Lecture 4 part 3 Flashcards
bovine mouth
- molar teeth (upper and lower)
- grind in lateral movement
- saliva
what is in bovine saliva
- buffer (bicarbonate)
- no enzymes but contains N, P, and Na which microbes use
- continuous production of saliva
when does production of saliva increase in bovine
during rumination and eating
when animals break down material, they usually excrete what
nitrogen
- makes it way back into saliva in ruminants
what is the ruminal wall like in young rumens
smooth
what are the compartments of the stomach
rumen
reticulum
omasum
abomasum
what makes the larger portion of the stomach of ruminants
rumen and reticulum
is ruminant digestion linear?
not really, digestion bounces around in different places
rumen
- fills almost entire left side
- papillae
- underdeveloped at birth
- largest portion in adult ruminants
- usually absorbs fatty acids
papillae
- finger like projections
- increase surface area
- develop over time after exposure to fiber/diet
- absorb VFAs
what are the functions of the rumen
stores
soaks
physical mixing and breakdown
fermentation via microbes
what does the rumen work with for mixing and regurgitation
reticulum
reticulum
- like a filter
- honey comb structure
- not completely separated from rumen
- lined with mucus membrane and intersecting ridges
- no enzymes
- also have papilla
functions of the reticulum
- moves ingesta back into rumen or omasum
- regurgitation during rumination
- still some fermentation
what is located at the bottom of the reticulum
the omasum
ruminoreticulum
- work together
- half wall of tissue that separate the two
omasum
- butchers bible
- no enzymatic activity
- spherical shape
- filled with muscular laminae
functions of omasum
- reduce particle size of ingesta
- some water absorption
- assist with physical breakdown
abomasum
- first glandular portion
- similar to simple stomach of non ruminants
- secretes enzymes
bovine small and large intestine
similar in structure and function to swine
- minimal fermentation happening
young ruminants
- like a monogastric
- have esophageal groove
what is important to feed young ruminants
hay and grain for papilla growth
what is the largest part of the digestive system in young ruminants
abomasum
what is the esophageal groove
- reticular groove
- continuation of esophagus into reticulum
- straw like structure
- muscle reflux to divert milk away to place where it can be digested first
why is the esophageal groove considered a neural reflux
as they sucks this develops
rumination
regurgitation
remastication
resalivation
reswallowing
- do this process mutltiple times
why does rumination occur
forage and feed quickly so they have to complete chewing at a later time
- prey animals
what influences digestion
particle density
- large, low density particles float on top of liquid
- small, dense particles settle to bottom
what do the large, low density particles that float on top form
fibrous mat so more mastication needed
what is the top part of rumen
like a gas cap
why it is a by product of fermentation
gas
what shape does the flow of ingesta follow
figure 8 pattern
what does the rumen house
microbes
- feed microbes first
what is important during regurgitation
burp to help release gas
how does the colonization of microbes occur
calf gains microbes from environment (diet)
what can microbes attach to
food
rumen wall
what make up rumen microbes
bacteria and protozoa (mostly bacteria)
what are most of the microbes in the rumen
obligate anaerobes (O2 free environment)
what is special about rumen bacteria and protozoa
very diverse
do all microbes have the same job in the rumen
no
- may have different food sources so may produce different products
what are the end products of microbial fermentation
- FVAs (major source of energy)
- ammonia
- gases
- microbial protein (major source of protein)
- heat
what are the three main things that come from VFA
acetate
propitiate
butyric
what is the most effiecient product of VFA
propionate because it is more efficient energy produced and can be directly converted to glucose
acetate
precursor for fat synthesis in mammary gland
high fibrous diet=
decreased propionate and increased acetate
- ex= high hay diet= high fibrous
including RAC in diet=
increased propionate and decreased acetate
what does a change of diet also change
outcome of fermentation by changing microbes
what type of relationship do cows and microbes have
symbiotic relationship
what happens when large amounts of grain or pelleted roughage are fed
- RAC/cellulose may pass out of rumen and be partially digested in intestine (by enzymes)
- lead to lower gut fermentation
- not as efficient
what happens if un-adapted to large amounts of grain
lead to bacteria that produce large amount of lactic acid
increase grain=
increase fermentation
if there is too much grain, what can happen
spill out of rumen and intestines cause fermentation but this is not efficient
what influences microbial populations
diet
ruminal acidosis
- abrupt change from fiber to grain
- increase starches and sugars
- increase fermentation rate, bacteria growth, FVAs (good)
- acid is decreases pH of rumen (bad; hurts microbes)
- papilla destroyed from low pH
what can ruminal acidosis lead to
metabolic acidosis which goes into bloodstream
what are the fates of nutrients consumed
- used by microbes, degraded into products absorbed directly from VFAs (feeding microbes first)
- modified during fermentation in rumen and digested in lower tract (microbes partially use it then goes elsewhere)
- escape fermentation in rumen and go thru hydrolytic digestion in GI
- escape fermentation in rumen and GI region so fermented and absorbed in colon/cecum
- escape digestion completely and excreted in feces
microbial protein
- upgrade of nitrogen to protein
- downgrade of high quality of protein to microbial
- rumen protein utilization is low
protein fermentation
- microbial protein has better amino acid profile than low quality dietary protein (corn)
- microbial protein has worse amino acid profile than high quality dietary protein (soybean meal)
how do dietary fats disrupt microbes
- saturate fats (add hydrogen)
- change location of double bonds
- alter bond orientation
- odd number of C in chain
what are 4 vitamins that may be problematic that microbes synthesize
- b12- cobalamin
- thiamine- high in RAC reduce synthesis
- niacin- involved in ketosis if deficient
- biotin- may be supplemented
gas production
- really difficult to measure
- greenhouse gases
up to 600L of gas/day - CO2, CH4, N
- trace amounts of O2, H2, and H2S
eructation
contractions of rumen forces gas forward and down to esophagus opening
- if esophagus not obstructed, gas escapes out
how can you treat bloat
- tubing: pour food safe mineral down tube
- trocar: small surgical incision and then placed into body wall
what are the two types of bloat
foamy
obstructive
