Chapter 4: Analysis of Pet Food Composition (Hill)

Question 1

Gross energy (GE) *

Answer 1

the total energy content of food.

Question 2

digestible energy (DE) *

Answer 2

energy intake (gross energy) - energy in feces

Question 3

metabolizable energy (ME) *

Answer 3

energy intake (GE) - energy in feces, urine, and combustible gas

Question 4

modified atwater factors for protein, fat, and carbs? What are they used for? ***

Answer 4

protein/carbs: 3.5
fat: 8.5

Used to calculate the ME density of pet foods

Question 5

atwater factors for protein, fat, carbs? *

Answer 5

protein/carbs: 4

fat: 9

Question 6

average 8 oz. cup contains about __g of an average dry diet *

Answer 6

90g

Question 7

metabolizable energy density (kcal/g) is best obtained from: *

Answer 7

feeding trials. Average for canned food = 1 kcal/g; dry food: 4 kcal/g

Question 8

is “95% fat free” low fat? *

Answer 8

NO. When you remove water, can be >40% calories from fat.

Question 9

____ determines how much of a diet an animal needs to eat *

Answer 9

energy density

Question 10

why do high fiber diets make %DM useless? *

Answer 10

high fiber diets have higher protein to make up for less carbs and animal has to eat more to meet energy requirements, thereby consuming more protein

Question 11

NFE = ***

Answer 11

nitrogen free extract; Estimates carbohydrate by difference:
100 - (moisture + protein + fat + ash + crude fiber)

This is known as a “proximate analysis (% as fed)”

Question 12

methods of stating pet food composition

Answer 12

% as fed (includes moisture)
% DM (excludes moisture, used in ruminants)
Relative to ME

Question 13

disadvantage of as fed analysis

Answer 13

comparison of canned, dry and semi-moist diets difficult b/c of variable moisture content

Question 14

We should eat less than __% kcal as fat

Answer 14

30

Question 15

disadvantage of dry matter analysis

Answer 15

doesn’t allow comparison of diets w/ different energy densities (energy density differs if the fat or fiber content differs b/w diets)

Question 16

Which parts of GA are presented as maximums?

Answer 16

crude fiber, moisture

Question 17

which parts of GA are presented as minimums?

Answer 17

crude protein, crude fat

Question 18

average analysis

Answer 18

represent better estimate of what is in food than guaranteed analysis and is required on Euro labels

Question 19

How to determine ME Intake (kcal/day)? *

Answer 19

ME density (kcal/g) x weight consumed (g/d)

Question 20

disadvantage of using modified atwater factors *

Answer 20

don’t allow for differences in digestibility of diets. They tend to underestimate the digestibility of fat and overestimate the digest. of carb in high fiber diets. Therefore, they underestimate ME in digestible high fat diets and overestimate digest. in poorly digestible high fiber diets

Question 21

calculation of %DM from an As fed analysis:

Answer 21

%DM of a nutrient = (% nutrient as fedx100/%DM of food) = (%nutrient as fedx100/(100-%moisture))

Question 22

ideal method for describing and comparing pet food composition

Answer 22

energy-based analysis.

• ME determines the amt. to feed
• only way to compare diets which vary widely in energy density

Question 23

Before deciding whether a nutrition experiement is properly controlled, ….

Answer 23

convert all nutrient analyses to an energy basis for comparisons (w/n an energy-based analysis)

Question 24

REVIEW TAKE HOME 1 CALCULATIONS

Answer 24

:’(