7 Major Macro Minerals for Cattle

7 Major Macro Minerals for Cattle

Minerals are essential for all bodily functions and is vital for overall cow performance. Minerals are divided into two categories based on the quantity of the mineral required by the animal. Macro minerals are required in a larger amount as a percent of the diet dry matter, and trace minerals are required in smaller amounts as parts per million (ppm). There are seven major macro minerals that are taken into account when balancing a cow’s diet.


Calcium (Ca)

Functions: bone and teeth formation, blood clotting, activation and stabilization of enzymes, transmission of nerve impulses, muscle excitability, and cardiac regulation. Interacts with phosphorus.

Toxicity: feeding over dietary concentrations over 1% may decrease dry matter intake. Levels as high as 1.8% have been fed with no apparent problems. Excess calcium rarely effects animals as they can tolerate high dietary concentrations. Chronically high dietary intake my reduce the absorption of cadmium, copper, fluorine, iodine, magnesium, manganese, phosphorus, palladium, zinc, and possibly other elements.

Deficiency: Retarded growth in young animals, osteoporosis, and oseteomalacia.


Phosphorus (P)

Functions: involved in acid-base buffer systems of blood and body fluids, cell differentiation, cell contents, energy transactions. Phosphorus has more biologic functions than any other mineral element. 80% of bodily phosphorus is found in bones and teeth, because of this role calcium and phosphorus supplementation is usually considered simultaneously. 

Toxicity: dietary levels over 1% P are considered toxic. Excessive P results in weak bones, downer cow syndrome, and urinary calculi.

Deficiency: reduced feed intake, unthriftiness, lethargy, reduced growth rate, loss of weight, reduced milk yield.


Magnesium (Mg)

Functions: enzymatic reactions, stability for the structure of ATP, nerve conduction, muscle function, and bone mineral formation.

Toxicity: dietary levels over 1% Mg as oxide are toxic. Excess dietary Mg reduces feed intake, retards growth, results in diarrhea, and emaciation.

Deficiency: irritability, trembling, frothing at the mouth, hyperesthesia, tetany, incoordination, convulsions, and sudden death.


Sulfur (S)

Functions: formation and maintenance of cartilage, bone, tendons, and blood vessel structure. Sulfur is found in the B-vitamins thiamin and biotin and is a component of the amino acids methionine and cysteine.

Toxicity: Maximum tolerable level is 0.4% for ruminants. Symptoms of acute toxicity include; dullness, colic, twitching of facial muscles, staggered gait, pale and muddy mucous membranes, weak and rapid pulse. Symptoms of chronic toxicity include; decreased feed intake, dehydration, rumen statis, rapid pulse, diarrhea, polioencephalomalacia, and metabolic acidosis.

Deficiency: reduced feed intake, weight gain, and performance. Rumen fermentation will be depressed because S is required for the synthesis of microbial protein.


Sodium (Na):

Functions: water metabolism, nutrient uptake, osmotic pressure, regulates acid-base equilibrium.

Toxicity: dietary levels over 7% Na are considered toxic. High intakes of NaCl increase severity of udder edema, muscle spasms, paresis, convulsions, blindness, diarrhea, abdominal pain, anorexia, thirst, salivation, and central nervous system impairment.

Deficiency: depressed appetite, decreased milk yield, tendency to lick, dry bristling coat. Deficiencies are common in grazing livestock.


Chlorine (Cl)

Functions: water metabolism and nutrient uptake, osmotic pressure, and acid-base equilibrium. Plays a role in protein digestion. Sodium and chlorine are commonly expressed together as a salt requirement.

Toxicity: when water consumption is restricted toxicity can occur even at low dietary levels.

Deficiency: heat stress increases requirements.


Potassium (K)

Functions: nerve impulses, co-factor for energy transfer and utilization, protein synthesis and carbohydrate metabolism. Involved in water metabolism and nutrient uptake, maintains osmotic pressure, and regulates acid-base equilibrium.

Toxicity: Intakes exceeding 4% of diet dry matter are considered high.  Symptoms include edema, reduced feed intake and weight gain.

Deficiency: Severe deficiency is rare in most normal conditions. Symptoms include rapid decline in feed and water intake, reduced body weight and milk production, pica, loss of hair gloss, decreased skin pliability, animals may become weak, poor intestinal tone, possible death.


Written by: Mariah Gull, M.S.

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