Small animal nutrition- Minerals

Macro-minerals

• Calcium

• Phosphorus

• Magnesium

• Sulfur

• Sodium

• Potassium

• Chloride

Electrolytes

• Sodium

• Potassium

• Chloride

Micro-Minerals (Trace minerals)

• Manganese

• Zinc

• Iron

• Copper

• Selenium

• Iodine

• Cobalt

• Molybdenum

• Chromium

Macro-minerals summary

• Typically, grams/day

• Reserves exist in bones

• Electrolytes are required daily to maintain

Micro-minerals summary

• Typically, milligrams/day

• Serve as co-factors/constituents of enzymes

• Co-function with vitamins

• Constituents/support formation of hormones

• Deficiency results in anemia

Optimal intake

The acceptable range of minerals in accordance to AAFCO specifications

Deficiency

When the minimum requirement for a nutrient has been established, clinical signs of deficiency may result if the minimum is not met

Toxicity

When the maximum tolerable level for a nutrient has been established, clinical signs of toxicity may result if the maximum is exceeded

Minimum recommendation of mineral and vitamins in dogs and cats

• Calcium:Phosphorus of 1.0:1.0

• All essential minerals and vitamins

Maximum recommendation of mineral and vitamins in dogs

• Calcium (narrower calcium range for large breeds)

• Phosphorus

• Calcium:Phosphorus of 2.0:1.0

• Iodine

• Selenium

• Vitamin A

• Vitamin D

Maximum recommendation of mineral and vitamins in cats

• Phosphorus

• Iodine

• Vitamin A

• Vitamin D

Mineral inter-relationships

• Bi-directional relationship- Both minerals affect the use of each other

• Uni-directional relationship- One mineral affects the use of the other (but not vice versa)

Calcium

• 99% is in bones and teeth

• The other 1% function to:

  • Blood clotting

  • Muscle function

  • Nerve transmission

  • Membrane permeability

Phosphorus

• 80% is in bones and teeth

• The other 20% functions to:

  • Energy metabolism (part of ATP)

  • Genetic material (part of DNA and RNA)

  • Cell membrane phospholipids

Magnesium

• Enzyme function

• Energy metabolism

• Muscle function

• Nerve transmission

PTH (parathyroid glands)

Homestasis:

• Not well established

• Excretion → GI tract and kidneys

Sulfur

• Skin, hair, wool, and feathers

• Cartilage

• Connective tissues

• Amino acids

• Hormones

• Vitamins

• Coenzymes

• Energy metabolism

Sodium, Potassium, Chloride

• Acid-base balance

• Osmotic balance

• Muscle function

• Nerve transmission

• Membrane permeability

• Digestion

• Absorption

• Potassium is a cofactor for enzymes involved in energy metabolism

• 3 Na out of cell, 2 K into cell

• Charged elements dissolved in fluid

Anti nutritional factors

• Phytates

• Thiaminases

• Tannins

• Avidin

• Goitrogens

Phytases

Decreases Zn absorption

• Grains/cereals (rice)

• Legumes (peas)

• Nuts (peanuts)

Tannins

Decrease intestinal Fe absorption

• Grains/cereals (barley, millet)

• Legumes (peas, beans)

• Fruits (apples, pears)

Thiaminases

Enzymes that breakdown thiamine

• Raw fish and shellfish

Avidin

A protein that binds biotin making it unable to be absorbed

• Raw egg whites

Goitrogens

Interfere with iodination

• Cabbage family (turnip, kale, rapeseed, brassica forages)

Manganese (Mn)

• In metalloenzymes

• Activates enzymes

• Bone matrix and cartilage development

• Reproduction

• Energy metabolism

• Lipid synthesis

• Is stored in the bone and liver

Zinc (Zn)

• Constituent/activator of >100 enzymes

• Nucleic acid metabolism

• Protein synthesis

• Carbohydrate metabolism

• Immunocompetence

• Skin/wound healing

• Cell replication and differentiation

• Growth and reproduction

• Hormone production

• Calcium decreases intestinal Zn absorption

Iron (Fe)

Structure and function

• Enzymes and proteins involved in:

  • Oxygen activation

  • Electron transport

  • Oxygen transport

Homeostasis

• Limited capacity of the body to excrete

• Homeostasis maintained by adjusting absorption

• Complexed to transferrin (in plasma) and in RBCs

• Stored in liver, bone marrow, spleen

Copper (Cu)

• Hematopoiesis

• Neurotransmitters

• Pigmentation

• Connective tissues

• Oxidative metabolism

• Superoxide radical defense

• Homeostasis maintained by adjusting its absorption

• Bound mainly to ceruplasmin (plasma)

• Metabolism in liver

Selenium (Se)

• Part of glutathione peroxidase

• Glutathione peroxidase and vitamin E work together synergistically

• Spares vitamin E and vice versa

• Thyroid hormone and iodine metabolism

• No homeostatic control of absorption

• Excretion is regulated (urine)

Iodine (I)

Constituent of the thyroid hormones

Cobalt (Co)

Constituent of vitamin B12

Molybdenum (Mo)

Enzyme cofactor

Chromium (Cr)

Role in glucose metabolism

Micro-nutrients and anemia

Minerals:

• Iron deficiency- Microcytic hypochromic

• Copper deficiency- Required for hematopoiesis