Week 5

Mineral and Vitamin Supplements

Vitamin Supplements

Text Transcript

Follow along with the audio...

• Vitamin A
• Plants do not contain vitamin A; vitamin A activity associated with carotenes
• Beta-carotene
• Carotene with highest vitamin A activity
• Chemically, two molecules of vitamin A
• Figure 10.7 – Chemical structure of beta-carotene



• In animal, converted to vitamin A
• Green plants favorable sources of carotene
  • Alfalfa-based products
• Yellow corn also contains carotene
• Vitamin A produced in animal tissues
  • Concentrated in tissues such as liver and kidneys
• Fish oils favorable sources of vitamin A
• Primary forms of vitamin A
  • Retinol, retinal, and retinoic acid
    • Figure 10.8 – Chemical structure of retinol



• Synthetic sources also available

  • Retinol acetate, propionate, and palmitate common sources
• Supplements added to feed mixture or to liquid supplement and fed
• Figure 10.9 – Vitamin A supplement



• Most probable to present toxicity issues
• Carotenes and vitamin A susceptible to oxidation
• Vitamin A value may be reduced by processing and/or storage
• Antioxidants added to minimize loss of vitamin A
• In general, vitamin A supplements stable
• Units
  • International Units (IU)
    • One IU vitamin A = 0.344 µg retinyl acetate
    • One IU vitamin A = 0.30 µg retinol
    • One IU vitamin A = 0.60 µg beta-carotene
• In general, added to animal rations
• Vitamin D
• Produced via irradiation of sterols in plant and animal tissues
• Primary chemical compounds with vitamin D activity
  • Vitamin D2
    • Ergocalciferol
      • Activated plant sterol
  • Vitamin D3
    • Cholecalciferol
      • Activated animal sterol
  • Four-legged animals convert D2 to D3
  • Poultry cannot efficiently convert D2 to D3
  • For all species, efficiency of utilization greater for D3
  • Vitamin D3 primary form in poultry rations
• Metabolically active form is 1, 25 dihydroxycholecalciferol (1, 25-(OH)2-D3)
  • Calcitriol
  • Synthesized with addition of one hydroxyl group in liver and one in kidney
  • Figure 10.10 – Chemical structure of calcitriol



• Sun-cured forage and fish oils favorable sources

  • Plants possess vitamin D activity after cell death
• Synthetic sources
  • Produced from yeast, plant, or animal sterols irradiated with UV light
    • Irradiated animal sterols and fish products contain D3
    • Irradiated yeast and plant products contain D2
• In mixed feeds, relatively stable
  • Stability influenced by feedstuffs in ration
• Requirement influenced by contents of Ca and P in ration
• Units
  • For poultry, standardized in International Chick Units
  • For other species
    • Expressed as International units
    • One IU vitamin D3 = 0.025 µg cholecalciferol
• In general, added to rations
• Several compounds possess vitamin E activity
• Tocopherols
• Alpha-tocopherol
• Highest vitamin E activity
• Figure 10.11 – Chemical structure of alpha-tocopherol


 

• Germ oils and green plants favorable sources
• Synthetic sources also available
• Figure 10.12 – Vitamin E supplement



• Requirements
• Distress and reproduction
• Presence of Se in ration
• Vitamin E susceptible to oxidation
• Units
  • Expressed in International Units
    • One IU vitamin E = 0.67 µg d-alpha-tocopherol
    • One IU vitamin E = 1 mg dl-alpha-tocopherol acetate
• Vitamin K
• Primary chemical compounds with vitamin K activity
• Vitamin K1, K2, and menadione
  • Figure 10.13 – Chemical structure of menadione

  

• Green plants favorable sources of vitamin K
• Additional feeds with vitamin K are soybeans and various grains
• Vitamin K2 synthesized by microorganisms
• Menadione primary synthetic source of vitamin K
• Ruminants consuming sweet clover or treated with medication may require supplemental vitamin K
• Menadione is reference standard for vitamin K activity
• Units
  • Expressed as mg
• Water-soluble vitamins
• Animal- and fish-based products, green plants, fermentation products, yeast, milk-based products, oilseed meals, and some seed parts favorable sources
• Bran layers fair to moderate sources
• Cobalamine
  • Only water-soluble vitamin not found in plants
  • Yeast and animal- and fish-based products favorable sources of cobalamine