Lecture 9- Minerals Flashcards

1
Q

What are the functions of minerals in metabolism?

A
  • Some participate with enzymes in metabolic processes
  • Some have structural functions (Ca, P in bone; S in keratin)

• Acid-base and water balance (Na, K, Cl)

  • Unique functions
  • e.g., Fe in heme, Co in B12, and I in thyroid hormones
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2
Q

What is the division/classification of minerals?

A
  • macro or major minerals
  • micro or trace minerals
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3
Q

What are macro or major minerals?

A
  • Sodium, potassium, magnesium, calcium, phosphorus, sulfur, chloride
  • Present in body tissues at concentrations >50 mg/kg (50 ppm)
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4
Q

What are micro or trace minerals?

A
  • Chromium, manganese, iron, iodine, cobalt, molybdenum, copper, zinc, fluoride, iodine, selenium, silicon, tin, arsenic, nickel…
  • Present in body tissues at concentrations <50 mg/kg (50 ppm)
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5
Q

What are the nutritionally important minerals?

A
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6
Q

What are the minerals in food?

A
  • Found in all food groups.
  • More reliably found in animal products.
  • Often other substances in foods decrease absorption (bioavailability) of minerals • Oxalate, found in spinach, prevents absorption of most calcium in spinach.
  • Phytate, form of phosphorous in most plants makes it poorly available

• Calcium and phosphorus are the most plentiful nutrients in the mammalian body

Dominant minerals in bone and teeth (skeleton stores minerals that can be used in times of

deficiency e.g. lactation)

99% of Ca is in bone; 80% P is in bone

The 20% of P in ‘other’ locations is important

• ATP/ADP, cell wall, RNA & DNA, acid base balance etc.

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7
Q

What is the iron requirement for men and women?

A

-women need much more iron

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8
Q

What are the factors affecting mineral requirements?

A
  • Physiological state/level of production • Interactions with other minerals
  • Tissue storage
  • Form fed

• inorganic vs organic forms

• Na selenite (inorganic) vs Na selenate (inorganic) (Absorbed by passive diffusion and little retained in tissue reserves
Large amounts excreted )

vs selenomethionine (organic =Actively transported through intestinal membranes during absorption & incorporated into tissue proteins )

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9
Q

What are the mineral interactions?

A

-pretty much everything interacts with everything!

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10
Q

What are the issues with deficiencies and excesses of minerals?

A
  • Most minerals have an optimal range • Below leads to deficiency symptoms
  • Above leads to toxicity symptoms
  • Mineral content of soils dictates mineral status of plants (i.e., feeds)
  • May take many months to develop, depends on what it is
  • Time impacted by body stores
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11
Q

How can Copper be toxic?

A
  • Copper is a cumulative poison
  • Animals are unable to excrete it properly so small amounts build up
  • Particularly in liver tissue
  • Species specific – pigs are tolerant but sheep susceptible

-copper pipes transport water= if old, copper leaks into the water supply and this build up in the animals over time

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12
Q

Whata are some characteristics of Calcium (macro-mineral)?

A
  • Most abundant mineral in animal tissues
  • Lots of functions
  • Bonestructure
  • Nerve function
  • Bloodclotting
  • Musclecontraction

• Cellular metabolism

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13
Q

What are some of the food sources of Calcium?

A
  • Milk and dairy products
  • High amounts
  • High bioavailability (fortified with vitamin D)
  • Green leafy vegetables
  • Poor absorption
  • Fish with bones?
  • Fortified juice/cereal
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14
Q

What are the symptoms of calcium deficiency in young and in old animals?

A

• Young animals:

  • Rickets (misshapen bones)
  • Enlarged joints
  • Lameness and stiffness

• Old animals = Milk fever

  • Occurs in lactating cattle, goats & sheep
  • 72 hours after calving
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15
Q

What is the incidence of milk fever and what does it depend on?

A
  • Incidence of milk fever
  • increase in Ca demands of lactation leads to reduced blood pH
  • More frequently in high-producing cows
  • Increases with cows’ age
  • More common in Jersey than other breeds

• Repeats common in cows with a previous history

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16
Q

What are the symptoms of milk fever?

A

• Symptoms of milk fever

  • Muscular spasms, loss of appetite,
  • low blood calcium (3-7) normal is 10 mg/100 ml
  • Depression, dull staring eyes, dilated pupils
  • Extreme cases: paralysis leading to unconsciousness and sometimes even death
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17
Q

What are the treatment and prevention of milk fever?

A
  • Intravenous injection of calcium gluconate
  • Provide adequate Ca and P during the dry period

• Transition period feeding important

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18
Q

What are Ca and P needed for and what should the dietary ratio?

A
  • Both Ca and P are required for bone formation and other non- skeletal functions
  • Dietary ratio of 1:1 to 2:1 is good for most animals (exception is laying hen, 13:1; Ca:non phytate phosphorus)
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19
Q

How is calcium absorbed?

A
  • Dependent on Vitamin D
  • Absorption depends on need

• Particularly high during growth, pregnancy and lactation

• Bioavailability decreased by:

• Phytates (grains)

  • Wheat bran
  • Low estrogen levels (postmenopausal women)
20
Q

How is calcium regulated in the body?

A
  • Plasma Ca is regulated tightly
  • Normal plasma concentration is 8-12mg/dl

• Three hormones involved in regulation

  • • Vitamin D3*- from kidney
  • • Parathyroid hormone* (PTH) -from parathyroid gland
  • • Calcitonin*- from thyroid gland

• PTH and Vitamin D3 act to increase plasma Ca, while calcitonin acts to decrease plasma Ca

21
Q

What is the connection between Calcium and bone health?

A
  • Bone growth is greatest during “linear growth”
  • Peaks out at around age 30 (humans)
  • Calcium in bones used as reservoir for other needs.
  • Maintains blood calcium homeostasis
22
Q

What is osteoporosis and what is its connection to Calcium?

A
  • Around age 40, bone breakdown exceeds formation.
  • Ideally, want very high bone mass when this begins.
  • By age 65, some women have lost 50% of bone mass.
23
Q

How can you prevent osteoporosis?

A

• Maintain adequate calcium and vitamin D intake—many recommend supplements?

  • Most are absorbed similarly
  • Costs vary widely
  • What’s wrong with dairy products?
  • Perform weight-bearing exercise
  • Take oestrogen supplements?
24
Q

What are the issues with excess calcium?

A
  • Generally from supplements not intake
  • Kidney stones
  • Influences absorption of iron, zinc, magnesium and phosphorus
  • Not so clear in human studies
25
Q

What is the function of phosphorus?

A
  • Component of bone
  • Constituent of phospholipids and nucleic acids

• Component of ATP => energy metabolism

26
Q

What are the symptoms of phosphorus deficiency?

A
  • Rickets or osteomalacia
  • ‘Pica’ or depraved appetite
  • Chronic cases => stiff joints + muscular weakness
  • decrease fertility, dysfunctional ovaries + irregular oestrus
  • Chickens: decrease egg yield, poor hatchability and shell thickness
27
Q

What are the sources of Phosphorus?

A
  • Good sources: milk + cereal grains (as phytic acid)
  • Poor sources: hays and straws
  • Excessive intake leads to deposits in bladder + urethra
  • Impact on environment has scientists revisiting nutritional requirements
  • Requirements are being lowered without any negative effects on reproduction or milk production
  • Bioavailability could be improved if phytate P can be reduced
28
Q

What are the functions of potassium?

A

• Functions of potassium

  • Osmotic regulation of body fluids
  • Acid-base balance
  • Nerve and muscle excitability
  • Activation of enzymes e.g. pyruvate kinase
29
Q

What are the symptoms of potassium deficiency?

A
  • Rare in farm animals
  • May occur in animals eating distillers grain
30
Q

What are the issues with potassium and feeding?

A
  • Most feeds have adequate potassium
  • Dehydration and diarrhoea cause increase potassium losses

• increase potassium intake interferes with Mg and Ca

31
Q

What are the functions of sodium (Na)?

A
  • Present in soft tissues and body fluids
  • Acid-base balance
  • Osmotic regulation of body fluids
  • Involved in nerve impulse transmission
  • Involved in sugar and AA absorption
32
Q

What are the symptoms of sodium deficiency?

A
  • decrease osmotic pressure resulting in severe dehydration
  • Poorgrowth=> reduced utilisation of digested proteins and energy
  • Hens, decreased egg production and decreased growth
  • Rats: eye lesions, reproductive disturbances and death
33
Q

What is the source of sodium?

A

-common salt

34
Q

What is the connection of sodium and health?

A
  • High blood sodium is associated with high blood pressure and risk of heart disease
  • However, high blood sodium rarely due to dietary excess.
  • Again, genetics and other factors are involved.
35
Q

Where is most of Mg found in the body and what are its functions?

A

• 70% of Mg is found in the skeleton

  • Functions of magnesium
  • Activates enzymes involved in energy metabolism
  • Involved in cell respiration
  • Moderates neuromuscular activity
  • Maintains integrity of cell membranes
36
Q

What are the symptoms of magnesium deficiency?

A

• Grass tetany also called hypomagnesaemic tetany, grass staggers, lactation tetany

37
Q

What is the incidence of grass tetany? (Mg)

A
  • Also affects sheep, stall-fed cattle and hill cattle
  • Ayrshire most susceptible, rare in Jersey
  • Frequent in grazing animals, particularly in spring
  • Acute cases: occur within 1-2 days of turn out
38
Q

What are the causes of grass tetany?

A
  • Poor magnesium absorption
  • Reserve Mg can not be mobilised fast enough
  • Blood Mg falls to 5mg/l (normal is 17-40mg/l)
39
Q

What are the symptoms, treatment and prevention of grass tetany (Mg deficiency)?

A
  • Inject magnesium sulphate or give Mg oxide orally
  • Graze forages high in Mg (legumes)
  • Increase P, reduce K and N fertilizers
  • increase Mg oxide in mineral mix supplement
40
Q

What are the functions of Sulphur?

A
  • Component of body proteins (cysteine, methionine)
  • Constituent of vitamins e.g. biotin and thiamine
  • Component of cartilage, bone, tendons and walls of blood vessels as chondroitin sulphate
  • Component of wool (about 4%), hair, feathers and gizzard lining
41
Q

What are the issues with feeding and sulphur?

A
  • Essential for microbial function in the rumen
  • Levels > 0.4% are toxic for ruminants
42
Q

What are the functions of Clorine, the signs of its deficiency and the sources of it?

A

• Functions of chlorine:

  • Regulates acid-base balance and osmotic pressure
  • Component of gastric secretions (e.g. HCl)

• Deficiency symptoms:

• Causes blood alkalosis

• Sources of chlorine:

  • Common salt (sodium chloride)
  • Swill can be rich source of salt
43
Q

What happens in animals if there is too much Cl and if there is too little?

A
  • Hens
  • Prevents feather picking and cannibalism
  • Too much salt is toxic
  • Causes excessive thirst, weakness and oedema
  • Salt poisoning is common in pigs and poultry
  • Pigs and chicks tolerate 20g/kg, and turkeys 10g/kg
  • Laying hens can tolerate  amounts if water is available
44
Q

What happens to infants when the mother has hypothyroidism?

A

• Brain damage, mental retardation, deafness, growth retardation etc.

• Goiter:

-Swelling at the base of the neck

-Difficulty swallowing, choking sensation

Hypothyroidism – lethargy, depression, impaired memory & attention, impaired thermoregulation, weight gain

  • Infertility, miscarriages, stillbirths, preterm deliveries
  • Toxicity can cause hyperthyroidism, fever, GI symptoms, weak pulse, coma
45
Q

What are the functions and required doses of iron?

A
  • Many metabolic functions
  • Haemoglobin
  • O2 transport, cell respiration
  • Component of various enzymes

• Energy production, immune system functions

  • Electron transport chain
  • Men require ~1 mg/day

• Women require ~1.4 mg/day • Pregnancy 4-6 mg/day

46
Q

What happens in iron deficiency (anemia)?

A

• 3 stages:

Depletion of stores (liver, marrow, spleen)

Decrease in transported iron

Insufficient supply to provide haemoglobin for new erythrocytes

  • Fatigue, restlessness, impaired thermoregulation, impaired immunity • Iron toxicity (supplements)
  • Cardiomyopathy, endocrine dysfunction, tissue injury, constipation, diarrhoea etc
47
Q

What are the details about cobalt and vitamin B12?

A
  • Ruminants have a need for cobalt
  • Required for the synthesis of B12 by rumen organisms
  • Ruminants have a need for B12 NOT cobalt
  • Sheep more susceptible to deficiency than other ruminants
  • As B12 is required for the microbial synthesis of methionine which is important for wool growth
  • Deficiency is hard to detect clinically (in ruminants) • Loss of appetite
  • Lethargy
  • Weeping eyes, scaly ears, pale skin etc.
  • Muscle wastage then death
  • Cobalt toxicity does not appear to exist (in ruminants)