12: Nutrient requirements of working dogs Flashcards
Why are there more studies of dogs with little exercise rather than high exercise? Most high exercise studies are in…Why?
Most dogs/pets fall into low exercise category; of interest to general population
Sled dogs and greyhounds bc of money (racing, betting)
Canine metabolism is unique because… Why is this beneficial?
muscles are adapted to use more fat
- muscle fibers highly oxidative
- metabolize more free f.a.
Fat has the greatest energy density per unit weight (less weight needs to be carried for same E)
During exercise, what metabolic process is used in dogs?
Beta-oxidation
Take ffa up from blood into muscle
Mobilize and burn ffa for muscle metabolism
In general, working dogs have greater requirement for what nutrients? Rule of thumb for MER calculation
Greater energy, protein, mineral and vitamin requirement
ME = maintenance + exercise
1.5 to 2.0 x adult MER
Nutrient requirements depend on…
- environment (temp, humidity)
- duration (minutes, hours)
- intensity of exercise (sprinting, endurance)
- stress level
- dog’s body composition (more muscle = higher E requirement) and temperament
Water requirement in sled dogs? Greyhounds?
Sled dogs: from 1 L/d resting to 5 L/d during 450 km race
- panting = water leaves body via lungs
- protein breakdown = ammonia needs to be excreted
Greyhounds:
- dehydration before race (more water = more weight)
- use water for positive reinforcement
- cold water bath and access to water immediately after
Energy requirement of sled dogs in resting in thermoneutral zone? In -20C with wind chill?
Thermoneutral environment = same E needs as adult dog at maintenance
-20C = ~215 kcal ME x BW^0.75
Energy for movement is proportional to… Energy requirement of active greyhound? Sled dog?
Proportional to distance traveled rather than speed
Greyhound racing 500 m twice weekly = ~143 kcal ME x BW^0.75
Sled dog during 3-day race, average speed 7 km/h, -7 to -35C = ~1,003 kcal ME x BW^0.75
Unique nutrient requirements of sled dogs
- require high fat (>50% of energy), high protein (>30% energy) diet
- less minerals and vitamins per unit energy bc of higher food intake
- more antioxidant vitamins (E, C) (free radicals produced in muscle)
Unique nutrient requirements of racing dogs
Moderately high fat (30 to 50% E), moderate protein (24% E) diet
Slides 10-13
Metabolic rates of different working dogs
Look
How do dogs adjust to diet energy density? Consequence?
Adjust food intake to E density
High energy density diets combined with little exercise can lead to obesity (high in saturated fat = palatable)
Why is it difficult to assess normal feeding behaviour in dogs
What is normal? Dog is domesticated; assessing normal behaviour is difficult
How many meals do dogs eat compared to cats?
Eat fewer, larger, more variable meals per day
- 4-8 meals/day ad libitum
- during light period
Why might dogs eat too rapidly?
Social facilitation
- perhaps leftover of competitive behaviour
