dogs by fjzhangxiaoquan


									Nutrient Requirements of Dogs and
              Feeding Companion Animals

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

I.     Nutrient deficiencies are unlikely
II.    Most likely problem: overfeeding
III.   Because of nutrient interactions, balance
       within diet and absolute quantity are
                   Nutrient Requirements

I.         Vary during lifetime
      A.     Higher demands: growth, reproduction, work
      B.     Lower requirement for adults
II.        Vary with animals:
      A.     Terriers more active than pugs at same weight
             Nutrient Requirement Standards

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

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

I.        Association of American Feed Control
          Officials (AAFCO): Standards of practical
          Nutrient Profiles based on commonly
          used food ingredients
     A.     Published 1992; used by feed companies in
     B.     Cats:
     C.     Dogs:
               Energy Expenditure

I.     Resting Metabolic rate
II.    Voluntary Muscular Activity
III.   Meal Induced Thermogenesis
IV.    Adaptive Thermogenesis
              Resting Metabolic Rate

I.     Major portion: 60 to 75% of ER
II.    Energy spent while sitting comfortably
       after a meal
III.   Energy cost of maintaining homeostasis
IV.    Changes with sex, reproductive status,
       thyroid condition, body composition, body
       surface area
           Voluntary Muscular Activity

I.    Most variable components: 30% in
      moderately active
II.   Affected by amount and intensity of
      activity and by body weight
          Meal Induced Thermogenesis

I.    Metabolic cost of digestion, absorption,
      metabolism and storage of nutrients
II.   About 10 % of the ingested calories
          Adaptive Thermogenesis

I.   Change in RMR in response to
     environmental stress
                Food and Energy Intake

I.        Regulated by:
     A.  Internal signals:
       1. gastric distension
       2. Physiological responses to sight, sound and
            smell of food
       3. Blood changes in nutrients, hormones
     B. External Signals
       1. Palatability
       2. Timing and size of meals
       3. Nutrient composition
DOGS: size
DOGS: activity
          Energy Requirements (ME in kcal/day)

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

Stage               X Maintenance Requirement
Post weaned                       2
40% adult weight                 1.6
80% adult weight                 1.2
Late gestation                1.25 to 1.5
Physical work                   2 to 4
Lower temperature             1.2 to 1.8

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

I.         Mature BW is between 2 and 6 kg
II.        ER is expressed per kg BW
      A.     Maintenance:
           1. 60 kcal/kg BW for moderately active
           2. 70 kcal/kg BW for very active
           3. 50 kcal/kg BW for sedentary
           4. Example: moderately active cat 4 kg BW
              a)   60 x 4 = 240 kcal
              b)   If dry food has 4200 kcal/kg
              c)   Cat needs 240/4200 = 0.057 kg or 57g = 2 oz
              d)   If 8-oz cup weights 3.5 oz, cat gets ½ cup/day

Stage              ER: kcal ME/kg BW

Post weaned                250

20 weeks                   130

30 weeks                   100

Late gestation     1.25 x Maintenance

Lactation          3 to 4 x Maintenance

I.   2 to 3 times DM intake

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

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

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

I.    Dogs – Can tolerate prolonged fasts and
      utilize fat reserves for energy
II.   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

I.        Purpose:
     A.     Provide EAA
     B.     Supply N for synthesis of NEAA
     C.     Animals do not require Protein, they require
            AA to
          1. Replace losses in skin, hair, digestive
              enzymes, mucosal cells
          2. AA losses from cellular catabolism
          3. Young animals have added requirement for
              growth of new tissue
                 PROTEIN REQUIREMENT

I.         Minimum intake of dietary protein that
           promotes optimal performance
II.        Evaluated as N balance
      A.     Zero = maintenance
      B.     Positive = growth, gestation, recovery
      C.     Negative = inadequate nutrition, illness
                   CAT’s PROTEIN

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

I.         Arginine
      A.      Cats require more arginine than other animals, they lack the enzyme
              required for synthesis of the arginine precursor, ornithine.
      B.      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.

II.        Taurine
      A.      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.
      B.      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).

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