Working dogs Flashcards
Sprint dogs are
High intensity physical activity
Can be sustained less then 2-3 min
Coursing (sight hounds)
Racing (greyhounds, whippets)
Weight pulling
Fli ball
Agility
Intermediate working dogs are
Physical activity lasting several minutes to a few hours
Trail running, bicycling
Herding trails
Hinting
Livestock management
Tracking, search and rescue
Police dogs
Service dogs
Endurance working dogs are
Physical activity lasting many hours
Sled pulling
Racing, expedition
Endurance
Type I muscle type is
Slow twitch
High oxidative capacity
Endurance
Type II muscle type is
Fast twitch
High glycolytic capability
Strength
How much does an intermediate working dog need x RER
1-5 x RER
How much energy does a sprint dog need
1.6-2 x RER
How much energy does endurance dogs need
> 5x RER
Other factors effecting energy needs of working dogs
Temperature
Humidity
Terrain
Altitude
By products of exercise
Heat
Acids (CO2 and arctic acid)
Free radicals
Energy sources
protein
carb
fat
ATP as a source of energy for working dogs
ATP is sole source of energy for muscle contraction
Amount is proportional to amount of work (distance and intensity)
Resting muscle only have enough ATP to fuel contractions for a few seconds
Creatine phosphate is rapidly converted to ATP, but stores also limited, only enough to support 5-15 seconds
Glucose as a energy source
Glucose can be used to generate anaerobic and aerobic metabolism
Anaerobic fast, but yields low
Aerobic slower, but greater yield
Glycogen stores relatively small, cannot sustain exercise for extended time
Fatty acids are used for
Fatty acids are stored in higher amounts, primary source for longer-lasting energy
Anerobic energy metabolism includes
Cr-P
Glycolysis
Aerobic energy metabolism
Glucose oxidation
Fat oxidation
Key considerations for diet in working dogs
Water
Energy
Fat
Carbohydrates
Proteins
Digestibility
Antioxidants
Water needs for working dogs
Heat dissipation leads to decrease in total body water and plasma volume
60% lost though fluid evaporation from upper resp tract
Water requirements double when ambient temp reaches 45*C
Allow unlimited water access
Energy needs depends on
Depends on intensity, duration and frequency of exercise
Source depends mostly on intensity
Energy needs of greyhounds
Greyhounds work at high intensity
Have lower energy requirements
Short duration frequency only a few times per week
Fats do what for food
8.5kcal/g
Practical means of increasing caloric density
Increases palatability
Increases digestibility
Lowers food intake
Slows gastric emptying
Improves digestion and energy intake
Fat needs of endurance dogs
Fat oxidation more important with increased duration
Proper introduction important
Up to 60% of energy for sled dogs
Ultra-endurance dogs up to 8-% (super fat loading)
Fat needs of intermediate working dogs
Fat needs for intermediate athletes proportionate to work done
30-55% of kcal for moderate work
45-65% of kcal for large amounts of work
Fat needs for sprinting dogs
Fat requirements of sprint dogs not different than other dogs
20-24% of kcal
Carbohydrates are and useful for
3.5kcal/g
Cannot be used to significantly increase caloric density
Carbohydrates include starches, sugars and fibre
Some level of fibre is helpful to avoid loose stool
However excess levels of fibre should be avoided
Bulky stools are extra weight
Why are carbs highly digestable
Carbohydrates should be highly digestible
Undigested carbohydrates result in “stress diarrhoea”
Increases fecal water loss
Sprint dogs need what for carbs
Anaerobic metabolism dominant energy generation
Higher carbohydrate levels maximize muscle glycogen
50-70% of kcal
What are the carb needs of intermediate working dogs
Depends on intensity and duration
Long bouts of low to moderate intensity require higher fats and lower carbs (as low as 15% of kcal)
Short bouts of higher intensity work require higher levels (up to 50% of kcal)
How much carbs do endurance dogs need
Require very little carbs
Carb levels kept low to allow for energy density (ie. fat) required
Less than 15% of kcal
Protein is and why does it increase
Structural, biochemical and (to lesser degree) energy requirements
Work increases the requirement for protein
Most often seen when intensity and duration increases above conditioning level
Used in the formation of new muscle tissue and repair of damage
What is the average amount of kcal/g of protein
3.5
Protein sources serve a structural and functional purpose by
Small amount of energy used (5-15%)
Skeletal muscle can be mobilized
Negative impact on performance
What happens to excess protein
Excessive dietary protein must be deaminated
Urea from amino acid breakdown is excreted via urine
Increased water loss
Why are proteins required
Require enough protein to meet anabolic requirements
Require enough non-protein energy nutrients (carbs, fats) to meet energy requirements
Protein preferentially used for structural rather than energy uses
Digestibility and amino acid content important to determine how it will be incorporated into tissue proteins
Exact requirements necessary remain inconclusive (24-40% of kcal)
Protein requirements of endurance dogs
Endurance dogs may require lower levels of protein in order to meet their high energy requirements (ie, fat)
Enhanced digestibility results in
maximum delivery of nutrients
Lower digestibility results in
greater fecal bulk
What should the total DM digestablity be
Total DM digestibility should exceed 80%
Antioxidants are important for working dogs because
Exercise results in increased oxygen consumption
Normal oxygen metabolism results in high reactive free radical molecules
Oxygen molecules split into single atoms with unpaired electrons
Scavenge the body to find matching electron
This can result in body damage
Antioxidants have excess electrons available to donate
The body normally responds with endogenous antioxidant systems
But with high intensity exercise these systems can be overwhelmed
Vitamins C & E, Selenium
Sprint nutrition requirements
Rely on anaerobic energy metabolism, esp glycolysis
1.6-2x RER
20-24% fat
50-70% carbohydrate
Min 24% protein
Intermediate nutrition requirement
Rely on aerobic energy metabolism, more on glucose oxidation
2-5x RER
30-65% fat
15-50% carbohydrate
Min 24% protein
Endurance nutrition requirement
Rely on aerobic energy metabolism, esp fat oxidation
5x RER
>75% fat
<15% carbohydrate
Min 16% protein
Feeding to maintain BCS
Tendency for working dogs to be lean (2-3/5)
Hunting dogs should be 2.5-3.5/5, but often higher
Why?
Greyhound often leaner (1-2/5)
When to feed sprint dogs
Food >4hrs before exercise
Allow free access to water, except immediately prior
High-carbohydrate within 30 minutes of performance
When to feed intermediate dogs
Feed after exercise or >4hrs before exercise
Free access to water at all times
Snacks given during exercise or at end of breaks <15 minutes before resuming exercise
Feed to adult maintenance during idle season
When initiating training, start new feeding schedule 6 weeks prior to season work
When to feed endurance dogs
Feed after exercise or >4hrs before exercise
Free access to water at all times
Snacks given during exercise or after exercise
Monitor fat tolerance (steatorrhea and decreased palatability)
