Vitamin B1

Question 1

What is the name of vitamin B1?

Answer 1

Thiamine

Question 2

What is thiamine important for?

Answer 2

it is a required cofactor of the enzyme that converts pyruvate to acetyl-coA

Question 3

What are common sources of thiamine?

Answer 3

yeast and meat and in the outer hull and germ of grain

Question 4

What can destroy thiamine?

Answer 4

heating it, pelleting, canning, sulfites and thiaminases

Question 5

What does refining grains do to thiamine?

Answer 5

it removes it

Question 6

What is a synthetic source of thiamine that can be added to diets?

Answer 6

thiamine HCL

Question 7

What can cause thiamine deficiency in animals?

Answer 7

it can occur due to inadequate amounts of thiamine in the diet, or due to thiaminases in feed that destroy it or convert it into anti-vitamin

Question 8

What does thiaminase 1 do to thiamine?

Answer 8

it cleaves the thiazole ring and destroys the biological activity of it

Question 9

What does thiaminase 2 do to thiamine?

Answer 9

it substitutes nicotinic acidfor the thiazole ring rendering it unable to be phosphorylated to make TPP

Question 10

What is thiaminase 3?

Answer 10

oxythiamine

Question 11

What does thiaminase 3 do?

Answer 11

it substitutes a hydroxyl group for the amino group on the pyrimidine ring

Question 12

What is oxythiamine and what does it do?

Answer 12

a potent anti-vitamin and effectively out-competes normal thiamine for the binding sites of thiamine dependent enzymes

Question 13

What are some clinical signs of thiamine deficiency?

Answer 13

neuritis, poor energy conversion, cardiomegaly

Question 14

What are some neurological signs that an animal is thiamine deficient?

Answer 14

uncoordinated gait and opisthotonus

Question 15

What does poor energy conversion in thiamine deficient animals lead to?

Answer 15

poor growth and poor nerve function

Question 16

What type of thiaminase is bracken fern poisoning?

Answer 16

thiaminase type 1

Question 17

What species does bracken fern poisoning affect?

Answer 17

the horse

Question 18

What does bracken fern poisoning cause?

Answer 18

scruffy physical appearance, weight loss, uncoordinated movements

Question 19

What is opisthotonus?

Answer 19

the spasming of muscles causing the severe arching of the neck, back, and spine due to thiamine deficiency

Question 20

What is cardiomegaly?

Answer 20

the abnormal enlargement of the heart due to thiamine deficiency

Question 21

What species does Chastek paralysis affect?

Answer 21

the fox, marine mammals, the mink, and the cat

Question 22

What is Chastek paralysis cased by?

Answer 22

eating a diet that contains RAW bullhead, herring, whitefish, and carp that contain high thiaminase activity

Question 23

What are symptoms of Chastek paralysis?

Answer 23

animals walk stiff-legged initially, then they have spastic convulsions, paralysis, and death

Question 24

What is polioencephalomalacia?

Answer 24

a thiamine deficiency in ruminants caused by rumen bacteria that produce thiaminases

Question 25

What can lead to an increase in thiaminase production by rumen bacteria?

Answer 25

when the ruminants are under acidotic conditions or when beef animals are on very high grain finishing diets

Question 26

What are symptoms of polioencephalomalacia?

Answer 26

energy starved tissues, necrosis of glial cells and cortical neurons, medial strabismus, cortical blindness, hyperesthesia, recumbancy and death

Question 27

What is amprolium?

Answer 27

a coccidiostat used in calves, lambs, poultry, and dogs to control Eimeria or Isospora

Question 28

What does amprolium do?

Answer 28

mimic thiamine structure to inhibit utilization by the paraside

Question 29

What does prolonged amprolium use cause?

Answer 29

thiamine deficiency