Factors Affecting Animal Growth: Nutrition

Question 1

Growth and development depends on the levels of essential nutrients in the diet including…

Answer 1

1) Fatty acids
2) Amino acids
3) Carbohydrates
4) Vitamins
5) Minerals

Question 2

What determines the composition of growth regarding nutrition?

Answer 2

The balance of nutrients consumed determines the composition of growth.

Question 3

What are the three nutrient requirements?

Answer 3

1) Maintenance requirements
2) Growth requirements
3) Production Requirements

Question 4

What are maintenance requirements?

Answer 4

Maintenance Requirements = maintain vital organs and bodily functions with little or no physical activity

Question 5

What are growth requirements?

Answer 5

• Dependent on the location of the animal on its growth curve
• Body tissues - muscle, bone, fat, nerve
• Includes growth of fetus in pregnant females

Question 6

What are production requirements?

Answer 6

• Physical activity, reproductive behaviors, work
• Lactation, wool, eggs

Question 7

What is nutrient partitioning? How is the utilization of nutrients partitioned?

Answer 7

• Nutrient Partitioning = The amount of nutrients consumed by an animal relative to the amount required for optimal growth and performance
• Utilization of nutrients is partitioned among various tissues and organs according to their physiological importance (most important to least important: brain and central nervous system > bone > muscle > fat)

Question 8

What are the conditions of altered nutrient partitioning?

Answer 8

1) Pregnancy
- fetus holds priority similar to the vital organs of the dam
- species differences, some wild animals will abort their fetus in order to survive

2) Transition from non-lactating (dry period) to lactating
- change in priority of nutrients from tissue gain to supporting lactation

Question 9

Regarding the transition from non-lactating (dry period) to lactating…
1) To support milk production, what’s the difference in efficiency between tissue mobilization and tissue weight gain?
2) How well is energy stored during lactation than during the dry period?
3) How well is energy stored during the dry period than during lactation?

Answer 9

1) The efficiency of tissue mobilization to support milk production is greater than the efficiency of tissue weight gain
2) Energy is stored with greater efficiency during lactation than during the dry period
3) Energy is stored with less efficiency for subsequent mobilization for lactation than for storage and utilization during lactation

Question 10

What is compensatory growth?

Answer 10

Refers to an animal’s growth after a period of nutritional stress or restriction

Question 11

In compensatory growth, the rate of growth is often _______ than that exhibited by a genetically identical animal during normal growth.

Answer 11

Greater

Question 12

Compensatory growth is also called…

Answer 12

…catch-up growth as increased growth rate enables animals to reach body weights similar to uncompromised animals

Question 13

How are abnormally high growth rates achieved so that nutritionally compromised animals catch up?

Answer 13

1) Low basal metabolism during nutrient restriction due to decreased visceral (organs and organ cavity) weight
- Maintained for a time during re-alimentation (time during which the growth curve is being corrected) and allows more dietary protein and energy for the growth of major tissues rather than basal metabolism.

2) An increase in feed intake during re-alimentation contributes to increased growth

Question 14

What can influence how much compensatory growth occurs?

Answer 14

Severity of nutrient restriction and stage of growth curve at which restriction takes place can influence how much compensatory growth occurs

Question 15

Nutrient restriction can be severe enough to _______ catch-up period.

Answer 15

Delay

Question 16

What can very severe starvation do to an animal?

Answer 16

Can permanently stunt growth so that animals cannot grow to a normal size. This enhances the onset of fattening.

Question 17

Feeding a high plane of nutrition late in the lifetime when muscle and bone have matured will…

Answer 17

Increase fat deposition

Question 18

What will happen to animals when they are started on a high level of nutrition and then switched to a low level later?

Answer 18

Will produce carcass with more muscle and less fat

Question 19

True or False: Different types of growth require different levels of protein and energy.

Answer 19

True!

Question 20

What are the nutrient requirements for growth?

Answer 20

1) Dietary protein
2) Dietary energy

Question 21

What does protein quality refer to regarding dietary protein?

Answer 21

Protein quality refers to the balance and bioavailability of essential amino acids in a foodstuff

Question 22

What is a biological value?

Answer 22

A measure of quality and refers to how much protein/amino acid is absorbed and incorporated into the body

Question 23

Is dietary protein more important in ruminants or monogastric animals?

Answer 23

Monogastric animals

Question 24

What do ruminants utilize regarding dietary protein?

Answer 24

Ruminants utilize rumen microbial protein for some amino acids

Question 25

Diets with sufficient energy but insufficient protein for tissue deposition results in...

Answer 25

Increased fat deposition

Question 26

What is dietary energy?

Answer 26

Energy required for maintenance and for growth of new tissues

Question 27

How are optimal energy levels for food animals determined?

Answer 27

Can be determined by increasing dietary energy intake to a point where lean (muscle) gain is maximized. After this point, energy is partitioned to fat.