Nutrition in the Sled Dog A Practical Overview
Key Points • Exercise leads to increased metabolism. • Nutrition cannot overcome deficits in genetics or training. • Water is the most important nutrient. • Assess the dog; touch the dog. • Assess the food: • Palatable, calorie dense, digestible and most of all, practical. Test the ration.
Canine Athlete • Genetics • Training • Nutrition
Genetics • Lineage of dogs. Some traits are inherited and some are taught. • Physiological traits can be inherited • Feet, coat, size. • Dogs selected for certain attributes over many, many years. All came from a wolf at one time or another.
Training • Exercise training - consistent performance of some type of exercise over a period of time. • Measurable adaptation - sufficient intensity, duration and frequency of systems being trained. • Intensity and duration must be increased until a level of overload is reached for the systems being trained (bone mass, muscle hypertrophy, plasma volume expansion and cardiovascular efficiency).
What does that mean? Train until you notice a difference in your dogs.
Nutrition • Exercise = Increased metabolism. The key is to provide the right amount of energy from the right sources. • Match the nutrition to the exercise type. • Sled dogs are endurance athletes, greyhounds are sprint athletes.
Nutrition can’t overcome deficits in genetics or training. Matching nutrition to the type of exercise allows the dog to perform to its genetic potential and level of training.
Quick Course on Muscle Physiology • Muscle metabolism Two types of muscle fibers: • Type 1 - slow twitch. These have higher oxidative capacity and endurance qualities; more aerobic. Needed for endurance dogs. • Type 2 - fast twitch. More anaerobic. Greyhounds have more of these. • Muscle fiber type is a function of genetics but some modification is possible through training.
Muscle physiology-cont.ATP(Adenosine-5'-triphosphate) • Almost all muscles are fueled by ATP. ATP is the sole source of energy for muscle contraction to occur. • ATP can come from multiple sources such as fat, protein and carbohydrates (CHO). Amount of ATP in muscle is used very quickly, and then the muscle must rely on outside sources of ATP for supply. • Type of aerobic (many ATP created) vs. anaerobic (few ATP created) metabolism will influence availability of ATP for use by the muscles.
Muscle physiology-cont. What happens when a muscle is used? • Heat 75-80% of the energy used to make the muscle work is converted to heat and needs to be dissipated. • Metabolic acid CO2, NH3/NH4, Lactate • Aerobic metabolism creates CO2 and H2O. CO2 is eliminated quickly via the respiratory and urinary systems. • Anaerobic metabolism creates lactic acid; more difficult to dispose of because this must be metabolized further. • Contraction • Water
Energy Cost of Running • Amount of energy used to cover a given distance is independent of velocity. It is a function of body size and distance.
Energy cost of pulling a sled • ERR (Energy Requirement of Running) = Distance X caloric use, according to size of the dog. • The % increase in the cost of running with weight or pulling a sled is equal to the % increase in gross weight. • ERR total while pulling a sled= <ERR x Gross weight (dogs body weight, sled, person, etc.) divided by dogs body weight> plus the original ERR. • You can figure out how much energy it takes to pull a sled for each dog in a team..
Primary sources of energy for the canine • Fatty Acids (60-80%) • CHO (10-20%) • Protein (5-15%) • Encourage the fatty acid as a fuel over the others.
Fat • Has twice the metabolizable energy compared to carbohydrates (CHO) or protein. • Total dry matter intake of a dog is limited to about 3.5% of body weight • Only practical way to increase energy density of the feed is to increase fat concentration in the feed.
Fat Feeding high levels of fat may positively effect endurance. • The more they train, the more the dogs’ body will use fat for fuel, IF fat is available. The dog will begin to prefer more and more fat as an energy source over proteins or carbohydrates. • How is endurance affected by this?
Fat • Increased dietary fat has been shown to raise the VO2 max and raise the maximal rate of fat use for energy. • High fat diets during training help to alter a dog’s metabolism so it is better able to utilize fat and save the carb stores. As more fat is introduced into the diet, the dog becomes more efficient at utilizing fat as the primary energy source. • This has been demonstrated with diets that are between 25-65% of calories that are supplied by fat.
Fat • Dogs can tolerate high levels of fat if the fat is gradually introduced and an adequate intake of non-fat nutrients is maintained. • High levels of fat can lead to perioxidative damage to cells and this is where anti-oxidant use maybe beneficial. • Essential fatty acids (EFA) should be at least 2% of dry matter in ration. Dogs can’t create essential fatty acids and require them to be supplemented. • Fat is a palatability enhancer.
Thus, energy density and palatability make dietary fat levels important for the canine athlete.
Essential fatty acids • Omega-6 Fatty Acids: • Linoleic acid (LA), found in corn, soy, canola, safflower and sunflower oil, whole grains, body fat of poultry (chicken, turkey, duck etc.). • Arachidonic acid (AA), found in the body fat of poultry, lean meat, egg yolks and some fish oils. • Gamma linolenic acid (GLA), found in black currant seed oil, borage oil and evening primrose oil. • Dihomogamma linolenic acid (DGLA), found in organ meats like spleen, kidney and adrenals and metabolized from GLA. • Omega-3 Fatty Acids: • Alpha linolenic acid (ALA)), found in flaxseed oil and to a lesser extent, canola, soy, and walnut oils. • Eicosapentaenoic acid (EPA), found in cold water fish and their oil. • Docosahexaenoic acid (DHA), found in cold water fish and their oil.
Omega 3 fatty acids • Optimal amount is controversial. How much for maximum anti inflammatory and antioxidant effects? • Chinook salmon, raw per 100g, has 2.4 g of EPA,DHA and DPA. • Salmon oil is 36 grams per 100 grams oil. • Derived from cold water fish; wild caught, not farm raised.
Omega 6/Omega 3 Ratio • Industry standards use a ratio of 5-10 to 1 omega 6 to omega 3 fatty acids. • A ratio of 4-5 to 1 may be beneficial. • Anti inflammatory effects • Source of omega 3 can be expensive. • Total amount of EFA’s need to be 2% or better of dry matter.
How much fat? • As a percentage of calories given per day, 45-65% of total calories. - or - • 25-40% of dry matter
Carbohydrates(CHO) • Dogs can derive a significant portion of the calories needed from CHO in diet only if the dogs aren’t doing much. • Less than 2X daily maintenance levels. • Glucose loading is not beneficial in canine athletes. • CHO used should be highly digestible to limit the fecal bulk. • Increased fecal bulk leads to inc water loss and stress diarrhea. • One study showed that an extra 150 g of stool in the colon would = a handicap of 7KG in a race horse.
Carbohydrates • Dogs only require around 15% of calories to be supplied as carbohydrates, but have been shown to live fine on a zero carb diet.
Protein/Amino Acids • Used for the building, repair and maintenance of muscles. • Dogs need more protein if they are going to work harder; • Onset of training • Duration or intensity of training bouts are increased • During events • Provides 5-15% of energy used. Discourage the use of protein for energy, as all known proteins in the body have a purpose and are not intended as a source of energy.
Proteins-cont’d • Skeletal muscle is used first when the body needs to use protein as an energy source. • Caloric density of protein is equal to CHO and half the value of fat. • Remember the energy density of food and the amount of dry matter a dog can consume in a day (3.5% of their body weight).
Protein use in the ideal food • Have enough high quality protein to meet the dogs’ anabolic needs and enough non-protein energy nutrients to meet its energy needs. • Proteins are to be used for synthetic processes and building, not energy. Protein is the most expensive part of a diet. CHO and fat are much less expensive. • Protein requirements are actually requirements for available amino acids (AA). The digestibility and essential AA content of ingested protein will make for better efficiency.
Protein • Use varied protein sources. • Several species to ensure the inclusion of all the essential amino acids, such as beef and chicken, egg and pork, fish, chicken and oatmeal. • Muscle meats and organ meats.
Protein • Protein requirement studies have shown a minimum of 24% and a maximum of 40% of calories need to be from protein. • On a dry matter basis this will be in the 35% range or better.
Protein • Too low protein % in diet can be displayed by: • Injuries, slow healing, diarrhea, fatigue. • Reasons for too little protein: • Poor digestibility • Rapid transit time • Not measuring correctly • Not anticipating amount/duration of exercise • Palatability • Not aware of true numbers - test the ration!
Protein • Can you have too much? • Usually not; it will become just an expensive source of energy. • Some sources can lead to diarrhea. Get the dogs used to whatever is in your diet slowly. • Kidney failure isn’t induced by high protein levels, it can be accentuated.
Water - the most essential nutrient • It is a solvent for nearly all biologic solutes and a medium for nutrients, wastes and heat. • Absorbs physical shock, lubricant. • 2/3 of body is water. • 62% of water is located within cells and 7% is located in the intravascular space (arteries/veins).
Water • 60% of heat dissipated during exercise is lost through fluid evaporation or urinary tract. • Significant loss of water impedes performance; • Very cold, dry temperatures increase loss. • Warm temps can decrease loss of water and lead to overheating. High humidity impedes loss as well.
Water loss and electrolytes • Dogs do not lose electrolytes to any large degree through exercise. • Dogs can lose an appreciable amount if vomiting or diarrhea, i.e., illnesses. If the dog is vomiting or has diarrhea, this can lead to significant sodium, chloride and potassium losses.
Water • Concentrate on water replacement. Keep the dog hydrated. • Offer water 3-4 times a day. • Baiting the water with meat, kibble, etc. Cold water. Type of bowl.
Metabolic water • This is water produced from the metabolism of nutrients. • Fat gives 107 grams of water for 100 grams of fat metabolized. • Protein gives 40 grams of water. • Carbohydrates give 55 grams of water.
Vitamins and Minerals • Important, but secondary; found in adequate amounts in commercial food. • Although vitamins and minerals are obviously important for exercise, it is unclear if exercise alters the requirements for these nutrients. • Calcium and magnesium for long distance dogs?
Calcium • High fat foods can lead to the formation of insoluble soaps in the gastrointestinal tract and this can trap calcium, thus making it less available for absorption. • Meat will contain high levels of phosphorus, almost no calcium. • Ground bone - must be finely ground for maximum absorption of calcium. • 1.2-2% calcium on a dry matter base in kibble have been successfully fed to athletic dogs.
Bone meal use Cramping often due to calcium issues. Should add when using high additions of muscle meats. Amount to use-approximately 1 tablespoon per 5 lbs meat or 15 grams per 2 kgs meat. Relationship with other vitamins.
Vitamins • Be careful when supplementing as vitamins can interfere with other vitamins’ absorption, availability and use. • Vitamin based disease can occur with either too little or too much of a vitamin given to a dog.
Free Oxygen Radicals • Exercise increases metabolic rate and opportunity for free radical production, especially with the amounts of free fatty acids used in the diets. Ensure adequate intake of antioxidative nutrients. • Increased consumption of polyunsaturated fatty acids and increased oxygen consumption may also increase an athlete’s risk of perioxidative membrane damage. • Dogs’ own antioxidants have been shown to be depleted with recurrent exercise.
Antioxidant Nutrients • Vitamin E, vitamin C, B-carotene, xanthins, blueberries, cherries, wine
Antioxidants-cont’d • Astaxanthin • Very potent , 500 times stronger than vitamin E. • Discovered with salmon farming when used as a pigment but found to greatly improve survival rates of fry. • Immune stimulant? • 5 mg per dog per day. • Sources-plankton,, yeast, synthetic.
Assessing the Food • Calorie dense. • Acceptable; palatable. • Highly digestible • Decrease fecal mass, decrease stress diarrhea. • Practical • If it is not, what the heckis the point? • Cost, form, storage, how many fed, etc.
Assessing food • If commercial diet constitutes 50-75% of the mixture on a weight basis and most of the added ingredients are wet ingredients or fat, it is unlikely that vitamin and mineral deficiencies will occur. • Test the ration. Send a portion of the finished food mix into a lab for analysis. Inexpensive and very enlightening.
Feeding based on where calories are derived 40-60% of calories from fats 30-40% of calories from proteins 10-15% of calories from carbohydrates Example: If the a 1 kg total meal is 2000 Cal, 800-1200C are from fat, 600-800C are from protein, 200C are from carbs.
Feeding based on dry matter • Fat should be 23-35% of dry matter. • Protein should be 34-40% of dry matter.
Assess the Feeding Method • Amount fed • Frequency of feeding • Timing of meals in relation to exercise • Access to water • Use of supplements