum has 2 pH’s what are they ?
6.4 and 4.2
what are laminae
Epithelium arranged in folds
how are nutrients absorbed in Omasum
through contracting of laminae to form vacuum to absorb nutrients. reticulo-omasalorifice.
what nutrients are absorbed in the Omasum?
water
VFA
bacteria
particles under 1mm
main functions of rumen ?
ferment
mix food with microbes
reduce particle size
eliminate gases
what is volume of the rumen ?
80-100L
what is rumen lined with ?
filiform and foliate epithelium
function of Cranial pillar ?
holds digesta away from oesophagus, allows eructation of gases.
what are 3 layers on components in rumen ?
liquid
fibre material
Gas cap
function of reticulum ?
foodstuff formed into bolus and propelled back up oesophagus to be regurgitated.
what does the reticulum control ?
the flow rate of digesta
how is the abomasum unique in the ruminant ?
only stomach involved in secretions. these are pepsin and HCL.
what origin are the majority of the amino acids that are broken down in the small intestine
of microbial origin
which stomach does protein digestion begin
begins in the abomasum continued in the small intestine.
what are 3 sources of rumen microbiota ?
bacteria
Archaea
Eukaryota
what % of bacteria is bound to feed particles ?
75%
what does rumen bacteria digest ?
sugar
starch
lipids
protein
difference between lipids and VFA’s
lipids are broken down in rumen VFA’s are not and lipids need to be bound to another particle eg phosphorus
what are 4 types of rumen bacteria ?
- cellulolytic bacteria
- amylolytic bacteria
- lactate using bacteria
- archaea hydrogen using bacteria
at what pH does cellulolytic bacteria work best in ?
6.2 - 7.0
how is the pH for cellulolytic bacteria regulated ?
- saliva
- VFA being rapidly absorbed
- Removal of hydrogen through methane
what is cut off % of fat before fibre breakdown is affected ?
5%
what are the primary substrates related to cellulolytic bacteria ?
cellulose
hemicellulose
pectin
what would a high amount of acetate suggest in a diet ?
that it was a high fibre diet
what % of rumen bacteria does amylolytic bacteria make up ?
25%
what does amylolytic bacteria ferment ?
starch
sugars
peptides
amino acids
at what pH does amylolytic bacteria thrive ?
5.5 - 6
how is lactate produced in rumen?
through amylolytic bacteria
what is lactate in rumen ?
very strong acid (VFA) that can rapidly drop rumen pH if produced in large quantities.
when can lactate become a problem with ruminants ?
during high sugar/starch diets if animals run out of feed lactate acid microbes produce large amounts on lactate dropping rumen pH causing acidosis.
what is the lactate using bacteria ?
megasphaera elsendii
how does lactate using bacteria help cellulolytic bacteria.
uses lactic acid as substrate for growth increasing rumen pH.
how does hydrogen using bacteria play a positive role in our environment ?
reduces the amount of methane produced as uses up hydrogen.
what % of the rumen mass is made up of protozoa ?
50%
in what diets are high levels of protozoa seen ?
high fibre diets
high starch diets
how long can it take for rumen bacteria to grow ?
15 + hours
why does archaea attach itself to protozoa ?
to get easy access to hydrogen
how is protozoa unique ?
eat large amounts of starch at one time and store it in bodies.
how does protozoa benefit the rumen?
slows down the production of acids increasing the rumen pH.
optimum pH for cellulose digestion ?
6.0 - 6.8
optimum pH for formation of VFA’s
6.2 - 6.6
optimum pH for synthesis of protein
6.3 - 7.4
optimum pH for lactate production?
5.9 - 6.2
what type of environment is fermentation?
anaerobic environment
what are 2 types of fermentation ?
glycolysis
fermentation of pyruvate
what are the 3 breakdown pathways of pyruvate ?
respiration
anaerobic glycolysis
fermentation
in the breakdown of pyruvate what does anaerobic glycolysis produce ?
lactic acid
where are VFA’s mostly absorbed ?
in the rumen with small % absorbed in omasum
where are most of the nutrients absorbed ?
in the small intestine
