Nutrient Requirements of Dogs and Cats

1. Nutrient Requirements of Dogs and Cats

2. Feeding Companion Animals Objectives: Maintain Health Promote a normal (not excessive) growth rate Support gestation and lactation Contribute to high performance

3. Feeding Companion Animals Nutrient deficiencies are unlikely Most likely problem: overfeeding Because of nutrient interactions, balance within diet and absolute quantity are important

4. Nutrient Requirements Vary during lifetime Higher demands: growth, reproduction, work Lower requirement for adults Vary with animals: Terriers more active than pugs at same weight

5. Nutrient Requirement Standards Provide guidelines for formulation Include current info on Minimum and maximum levels of nutrients Requirements for different life stages and activities Estimates of bio availability for nutrients in feed ingredients

6. Nutrient Requirement Standards National Research Council (NRC): Minimum Daily Requirements No safety factors or bioavailability Used for cats and dogs before 1992

7. Nutrient Requirement Standards Association of American Feed Control Officials (AAFCO): Standards of practical Nutrient Profiles based on commonly used food ingredients Published 1992; used by feed companies in 1993 Cats: http://www.peteducation.com/article.cfm?cls=1&cat=1397&articleid=657 Dogs: http://www.peteducation.com/article.cfm?cls=2&cat=1659&articleid=662

8. Energy Expenditure Resting Metabolic rate Voluntary Muscular Activity Meal Induced Thermogenesis Adaptive Thermogenesis

9. Resting Metabolic Rate Major portion: 60 to 75% of ER Energy spent while sitting comfortably after a meal Energy cost of maintaining homeostasis Changes with sex, reproductive status, thyroid condition, body composition, body surface area

10. Voluntary Muscular Activity Most variable components: 30% in moderately active Affected by amount and intensity of activity and by body weight

11. Meal Induced Thermogenesis Metabolic cost of digestion, absorption, metabolism and storage of nutrients About 10 % of the ingested calories

12. Adaptive Thermogenesis Change in RMR in response to environmental stress

13. Food and Energy Intake Regulated by: Internal signals: gastric distension Physiological responses to sight, sound and smell of food Blood changes in nutrients, hormones External Signals Palatability Timing and size of meals Nutrient composition

14. DOGS: size

15. DOGS: activity

16. Energy Requirements (ME in kcal/day) DOGS Calculation difficult: variety of body sizes Change with body surface, not weight Body surface correlated with BW0.67 Inactive dogs: 99 x Wkg0.67 Active dogs: 132 x Wkg0.67 Very active dogs: 160 x Wkg0.67 Example: active dog weighing 10 kg Requires: 132 x 100.67 = 617 kcal/day Diet has 3800 kcal/kg (1727 kcal/lb) Needs: (617 / 3800) kg = 0.16 kg = 5.6 oz If 1 8-oz cup of food weights 4 oz, dog needs 1.5 cups

17. DOGS

18. DOGS Breed Differences Small breed dogs: mature body weight less than 20 pounds. Medium breed dogs: between 20 and 50 pounds Large breed dogs: mature dogs weighing 50 to 100 pounds. Giant breed dogs: mature body weight greater than 100 pounds. Large, fast-growing dog breeds require less food per pound of body weight than small breeds.

19. CATS Mature BW is between 2 and 6 kg ER is expressed per kg BW Maintenance: 60 kcal/kg BW for moderately active 70 kcal/kg BW for very active 50 kcal/kg BW for sedentary Example: moderately active cat 4 kg BW 60 x 4 = 240 kcal If dry food has 4200 kcal/kg Cat needs 240/4200 = 0.057 kg or 57g = 2 oz If 8-oz cup weights 3.5 oz, cat gets � cup/day

20. CATS

21. WATER 2 to 3 times DM intake

22. CHO All animals require CHO (glucose) Supplied by Diet Cooked starch is excellent energy source Sucrose and lactose not well tolerated Fiber: normal GIT function Endogenously Gluconeogenic pathway: always active in carnivores Cat maintains normal glucose even when fasting or fed CHO free diet Dogs meet their requirement during growth & maintenance provided diet has enough fat and protein

23. FAT Both cats and dogs maintain health when fed diets with wide ranges of fat if other nutrients are adjusted Cat foods have more fat than dog foods High fat foods not good for sedentary animals

24. FAT Fat is a source of EFA Linoleic Arachidonic Linolenic Dog diet requires linoleic and he can make others (1% of diet and 5% of total fat) Cat diet must have linoleic (0.5%) and arachidonic (0.02%)

25. FAT Dogs � Can tolerate prolonged fasts and utilize fat reserves for energy Cats � Do not mobilize fat reserves for energy very efficiently and, in fact, break down non-fatty body tissues for energy. This can lead to a very dangerous feline disorder called hepatic lipidosis

26. PROTEIN AND AMINO ACIDS Purpose: Provide EAA Supply N for synthesis of NEAA Animals do not require Protein, they require AA to Replace losses in skin, hair, digestive enzymes, mucosal cells AA losses from cellular catabolism Young animals have added requirement for growth of new tissue

27. PROTEIN REQUIREMENT Minimum intake of dietary protein that promotes optimal performance Evaluated as N balance Zero = maintenance Positive = growth, gestation, recovery Negative = inadequate nutrition, illness

28. CAT�s PROTEIN Cats require 20 amino acids to synthesize all the needed body proteins. Ten can be synthesized in the liver from carbon and nitrogen: dispensable amino acids (nonessential amino acids). The other 10 amino acids are indispensable (essential amino acids) because they cannot be synthesized in sufficient quantities to meet the animal's needs For phenylalanine and methionine, approximately one-half the requirement may be met by the dispensable amino acids tyrosine and cystine.

29. CATS PROTEIN Arginine Cats require more arginine than other animals, they lack the enzyme required for synthesis of the arginine precursor, ornithine.� Arginine is required for normal protein synthesis and ammonia detoxification.� Arginine enables conversion of ammonia to urea.� Cats can develop severe hyperammonemia from anorexia or ingestion of an arginine-free meal.� Taurine Cats also require taurine, present only in animal tissues.� Cats cannot synthesize enough taurine to meet obligate intestinal loss. The cat uses only taurine for bile salt synthesis (in comparison to dogs, that can substitute glycine), causing an ongoing obligate loss of taurine with excreted bile salts.� Most animals produce both glycine and taurine conjugates of cholesterol for secretion as bile acids, but cats can only use taurine. Intestinal reabsorption of bile acids is not 100 percent efficient, so some taurine is continually lost in the feces. Although not incorporated into protein, taurine is required for normal cardiovascular (taurine deficiency has been proved to cause dilated cardiomyopathy in cats), reproductive, and visual function (taurine deficiency has also been proved to cause retinal degeneration).