Companion Animal Nutrition
November 5, 2012
M.E. Persia
Iowa State University
4/16/2012
Carnivores
Taxonomy
• Domestic Cat
– Phylum
– Class
– Order
– Family
– Genus
– Species
Animalia
Mammalia
Carnivora
Felidae
Felis
catus
Taxonomy
• Domestic Dog
– Phylum
– Class
– Order
– Family
– Genus
– Species
Animalia
Mammalia
Carnivora
Canidae
Canis (wolves, coyotes,jackels)
(Vulpes = foxes)
familiaris
Domestication
• Dog (15,000 years ago)
– Genetic lineage
• Fox-like canids (Arctic fox, red fox, raccoon dog, bat-eared
fox)
• South American canids (Crab-eating fox, maned wolf, bush
dog)
• Wolf-like canids (jackals, gray wolf, dogs, African hunting
dog)
• Cat (12 – 15,000 years ago)
– 15,000 years ago (Mediterranean)
– European wildcat (Felis sylvestris)
44 Essential Nutrients
Carbohydrate
Metabolism
Protein
Metabolism
• Nutrigenomics – effects of nutrients on
gene expression.
• Known genomes
• Nutrients influence gene expression
• mRNA production (transcription)
• mRNA processing
• Protein production (translation)
• Post-translational modifications
Those directly impact the metabolic
status of the animal.
Fat
Metabolism
Urea Cycle
How then did domestication alter
nutrient needs of dogs and why are
their needs different than wolves?
The Petfood Industry
Historical Timeline
James Spratt = “Spratt Cakes”
1866
FH Bennett = Milk Bone
1908
20’s and 30’s
Canned
Oatmeal and Cornflakes
Pelleting
40’s and 50’s
World War II Rationing
“Dog’s Need Meat”
B12 deficiency
1954 1st Extrusion
The Petfood Industry
Historical Timeline
50’s and 60’s
Began a societal shift
toward
Pets as family
Companion animal
research
70’s and 80’s
Therapeutic and clinical
diets
1990’s to present
Holistic, natural, and
organic diets
Raw diets
Nutrigenomics
Petfood Myths
• #1 pet-foods are not regulated
– False
– Heavily regulated and inspected
– Agencies involved in Petfood industry
• FDA, USDA, DHS, CDC, EPA, FTC, AAFCO
– US Marshals
• FDA audits companies for vendor documents
• AAFCO (Association of American Feed Control Officials) –
operates through state level bills with individual state health
and agricultural agencies.
• Recalls – melamine…what went wrong?
Feeding Commercial Diets
• Good news
–
–
–
–
–
Commercial diets must supply analytical compositions
Regulated by FDA
Nutrients must meet or exceed requirements (NRC, AAFCO)
Monitored and recalled
Big companies have some advantages
• Bad news
–
–
–
–
Not required to test regularly
Quantity has nothing to do with quality
Feed companies can change their formulas
Requirements are published in a different unit than analyses on
the product
– Ingredient consistency
AAFCO Statements
• “…formulated to meet the nutritional levels
established by the AAFCO dog (cat) food
nutrient profiles for all life stages”.
– Adequacy statement
• “…intended for intermittent or supplemental
feeding only”
– Not an adequacy statement
Processing
• Extruded
– 10 – 12% moisture; must contain significant carbohydrate.
– Higher in starch and lower in fats and proteins than canned.
• Canned
– 70 – 80% moisture; contain higher concentrations of fat and protein,
meats.
– Retort process – heat and pressure cooking after the can has been
filled and sealed. Doesn’t have to be just cans.
•
•
•
•
•
•
Pelleted
Semi-Moist
Expanded
Dehydrated
Baked
Canned
Major Processing Considerations
• Starch-Lipid complexes
• Maillard reactions
• Fat concentrations – majority of fat must be
added/sprayed on after extrusion
• Nutrient losses
– Thiamin - > 70% is lost to heat
Ingredients Used: Proteins
• Protein Sources
– Meats (turkey, chicken, etc…)
• clean flesh and skin with or without bone - exclusive of feathers,
heads, feet, and entrails.
– Meat meals (chicken meal)
• Dry, rendered (cooked down) product from clean flesh and skin…
– By products (chicken by-products)
• rendered, clean parts of the carcass of slaughtered chicken, such
as heads, feet, viscera, etc…
– By product meal (poultry by product meal)
• ground, rendered, clean parts of the carcasses of slaughtered
poultry…
– Plant proteins
• Soy bean meal
• Corn gluten meal
Proteins as Ingredients
• Rendering reduces digestibility and protein
quality of meats (more with poultry than
other meats).
• Species rendered products have higher
protein quality than unidentified species
(chicken meal is better than poultry meal) –
although some differences are minor.
Ingredients used: Carbs
• Meals
– (Corn) = entire corn kernel, finely ground
• Grits, midds, mill run =
– Are coarsely ground grains from which the bran and
germ have been removed, usually screened to
uniform particle size.
• Flour
– (Corn) Fine sized hard flinty portions of ground corn
containing little or none of the bran or germ, highly
processed. (wheat or rice flour).
Understanding the Guaranteed Analysis
Nutrient
As Fed Basis
Moisture, %
Dry matter, %
Protein, %
Fat, %
Fiber, %
Protein: fat
78.0
8.0 (8/.22) =
5.0
1.0
Dry Matter
22.0
36.4
22.7
4.5
1.6
Understanding the Guaranteed Analysis
Nutrient
As Fed Basis Dry Matter
Moisture, %
Dry matter, %
Protein, %
Fat, %
Fiber, %
Ash
Protein: fat
11.0
22.0
12.0
4.0
8.0
8.0
(22/.89)
=
89.0
24.7
13.5
4.5
8.9
1.8
Some guidelines
• High quality proteins as top 2
– Fresh meat should be followed by a
meal (Chicken, chicken meal…)
• Know the species
• Fractions are OK
– Watch for splitting, location on list
• Select for a Protein to Fat ratio of 1.5 – 2.0
What is splitting
• Venison meal, dried potatoes, potato starch,
potato protein, pea protein, sunflower oil
venison meal
dried potato
potato starch
potato protein
pea protein
Where do you find nutrient requirements?
• NRC for Domestic Cat (National Research Council)
– National Academies
• www.nap.edu = $265.50
• AAFCO (Association of American Feed Control
Officials)
– www. aafco.org = $50.00
NRC Presentation of Requirements
• Requirements expressed relative to ME rather than DM.
– ME determines the amount of food consumed.
– If energy density of the diet changes, nutrients don’t change if
expressed on an ME basis.
– 4,000 Kcal per Kg.
• Requirements based on body weight:
– 15 Kg dog consuming 1,000 Kcal daily = maintenance
– 5.5 Kg puppy consuming 1,000 Kcal daily = growth
– 22 Kg lactating female with 8 puppies consuming 5,000 Kcal
daily = lactation
– Expressed as a factor of Metabolic Body Weight (MBW):
• BWKg 0.75 for dogs
• BWKg 0.67 for cats
Why basing on ME is more ideal
Energy Density of Diet,
(Kcal of ME per Kg)
To consume 240 Kcal
4,000
3,000
Amount feed to meet energy (g)
60
80
If nutrient density is the same 0.008 g/g food
0.48
0.64
Adjusted nutrient concentration (g)
0.008
0.006
Nutrient requirement 0.48 g/day
To correct when you don’t have a 4,000 Kcal diet:
(Nutrient requirement x Kcal in the diet) / 4,000 = adjusted requirement
Canine Nutrient Recommended Allowances - Puppies
(2006, NRC)
Nutrient
Amt/Kg DM
(4000 Kcal)
Amt/1,000
Kcal
Amt/MBW
Protein (g)
Fat (g)
Vitamin A, (RE)
Vitamin D (ug)
Vitamin E (mg)
Calcium (g)
Phosphorus (g)
175
85
1,515
13.8
30
12
10
43.8
21.3
379
3.4
7.5
3
2.5
12.2
5.9
105
0.96
2.1
0.68
0.68
Feline Nutrient Recommended Allowances
(2006, NRC)
Nutrient
Amt/Kg DM
(4000 Kcal)
Amt/1,000
Kcal
Amt/MBW
Protein (g)
Fat (g)
Vitamin A, (RE)
Vitamin D (ug)
Vitamin E (mg)
Calcium (g)
Phosphorus (g)
Taurine (g)
200
90
1,000
7
38
2.9
2.6
0.40
50
22.5
250
1.75
10
0.72
0.64
0.10
4.96
2.2
24.7
0.17
0.94
0.071
0.063
0.010
CARNIVORE IDIOSYNCRACIES
Skeletal Adaptations
• Fused wrist bones
– absorbs shock of
running
• Short collarbone
– increased mobility and longer stride
• Flexible spine
• Felids have retractile
claws
Digestive Anatomy and Physiology
Digestive Tract
• Short digestive tract
– 4 meters (human = 8 – 9 meters)
– Ratio of body length to intestine:
•
•
•
•
Human = 1:10
Dog = 1:6
Cat = 1:4
Horse = 1:12
• Stomach
– Low pH (increased water intake lowers pH)
– Pepsin (most active with ingestion of collagen)
– Lipase
Sagawa et al., 2009; Reece, 2006; NRC, 2006
Advantages to short digestive tract
• Rapid digestion and absorption of proteins and
fats
• Very fast passage rate
– Microbes quickly pass
• Ability to eat raw diets and whole prey
• Low capacity for fermentation
– Few putrefactive compounds produced
– Limited ability to digest complex carbohydrates
• Starch needs to be cooked for use as a viable carbohydrate
source!
CATS
• High protein requirement
• Specific requirement for amino acids:
– Arginine
– Taurine
– Phenylalanine
and tyrosine
(black cats)
•
•
•
•
Arachidonic Acid
Vitamin A
Vitamin D
Inability to convert tryptophan to niacin
Requirements for Protein
• Obligate or True carnivores
– Protein requirements for cats are 2-5
times greater than omnivores.
• Cat NRC 2006 protein = 50 g/1000 kcal
• Dog NRC 2006 protein = 25 g/1000 kcal
Protein Metabolism – The Urea Cycle
Cats can not down regulate this cycle. It moves at a constant rate, always breaking down
protein to supply the nitrogen to the urea cycle.
NH 3+
Urea
Ornithine
Citrulline
Arginine
Arginosuccinate
– When we eat a high protein diet:
• High liver metabolic enzyme activity
• High amino acid breakdown
• High nitrogen disposal
• High rate of gluconeogenesis
• Advantage of this metabolic adaptation:
Catabolize excess amino acids and
remove excess nitrogenous wastes
Black Cats
phenylalanine
• Higher requirement for
– Phenylalanine
– Tyrosine
• Black color is determined by
the proportion of Eumelanin
(black pigment) to
Pheomelanin
(red-brown pigment)
• Requirement of 3.8 g/1,000 kcal
• Anderson et al. J.Nutr.132:
2037-2042, 2002
Why taurine?
• What is taurine?
– Free amino acid found in
tissues
Cysteine
Pyruvate
• Where is it found?
– Heart (myocardium)
• Dilated cardiomyopathy
– Eye (retina)
• Feline central retinal
degeneration
– Requirement
(2006, NRC) = 1.7 g/kg
Taurine
Arachidonic acid
• What is it?
– Fatty acid
– Requirement = 0.015 g/1,000 kcal
– Synthesized from linoleic acid
• Deficiency of arachidonic acid
– Poor growth, hair loss, rough hair
coat, poor immunity, slow healing,
skin lesions, fatty livers.
Vitamins (A, D)
• Most mammals synthesize or convert
compounds to active forms of vitamins A, D,
and niacin.
– Vitamin D conversion in skin.
– Carotenoid conversion to A.
• Very high concentrations of A in liver.
Diet Decisions and Alternatives
•
•
•
•
Commercial Diets
Whole prey
Raw
Mixed?
Whole Prey:
Where do nutrients come from
Hides, fur, hooves, connective Muscle = protein (amino
tissue = provide minerals
acids), fat (fatty acids),
(Zn); fiber; dental health,
energy
natural glucosamine
Blood = protein, fat, energy,
vitamins (heart), water
Organs = vitamins (A, D),
protein, fat, energy, taurine,
carbohydrates, fiber
Bones = Minerals (calcium;
dental health)
Whole Prey Nutrients
Item
Dry matter
Raw
diet
39.0
Rat
Deer
30.2
Pig
36.9
28.9
---------------% DM-------------Organic Matter, %
94.8
89.3
86.2
88.1
Crude Protein, %
47.1
52.9
57.0
50.7
Fat, %
30.4
28.0
24.5
33.2
GE, kcal/g
6.5
5.9
5.6
5.8
Protein: Fat
1.5
1.9
2.3
1.5
Dierenfeld, 2002; Morris 2011 (unpublished lab data)
Biological Research:
Comparison of Organic Matter digestibility (%) of chicken
based diets in African wildcats and domestic cats
93.61
94.11
A.wildcats
domestic
87.8
87.32
86.02
85.69
85.12
83.29
Canned
Kibble
Raw Ground
Whole Prey
Nutrient Digestibility of extruded, raw, and cooked beef based
diets in domestic cats
Item
Extruded
Raw
Cooked
DM, %
78.2
86.7
83.8
OM, %
83.9
90.5
88.5
Protein, %
81.6
93.3
92.9
Fat, %
91.3
95.5
95.3
Energy, %
84.7
91.5
89.8
Mineral Considerations
• Ca:P ratio imbalance (aim for 1:1 - 2:1)
• Whole prey
– Rat - whole
– Chick - whole
– Fish
1.4:1
1.5:1
1.8:1
• Muscle meats
– Beef
– Bison
– Elk
1:17
1:12
1:25
• Organ meats
– Liver (beef)
– Spleen
– Heart
1:77
1:33
1:30