Selenium & Molybdenum

Question 1

early work on selenium was concerned with its toxic effect on what kind of animals?

Answer 1

grazing

Question 2

In 1935 at the S. Dakota Expt. Station it was first demonstrated that selenium was the toxic factor in the forage which causes what disease

Answer 2

“alkali disease” or “blind staggers”

Question 3

In certain areas which have Se deficient soils (where most grains and forages are low in Se) a disease of calves and lambs known as _____ ______ ______ occurs frequently

Answer 3

White muscle disease

Question 4

addition of how much Se in the ration of the dam has been successful in preventing white muscle disease

Answer 4

0.1 ppm

Question 5

4 consequences of Se deficiency

Answer 5

1) INcrease mortality of newborn lambs and calves
2) white muscle disease in lambs and calves
3) exudate
4) liver necrosis in rats - also prevented by vit. E

Question 6

____ is a component of the enzme glutathione peroxidase that eliminates the peroxides which oxidize other components which cause damage

Answer 6

Se

Question 7

Se protects the body from peroxides in

Answer 7

cytoplasm

Question 8

Se is readily absorbed in the _________ ________ and transported in the plasma to all parts of the body

Answer 8

anterior duodenum

Question 9

Se is primarily stored in the _____ & _______

Answer 9

liver and kidneys

Question 10

Se is excreted via

Answer 10

urine>feces>expired air

Question 11

animals containing high concentrations of Se also lose some in ___ and _____

Answer 11

hair and hoofs

Question 12

Consequences of selenium toxicity

Answer 12

hair loss: mane & tail in horses; tail in cattle; general hair loss in swine.
hoofs slough off, lameness occurs, feed consumption decreases and eventual death from starvation occurs.

Question 13

what levels must be reached for acute Se toxicity

Answer 13

500 ppm

Question 14

any soil containing more than ___ Se are potentially dangerous

Answer 14

0.5 ppm

Question 15

Where is Molybdenum distributed

Answer 15

throughout the body, with the concentration varying among the different tissues

Question 16

like Se, molybdenum is primarily known for its toxic effects to

Answer 16

grazing animals of certain areas of the world

Question 17

the essentiality of Mo is largely ascribed to its cofactor role for ____ _____ and _____ _____

Answer 17

xanthine oxidase and aldehyde oxidase

Question 18

a metalloflavoprotein enzyme that is essential in purine metabolism

Answer 18

xanthine oxidase

Question 19

Mo is a possible nutritional role in the growth of lambs via

Answer 19

potential stimulatory effects on rumen microbes

Question 20

Mo is necessary in the nitrate reductase system to convert

Answer 20

nitrates to nitrites in plants

Question 21

if the reduction of nitrates to nitrites does not occur we can get ___ ___ from the plants when fed to animals

Answer 21

nitrate toxicity

Question 22

Mo is readily absorbed from the

Answer 22

digestive tract

Question 23

excessive dietary sulfate reduces

Answer 23

Mo absorbability

Question 24

Mo is primarily excreted through the

Answer 24

Kidneys

Question 25

disease characterized by severe scouring (diarrhea) and loss of condition in cattle confined to these pastures

Answer 25

teartness

Question 26

Animals affected by Molybdenum toxicity

Answer 26

cattle > sheep , horses not effected

Question 27

Tolerance of animal species to Mo: 
ruminants 
chicks
rabbits
horses

Answer 27

toxic level of Mo, ppm
R: 10
C: 300
Rab: 500
H: >1000

Question 28

3 things tolerance of Molybdenum is affected by

Answer 28

1. chemical form of molybdenum
2. copper status and copper intake of the animal
3. level ofintake of other metals, including Zn and Pb

Question 29

Se deficiency areas are predominately

Answer 29

pacific NW, the NE and along the SE seaboard

Question 30

*** Se toxicity is more likely in what state? Florida or South Dakota?

Answer 30

South Dakota