Fundamentals of Small Animal Nutrition

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Fundamentals of Small Animal Nutrition

• Dr. Randy Ackman
• Nutrient Content of Pet Food

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Nutrient Content of Pet Food

• Two ways determine nutrient levels
• Proximate analysis
• Most accurate
• Laboratory analysis on finished product
• Provides percentages of
• Moisture
• Crude protein
• Crude fat
• Ash (minerals)
• Fiber
• NFE
• Reports only maximums and minimums

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Nutrient Content of Pet Food

• Calculation Method
• Calculation of the average nutrient content of
  the foods ingredients using values reported in
  tables
• Amount of essential nutrients in each ingredient
  is summed
• Less costly
• Less time consuming
• Significant sources of error

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Nutrient Content of Pet Food

• Downfalls of calculation method
• Lack of complete and accurate data for many
  nutrients in commercial dog food
• Tables contain approximations
• Table may be out dated
• Grain yields increase protein levels decrease
• Corn average protein content is 7.87
• Range of 5.97 to 10.25
• Also in oats, sorghum

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Nutrient Content of Pet Food

• Downfalls of calculation method (cont)
• Quality of ingredients cannot be determined and
  is not considered
• Quality of ingredients affects
• Availability
• Standard tables reflect averages
• Processing affects quality of nutrients
• Nutrient loss
• Digestibility
• Availability

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Nutrient Content of Pet Food

• Determination of Digestibility
• AAFCO does not require companies to list
  digestibility
• Digestibility
• Measure of diets quality because it directly
  determines proportion of nutrients in the food
  available for absorption
• Measured through feeding trials
• Measure disappearance of nutrients as they travel
  through GI tract

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Nutrient Content of Pet Food

• Digestibility
• Test diet fed pre test (5-7 days)
• Amount of food fed is measured
• Amount of fecal material excreted is measured
• Nutrients of each are measured
• Expressed as percentages
• Called digestion coefficient
• Apparent digestive coefficients
• Fecal matter contains waste not from the food

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Nutrient Content of Pet Food

• True digestibility measured by
• Deducting normal metabolic loss of the nutrient
  from the amount of the nutrient measured in the
  fecal matter
• Usually done for protein
• Low- protein to protein free diets fed for
  baseline
• Cellular loss
• Enzymatic loss

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Nutrient Content of Pet Food

• Current AAFCO standard is calculation method
• If digestibility trials used to determine ME
  values
• Cannot vary 15 of calculation method

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Nutrient Content of Pet Food

• Expression of Nutrient Content
• AF as fed
• DMB dry matter basis
• Water dilutes nutrients
• 25 protein
• 25 moisture semisolid food
• 10 moisture dry food
• Calculate protein on dry matter basis

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Nutrient Content of Pet Food

• Nutrient Density
• Calculating levels of nutrients as a proportion
  of ME
• Most accurate
• Allow accurate comparison to all foods
• DMB does not differentiate between energy content
  only water
• Why is this important?
• Accounts for differences in
• Water and energy content

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Nutrient Content of Pet Food

• Nutrient Density
• Expressed as a percentage of ME or
• g/1000kcal of ME or
• Units /1000kcal of ME if vitamin or mineral
• p171
• Marginal vs high protein diet
• Obesity or protein deficient
• Applies to all nutrients

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Nutrient Content of Pet Food

• Balance diet so that
• When caloric requirements are satisfied
• All nutrients are met at same time
• Express nutrient density as
• of ME or units per 1000 kcal ME
• Avoid percentage by weight

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Nutrient Content of Pet Foods

• Comparison of Calorie distribution
• Hard working dogs require
• High protein to maintain muscle
• Higher fat content
• For example
• Protein 32, fat 56, and carbohydrate 12 of ME
  calories
• Less active dogs
• Less protein and less fat
• Protein 26, fat 38, and carbohydrate 36 of ME
  calories
• Growing dogs
• Protein 27, fat 41, and carbohydrate 32 of ME
  caloires

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Nutrient Content of Pet Food

• Calculating ME/ kg
• Crude protein not less than 26
• Crude fat not less than 15
• Crude fiber not more than 5
• 100- 26-15-5-7(mineral-ash)47
• Use modified Atwater conversions
• Calories per 100g of food 383 kcal
• Calories of ME per kg of the food is 3830 kcal

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Nutrient Content of Pet Food

• Common Pet Food Ingredients
• Ingredient list
• Cannot reference quality
• Diet must conform to pet food label
• Identify source of nutrient
• Protein
• A contributor of protein if protein content of
  ingredient () is greater than protein content of
  diet ()
• Ingredient is a protein source

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Nutrient Content of Pet Food

• Protein Sources
• Plant sources
• Animal sources
• Combination of both
• Animal protein
• Superior amino acid quality (high quality)
  compared to plant protein
• Ranges from excellent quality to poor quality
• Plant (grain) protein
• Consistent in ability to supply amino acids

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Nutrient Content for Pet Food

• Animal Protein
• Beef
• Chicken
• Chicken byproduct meal
• Chicken meal
• Dried egg
• Fish
• Fish meal
• Meat and bone meal
• Meat byproducts
• Meat meal

• Lamb
• Lamb meal
• Rabbit

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Nutrient Content of Pet Food

• Meat
• Any species of slaughtered mammal
• Pork, beef, sheep, horse etc
• Combination of flesh, skin, /- bone
• Byproduct
• Secondary products are included
• Ie parts of carcasses may contain
• Bone, head, viscera, feet, but no feathers

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Nutrient Content of Pet Food

• Meal
• Any ingredient that has been ground or otherwise
  reduced in particle size
• Ie chicken meal
• Dry ground whole chicken exclusive of heads,
  feet, viscera

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Nutrient Content of Pet Food

• Grain protein sources
• Corn gluten meal
• Soy flour
• Soy grits
• Soybean meal
• Alfalfa meal
• Flax seed meal
• Wheat germ

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Nutrient Content of Pet Food

• Corn gluten meal
• Dried residue after starch has been removed and
  bran has been separated
• Relatively consistent in quality
• Not as digestible as high-quality animal protein
• High proportion on DM basis
• Deficient in lysine and tryptophan

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Nutrient Content of Pet Food

• Soybean Products
• TVP
• Meal, flour, grits
• 70-87 digestibility
• Limiting in methionine
• Rich in lysine
• Complements corn meal gluten

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Nutrient Content of Pet Food

• Soy
• Protein well digested
• CHO portion is poorly absorbed
• Fermented in colon by bacteria
• Production of SCFA and gas
• Osmotic action
• Yields loose stools and flatulence
• Due to oligosaccharides

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Nutrient Content of Pet Food

• Raw soy
• Phytate
• May inhibit absorption of nutrients
• Trypsin inhibitors
• Heat labile and destroyed during processing
• Hemagglutinins
• Also destroyed upon heating

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Nutrient Content of Pet Food

• Carbohydrate sources
• Corn
• Rice
• Grain sorghum
• Wheat
• Oats

• Lesser
• Barley
• Carrots
• Flax seed
• Molasses
• Peas
• Potatoes

In form of starch
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Nutrient Content of Pet Food

• Carbohydrates
• Cooking
• Greatly increases digestibility of starch
• Dietary fiber
• Not digested
• Included with carbohydrates
• Sources
• Beet pulp, rice bran, apple and tomato pomace,
  peanut hulls, citrus pulp, oat bran, rice, and
  wheat
• Pulp
• Residue after juices have been extracted
• Pomace
• Pulp of fruit

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Nutrient Content of Pet Food

• Fat source
• Fat and essential fatty acids
• Enhances palatability
• Animal fats and oils
• Animal fat fat that comes form tissues of
  animals or poultry
• 90 total fatty acids
• Poultry fat or beef fat
• Single type of animal fat
• Animal fat
• More than one source of animal fat

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Nutrient Content of Pet Food

• Fat sources
• Vegetable fat
• Vegetable oil extracted from plant seeds
• Corn, safflower, soybean
• Flax seed
• Excellent source of omega-3 fatty acid linolenic
  acid
• Borage oil
• Linolenic acid and omega 6 fatty acid

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Nutrient Content of Pet Foods

• Vitamin and Mineral Sources
• Purified forms only in small amount
• Most are present in other nutrients
• Low on ingredient list
• Consider
• Bioavailability
• Adequate amounts
• Relationship between minerals
• Ie excess Ca, Cu, and Vit D inhibit absorption of
  Zn

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Nutrient Content of Pet Food

• Vitamins and minerals
• Loss during processing and storage
• High heat in canning
• Loss in B vitamins thiamin and folic acid
• Extrusion
• Vitamin A, riboflavin, folic acid, niacin, and
  biotin

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Nutrient Content of Pet Food

• Sources of Vitamins and minerals
• Potassium chloride
• Calcium carbonate
• Dicalcium phosphate
• Monosodium phosphate
• Manganese sulfate
• Copper sulfate
• Zinc oxide
• Ferrous sulfate

• D-activated animal sterol
• Alpha-tocopherol
• Thiamin
• Niacin
• Calcium pantothenate
• Pyridoxine
• Folic acid
• Biotin

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Nutrient Content of Pet Food

• Additives and preservatives
• Additives
• Are included in pet foods
• Preserve products
• Color
• Flavor
• Texture stability
• Nutrient content

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Nutrient Content of Pet Food

• Product must through out shelf life be
• Free of toxin
• Free of contamination (bacterial)
• Proven nutritious
• Safe for consumption

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Nutrient Content of Pet Food

• Preservatives
• Dry food
• Low moisture inhibits growth
• Canned food
• Heat sterilization and anaerobic conditions
• Semimoist
• Low pH
• Humectants bind water
• Makes unavailable for bacteria
• Chemicals
• Potassium sorbate

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Nutrient Content of Pet Food

• Most important preservative
• Antioxidant preserves fat (animal, plant, ADEK)
• Prevents oxidative degradation (lipid
  peroxidation)
• Three stages
• Initiation
• Free radical (usually oxygen) attacks a PUFA
  resulting in formation of fatty acid radical
• Then reacts with more oxygen to form peroxide
• Propagation
• Autocatlalzes until FAs are gone
• Decomposition
• Offensive odors, tastes
• Loss of calories
• Toxin formation

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Nutrient Content of Pet Food

• Types of antioxidants
• Natural derived
• Found in vegetable oils and some grains
• Vitamin E
• Alpha good biologically
• Gamma, delta better antioxidants
• Vitamin C
• Synthetic
• BHT butylated hydroxytoluene
• BHA - butylated hydroxyanisole
• TBHQ tertiary butylhydroquinine