Minerals

Question 1

What are the minerals functions classification? Give examples

Answer 1

catalytic: Some mineral elements are firmly bound to the proteins of enzymes , while others are present in prosthetic groups in the chelated form in metalloprotein complexes. Examples of naturally occurring chelates are the chlorophyll, cytochromes, haemoglobin and vitamin B12.

physiological/eletrochemical: Na, K and Cl are concerned with the maintenance of acid-base balance, membrane permeability and the osmotic control of water distribution within the body.

Structural: Ca and P are essential components of the skeleton and sulphur is necessary for the synthesis of structural proteins.

regulatory function in controlling cell replication and differentiation: Zn acts in this way by influencing the transcription process, in which genetic information in the nucleotide sequence of DNA is transferred to that of an RNA molecule.

Question 2

Give some examples on ways that the minerals can interact

Answer 2

• formation of unabsorbable compounds,
• competition for metabolic pathways
• induction of metal-binding proteins.

Question 3

Which mineral form has, theoretically, higher absorbability: organic (chelated) or inorganic?

Answer 3

organic

Question 4

What can improve the palatability of mineral feed blocks in animals at pasture?

Answer 4

inclusion of oil or molasses

Question 5

How can a farmer increase the amount of trace elements in the pasture?

Answer 5

Spraying the pasture with soluble salts of trace elements can increase the element
content of the pasture. Alternatively, trace elements can be included in fertilisers in
order to increase the herbage content via the soil. However, if the deficiency is due
to poor availability of the element, then this type of application will not be successful.

Question 6

how can the dietary electrolyte balance be checked in the diets of pigs and poultry?

Answer 6

Dietary influence in this respect may be assessed by measuring the dietary electrolyte balance, defined as:
Na+ + K+ - Cl
where Na+, K+ and Cl- are the concentrations of the elements in mequiv per unit weight

Question 7

Ideally, other elements making a contribution to electrolyte balance should
be considered and a more sophisticated assessment may be achieved by calculating (Na+ + K+ + Ca++ + Mg++) - (Cl- + H2PO4 - + HPO4 - - + SO4- -). What is the terminology of such assessment?

Answer 7

dietary undetermined anion

Question 8

Why is the manipulation of the cation–anion difference recommended as part of the dietary management of dairy cows?

Answer 8

It is recommended in order to avoid hypocalcaemia or milk fever

Question 9

What is the role of the metabolic acid-base balance in the pth and synthesis of 1,25-dihydroxycholecalciferol?

Answer 9

Conditions that promote an alkalotic state (high dietary cations, Na+ and K+) reduce the sensitivity of bone to PTH and can limit the release of calcium. Conversely, an acidotic state (high dietary anions, Cl- and S- - ) increases the sensitivity to PTH, increases 1,25-dihydroxycholecalciferol production and hence increases the calcium supply from the bones and diet.

Question 10

What is the terminology of these equations? An what are they used for? (Na+ + K+) - (Cl- + SO4
- -) or (Na+ + K+) - (Cl- + S- -)

Answer 10

dietary cation–anion difference
(DCAD) is used when calculating and manipulating the acid–base balance of the diet.

Question 11

What is milk fever? What can be done to prevent is (diet)?

Answer 11

Milk fever, also known as hypocalcemia or parturient paresis, is a metabolic disorder that affects lactating mammals, including cows, goats, and sheep. It occurs shortly before or after giving birth when there is a sudden drop in blood calcium levels.

During pregnancy, the demand for calcium increases as the developing fetus requires it for bone growth. When the animal gives birth, there is a rapid onset of milk production, which further depletes calcium levels. The parathyroid gland is unable to
respond rapidly enough to increase calcium absorption from the intestine to meet
the extra demand.

In practice, manipulation of the diet involves minimising foods high in potassium and sodium. Grass silage is the major problem, often containing 30–40 g potassium/kg DM, and alkali-treated grain and molasses should also be avoided. The cereal by-product, brewer’s grains, is a food that is low in sodium and potassium. Unlike the low-calcium diet strategy, the DCAD strategy requires a moderate-to-high calcium intake to be maintained. Supplementary anionic salts (e.g. ammonium chloride, ammonium sulphate, magnesium chloride, calcium chloride) can be used to adjust the DCAD, but they tend to be unpalatable. It is recommended that
the diets are given for at least two weeks but no more than four weeks before calving.

Question 12

Which gland controls the resorption of Ca? And how does it work?

Answer 12

The resorption of calcium is controlled by the action of the parathyroid gland. If animals are fed on a low-calcium diet, the ionic calcium concentration in the extracellular fluid falls, the parathyroid gland is stimulated and the hormone produced causes resorption of bone, liberating calcium to meet the requirements of the animal. Since calcium is combined with phosphorus in bone, the phosphorus is also liberated and excreted by the animal.

The PTH also plays an important role in regulating the amount of calcium absorbed from the intestine by influencing the production of 1,25-dihydroxycholecalciferol, a derivative of vitamin D, which is concerned with the formation of calcium-binding protein (see p. 80). Finally, the hormone stimulates
the kidney to resorb urinary calcium.

Question 13

What condition is caused by low Ca/P/ vit D or abnormal Ca:P raito in the diet of young and adult animals?

Answer 13

Rickets (young) and osteomalacia (adults)

Question 14

How is the excess of phosphorous excreted in monogastric and ruminants?

Answer 14

The excess is excreted via the kidney or the gut (via saliva). In monogastric animals, the
kidney is the primary route of excretion. Plasma phosphorus diffuses into saliva, and in ruminants the large amount of chewing during rumination results in saliva being the major input of phosphorus into the rumen rather than the food itself.

Question 15

what are the main roles of potassium in the body?

Answer 15

Potassium plays an important part in nerve and muscle excitability and is also involved in carbohydrate metabolism. Also, osmotic regulation of the body fluids and in the acid–base balance in the animal

Question 16

what are the main roles of sodium in the body?

Answer 16

• transmission of nerve impulses and in the absorption of sugars and amino acids from the digestive tract
• acid–base balance and osmotic regulation
  of the body fluids.
• is the chief cation of blood plasma and other extracellular fluids of the body

Question 17

What does sodium deficiency cause?

Answer 17

lowering of the osmotic pressure, which results in dehydration of the body.
- poor growth and reduced utilisation
of digested proteins and energy

Question 18

what are the main roles of chlorine in the body?

Answer 18

• osmotic regulation
• importance in the gastric secretion,
  where it occurs as hydrochloric acid as well as chloride salts.

Question 19

What does chlorine deficiency cause?

Answer 19

Abnormal increase of the alkali reserve of the blood (alkalosis) caused by an excess of bicarbonate
- retarded growth

Question 20

Where can you find most of the sulphur in the animal body?

Answer 20

Most of the sulphur in the animal body occurs in proteins containing the amino acids cystine, cysteine and methionine. The two vitamins biotin and thiamin, the hormone insulin and the important metabolite coenzyme A also contain sulphur.
Sulphur-containing compounds are also important in elements of the respiratory process, from haemoglobin through to cytochrome
Only a small amount of sulphur is present in the body in inorganic form

Question 21

Which condition is associated with low Mg in ruminants?

Answer 21

hypomagnesaemic tetany. Clinical signs of the disease are often brought on by stress factors such as cold, wet and windy weather. The exact cause is unknown. Typical symptoms of tetany are nervousness, tremors, twitching of the facial muscles, staggering gait and convulsions.

Question 22

Which nutrient absorption con be impaired by copper deficiency?

Answer 22

A deficiency of copper impairs the animal’s
ability to absorb iron, mobilise it from the tissues and utilise it in haemoglobin
synthesis.

Question 23

What are symptoms of copper deficiency?

Answer 23

anaemia, poor growth, bone disorders, scouring, infertility, depigmentation of hair and wool, gastrointestinal disturbances, and lesions in the brain stem and spinal cord.

• enzootic ataxia -associated with pastures low in copper content
• swayback - complete paralysis of the newborn lamb to a swaying staggering gait that affects, in particular, the hind limbs -> Swayback has been reported to occur on pastures apparently normal or even high (7–15 mg/kg DM) in copper content.
  -falling disease’ was found to be related to progressive degeneration of the myocardium of animals grazing on copper-deficient pastures.

Question 24

What is the complex effect of molybdenum on copper retention in animals?

Answer 24

Molybdenum’s effect on copper retention is complex and occurs only in the presence of sulfur. In the animal’s stomach, ruminal microorganisms convert sulfur to “sulphide,” which then reacts with molybdenum to form “thiomolybdate.” Thiomolybdate combines with copper to create insoluble “copper thiomolybdate” that binds to food particles in the rumen, limiting the absorption of dietary copper. If excess thiomolybdate is formed, it might be absorbed from the digestive tract, affecting the animal’s copper metabolism systemically.

Question 25

Which minerals can decrease copper absorption when fed in high concentration?

Answer 25

Iron, manganese and zinc

Question 26

A number of disorders of cattle and sheep, characterised by emaciation, anaemia
and listlessness, have been described as
‘pining’, ‘salt sick’, ‘bush sickness’ and ‘wasting disease’. Which dietary deficiency is it associated with?

Answer 26

deficiency of cobalt caused by low concentrations of the element in the soil and herbage.

Question 27

Why is cobalt important in the nutrition of ruminants?

Answer 27

Cobalt is required by microorganisms in the rumen for the synthesis of vitamin B12. If the diet lacks sufficient cobalt, the rumen microorganisms cannot produce enough vitamin B12 to meet the animal’s requirements, leading to symptoms of pining.

Question 28

What is the aetiology of slipped tendon in chicks?

Answer 28

manganese deficiency + high dietary intake of ca, p or deficiency of choline

Question 29

Where is zinc accumulated in the body?

Answer 29

in the bones

Question 30

What is characterized by zinc deficiency in pigs? and in chicks?

Answer 30

Zinc deficiency in pigs is characterised by subnormal growth, depressed appetite,
poor food conversion and parakeratosis.

Gross signs of zinc deficiency in chicks are retarded growth, foot abnormalities, ‘frizzled’ feathers, parakeratosis and a bone abnormality referred to as ‘swollen hock syndrome’.

Question 31

What are the symptoms of excess of zinc in cats?

Answer 31

seizures
may also induce coper deficiency

Question 32

Which metalloenzyme contains molybdenum? (important in the purine metabolism)

Answer 32

xanthine oxidase

Question 33

Which vitamin has a close importance with selenium?

Answer 33

vit E
Selenium has a sparing effect on vitamin E by ensuring normal absorption of the vitamin. Selenium also reduces the amount of vitamin E required to maintain the integrity of lipid membranes and aids the retention of vitamin E in plasma. Conversely, vitamin E spares selenium by maintaining the element in its active form and preventing its loss.
Vitamin E and selenium have roles in the immune system and protect against
heavy metal toxicity.

Question 34

What is the major role from Selenium?

Answer 34

The other major role of selenium is in the production of the thyroid hormones. Which it is a component of the enzyme type I iodothyronine deiodinase (ID1), which converts T4 to the physiologically active T3. When there is a deficiency of selenium, the ratio of T4:T3 increases.

Question 35

Which mineral is a component of the enzyme “carbonic anhydrase,” involved in maintaining acid-base balance in the body?

Answer 35

zinc

Question 36

A deficiency in which mineral can lead to “perosis” or “slipped tendon” in poultry?

Answer 36

manganese

Question 37

Which mineral is involved in maintaining the acid-base balance and proper nerve function in animals?

Answer 37

Sodium

Question 38

Which mineral is a component of the antioxidant enzyme “superoxide dismutase” and helps protect cells from oxidative damage?

Answer 38

Manganese

Question 39

A deficiency in which mineral can lead to “swollen hocks” and “reproductive issues” in poultry?

Answer 39

Manganese

Question 40

Which mineral is essential for the function of numerous enzymes involved in energy metabolism in animals?

Answer 40

Zinc

Question 41

A deficiency in which mineral can lead to “white muscle disease” in young animals?

Answer 41

Selenium

Question 42

What are the functions of Calcium?

Answer 42

The primary function of Ca is to maintain mineralization of bones and teeth, where 98% of body stores are found. Ca also plays a role in nerve and muscle impulse transmission, pH balance, enzyme activation, blood clotting, and mineralization of eggshells

Question 43

Which type of phosphorous is not recommended in foods for dogs and cats with CKD?

Answer 43

inorganic phosphorous - they are more bioavailable than organic forms (bone material for ex)

Question 44

When the bioavailability of trace elements would be reduced?

Answer 44

The bioavailability of trace elements is reduced by a high content of certain minerals (e.g. calcium), the level of other trace elements (e.g. high zinc decreases copper absorption) and sources of phytic acid (e.g. cereals and legumes).

Question 45

Why should copper oxide not be considered as a copper source for dogs’ and cats’ food?

Answer 45

Due to its low availability