(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
