18 – Minerals and Vitamins Conclusion

Question 1

Chromium (Cr)

Answer 1

• Involved with CHO, lipid, protein and nucleic acid metabolism
• Cofactor with insulin
  o Known to promote insulin activity and enhance CHO metabolism in pigs

Question 2

Insulin effects

Answer 2

• Promotes anabolic processes (molecule assembly)
• Inhibits catabolic processes
• *net effect: promoting protein synthesis (muscle growth) while inhibiting fat deposition

Question 3

Cr utilization depends on its form

Answer 3

• Valence: Cr 3+ is utilized, Cr 6+ is NOT
• Chemical form: organic Cr is used, inorganic is not

Question 4

What is chromodulin composed of?

Answer 4

• 4 types of AA residues
  o Glycine
  o Cysteine
  o Glutamate
  o Aspartate
  o (nicotinic acid)

Question 5

Chromodulin

Answer 5

• *an intracellular low molecular weight chromium-binding protein
• Binds 4 chromium ions for maximal activity
• *potentiates insulin activity w/o changing insulin concentration

Question 6

Cr and pig production

Answer 6

• Cr supplemented pigs had
  o Better feed conversion
  o Increased carcass traits (increase carcass lean, increased loin muscle area, reduced tenth rib backfat thickness)

Question 7

Chromium sources

Answer 7

• Inorganic Cr: not well absorbed from SI
• *absorption is higher for chelated Cr
  o Sources: chromium picolinate, chromium yeast

Question 8

Vitamin A

Answer 8

• Fat soluble vitamin
• Retinol, retinal, retinoic acid (found in animal productions
• Provitamin A: carotenoids

Question 9

Provitamin A: carotenoids

Answer 9

• Found in plant products
• Used to produce orange flesh in cultured salmonids

Question 10

What are the 4 forms of vitamin A?

Answer 10

1. Retinol
2. Retinal
3. Retinoic acid
4. Plants vitamin A=carotenoid (provitamin)

Question 11

Retinol

Answer 11

• Convert to other forms or storage as retinyl esters form

Question 12

Retinal

Answer 12

• Chemical basis of animal vision

Question 13

Retinoic acid

Answer 13

• Metabolite of retinol
• Requirement for growth and development for all vertebrates
  o Embryo development, cellular differentiation, gene expression

Question 14

What are vit A requirements defined in?

Answer 14

• Retinol equivalents (RE)
• 1 RE=1 microgram of all-trans retinol

Question 15

Bioavailability of carotenoids

Answer 15

• Pigs are less efficient in converting carotenoids into usable Vit A than poultry
• Vit A and carotenes are transported across the gut epithelium the SAME as fatty acids=PASSIVE DIFFUSION
• In epithelial cell, carotenes are converted to retinol

Question 16

What are some functions of Vit A?

Answer 16

• Vision
• Immunity
• Bone health
• Gene regulation

Question 17

Vision: Vit A

Answer 17

• Retinal needed for rhodopsin function in rods

Question 18

Immunity: Vit A

Answer 18

• Maintains normal skin health by switching on genes and differentiating immature skin cells (keratinocytes) into mature epidermal cells
• Maintains lymphocytes and myelocytes

Question 19

Bone health: Vit A

Answer 19

• Optimal retinoic acids levels are needed to maintain balance between osteoblast and osteoclast activity

Question 20

Gene regulation: Vit A

Answer 20

• Retinoic acid regulates expression of RXR target genes
• Hox genes also affected that control anterior-posterior axis in early embryo stage
• *Birth defects: both vit A deficiency and excess

Question 21

Vit A deficiency

Answer 21

• Classic=night blindness
• Epithelial keratinization, mucosal membrane atrophy
• Low conception rate and libido
• Decreased immunity
• Generally causes reduced feed intake and growth

Question 22

Vit A toxicity

Answer 22

• Most toxic vitamin
• *when at 10x requirement
• Developmental deformities
• Skeletal deformation and fractures in adults
• Peeling skin
• Increased intracranial pressure
• Hyper-irritability
• Convulsions
• Death
• *bear and seal livers=extremely high in Vit A

Question 23

Carotenoids toxicity

Answer 23

• Less toxic, but can lead to yellow-orange skin if carrots or other high carotenoid foods eaten