midterm

Question 1

2 major roles of digestive tract

Answer 1

barrier to the environment, digestion and absorption of nutrients

Question 2

what metabolism happens in rumen?

Answer 2

aerobic and anaerobic metabolism

Question 3

rumen epithelium

Answer 3

stratified squamous epithelium
metabolizes SCFA ad VFAs

Question 4

reticulum

Answer 4

allows for rumination, reason why cows can eat fast, honeycomb lining, contains undigested feed and feed that is being digested

Question 5

omasum

Answer 5

soccer ball, lots of folds, small particle size removes moisture. involved in water and VFA absorption

Question 6

abomasum

Answer 6

true stomach, secretes acid and pepsin, reabsorbs water w lower pH (2-4). kills the microbes from the rumen to make protein.

Question 7

esophageal groove

Answer 7

connects esophagus to omasum, in calves. allows milk to pass reticulorumen

Question 8

duodenum

Answer 8

releases a lot of enzymes, first part of small intestine. starts at pylorus, digestion and absorption

Question 9

jejunum

Answer 9

all coiled up, middle part of small intestine, lots of absorption bc so long

Question 10

illeum

Answer 10

final section of small intestine, absorption and immune responses.

Question 11

mucous secretion - brunners glands

Answer 11

mucus rich alkaline secretion produced, neutralizes acid, to lubricate and protet

Question 12

Peyers patch

Answer 12

immune surveillance of intestinal rumen, where immune memory gets formed. facilitates immune response

Question 13

cecum

Answer 13

large blunt tipped tube, where fermentation, absorption and passage happens

Question 14

colon

Answer 14

connects midgut w rectum, site of fermentation, absorption and passage

Question 15

gastrointestinal epithelium

Answer 15

mixture of absorptive, goblet, paneth and neuoendocrine cells. richness and diversity increases throughout the lower gut. cell junction proteins are expressed differently

Question 16

rumen mat

Answer 16

several natural divisions in the rumen, gas rises to surface, partially digested feed settles to the bottom

Question 17

4 R’s of ruminating

Answer 17

relaxation - esophageal sphincter allows digesta in
reverse peristalsis - feed up to mouth
re-masticating
re-swallowing

Question 18

ruminal epithelium type

Answer 18

stratified squamous

Question 19

intestinal epithelium

Answer 19

columnar

Question 20

main polysaccharides digested by dairy cows

Answer 20

starch, cellulose, pectin, hemicellulose

Question 21

butyrate

Answer 21

used for energy source for the rumen wall

Question 22

propionate

Answer 22

primary glucose precursor of the cow

Question 23

acetate

Answer 23

used for energy throughout the cow

Question 24

microbial protein synthesis

Answer 24

incorporates ammonia, AAs and peptide into bacterial protein
fermentable carbs influence bacterial protein synthesis

Question 25

rumen bacteria

Answer 25

major contributor to microbial fermentation, dynamic pop w large diversity symbiotic relationship

Question 26

additional nutritional req of bacteria

Answer 26

NH3, CO2, acetate, branched amino acids (Va, Leu, Iso), minerals, vitamins

Question 27

protozoa

Answer 27

50% microbial biomass an fermentation end products, uses starch, sugars and amino acids. slows rate of CHO fermentation. deanimate AAs and contributes to NH3 production in the rumen, sensitive to low pH

Question 28

protozoa and microbial protein

Answer 28

sequester protein in the rumen, only 20-40% leave rumen.

Question 29

anaerobic fungi

Answer 29

cellulolytic, attach and grow on plant fragments, penetrate into tissues that are inaccessible to bacteria. susceptible to low rumen pH

Question 30

acetate:propionate ratio

Answer 30

decrease, more propionate = less methane. increases energy and glucose avail to animal. less energy lost as methane.

Question 31

methanogenesis

Answer 31

forming methane from microbes. symbiotic relationships involving interspecies hydrogen exchange w rumen. can be associated intercellular lily and extracellularly

Question 32

monensin

Answer 32

alters microbiota to increase propionate production, inhibits gram positive bacteria. produces more propionate and acetate

Question 33

SARA

Answer 33

20% of lactating dairy cattle, rumen and mucosal damage, liver abbesses, laminitis, inflammation, depressed intake, growth, fibre degradation, milk and milk fat

Question 34

detecting SARA

Answer 34

difficult to obtain consensus on pH thresholds for SARA detection l

Question 35

hingut acidosis

Answer 35

manure is the main indicator, more fermentable products make it through. bacteria in hindgut can't break down as good

Question 36

acidosis is associated with

Answer 36

- altered rumen microbes, damage of gut epithelium, whole animal inflammatory response, liver abscesses, etc

Question 37

NFC -

Answer 37

non-fibre carbs

Question 38

difference between NDF and ADF

Answer 38

NDF - intake, ADF - indigestible

Question 39

NDF

Answer 39

neutral detergent fiber

Question 40

ADF

Answer 40

acid detergent fibre

Question 41

NFC

Answer 41

non- fibre carbohydrates

Question 42

NDICP

Answer 42

neutral detergent insoluble protein

Question 43

WSC

Answer 43

water soluble carbohydrates

Question 44

NSC

Answer 44

starch and sugar

Question 45

ash

Answer 45

dirt and mineral feed content

Question 46

cellulose

Answer 46

harder to break down , has most structure w a lattice shape

Question 47

pectin

Answer 47

fastest to break down

Question 48

factors that impact forage quality

Answer 48

type and variety of forage, repro maturity, soil quality, water avail, Fert use, time of szn, enviromental temp, drying conditions, morphology (C3 vs C4) particle size, harvest height

Question 49

legume v grass

Answer 49

legume is higher CP, fibre higher lignin, less digestible in rumen, legume more fragile passes through faster, less rumen fill. legumes more Ca than grass

Question 50

amylose

Answer 50

glucose polymer bound to each other through alpha 1-4 glycosidic bonds

Question 51

amylopectin

Answer 51

highly branched polymer of glucose containing alpha 1-4 and alpha 1-6 glycosidic bonds

Question 52

most valuable metrics for feed evaluation

Answer 52

NDF, NDFD and starch

Question 53

relative fermentability

Answer 53

soluble carbs get fermented at feeding, next is pectin, cellulose is much later

Question 54

alpha-amylase

Answer 54

starch digestion beyond the rumen, secreted by the pancreas

Question 55

maltase and isomaltase, and sodium dependent glucose transporter

Answer 55

post ruminal starch digestion in small intestine brush border

Question 56

gluconeogenesis

Answer 56

glucose req by brain, RBCs, adipose tissue, mammary gland. ruminants synthesize glucose from propionate. also amino acids. lactate and glycerol

Question 57

how much energy in 1 glucose?

Answer 57

38 ATP

Question 58

how much energy in 1 acetate?

Answer 58

10 ATP

Question 59

how much energy in 1 propionate?

Answer 59

18 ATP

Question 60

mcal to increase BCS from 2-3 in cattle

Answer 60

500 mcal to gain 1 BCS

Question 61

crude protein

Answer 61

NPN an true protein