9: Nutrient requirements for adult dogs Flashcards
What is an adult dog
Young to middle-aged dogs
Fully grown (about 12 months)
Not over 5-7 years
Goals of adult dog nutritional management
Maximize longevity, quality of life and disease prevention
Factors influencing energy requirements of dogs
- Gender and neuter status
- Breed
- Age (growth)
- Reproduction: gestation and lactation
- Activity level (sport/working dogs)
- Environment
How does breed affect nutrition?
- different breeds may be at risk for specific diseases or metabolic alterations
- maintenance energy requirement varies with differences in lean body mass, temperament and activity level
How does activity level affect energy requirements
- standing requires 40% more energy than lying
- consistently higher level of physical activity increases lean body mass (increased energy use even at rest)
Changing feeding practices based on activity level
- activity cannot be defined precisely
- feeding recommendations should initially be conservative
- avoid overfeeding to prevent obesity
Environmental factors that affect energy requirement
Temperature, humidity, type of housing, stress level and degree of accclimatization
Animal factors that affect tolerance to environmental factors
- Isolative characteristics of skin and coat (subcutaneous fat, hair length and coat density)
- difference in stature, behaviour and activity
Interaction with breed!
Heat losses at lower critical temperatures? How does it vary with breed?
Heat losses are minimal (minimum metabolic rate)
- Longhaired breeds = 15 to 20 C
- Shorthaired breeds = 20-25 C
- Arctic breeds = 10 to 15 C
Slide 11
Graph
Energy needs for body cooling? When?
When ambient temperature higher than dog’s thermoneutral zone
- small increase in E requirement
- drastic increase in water requirement
Why are energy requirements of animals with differing weights not directly related to BW
Energy used by the body is also related to total body surface area. Need interspecies mass exponent (0.75 in dogs)
Maintenance energy requirement in dogs
130 kcal ME x kg BW^0.75
Why is resting fed metabolic rate higher than BMR? By how much? MER = ?(in terms of BMR)
Dietary thermogenesis
Approx 15% higher than BMR in adult dogs
MER = BMR + thermoregulation + regular activity + fed
Slide 14
Breeds/activity levels above and below average requirements
Dog water requirement
- Body has limited capacity to store water
- water deprivation will result in death
- require a constant of water to replace losses through urine, feces, and respiration
Factors affecting voluntary water intake in dogs
- Environmental temperature (panting = loss of water vapour)
- type of diet fed (dry=increase intake)
- dogs activity level
- physiological state (e.g. lactation)
- health
- energy intake (more E = more metabolic waste products e.g. heat from nutrient metabolism, high CP diets)
How do dogs adapt water intake based on food?
Dry dog food has 7-12% water, canned food has up to 78% water
Dogs fed canned food have lower voluntary water intake than dogs fed dry food
What is metabolic water
Produced during oxidation of energy containing nutrients in body
5-10% of total daily water intake
How can we estimate water requirement by measuring energy intake
1 kcal energy = 1 ml of water
When is there no benefit to extra dietary protein?
When AA requirements are met
- excess must be deaminated by the liver
- nitrogen-byproduct excreted via kidneys
What do adult dogs need protein for
Maintenance and activity
Slide 20
Look
Nitrogen balance in adult vs growing animals
In adults, N in food minus N in feces and urine should = 0 (appropriate protein intake)
For growing animals, account for weight gain (should have a positive nitrogen balance)
Why is apparent ileal digestibility of protein/aa more accurate than apparent total tract digestibility?
Amino acids can only be absorbed in the small intestine, not LI
A lot of microbial affects on protein/aa in LI that cause an error in determining digestibility of aa
SI (ileal-cannulation) most accurate way of determining digestibility of aa
Recommended CP allowance for adult maintenance? Why use CP instead of aa requirement?
25 g CP/1,000 kcal ME
CP analysis is cheap, aa analysis is expensive
What are the functions of arginine (4)
- key intermediate in urea cycle (detoxification of nitrogenous wastes)
- release of several hormones and metabolic mediators (e.g. insulin, glucagon)
- precursor of biogenic amines
- precursor of neurotransmitters
Arginine deficiency in dogs
Dogs consuming a meal without arginine will develop signs of ammonia toxicity
- tremors, vomiting, profuse salivation and hyperglycemia
Dog tolerance to fat
- tolerate high amounts of fat in diet (70% of energy in form of fat)
- dogs adapt to wide range of fat types and amounts
Considerations when feeding diets high in fat in dogs
- Ensure adequate intake of protein, minerals and vitamins
- adjustment for high energy value
What source of fat should we be careful with in dogs?
Tallow (beef fat) is low in linoleic acid (essential fa)
Dietary fat digestibility
- apparent digestibility of fat: 70 to 95% (more digestible than protein or CHOs)
- plant sources (oils) more digestible than animal fats
Essential f.a. in dogs
- linoleic and a-linolenic acid
- dogs can synthesize sufficient arachidonic acid from linoleic acid
- dietary long-chain PUFA (EPA and DHA) can help prevent skin disease
Low amounts of fat in diet lead to…
- deficiencies in total energy
- essential f.a. deficiency = hair loss, development of a dry, dull coat and skin lesions and infections
- decreased food palatability
Consequences of overfeeding fat
- diarrhea
- weight gain and obesity (high palatability of energy dense diet)
Linoleic acid:a-linolenic acid ideal ratio in dogs
26:2.6 (more linoleic acid needed)
Why don’t dogs have an absolute dietary requirement for CHOs? Instead they have…
Dogs have multiple mechanisms to maintain blood glucose
Can convert excess aa, fat, fiber into glucose
They have a requirement for glucose and glucose precursors (from lipolysis and gluconeogenesis)
pros and cons of dietary fiber in adult dog? Optimal fiber level?
Increases bulkiness that contributes to satiety
Helps weight loss in obese dogs (calorie dilution)
But can decrease digestibility of other nutrients
3-7% DM
Slide 32
Safe upper limits of selected non-digestible CHOs
Ca and P deficiency in adult dogs
Skeletal abnormalities (most important in growing dogs)
Consequence of excess P
may accelerate progression of chronic renal disease in susceptible dogs (P needs to be excreted via kidneys)
Ca : P ratio
Not less than 1:1
