10: Life cycle nutrition of growing dogs

Question 1

Three critical phases during first 12 months of life

Answer 1

1. Nursing phase
2. Weaning period
3. Post-weaning period

Question 2

Mortality in newborn dogs

Answer 2

10 to 30% in 1st week of life
Birth weight highly correlated to mortality

Question 3

Body temperature in newborn dogs

Answer 3

• Poikilothermic (body temp similar to environment) during first 3 weeks
• low levels of body fat
• need warm environment
• bitch may push puppy away or neglect it if it has low skin temperature

Question 4

When is colostrum produced? DM content?

Answer 4

24 to 48 h after giving birth

High DM content
- viscous and sticky
- suckling can be difficult for weak puppies
- DM content decreases 12 to 24 hours after birth

Question 5

Nutrients in colostrum

Answer 5

• 2x as much protein as mature milk (globulins (IgG))
• high levels of Ca, Mg, P, Fe, Zn and Cu
• high in vitamin A
• low lactose level (1%)
• laxative effect
• growth factors (insulin-like growth factor 1)

Question 6

Why is it so important for puppies to drink colostrum within 24 hours of birth

Answer 6

Immature immune system at birth
- depend on immunoglobulins in colostrum (passive transfer)
- transplacental transfer of immunoglobulins only 5 to 10% of IgG
- gut closure to Ig

Question 7

Composition of milk?

Answer 7

Supports normal growth rate
- water, protein, fat, lactose, minerals and vitamins
- highly digestible

Question 8

Energy requirement of puppies during nursing

Answer 8

Energy for maintenance + growth

25 kcal/100 g BW

Question 9

Why do puppies huddle?

Answer 9

For warmth
Decrease maintenance requirements during first week of life (lower critical temp expands) = more E for growth

Question 10

Protein digestibility of milk and nitrogen retention in first week

Answer 10

Digestibility = 99%
N retention = 90%

Question 11

What aa is milk rich in

Answer 11

Rich in arginine, lysine and branched-chain aa

Question 12

Body fat gain during first month of life? Therefore…

Answer 12

50% of BW gain is fat

After two weeks, 10% body fat
After 1 month, 17% body fat

Therefore milk must contain a lot of fat

Question 13

Primary CHO in milk? How is it absorbed?

Answer 13

Lactose (3 to 3.5%)
Absorbed readily after digestion
- intestinal lactase activity high until 4 months of age
- pancreatic amylase insignificant at 4 wks

Question 14

How does lactose control bacterial colonization? Health benefits?

Answer 14

Favours colonization of beneficial bacterial species (fermented into lactic acid in the gut decreases pH = exclusion of pathogenic bacteria)

To avoid diarrhea, lactose should be main CHO during first weeks

Question 15

Sufficiency of Ca and P levels in milk? What is the concern?

Answer 15

Ca and P levels in milk are sufficient

But calcification of the skeleton does not keep pace with the increase in body size until after weaning

Question 16

Milk as a source of iron? What is the solution

Answer 16

Milk is a poor source of Fe (puppy requirements higher than intake)

Fe accumulates in liver of fetus in last week of pregnancy and is used as a nutrient source until additional food (with Fe) is provided at weaning

Question 17

What changes should you make to the bitches diet during weaning?

Answer 17

Restrict food intake 1 to 2 days before weaning. This means less nutrients will be available for milk production and mammary gland engorgement will reduce (prevent mastitis)

No food at weaning

Restrict food intake 1 to 2 days after weaning

Question 18

Advantages of eating solid foods for puppies

Answer 18

• decreased reliance on bitch
• decreased nutritional burden of the bitch
• reduced Fe deficiency
• reduces weaning stress

Question 19

When do puppies start eating solid food? How are they introduced to it?

Answer 19

Between 3 to 4 weeks (when deciduous teeth begin to erupt)

Come into contact with bitch’s food while playing, start eating small amounts

Question 20

What kind of food should you use to introduce puppies to solid foods? Describe it

Answer 20

Gruel can stimulate food intake from 3 weeks of age

Blend a moist weaning puppy food or lactation food or growing food with warm water or milk replacer
High in nutrients, very digestible
Have more water at first, then decrease

Question 21

What happens at five weeks of age? When is weaning complete?

Answer 21

5 weeks: puppies should eat sufficient quantities of solid food. Bitch’s milk production will decline

Weaning completed at 6 to 7 weeks (remove puppies from dam while feeding same diet)

Question 22

Goal when feeding a growing dog?

Answer 22

Create a heallthy adult
- optimize (NOT maximize) growth
- minimize obestiy
- minimize development of orthopaedic disease

Question 23

How does nutrition play a role in health and development during the growth phase

Answer 23

• immune system
• body composition
• growth rate
• skeletal development

Question 24

Energy in the postweaning phase is required for…

Answer 24

Maintenance + growth

Question 25

How much energy intake is used for growth in first weeks after weaning? What happens later?

Answer 25

50% energy intake for growth (50% maintenance)

Gradually, growth curve reaches a plateau and proportion of energy needed for maintenance becomes more important

Question 26

Slides 22,23

Answer 26

Growth curves

Question 27

What is the daily ME energy requirement formula for growth of puppies after weaning? What is P? Slide 25

Answer 27

MER x correction factor for growth

P = actual BW/mature BW

Question 28

Important considerations of postweaning energy requirements in large and giant breed dogs

Answer 28

• optimal not maximal growth is important for proper skeletal development
• excessive energy intake impairs endochondral bone formation

Question 29

When is arachidonic acid provided in the diet for dogs?

Answer 29

During postweaning growth
Added as a safety factor (adult dogs can synthesize it, not entirely sure about puppies)

Question 30

When are fat requirements highest in dogs?

Answer 30

suckling period>postweaning>adult maintenance

Question 31

When are Ca and P requirements greatest in dogs?

Answer 31

Greatest need during active formation of bones and teeth

Question 32

Describe Ca homeostatic mechanisms in puppies

Answer 32

Less precise in puppies
- 2 to 6 months of age Ca absorption always >40%
- Absorption more regulated after 10 months

Question 33

Recommended Ca:P ratio in growing dogs

Answer 33

1:1

Question 34

Describe calcium deficiency in growing dogs? Excess?

Answer 34

Deficiency = nutritional secondary hyperparathyroidism
Decrease in blood (extracellular fluid) Ca = increase in parathyroid hormone -> increase in calcitriol. Calcitriol and PTH mobilize Ca from skeletal tissue (decrease in bone mineral content = osteomalacia, fractures)

High extracellular Ca = calcitonin release which deposits Ca into bone (decreased blood Ca) = large increase in bone mineral content (osteochondrosis, radius curvus, stunted growth, decreased bone turnover)

Question 35

What happens when puppies are fed diets with low energy density and digestibility postweaning?

Answer 35

Puppy must eat large quantities of food
Increases risk of flatulence, vomiting, diarrhea, pot-bellied appearance

Puppy food should be more digestible than average

Question 36

CHO recommendations postweaning?

Answer 36

No recommendation
Suggestion 20% DM CHo until 4 mo