Chapter 21: Nutritional Contributions of Minerals to Humans and Animals

• Chapter overview:– Chapter 21 presents the impacts of minerals on

animal health:• identification and major sources of minerals• functions of minerals• impacts of mineral deficiencies

General Comments:

• There appears to be little difference in requirements for the minerals between species

• Requirements can be significantly impacted by other organic or inorganic components of the diet– Example: phytin binds phosphorus and

increases zinc requirement

General Comments:

• Minerals are abundant in many natural feedstuffs, but

• Supplementation of feeds and foods with common inorganic major sources of minerals is typical

The Minerals:• Minerals are generally categorized as:

– Macrominerals: those required in larger amounts, such as Ca, P, Mg, Na, Cl, K, S

• example: calcium requirement may be 0.5% in some diets

– Microminerals: those required in very small amounts, such as Fe, Cu, I, Co, Zn, Mn, Se, Mo, F

• example: Zn requirement may be 50mg/kg (0.005%) in some diets

The Macrominerals:

Calcium (Ca):

• Functions - bone and tooth formation, blood clotting, muscle contraction

• Deficiency symptoms - rickets, slow growth, osteomalacia, tetany, thin-shelled eggs

• Major sources - milk, legumes, bone meal, dicalcium phosphate, limestone

Phosphorus (P):

• Functions - bone and tooth formation; part of DNA, RNA, and many enzyme systems

• Deficiency symptoms - rough hair coat, pica, slow growth

• Major sources - milk, eggs, oilseeds, cereal grains, bone meal, dicalcium phosphate

Magnesium (Mg):

• Functions - enzyme activator, component of skeletal tissue

• Deficiency symptoms - anorexia, hyperirritability, muscular twitching and tetany, profuse salivation

• Major sources - abundant in feeds, especially green, leafy vegetables and grains

Sodium (Na):

• Functions - muscle contraction, maintenance of osmotic pressure of body fluids

• Deficiency symptoms - loss of appetite and weight, salt craving, soil eating,

• Major sources - common salt added to supplements or in free-choice blocks

Chlorine (Cl):

• Functions - maintenance of osmotic pressure of body fluids, acid-base activity, production of HCl in stomach

• Deficiency symptoms - craving for salt, reduced appetite

• Major sources - common salt added to supplements or in free-choice block form

Potassium (K):

• Functions - maintenance of electrolyte balance, enzyme activator, muscle function

• Deficiency symptoms - heart lesions, weight loss, reduced appetite, muscle weakness, poor wool growth

• Major sources - widely distributed throughout feeds and foods

Sulfur (S):

• Functions - component of sulfur-containing amino acids

• Deficiency symptoms - slow growth, poor feed efficiency, slow wool growth in sheep

• Major sources - oilseed meals, forages, cereal grains

The Microminerals:

Iron (Fe):

• Functions - carrier of oxygen as a component of hemoglobin and myoglobin, component of many enzyme systems

• Deficiency symptoms - anemia, diarrhea, loss of appetite

• Major sources - eggs, forages and grains, soil (example: rooting by pigs in soil)

Copper (Cu):

• Functions - erythropoiesis, component of coenzyme system, hair pigmentation, collagen and elastin synthesis

• Deficiency symptoms - depraved appetite, stunted growth, diarrhea, bleached hair and wool, ataxic gait, anemia

• Major sources - common in normal grains and forages

Iodine (I):

• Functions - component of thyroxine• Deficiency symptoms - goiter, hairless pigs

and woolless lambs at birth, poor performance

• Major sources - added to almost all salt sources (“iodized salt”), cod-liver oil

Cobalt (Co):

• Functions - component of vitamin B12, red blood cell formation, rumen microorganism function

• Deficiency symptoms - loss of appetite and emaciation, weakness, rough hair coat, anemia

• Major sources - inorganic cobalt supplementation in the diet

Zinc (Zn):

• Functions - enzyme activator and component

• Deficiency symptoms - poor growth, feathering, and hatchability; anorexia; parakeratosis

• Major sources - widely distributed in feeds, with forages being major sources

Manganese (Mn):

• Functions - growth, bone formation, enzyme activator

• Deficiency symptoms - lowered egg shell strength and hatchability, perosis in poultry, lameness and stiffness

• Major sources - widely distributed in cereal grains, oilseeds, and legumes

Selenium (Se):

• Functions - related to vitamin E function, destroys peroxides (antioxidant)

• Deficiency symptoms - necrosis of liver, white muscle disease in ruminants

• Major sources - oilseeds and grains• Note - excess is quite toxic

Molybdenum (Mo):

• Functions - component of enzyme systems• Deficiency symptoms - deficiency

relatively unknown• Major sources - widely distributed in feeds

and foods• Note - deficiency of Mo accentuates Cu

toxicity, excess Mo reduces Cu absorption

Fluorine (Fl):

• Functions - tooth enamel formation, prevention of tooth decay in humans

• Deficiency symptoms - poor enamel formation

• Major sources - fluoride added to water• Note - narrow range of “requirement”;

excess causes tooth enamel abnormalities

Other mineral considerations:

• Although only produced under laboratory conditions, deficiency symptoms can be created for:– Vanadium– Arsenic– Nickel– Tin