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
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
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