Fundamentals of Small Animal Nutrition

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Fundamentals of Small Animal Nutrition

• Dr. Randy Ackman
• Vitamins

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Vitamins

• Vitamins
• 1- organic compound different from protein, CHO,
  and fat
• 2- must be component of the diet
• 3- it must be necessary in minute amounts to
  support normal physiologic function
• 4- absence causes a deficiency or syndrome
• 5- must not be synthesized in sufficient
  quantities to support normal physiologic function

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Vitamins

• Vitamer
• Isomer of a vitamin
• May have different if any biologic properties
• i.e. Vitamin E
• Many forms
• a- tocohperol
• Biologically active
• ? tocopherol
• Biologically much less active
• In vitro antioxidant

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Vitamins

• Provitamin
• Compound requires activation step to become
  biologically active
• ß-carotene
• Cleaved twice by enzymes to become retinol

http//arbl.cvmbs.colostate.edu/hbooks/pathphys/mi
sc_topics/vitamina.html
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Vitamins

• Two Categories
• Fat soluble
• Vitamin A
• Vitamin D
• Vitamin E
• Vitamin K

http//oregonstate.edu/instruction/bb450/stryer/ch
08/Slide79.jpg
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Vitamins

• Water soluble
• Thiamin B1
• Riboflavin B2
• Niacin
• Pyridoxine B6
• Pantothenic acid
• Folic Acid
• Cobalamin B12
• Choline
• Biotin
• Vitamin C
• Ascorbic acid

http//oregonstate.edu/instruction/bb450/lectureno
teskevin/enzymesoutline.html
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Vitamins

• AAFCO
• K-9
• 3 fat soluble
• Vitamin K not recognized
• 8 water soluble
• Vitamin C and biotin not recognized

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Vitamins

• Functions
• Cofactors in enzymatic reactions
• DNA synthesis
• Energy release from nutrient substrates
• Bone development
• Calcium homeostasis
• Normal eye function
• Blood clotting
• Free radical scavenging
• Donate an electron
• Amino acid an protein metabolism
• Nerve impulse transduction

http//www.mangosteen-juice.tv/images/free-radical
s.jpg
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Vitamins

• Fat Soluble Vitamins
• Require bile salts
• Passively absorbed
• Duodenum mostly
• Form chylomicrons
• Stored in lipid depots
• Stored in liver too
• Less chance of deficiency
• Greater likelihood of toxicity

http//www.colorado.edu/epob/epob1220lynch/image/f
igure16e.jpg
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Vitamins

• Water soluble vitamin absorption
• Some absorbed passively
• Excreted in urine
• Some absorbed via active transport
• Require carrier pump
• Limited storage
• Less likely to toxicity
• More likely to have deficiency

http//bakerinstitute.vet.cornell.edu/companion_an
imal/dog/CCV.jpg
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Vitamins

• Factors affecting vitamin status
• Anorexia
• Depletes all vitamin stores
• Polyuric diseases
• Depletes water soluble vitamins
• Renal failure
• Vitamin D deficiency, renal tubules conversion
• Antibiotics
• Affect GI flora
• Decrease vitamin K synthesis
• Diuretics
• Same as polyuric states
• Levels of other nutrients
• Required cobalamin related to folic acid,
  methionine and choline are interdependent

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Vitamins

• Vitamin A
• Related compounds
• Retinol
• Retinal
• Retinoic acid
• Bone Growth
• Reproduction
• Maintenance of epithelial tissue
• Rhodopsin formation
• Retinal and opsin
• Visual purple (rods)

http//www-personal.une.edu.au/sglover/CHEM30320
Chapter20120HTML/img036.gif
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Vitamins

• Vitamin A
• Cats lack the enzyme for splitting beta carotene
• Must receive preformed Vitamin A

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Vitamins

• Vitamin D
• Sterol compounds
• Two forms
• Cholecalciferol (D3)
• Can be produced from provitamin
  7-dehyhrocholesterol with uv light
• Animals
• Ergcalciferol (D2)
• Plants

http//www.mja.com.au/public/issues/177_03_050802/
now10763_fig.jpg
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Vitamins

• Vitamin D
• Functions
• Enhance intestinal absorption of calcium
• Stimulates calcium binding protein
• Net activity
• Increase blood calcium and phosphorous

Calcitrol
http//sprojects.mmi.mcgill.ca/nephrology/presenta
tion/images/90no2.gif
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Vitamins

• Vitamin E
• Tocopherols
• a-tocopherol most biological active form
• ? form used in pet food
• Stored in liver
• Potent antioxidant
• Donates electrons to free radicals
• Stops oxidation of fats
• Rancidity
• Prevents peroxidation
• Protects vitamin A

http//cats.med.uvm.edu/cats_teachingmod/family_pr
actice/modules/nutrition/vitamine/freeradical.jpg
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Vitamins

• Vitamin E
• Vitamin E and Selenium
• Selenium cofactor of glutahionine peroxidase
• Prevents formation of peroxides during fat
  metabolism
• Vitamin E
• Spares selenium by preventing the oxidation of
  cell membrane fatty acids

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Vitamins

• Vitamin K
• Quinones
• Vitamin K1 (phyloquinone)
• In green plant naturally
• Vitamin K2 (menaquinone)
• Synthesized by intestinal bacteria
• Vitamin K3 (menadione)
• Synthetic
• 2-3 X activity of natural vitamin K

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Vitamins

• Vitamin K
• Blood clotting
• Liver production of prothrombin
• Liver production of clotting factors VII, IX, X
• Cofactor for enzyme that facilitates binding of
  prothrombin and calcium

http//www.fao.org/DOCREP/004/Y2809E/y2809e06.jpg