Microminerals

Question 1

copper biological function

Answer 1

-needed for enzymes associated with iron metabolisms
-component of superoxide disumate SOD
-required for hemopoiesis
-elastin and collagen formation
-melanin and other pigment formation
-keratin disulfide bond
-absorption of Fe in SI

Question 2

copper absorption and metabolism

Answer 2

-Cu+2 more readily absorbed than Cu+1
absorption in SI, not energy dependent,
-organic acids and metalothioneine increased absorption
-liver main storage organ
-in ruminants, presence of Mo and S reduces Cu absorption through formation of tetrayhiomolybdate which is excreted in feces, may protect against copper toxicity
-Zn and phytic acid antagonists

Question 3

copper natural forms

Answer 3

found in blood in three forms
-loosely bound to albumin
-firmly bound to ceruplasmin
-plasma amino acids

Question 4

copper deficiency

Answer 4

anemia, poor bone formation, neonatal ataxia (swayback), reduced immunity, steely wool in sheep

Question 5

copper toxicosis

Answer 5

-large species difference
-in swine, 250ppm stimulates growth and feed efficiency
-copper has antimicrobial effect

Question 6

minimum toxic dose of copper in cattle, poultry, sheep

Answer 6

cattle 50-80ppm
poultry >400ppm
sheep 20-25ppm

Question 7

how to determine copper status of a ruminan

Answer 7

blood samples inaccurate, liver keeps blood levels steady until its an emergency
-only good test is liver biopsy

Question 8

zinc distribution

Answer 8

liver, kidney, muscle, bone, pancreas, spleen, skin, wool/hair

Question 9

zinc biological function

Answer 9

-component of enzyme systems (carbonic anhydrase, carboxypeptidase, dehydrogenases, alkaline phosphatase, ribonucleases and DNA polymerases)
-component of insulin
-required for nucleic acid and protein synthesis

Question 10

zinc absorption and metabolism

Answer 10

-absorption in SI and across rumen
-carrier mediated
-presence of small ligands (kelates) enhance uptake
-once absorbed, abbed to zinc pool within cell
-storage form of metalothionine (appears to be a detoxification agent)
-transported throughout body in albumin
-low body stores, most in liver
-primary secretion via feces
-high Ca and phytic acid depresses Zn absorption

Question 11

zinc deficiency

Answer 11

geographically deficiency
excessive alcohol intake
vegetarian diet (phytic acid)
-reduced growth, anorexia, parakeratosis (erosion of skin from extremities), slowed bone formation, effects male repro organs, delayed wound healing, decreased glucose tolerance

Question 12

zinc toxicosis

Answer 12

1000ppm
gastric distress, diarrhea, weight loss, death

Question 13

iodine biological function

Answer 13

-component of thyroxin (T4) and triiodothyronine (T3) which are produced by thyroid (higher bio activity)
-T4 controls basal metabolic rate

Question 14

iodine absorption and metabolism

Answer 14

majority absorption in stomach and entire GIT (very effective)
can be absorbed through skin
excreted in urine

Question 15

iodine deficiency

Answer 15

goiter, lowered metabolic rate, cretinism, myxedema (hard edema), poor growth and reproduction
-goitrogens are compounds that bind iodine

Question 16

iodine toxicosis

Answer 16

inhibits thyroxine release and mimics deficiency symptoms