(T2) Lecture 6a - Life cycle nutrition of dogs Flashcards
What are the 3 critical phases during the first 12 months of a dog’s life?
- Nursing phase
- Weaning period
- Post-weaning period
Why are large-breed puppies more susceptible to malnutrition at birth?
- much larger mature BW
- born more premature
Why does birth weight highly correlated to mortality (hypoglycemia, sepsis)?
- Lower the BW the greater the chance of animals becoming sick and dying
- Hypoglycemia = low blood glucose = didn’t get enough nutrients from colostrum = gut wall enterocytes aren’t properly fused and bacteria passes through causing a local infection (sepsis).
What does daily weighing of nursing puppies indirectly measure?
Evaluation if quality and quantity of milk is adequate
Body temperature in newborn dogs
- Poikilothermic during first 3 weeks of life; aka cannot maintain their own body tmp bc they are very low in body fat so they have a higher thermoneutral zone
- low level of body fat
- need warm enviro
- room for bitch
- bitch may push puppy away or neglect it with low skin temp due to an evolutionary perspective; why spend energy when there is a low change of survival, spend more energy on puppies with a greater chance
What is colostrum?
First, special milk secreted by mammary gland within 24-48 hr after giving birth; concentrated source of energy and selected nutrients
What is colostrum high in?
High DM content
- viscous and sticky (due to high density of nutrients)
- suckling is difficult for weak puppies (bc of above point)
- DM content decreases 12-24 hrs after birth = decrease in protein
What is the composition of colostrum?
- twice as much protein as mature milk
- particularly IgG
- milk is rich in IgA - high levels of Ca, Mg, P, Fe, Zn, and Cu
- decrease within 2-3 days - high vit A
- low lactose level
- laxative effect
- to stimulate gut flow and peristalsis - other factors
- ex. growth factors to stimulate intestine growth
What is an example of milk-borne growth factor?
- IGF-1
- EGF
- both stimulate intestinal growth (needs to become an active organ)
Why is colostrum important for immune fxn in puppies?
- Immature immune system at birth
- Depend on immunoglobins in colostrum (passive transfer)
- Transplacental transfer of immunoglobulins is low
- very important that puppies drink colostrum within 24 hrs
What is a complete food for neonates?
Milk
What does the composition of milk support? What is the composition
NORMAL growth rate of neonates (milk does not maximize growth which is a good thing)
- water, protein fat, lactose, minerals, vitamins
- highly digestible
- compo does not change much during lactation
Why is knowing the nutrient profile of milk important?
- Important when assessing and formulating milk replacers
- Reflects enormous anabolic activity of puppies
Energy requirement
Energy requirement = energy for maintenance + growth
Why do puppies sleep 80% of the time and huddle?
Sleep: less energy required for activity and therefore less needed for maintenance
Huddle: less energy required for maintaining body temp therefore less needed for maintenance
How are protein requirements met during the nursing period?
Protein requirements met with ingestion of adequate amounts of milk
- protein digestibility of milk up to 99% and high N retention; not a lot of excretion = high protein synthesis rate = good for regular growth
- rich in arginine, lysine and branched-chain AA
Why must dog milk contain a lot of fat?
Fat reserves at birth are VERY low. During the first month 50% of BW gain is fat.
Milk FA profile is highly variable depending on what mom is eating. Want omega 6 and 3 LCPUFA bc they are important for brain development.
What is the primary carbohydrate in milk?
Lactose = glucose + galactose
- lactose is absorbed readily after digestion; intestinal lactase activity is high until ~4 months; pancreatic amylase insignificant at 4wks of age
- lactose favours colonization of beneficial bacterial species = competitive exclusion of pathogens
Why is lactose important as the main CHO source during the first weeks of life to avoid diarrhea?
Gut is set up to digest lactose and whatever is not used is fermented resulting in a lower chance in diarrhea. Lactose favours colonization of beneficial bacterial species
- competitive exclusion of pathogenic bacteria
- lactate being produced int he gut also helps reduce pH and kickstart protein digestion which is another mechanism of avoiding pathogenic bacteria
Calcification of the skeleton does not keep pace with the increase in body size until after weaning so why do you not want to overfeed energy during lactation?
BC you have a greater increase in body mass than what the skeleton can support; no excess energy in milk.
- want a strong skeleton to support gradual increase in body mass
How do puppies deal with milk being a poor source of iron?
- accumulation of Fe in liver during last week of pregnancy to be gradually released to continue to support growth of the puppy.
- during first 3-4 wks body iron stores and hematocrit and hemoglobin values decrease below levels at birth
- Fe reserves increase with additional food at weaning; body Fe stores normalize around 4 months
How is food intake of the bitch changed during weaning?
Restriction of food intake 1-2 days before weaning
- less nutrients available for milk reduction = reduction of mammary gland engorgement
- demand drop, product should stop quickly = preventing mastitis
- no food at weaning
- restriction of food intake 1-2 days after weaning
What are 4 advantages of dogs eating solid food (weaning period)?
- decreased reliance on bitch
- decreased nutritional burden of the bitch
- decreased Fe deficiency
- reduces weaning stress
When do puppies start eating solid food?
Between 3-4 weeks of age
- when deciduous teeth begin to erupt
- come into contact with bitch’s food while playing
- start eating small amounts
What is used to stimulate food intake from 3 weeks of age?
Gruel
What is gruel?
Blending of a moist weaning puppy food or lactation food or growing food with warm water or milk replacer
- high in nutrients
- very digestible (high in animal ingredients)
During the weaning period the puppies go from gruel and then their interest in solid food increases. What happens when interest shows, what happens at 5 weeks of age, and when should weaning be complete?
- water content in gruel can be reduced
- at 5 weeks puppies should eat sufficient quantities of solid food and bitch’s milk production will decline
- weaning completed at 6-7 wks and puppies should be removed from the dam and fed same diet after weaning to minimize stress and diarrhea
What is the feeding goal from postweaning to adulthood?
Create healthy adult
- optimize growth (NOT maximize)
- minimize obesity
- minimize developmental orthopaedic disease
How does nutrition play a role in health and development?
- immune system
- body composition
- growth rate
- skeletal development
Generally what is the energy requirement post weaning?
Energy requirements = energy for MAINTENANCE + GROWTH
What is growth rate like post weaning?
Growth rate high in first weeks after weaning
- 50% energy intake for maintenance, 50% for growth
Gradually growth curve reaches a plateau
- proportion of energy needed for maintenance becomes more important
- energy need for growth becomes less important
How does energy intake change during the weaning-50% of adult BW time frame?
Double the maintenance energy is required
How is the daily metabolizable energy requirements for growth of puppies after weaning established?
The formula used establishes MER then there is a correction that describes how far along the puppy is relative to reaching mature BW
Postweaning, what is important about the energy requirement for large and giant breeds?
- optimal NOT MAXIMAL GROWTH is an important factor for proper skeletal development
- excessive energy intake impairs endochondral bone formation
What happens to protein requirements postweaning?
Protein requirement follows pattern comparable to energy requirements
- same nutrient profile throughout growth
- protein requirements different quantitatively and qualitatively from adult dogs
How does the fat amount needed in the diet compare in the suckling period, postweaning period, and adult maintenance period?
suckling period > postweaning > adult maintenance
- highest in suckling bc the puppy needs to accumulate fat deposites
What are the 2 essential fatty acids for dogs?
- Linoleic acid
- Alpha-linolenic acid
*for growing dogs it is better to be safe than sorry so arachidonic acid is added as well in case they have an insufficient capacity to synthesize it right after weaning.
When are Ca and P requirements the highest?
Greatest needs during active formation of bones and teeth
- roughly in a 1:1 ratio
In growing dogs, what is a calcium deficiency you need to look out for?
Nutritional secondary hyperparathyroidism
Nutritional secondary hyperparathyroidism
Not enough Ca in diet
= decrease in Ca in extracellular fluid
= stimulates the parathyroid hormone to release calcitriol
= calcitriol stimulates Ca release from skeletal tissue to try and increase Ca in blood circulation
= decrease in bone mineral content
= osteomalacia and fractures
Who is particularly at risk for nutritional secondary hyperparathyroidism?
Large- and Giant-Breed puppies
What happens if growing dogs receive a calcium excess?
Ca increase
= increase in Ca in extracellular fluid
= more calcitonin released by thyroid
= upregulates how much Ca is being untaken in bone
= large increase in bone mineral content
= osteochondrosis, radius curvus, decreased bone turnover, increased bone mineral content
