Lecture 2 - Dog nutrition

Question 1

a crucial step in early dog domestication.

Answer 1

The genomic signature of dog domestication reveals adaptation to a starch-rich diet.

Question 2

Feed passes the digestive system in what time frame in:
◼ Dogs:
◼ Cats:

Answer 2

Dogs: 12 – 30h
Cats: 12 – 24h

Question 3

20 kg dog produces how much saliva in a 24h period?

Answer 3

0,5l saliva in 24h

Question 4

Salivary composition changes according to

Answer 4

the diet.

◼ More meat = more mucin in saliva.
◼ Dry feed = more watery saliva.

Question 5

Is amylase present in dog saliva?

Answer 5

Amylase presence is variable.

Only in dogs that eat a starch-rich diet seem to have small amounts of amylase (less than e.g. humans).

Dogs don’t chew though so the amylase doesn’t really have time to work in the mouth.

Question 6

Dog stomach pH

Answer 6

pH 1,8 - 2,5

Mucin and bicarbonate ions (HCO3-) as protection.

Question 7

Digestion of fats begins with

Answer 7

gastric lipase

Question 8

Protein digestion by

Answer 8

Hydrochloric acid HCl + proenzyme pepsinogen = pepsin

also, Pepsin + pepsinogen = more pepsin

Question 9

Pepsin does not work when pH is

Answer 9

> /= 3

Question 10

Amylase needs a pH of?

Answer 10

pH must be over 6 or else doesn’t work very well (small amounts might)

Question 11

What is intrinsic factor?

Answer 11

a glycoprotein substance secreted by the stomach which enables the body to bind and absorb vitamin B12 (cobalamin).

Question 12

pH of the duodenal chyme?

Answer 12

pH 6,5- 7

Question 13

What activates pancreatic lipase?

Answer 13

bile (salts)

Question 14

Pancreatic juice contains what digestive enzymes (4+)

Answer 14

◼ Trypsinogen
◼ Procarboxypeptidase
◼ Lipase
◼ Amylase
◼ bicarbonate

Question 15

Small intestine Epithelial cells renew in what time-frame

Answer 15

2-3 days

Question 16

Chyme passes the small intestine in how many hours?

Answer 16

3-4 hours

Question 17

B12 and bile salts absorption occurs in what portion of the GI tract?

Answer 17

End of the ileum

(So in case part of the ileum requires removal, B12 absorption follow up is required.)

Question 18

Luminal phase of digestion refers to:

Answer 18

Action of Enzymes from saliva, stomach, pancreas etc.

Question 19

Membranous phase of digestion refers to:

Answer 19

Action of enzymes from the epithelial cells/brush border.

Question 20

Trypsinogen is activated by?

Answer 20

enteropeptidase/kinase (same thing)

becomes active trypsin

Question 21

Each proteolytic enzyme in GI epithelial cells is
specialized to break a

Answer 21

peptide bond adjacent to a particular AA or related AAs.

Question 22

What size peptides can be absorbed by GI epithelial cells?

Answer 22

Mono-, di- and tripeptides can be absorbed to
epithelial cells.

Di-s and tri-s are broken to monos in epithelial cells.

Question 23

glucose + fructose make

Answer 23

sucrose

Question 24

glucose + glucose makes

Answer 24

maltose

Question 25

glucose + galactose

Answer 25

lactose

Question 26

What is colipase?

Answer 26

Pro-colipase + trypsin → colipase

Colipases are coenzymes that break down fats to fatty acids and glycerol.

Colipases are required for optimal activity of lipase because its silly and is actually hydrophilic so to access the fats, colipase gives it access through the bile salts that form packages around dietary lipids.

Question 27

what exactly are foundin micelles?

Answer 27

FA and monoglycerides are packaged into micelles so they can get through the brush border and directly absorb.

Question 28

Fatty acids and monoglycerides are packaged where into what

Answer 28

into triglycerides inside the GI epithelial cells.

then they are packaged into chylomicrons and move to the lymphatic system for distribution.

Note, that short and medium chain fatty acids are able to absorb directly into the blood (e.g. milk & coconut fat).

Question 29

food allergies are toward

Answer 29

proteins.

food intolerance relates to carbohydrates.

Question 30

‘Food’ for the epithelium cells of large intestine is

Answer 30

Volatile fatty acids

Question 31

Absorption of what in the Large intestine

Answer 31

water, electrolytes and VFA

Question 32

Gross energy =

Answer 32

fecal energy + digestible energy

Question 33

digestible energy =

Answer 33

urinary energy + metabolizable energy

Question 34

metabolizable energy =

Answer 34

heat increment + net energy

Question 35

net energy =

Answer 35

maintenance + production

Question 36

formula
ME =

Answer 36

(GrossEnergy (food)) − [FecalEnergy + UrineEnergy]

Question 37

RER (RMR)

Answer 37

resting energy(/metabolic) rate

this is during digestion/digestive processes.

Question 38

MER =

Answer 38

maintenance energy requirement

Question 38

BMR (BER) =

Answer 38

basal metabolic rate

this is after digestion/ no active digestion.

Question 39

DER =

Answer 39

daily energy requirement

Question 40

How do you Calculate RER
(resting energy requirement)

Answer 40

Two ways:
Body weight
ME(kcal) = 30 x body weight (kg) + 70

Metabolic weight
ME(kcal) = 70 x (body weight (kg)0,75)

Question 41

formula for RER calculated with basic body weight (resting energy(metabolic) rate)

Answer 41

30 x kg+ 70 = kcal

Question 42

formula for RER calculated using metabolic weight (resting energy(metabolic) rate)

Answer 42

70 x (kg^0,75) = kcal

Question 43

How to calculate DER (daily energy requirement)?

Answer 43

DER = coefficient (from table) x RER

Question 44

Digestibility coefficient means

Answer 44

how much of the nutrients is digested and absorbed

◼ Fat: 90%
◼ Protein: 80%
◼ DC: 85%

Question 45

Modified Atwater factors

Answer 45

Dig.Carbs: 3,5 (4,0) kcal/g
PROTEIN: 3,5 (4,0) kcal/g
FAT: 8,5 (9,0) kcal/g

for wet food, use the numbers in the parantheses

Question 46

what is considered high calorie feed

Answer 46

> 4,000 kcal / kg

Question 47

what is considered low calorie feed

Answer 47

< 3,200 kcal / kg