31: trace elements 2

Question 1

briefly descirbe the function of selenium and vit E?

Answer 1

-cellular antioxidants: protect them against damage by products of oxidative metabolism (lipid peroxidases and free radicals)

Question 2

which body tissues are msot susceptible to damage from selenium/vit E deficiency?

Answer 2

ones with high rate of oxidative metbaolism: skeletal, cardiac, resp muscle

Question 3

Answer 3

-dietary antioxidants mainly PUFA, polyunsaturated fatty acids

Question 4

how is the correlation btwn pasture selenium levels & clinical disease?

Answer 4

strong correlation unlike many other trace elements
-selenium isnt stored in the body

Question 5

vitamin E levels in green pastuees?
vitamin E levels post storage?

Answer 5

-high levels in green pastures. rapidly declines during storage

Question 6

main clinical disease/sign of selenium/vit E deficiency?

what does this present like?

Answer 6

nutritional muscular dystrophy/ white muscle disease

Question 7

some other clinical signs of selenium/vit E deficiency? (other than WMD)

Answer 7

Question 8

diagnosis of nutritional muscular dystrophy aka white muscle disease

Answer 8

-msucle damage: creatine kinase, AST
-PM
-selenium status

Question 9

assessment of selenium status?

Answer 9

Question 10

iodone is essesntial for the production of __________

Answer 10

thyroid hormones, esp such as thyroxine

Question 11

secondary iodine deficiency is caused by the intake of _________

Answer 11

goitrogens
(naturally occuring substances that distrupt thyroid hormones)

Question 12

clinical signs of iodine deficiency in calves/lambs?

Answer 12

• abortion, stillbirths
• Weak – high perinatal mortality
• Enlarged thyroid gland (goitre)
• Areas of alopecia & oedema

Question 12

what are the two types of goitrogens?

which can be overcome by additional iodine supplementation?

Answer 12

thiocynate: (can be overcome w additional iodine)

thiouracil

Question 13

diagnosis methods of iodine deficiency?

Answer 13

-soil n pasture levels
-thyroid iodine contents
-thyroid histopathology
-plasma inorganic iodine
-T4