Lecture 14

Question 1

What element is required for the synthesis of Vitamin B12 within ruminants?

Answer 1

Cobalt

Question 2

What is a the best source of Vitamin B12 in the diet?

Answer 2

Liver (except for rumen liver)

Question 3

True/False

“Ruminants are able to synthesise Vitamin B12 in the diet whereas monogastrics are required to consume it preformed”

Answer 3

True

Question 4

True/False

“Cereal grains are very good source of cobalt”

Answer 4

False

Question 5

What is the most distinctive B12 deficiency?

Answer 5

Problems with the synthesis of methionine. This causes poor growth and pool wool production.

Question 6

How can the Vitamin B12 status be assessed?

Answer 6

• Blood Methylmalonic acid (MMA)
• Increased MMA = a lack of mutate activity
• Early indicator of deficiency

Question 7

How can a cobalt/B12 deficiency be treated?

Answer 7

• The use of an injection or a oral drench

- Supplementation of cobalt

Question 8

What breed of dog is malabsorption of Vitamin B12 common in?

Answer 8

Giant Schnauzers

Question 9

Where is Vitamin E commonly stored in the body?

Answer 9

Vitamin E is commonly stored in fatty tissue, liver and muscle.

Question 10

What is the best source of Vitamin E in the diet?

Answer 10

Vegetable Oils

Question 11

How is the stability of Vitamin E reduced?

Answer 11

heat, exposure to sunlight, per-oxidising lipids

Question 12

What is the main function of Vitamin E?

Answer 12

Vitamin E is an anti-oxidant to prevent tissues from perioxidation - it is a free radical scavenger

Question 13

What does an increase in selenium and glutathione peroxidase mean for Vitamin E?

Answer 13

Increase in selenium and glutathione peroxidase act to prevent lipid perioxidation meaning less Vitamin E is needed.

Question 14

What does an increase in PUFA mean for Vitamin E requirements?

Answer 14

Increases the amount of Vitamin E that will be required.

Question 15

What are some common signs that would be observed with a Vitamin E deficiency?

Answer 15

1. Nutritional muscular dystrophy
2. Pancreatitis - yellow fat tissue
3. Reproductive failure
4. De-arrangement of cell permeability

Question 16

What is the function of the selenium?

Answer 16

Selenoenzyme glutathione peroxidase is an antioxidant. Selenium function is linked to Vitamin E.

Question 17

Where are the glutathione peroxidases most active?

Answer 17

These have the highest activities in the liver and the RBC.

Question 18

What are the roles of selenium?

Answer 18

1. Antioxidant
2. Immune function
3. Basal metabolism
4. Reproductive function

Question 19

What are the major dietary sources of selenium?

Answer 19

High concentrations brazil nuts and in fish.

Question 20

What is the relationship of glutathionase peroxidase with Vitamin E?

Answer 20

Vitamin E and glutathionase peroxidase are both anti-oxidants. They both have a mutual ‘sparing’ effect on each other.

Question 21

What are the signs of Vitamin E/Se deficiency and what animals does it normally occur in?

Answer 21

• These normally occur in young, rapidly growing animals

- Deficiencies can be responsive to a combined lack of either of these

Question 22

What are the signs of selenium deficiency in ruminants?

Answer 22

1. Nutritional muscular dystrophy
2. Reproductive disorders
3. Poor growth and wool production
4. Impaired immune responses

Question 23

How is the selenium status assessed in an animal?

Answer 23

Measurement of glutathione peroxidase in the blood

Question 24

When are selenium deficiencies often seen?

Answer 24

Selenium deficiencies are often seen in spring when there is rapid plant growth and rapidly growing animals.

Question 25

When is a Vitamin E deficiency often seen?

Answer 25

Vitamin E deficiencies are often observed over log dry summers (dry feed ).

Question 26

What is a condition seen with a selenium deficiency in horses?

Answer 26

A common condition seen with selenium deficiency is horses is laminitis.