Lecture 4 part 3

Question 1

bovine mouth

Answer 1

• molar teeth (upper and lower)
• grind in lateral movement
• saliva

Question 2

what is in bovine saliva

Answer 2

• buffer (bicarbonate)
• no enzymes but contains N, P, and Na which microbes use
• continuous production of saliva

Question 3

when does production of saliva increase in bovine

Answer 3

during rumination and eating

Question 4

when animals break down material, they usually excrete what

Answer 4

nitrogen
- makes it way back into saliva in ruminants

Question 5

what is the ruminal wall like in young rumens

Answer 5

smooth

Question 6

what are the compartments of the stomach

Answer 6

rumen
reticulum
omasum
abomasum

Question 7

what makes the larger portion of the stomach of ruminants

Answer 7

rumen and reticulum

Question 8

is ruminant digestion linear?

Answer 8

not really, digestion bounces around in different places

Question 9

rumen

Answer 9

• fills almost entire left side
• papillae
• underdeveloped at birth
• largest portion in adult ruminants
• usually absorbs fatty acids

Question 10

papillae

Answer 10

• finger like projections
• increase surface area
• develop over time after exposure to fiber/diet
• absorb VFAs

Question 11

what are the functions of the rumen

Answer 11

stores
soaks
physical mixing and breakdown
fermentation via microbes

Question 12

what does the rumen work with for mixing and regurgitation

Answer 12

reticulum

Question 13

reticulum

Answer 13

• like a filter
• honey comb structure
• not completely separated from rumen
• lined with mucus membrane and intersecting ridges
• no enzymes
• also have papilla

Question 14

functions of the reticulum

Answer 14

• moves ingesta back into rumen or omasum
• regurgitation during rumination
• still some fermentation

Question 15

what is located at the bottom of the reticulum

Answer 15

the omasum

Question 16

ruminoreticulum

Answer 16

• work together
• half wall of tissue that separate the two

Question 17

omasum

Answer 17

• butchers bible
• no enzymatic activity
• spherical shape
• filled with muscular laminae

Question 18

functions of omasum

Answer 18

• reduce particle size of ingesta
• some water absorption
• assist with physical breakdown

Question 19

abomasum

Answer 19

• first glandular portion
• similar to simple stomach of non ruminants
• secretes enzymes

Question 20

bovine small and large intestine

Answer 20

similar in structure and function to swine
- minimal fermentation happening

Question 21

young ruminants

Answer 21

• like a monogastric
• have esophageal groove

Question 22

what is important to feed young ruminants

Answer 22

hay and grain for papilla growth

Question 23

what is the largest part of the digestive system in young ruminants

Answer 23

abomasum

Question 24

what is the esophageal groove

Answer 24

• reticular groove
• continuation of esophagus into reticulum
• straw like structure
• muscle reflux to divert milk away to place where it can be digested first

Question 25

why is the esophageal groove considered a neural reflux

Answer 25

as they sucks this develops

Question 26

rumination

Answer 26

regurgitation remastication resalivation reswallowing - do this process mutltiple times

Question 27

why does rumination occur

Answer 27

forage and feed quickly so they have to complete chewing at a later time - prey animals

Question 28

what influences digestion

Answer 28

particle density - large, low density particles float on top of liquid - small, dense particles settle to bottom

Question 29

what do the large, low density particles that float on top form

Answer 29

fibrous mat so more mastication needed

Question 30

what is the top part of rumen

Answer 30

like a gas cap

Question 31

why it is a by product of fermentation

Answer 31

gas

Question 32

what shape does the flow of ingesta follow

Answer 32

figure 8 pattern

Question 33

what does the rumen house

Answer 33

microbes - feed microbes first

Question 34

what is important during regurgitation

Answer 34

burp to help release gas

Question 35

how does the colonization of microbes occur

Answer 35

calf gains microbes from environment (diet)

Question 36

what can microbes attach to

Answer 36

food rumen wall

Question 37

what make up rumen microbes

Answer 37

bacteria and protozoa (mostly bacteria)

Question 38

what are most of the microbes in the rumen

Answer 38

obligate anaerobes (O2 free environment)

Question 39

what is special about rumen bacteria and protozoa

Answer 39

very diverse

Question 40

do all microbes have the same job in the rumen

Answer 40

no - may have different food sources so may produce different products

Question 41

what are the end products of microbial fermentation

Answer 41

- FVAs (major source of energy) - ammonia - gases - microbial protein (major source of protein) - heat

Question 42

what are the three main things that come from VFA

Answer 42

acetate propitiate butyric

Question 43

what is the most effiecient product of VFA

Answer 43

propionate because it is more efficient energy produced and can be directly converted to glucose

Question 44

acetate

Answer 44

precursor for fat synthesis in mammary gland

Question 45

high fibrous diet=

Answer 45

decreased propionate and increased acetate - ex= high hay diet= high fibrous

Question 46

including RAC in diet=

Answer 46

increased propionate and decreased acetate

Question 47

what does a change of diet also change

Answer 47

outcome of fermentation by changing microbes

Question 48

what type of relationship do cows and microbes have

Answer 48

symbiotic relationship

Question 49

what happens when large amounts of grain or pelleted roughage are fed

Answer 49

- RAC/cellulose may pass out of rumen and be partially digested in intestine (by enzymes) - lead to lower gut fermentation - not as efficient

Question 50

what happens if un-adapted to large amounts of grain

Answer 50

lead to bacteria that produce large amount of lactic acid

Question 51

increase grain=

Answer 51

increase fermentation

Question 52

if there is too much grain, what can happen

Answer 52

spill out of rumen and intestines cause fermentation but this is not efficient

Question 53

what influences microbial populations

Answer 53

diet

Question 54

ruminal acidosis

Answer 54

- 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

Question 55

what can ruminal acidosis lead to

Answer 55

metabolic acidosis which goes into bloodstream

Question 56

what are the fates of nutrients consumed

Answer 56

1. used by microbes, degraded into products absorbed directly from VFAs (feeding microbes first) 2. modified during fermentation in rumen and digested in lower tract (microbes partially use it then goes elsewhere) 3. escape fermentation in rumen and go thru hydrolytic digestion in GI 4. escape fermentation in rumen and GI region so fermented and absorbed in colon/cecum 5. escape digestion completely and excreted in feces

Question 57

microbial protein

Answer 57

- upgrade of nitrogen to protein - downgrade of high quality of protein to microbial - rumen protein utilization is low

Question 58

protein fermentation

Answer 58

- 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)

Question 59

how do dietary fats disrupt microbes

Answer 59

- saturate fats (add hydrogen) - change location of double bonds - alter bond orientation - odd number of C in chain

Question 60

what are 4 vitamins that may be problematic that microbes synthesize

Answer 60

- b12- cobalamin - thiamine- high in RAC reduce synthesis - niacin- involved in ketosis if deficient - biotin- may be supplemented

Question 61

gas production

Answer 61

- really difficult to measure - greenhouse gases up to 600L of gas/day - CO2, CH4, N - trace amounts of O2, H2, and H2S

Question 62

eructation

Answer 62

contractions of rumen forces gas forward and down to esophagus opening - if esophagus not obstructed, gas escapes out

Question 63

how can you treat bloat

Answer 63

- tubing: pour food safe mineral down tube - trocar: small surgical incision and then placed into body wall

Question 64

what are the two types of bloat

Answer 64

foamy obstructive