Nutrition 2: Minerals

Minerals

Inorganic elements of food

Percentages

What is used to measure macrominerals?

Parts per million (ppm)

What is used to measure microminerals?

Calcium, phosphorus, sodium, magnesium, potassium, chlorine, sulfur

Seven macrominerals

Iron, zinc, copper, iodine, selenium, manganese, cobalt, molybdenum, fluorine, boron, chromium

Eleven microminerals

2-3% of dry matter

General mineral requirement

Structural components of organs and tissues, constituents of body fluids (electrolytes), reaction catalysts/co-factors

Functions of minerals

Excess/deficiencies, needs vary over time, dietary components, mineral interactions

Considerations of mineral requirements

Dietary fibers

Interfere with absorption of minerals

Synergistic, antagonistic

Types of mineral interactions

Sharing same transport channels, interfering with storage, competing for transport protein

Types of antagonistic mineral interactions

Chemical form (influences solubility); amounts/proportions of other dietary components; age, gender, and species of animal; intake and need of minerals; environmental factors

Factors influencing mineral availability

Organic forms

Which is more bioavailable: organic forms or inorganic forms?

Meat-derived

Which is more bioavailable: meat-derived or plant-derived?

Sulfate/chloride form, carbonates, oxides

List from most to least bioavailable:

• Carbonates

• Oxides

• Sulfate/chloride form

Active, facilitated

Forms of transcellular transport

Active transcellular transport

Which type of transport?:

Requires transporter

Saturable

Requires energy

Facilitated transcellular transport

Which type of transport?:

Requires transporter

Saturable

Does not require energy

Paracellular absorption

Which type of transport?:

Gradient-dependent

No transporter required

No saturation

Does not require energy

Calcium

Major physiological function of which mineral(s)?:

• Bones

• Muscle function

• Nerve conduction

Phosphorus

Major physiological function of which mineral(s)?:

• Bones

• Nucleic acids

• Phospholipids

• Metabolism of sugars, proteins, and fats

Potassium

Which mineral is the most abundant intracellular cation?

Potassium

Major physiological function of which mineral(s)?:

• Muscle contraction

• Nerve conduction

• Acid-base balance

• Osmotic pressure

Sodium and chlorine

Which minerals are the most abundant extracellular cation and anion?

Sodium and chlorine

Major physiological function of which mineral(s)?:

• Osmotic pressure

• Acid-base balance

• Nerve conduction

• Muscle contraction

• Nutrient absorption

Magnesium

Major physiological function of which mineral(s)?:

• Component of bones and intracellular fluids

• Neuromuscular transmission

• Enzyme function

Iron

Major physiological function of which mineral(s)?:

Oxygen transport

Iodine

Major physiological function of which mineral(s)?:

T3 and T4

Zinc

Major physiological function of which mineral(s)?:

• Constituent or activator of >200 metabolic enzymes

• Nucleic acid/carbohydrate metabolism

• Protein synthesis

• Growth, reproduction

Decreased growth, impaired reproduction, anorexia

Clinical signs of zinc deficiency

(Relatively non-toxic) Vomiting, diarrhea, decreased appetite

Clinical signs of zinc excess

Goiter, lethargy

Clinical signs of iodine deficiency

Goiter

Enlarged thyroid

Goiter, fever

Clinical signs of iodine excess

Goiter

What is an important clinical sign that can be observed when an animal has either a deficiency or an excess of iodine?

Anemia

Important clinical sign of iron deficiency

Hepatic dysfunction, hemosiderosis

Clinical signs of iron excess

Tetany

Most important clinical sign of magnesium deficiency

Tetany, slowed growth, decreased bone mineralization, muscle weakness, convulsions, anorexia, vomiting

Clinical signs of magnesium deficiency

Bladder stones, flaccid paralysis

Clinical signs of magnesium excess

Water imbalance, fatigue, anorexia

Clinical signs of sodium and chloride deficiencies

Thirst, constipation, seizures

Clinical signs of sodium and chloride excess

Locomotive problems, heart weakness, heart failure

Clinical signs of potassium deficiency

Paresis, bradycardia

Clinical signs of potassium excess

Pica

Most important clinical sign of phosphorus deficiency

Pica, decreased growth, decreased appetite, decreased bone mineralization

Clinical signs of phosphorus deficiency

Calcification of soft tissues, urinary calculi

Clinical signs of phosphorus excess

Tetany

Most important clinical sign of calcium deficiency

Tetany, convulsions, decreased growth, decreased appetite, decreased bone mineralization

Clinical signs of calcium deficiency

Decreased feed efficiency, urinary calculi

Clinical signs of calcium excess

Grass tetany or grass staggers

• Condition in horses and ruminants

• Rapidly growing grasses tend to be rich in potassium and very low in magnesium/calcium

  • Clinical signs are thought to be mainly due to low magnesium

  • Treatment: magnesium supplementation

Big head or nutritional secondary hyperparathyroidism

• Condition in horses

• Excessive bran in diet (and other dietary imbalances): high in potassium and low in calcium

• Low levels of available (serum) calcium stimulate parathyroid chief cells to release parathyroid hormone (PTH)

• PTH induces osteoclast-mediated resorption of bone

• Bone is replaced by copious fibrous tissue

Goiter

• Most commonly due to an iodine deficiency in domestic species

  • Low iodine in diet

  • Ingestion of goitrogenic drugs, chemicals, and foods

• Deficiency of iodine → Reduced ability of thyroid to make T3 and T4

• Reduced circulating T3 and T4 → Pituitary makes more thyroid-stimulating hormone (TSH)

• More TSH → Hyperplasia of thyroid gland → ___ development

• Not synonymous with hypothyroidism

Low iron reserve, low iron in colostrum, insufficient contact with dirt

Why is anemia common in newborn piglets (and therefore important that piglets receive iron injections)?

Copper storage hepatopathy

Condition that 30-60% of Bedlington terriers are thought to be affected with

Caused by mutation in COMMD1 gene that affects copper excretion in liver

Copper toxicity

Sheep are most sensitive to this condition.

• Many factors that alter copper metabolism influence chronic copper poisoning by enhancing the absorption or retention of copper.

• Low levels of molybdenum or sulfate in the diet are important examples.

• The toxicosis remains subclinical until the copper that is stored in the liver is released in massive amounts.

Intravascular hemolysis, lipid peroxidation

What does a sudden increase in blood copper concentration cause?

Hemoglobinuric nephrosis

Result of intravascular hemolysis