Vitamins

Question 1

The conversion of Arachidonic acid into prostaglandins and thromboxanes can be facilitated by which Vit?

Answer 1

Vit E, leading to an alteration of the immune response

Question 2

What are the symptoms related to vit E Deficiency?

Answer 2

Encephalomalacia (crazy chick disease), exudative diathesis, muscular dystrophy, myopathy of the ventricular, increased fragility of the red blood cells

Question 3

What are symptoms of excess of Vit E?

Answer 3

Symptoms associated with deficiencies of other fat-soluble vits

Question 4

Why is Vit K very important?

Answer 4

For the clotting mechanism, functioning as antihemorrhagic

Question 5

Scurvy is caused by a deficiency of which vitamin? And what are the symptoms related?

Answer 5

Deficiency of vit C, characterized by symptoms like joint pain, gum bleeding, skin bruising, and impaired wound healing

Question 6

Is Ascorbic acid necessary for the maintenance of normal collagen
metabolism?

Answer 6

Yes, Vitamin C is an essential cofactor in the hydroxylation of specific amino acids, particularly proline and lysine, during collagen synthesis.

Question 7

Does feed manufacturing improve the bioavailability of the added vitamins?

Answer 7

Yes, manufacturing processes can improve the stability, solubility, and digestibility of added vitamins, making them more bioavailable for the animals that consume the feed.

Question 8

Which vitamin B can be stored in the body tissues in appreciable amounts?

Answer 8

cobalamin (B12)

Question 9

Which food sources give Vit A?

Answer 9

Vitamin A accumulates in the liver and this organ is likely to be a good source
The oils from livers of certain fish
Egg yolk and milk fat

Question 10

Which provitamin/precursor is the main source of vitamin A? And where is it converted?

Answer 10

b-carotene
Conversion of carotene into vitamin A can occur in the liver but usually takes place in the intestinal mucosa
It is apparent from the structure of b-carotene that, theoretically, hydrolysis of one molecule of the C40 compound should yield two molecules of the C20 compound retinol.

Question 11

Which animal specie cannot convert b-carotene in vit A?

Answer 11

Cats do not have the enzyme to convert carotene to vitamin A.
Since their diet comprises meat, which usually contains sufficient vitamin A and low levels of carotenoids, the conversion pathway is redundant

Question 12

What is the importance/role of vitamin A in the body?

Answer 12

• eye, renewing the light sensitivity from the retina
• involved in the formation and protection of epithelial tissues and mucous membranes -> important in growth, reproduction and immune response
• immune system and epithelial integrity
• scavenger of free radicals

Question 13

What are the symptoms of deficiency of Vit A?

Answer 13

night blindness, keratinisation of the skin and cornea, susceptibility to infection and infertility.

In adult cattle, a mild deficiency of vitamin A is associated with roughened hair
and scaly skin.
deficiency may lead to infertility; and in pregnant animals, deficiency may lead to failure of embryo growth, disrupted organ development, abortion, short gestation, retained placenta or the production of dead, weak or blind calves.

Question 14

Why the NRC increased the recommended allowance of vit A for dairy cows?

Answer 14

In recognition of the role of vitamin A in stimulating cell-mediated immunity and in increasing disease resistance and of the potential ruminal destruction of the vitamin with high-concentrate diets

Question 15

Which production type is more prone to vit A deficiency? Pigs reared indoors or outdoors?

Answer 15

Where pigs are reared out of doors and have access to green food, deficiencies are unlikely to occur, except possibly during the winter. However, pigs kept indoors on concentrates may not receive adequate amounts of vitamin A in the diet and supplements may be required.

Question 16

Which are the 2 most important forms of vit D?

Answer 16

The two most important forms are ergocalciferol (D2) and cholecalciferol (D3).

Question 17

Which are the precursors of vit D2 and D3?

Answer 17

ergosterol and 7-dehydrocholesterol, as being precursors of vitamins D2 and D3, respectively.

Question 18

explain the metabolism of Vit D (absorption)

Answer 18

Dietary vitamins D2 and D3 are absorbed from the small intestine and are transported in the blood to the liver, where they are converted into 25-hydroxycholecalciferol. The latter is then transported to the kidney, where it is converted into 1,25-dihydroxycholecalciferol, the most biologically active form of the vitamin.

Question 19

Which specie cannot obtain vit D by exposure to sunlight?

Answer 19

Cats

Question 20

How does vit D plays a role in regulating calcium?

Answer 20

The amount of 1,25-dihydroxycholecalciferol produced by the kidney is controlled by the parathyroid hormone. When the level of calcium in the blood is low (hypocalcaemia), the parathyroid gland is stimulated to secrete more parathyroid hormone, which induces the kidney to produce more 1,25-dihydroxycholecalciferol, which in turn enhances the intestinal absorption of calcium.
In addition to increasing intestinal absorption of calcium, 1,25-dihydroxycholecalciferol increases the absorption of phosphorus from the intestine and also enhances calcium and phosphorus reabsorption from the kidney and bone.

Question 21

what does a deficiency of vit D cause? And what are the symptoms? Which mineral deficiency could cause the same dieases?

Answer 21

young animals: Rickets, a disease of growing bones in which the deposition of calcium and phosphorus is disturbed; as a result, the bones are weak and easily broken and the legs may be bowed.

old animals: osteomalacia, in which there is reabsorption of bone already laid down.

Rickets and osteomalacia can also be caused by lack of calcium or phosphorus, or an imbalance between these two elements.

Question 22

What food are good sources of Vit E?

Answer 22

Green fodders are good sources of a-tocopherol, young grass being a better source than mature herbage. The leaves contain 20–30 times as much vitamin E as the stems.
Cereal grains are also good sources of vitamin E, but the tocopherol composition
varies with species. Wheat and barley grain resemble grass in containing mainly a-tocopherol, but maize contains, in addition to a-tocopherol, appreciable quantities of g-tocopherol.

Question 23

What are the functions of Vit E?

Answer 23

Antioxidant, development and function of immune system *protection against infection
regulation of cell signal and gene expression

Question 24

What is caused by the deficiency of vit E?

Answer 24

• in farm animals is muscle degeneration (myopathy).
• In pigs, the two main diseases associated with vitamin E and selenium deficiency
  are myopathy and cardiac disease.
• In chicks may lead to a number of distinct diseases: myopathy, encephalomalacia, and exudative diathesis
• In horses, vitamin E deficiency results in lameness and muscle rigidity (‘tying up’) associated with skeletal and heart muscles.

Question 25

Explain the metabolism of Vit K

Answer 25

Vitamin K is necessary for the synthesis of prothrombin in the liver. In the bloodclotting process, prothrombin is the inactive precursor of thrombin. Prothrombin normally must bind to calcium ions before it can be activated.

Question 26

What is caused by the deficiency of vit K?

Answer 26

Symptoms of vitamin K deficiency have not been reported in ruminants, horses and pigs under normal conditions, and it is generally considered that bacterial synthesis in the digestive tract supplies sufficient vitamin for the animal’s needs. This is also usually the case with dogs and cats. The symptoms of vitamin K deficiency in chicks are anaemia and a delayed clotting time of the blood; birds are easily injured and may bleed to death.

Question 27

name the vitamins from the complex B

Answer 27

thiamin, riboflavin, nicotinamide, pyridoxine, pantothenic acid, folic acid, biotin, cyanocobalamin

Question 28

Which vitamins can be synthesised by microbial action in the rumen and generally this will provide satisfactory amounts for normal metabolism in the host and secretion of adequate quantities into milk?

Answer 28

Vitamins from the complex B

Question 29

What are the signs of Thiamin deficiency?

Answer 29

Early signs of thiamin deficiency in most species include loss of appetite, emaciation, muscular weakness and a progressive dysfunction of the nervous system.

Question 30

What is happening in the metabolic pathways of an animal fed a thiamin-deficient diet?

Answer 30

On a thiamin-deficient diet, animals accumulate pyruvic acid and its reduction product lactic acid in their tissues, which leads to muscular weakness. Nerve cells are particularly dependent on the utilisation of carbohydrates, and for this reason, a deficiency of the vitamin has a particularly serious effect on nervous tissue. Since acetyl coenzyme A is an important metabolite in the synthesis of fatty acids, lipogenesis is reduced. The pentose phosphate pathway is also impaired by a deficiency of thiamin, but there is little effect on the activity of the citric acid cycle.

Question 31

What is the importance of Riboflavin for the metabolism?

Answer 31

Riboflavin is an important constituent of the flavoproteins. There are several flavoproteins that function in the animal body; they areall concerned with chemical reactions involving the transport of hydrogen. It is also the coenzyme for acyl-CoA dehydrogenase.

Question 32

Which amino acid is a precursor of nicotinamide?

Answer 32

Tryptophan

Question 33

What are the names of 2 important coenzymes from nicotinamide? And what are their functions?

Answer 33

nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). NAD is involved in the oxidative phosphorylation system, the tricarboxylic acid (TCA) cycle and the metabolism of many molecules, including pyruvate, acetate, b-hydroxy-butyrate, glycerol, fatty acids and glutamate; NADPH is the hydrogen acceptor in the pentose phosphate pathway and is involved in the synthesis of fatty acids.

Question 34

In which diet type are pigs and poultry susceptible to nicotinamide deficiency?

Answer 34

Deficiency symptoms are particularly likely in pigs and poultry if diets with a high maize content are used, since maize contains very little of the vitamin, or of tryptophan.

Question 35

What is the importance of pantothenic acids?

Answer 35

Pantothenic acid is a constituent of coenzyme A, which is an important coenzyme in fatty acid oxidation, acetate metabolism, and cholesterol and steroid synthesis.

Question 36

Which substance is present in raw white eggs that lead to biotin deficiency?

Answer 36

Avidin -> prevents de absorption from biotin in the intestines.

Question 37

Which amino acid is a precursor of choline?

Answer 37

methionine

Question 38

what is the important role of choline in lipid metabolism?

Answer 38

It plays an important part in lipid metabolism in the liver, where it converts excess fat into lecithin or increases the utilisation of fatty acids, thereby preventing the accumulation of fat in the liver.

Question 39

Low levels of _______ (mineral) can lead to cobalamin deficiency in ruminants.

Answer 39

Cobalt

Question 40

What are the important roles of Vitamin C?

Answer 40

The vitamin is necessary for the maintenance of normal collagen metabolism. It also plays an important role in the transport of iron ions from transferrin, found in the plasma, to ferritin, which acts as a store of iron in the bone marrow, liver and spleen. As an antioxidant, ascorbic acid works in conjunction with vitamin E in protecting cells against oxidative damage caused by free radicals

Question 41

Which vitamin can be synthesized from tryptophan? Which specie cannot synthesize tryptophan and needs higher amounts of this vit?

Answer 41

Niacin (vit B3). Ducks need 2x the amount than other poultry. The def of niacin in ducks results in bowed legs

Question 42

A lack of cobalt can lead to a deficiency of _____?

Answer 42

Cobalamin (Vit B12)

Question 43

Which Vit is highly stored in the liver of polar bears, seals and walrus? (That if you would eat this liver you could get hypervitaminosis)

Answer 43

Vit A

Question 44

Which vit can be destroyed by high levels of copper, iron, zinc and manganese?

Answer 44

Vit E

Question 45

The deficiency of which vita can lead to: -White muscle disease in ruminants - Toxic liver dystrophy in swine - crazy chicken disease (encephalomalacia) in birds - Steatitis in cats, foxes and mink - Anemia and cardiomyopathy in primates

Answer 45

Vit E deficiency

Question 46

Should biotin and vitamin K be added to food for dogs? And for cats?

Answer 46

For healthy dogs, biotin (Vit B7) and Vit K do not need to be added to the food unless the food contains antimicrobial or anti-vitamin compounds. The same for biotin in cats. For cats fed a high fish diet however, vit K should be supplemented, as it may increase the risk of prolonged coagulation time.