Bovine Engineering & Consulting - Gearld Fry

Minerals are Essential for Healthy Livestock

by Geardy Fry

Mineral nutrition is one of the least understood components of the bovine diet.  I consider mineral supplements to be an indispensable management tool that the American cattle person must learn how to use in order to maintain the productivity of his/her herd and avoid unintended, expensive losses.  Next to implementing a well managed breeding program, compensating for mineral deficiencies created by depleted soils and other environmental factors is probably the most important responsibility we have for keeping our livestock healthy and reproductively sound.  If we, as cattle producers, do not understand the logistics of mineral nutrition then we are at the mercy of the trained consultant working for a big mineral company, a feed store manager (who may not even own a cow), the veterinarian who charges by the hour, or perhaps just as bad the fallacies of our own ignorance.  In any event, more often then not we don’t get the proper mineral nutrition into our animals that it takes to put an end to the health and performance problems that take away profits (mastitis, cow pox, ringworms, foot rot, parasite infestation, ecoli scours, retained placenta, reproduction, pink-eye and many other).

 The key to mineral nutrition is not only bioavailability but also balance in the ration.  Minerals that are fed in the correct proportions for your particular environment will provide the support your animals need to stay healthy and reproduce abundantly.

A properly balanced mineral supplement can virtually eliminate most health problems including Ecoli scours in baby calves and diarrhea in the adult animals.  Early shedding of the winter hair coat come springtime is very important and closely associated with reproduction ability and good health.   Both are affected and can be greatly improved with proper balanced mineral nutrition.

Dairy cows probably suffer more from mineral deficiencies than beef animals because of the pressure put on them to produce great volumes of milk.  Most dairy cows are in confinement and living in a monoculture-type environment. 

It has been my experience that, for the most part, it is a low or slow immune response resulting from inadequate or imbalanced mineral nutrition that causes low pregnancy rates, high levels of mastitis, and high bacteria cell counts in the milk.  Taking away a cow’s ability to find and choose her own food, keeping her confined - unable to move freely -  or circulate toxins out of her body and instead bringing her every bite she consumes to where she stands, requires a very keen artistic knowledge of animal biology and a very keen artistic eye to watch her for symptoms associated with mineral deficiencies and/or other nutritional imbalances that come with confinement management if one is to keep health problems at bay.

It was during the mid 1970’s that a large majority of my young calves came down with Ecoli scours and it was near devastating.   I had to find out why and how to prevent it in the future.  I learned through the trauma of that sickness the critical importance of minerals in the bovine diet, the role they play in the health of my cows and their calves, and whether I could continue to take the losses or find the solutions and continue to support my family.

I began the search for answers and through the process of educating myself about mineral nutrition.  I learned what the essential minerals were and the amount of each that was required to keep my animals healthy.  I studied the list of contents on many different mineral bags and taught myself how to convert parts per million (ppm) into milligrams per ounce (mg/oz.) and how to convert percentages (%) to milligrams per ounce.  These are the various units of measure for the minerals that are listed on the tag or label of the mineral bag.

It is my intent here to share with you what I’ve discovered regarding minerals and what amounts of each is necessary to promote and sustain the health of our cattle.  Many of these minerals are actually inorganic metals and are called micronutrients because they are only needed in small, minute amounts.  Regardless they are needed in a “big way” to keep the endocrine, digestive, reproductive, immune and other animal biological systems functioning properly.

Now, when you look at the tag on a mineral bag you will notice that the calcium and phosphorus amounts are given as a ratio.  Common ratios are 1.5-1, 2-1, or even 1-1 calcium to phosphorus.  There really are many different mixture amounts used in the mineral formulation and in some areas where the soil phosphorus is known to be in the high side, there could be very little or none of this mineral put in the mix.

Cattle do require salt and it is normal for cows to consume about 2 ounces a day.  Adding salt to the mineral mix is a common way to control or limit over consumption. 

Some people will buy mineral and salt separately and then mix the two together pound for pound.  That concoction will have very little value to the animal.  A typical 50# bag of mineral is designed to be fed at the rate of 2 to 4 ounces per animal/day.  Each ounce supplies specific amounts of the many different minerals and is to be fed at the recommended rate to achieve the desired response.  Adding additional salt will decrease daily intake and dilute the mixture thus reducing the effectiveness (benefits) of the minerals for your cows, bulls and calves.

The pH of the water that your animals consume is important and can have negative consequences if it is too low or too high. 

The ideal range for water pH is between 6.3 and 7.2.  An easy way to check your water pH is with Litmus paper.  If your water has a high pH, is high in iron, sodium or other minerals, your cattle may not drink all that they require to stay adequately hydrated.  The chemical effect of water that is high in iron is that copper becomes bound and unavailable which most definitely creates health problems.

In the ideal world, cattle would get the correct amounts of all the required minerals from the grass and forages they consume.  But for many reasons, from environment (and uterine environment) to genetics to management, our cattle do not get the minerals they require to maintain health and a high reproductive status and therefore must be supplemented accordingly.  Lush green grass and legumes growing from a living, fertile soil will provide many of the nutrients (minerals) that cattle need to meet the demands we place on them and as such should not need the level of supplementation that they would require at other times of the year or when pasture growing conditions change from favorable.

Research has determined the mineral dietary requirements for cattle and the information below lists these minerals and what amounts the identified author has determined to be necessary for a cow to consume each day to remain healthy, reproduce and thrive in their environment.

The following values are not intended to be a specific formula that will accurately match your animals’ needs.  Because conditions are different and unique to each farm/ranch, the following information is presented as a guide to help you understand and recognize the role minerals play in the health of your livestock.  Notice how some minerals affect others.

Animals can experience mineral deficiencies as well as mineral toxicities and often times the physical signs are similar.   When you learn how to identify both deficiency and toxicity signs and know their affects, you then realize how to adjust your mineral program so that it will support the highest levels of health and production in your cow herd.

The following information that is in italics font comes straight from the book Mineral Levels In Animal Health: Diagnostic Data written by Robert Puls. The book is a master piece for learning how to manage your cattle’s health. It was published by Sherpa International, 1062-256th Street, Aldregrove, BC V4W  2J3. Phone/fax 604-856-7534.


Deficiency Signs:

Dullness, lethargy, trembling of hindquarters and weakness of legs with broken or weak bones after prolonged deficiency.  Subclinical hypocalcaemia can occur – stillborn calves and retained placentas may result.

Milk fever is one of the major calcium deficiencies that plague the dairy industry.
Calcium cont.


Possible osteopetrosis, vertebral ankylosis and degenerative osteoarthritis.  May reduce fat digestibility. Metastatic Ca deposition in skeletal and cardiac muscle.

Dietary requirements for calcium range from 7500 to 8500 milligrams per/day.
Purchased mineral will be in the 12% range. That 12% percent = 3408 milligrams calcium per ounce.


Deficiency Effects:

Reduced feed intake and milk yield, unthriftness, lethargy, reduced growth rate, impaired reproduction (silent heat, low fertility) and bone abnormalities. May increase metritis and reduce immune response. Marginal deficiency signs resemble those of Cobalt deficiency. Sever deficiency causes pica (chewing on wood or other unnatural objects).  Phosphorus deficiency reduces performance more quickly than calcium.


Excessive dietary phosphorus in relation to calcium results in weak bones, downer cow syndrome and urinary calculi. Maximum tolerated dietary level approximately 1.0% regardless of calcium level.

The Dietary requirement for phosphorus is approximately 4000 milligrams per head/day.
Purchased mineral will be in the 6% range. That 6% = 1488 milligrams per ounce.


Deficiency Signs and Effects:

Poor or faded hair coat, reduced growth rate, or diarrhea if molybdenum induced.  Sudden death with no prior signs if pure copper or Fe (iron) induced.
Reduced fertility in cows and semen quality in bulls.  Retained placenta.  Increased incidence of abomasal ulcers.  Inability to suckle, incoordination, stiff gait, opisthotonus or lateral recumbancy in new born and young calves. Improper bone development, heal cracks, sole abscesses, foot rot or impaired keritinization manifested as coarse hair. Cardiovascular disease and reduced immune response.  Cattle may have extremely high or low copper status without showing any signs of toxicity or deficiency.  Erythrocyte superoxide dismutase activity declines with deficiency but less rapidly than serum copper.

Toxicity signs and Effects:

Depression, anorexia, frequent recumbancy, abdominal discomfort, jaundice and decreased milk production. Hemolytic crises, hemoglobinuria and hemoglobinaemia.  Tolerable copper excess may impart oxidized flavor to milk and reduce sulphur available to rumen flora with consequent reduced productivity.
Copper absorption from diet decreases as animal matures – 90% at birth to <10% at 50 days.

Dietary requirements for copper range from 150 to 250 milligrams per day.
Purchased minerals may be 2500 PPM. That 2500 PPM is 71 milligrams per ounce.


Deficiency Signs – Severe:

White muscle disease, diarrhea, muscle stiffness, sudden death due to cardiac failure with no prior signs of sickness.  Occasionally recumbancy particularly in parturient cows - similar to milk fever syndrome.

Deficiency Signs – Marginal:

Retained placentas, abortions, weak, stillborn or lethargic calves often unable to stand or suckle reduced fertility, cystic ovaries, metritis, delayed conception, erratic, weak or silent heat periods and poor fertilization.  Reduced growth rate, reduced immune response apparent as pneumonia, scouring, foot rot and mastitis etc.

Toxicity Signs:

Acute signs - lassitude, inappetance, dyspnea and death.  Blind staggers or Alkali Disease, loss of hair, cracked or deformed hooves and lameness. Current research indicates blind staggers may not be caused by selenium. Toxicity of the selenium accumulating plants (Astragalus Sp.), may not be due to Selenium but other organic toxins in the same plants.

The dietary requirement for selenium for the cow range from 4 to 6 milligrams a day.
Only 3 milligrams per helping/day of selenium is allowed by law.  Purchased mineral is commonly close to 26 PPM. That 26 PPM is 0.73 milligrams per ounce. 


Deficiency Signs:

Reproductive failure; suppressed estrus, stillbirths, abortions, gestation period extended by up to 9 days, hairless or weak calves, retained placenta.  Goiter, reduced milk yield, foot rot, respiratory diseases, mastitis and actinomycosis are prevented or respond to EDDI therapy.

Acute Toxicity Signs:

Anorexia, excessive salivation, hyperthermia, coughing, nasal and ocular discharge, bronchopneumonia and abortions.  Individual animals show apparent inability to metabolise and excrete EDDI.

Dietary Iodine requirements range from 25 to 28 milligrams per cow/day.
Purchased minerals that contain iodine commonly have 3 to 5 milligrams per ounce. Some manufactures have higher amounts and it will be labeled in PPM.


Deficiency Signs:

Clinical signs occur in calves, whereas subclinical deficiency is more likely in adults.  Weak hoof horn with increased susceptibility to interdigital dermatitis or foot rot.  Reduced conception rate, severely impaired spermatozoan maturation.  Reduced feed intake and growth rate.  Lethargy.  Reduced immune response. Parakeratosis.  Zinc is essential for normal wound healing and synthesis of collagen in bone.


Toxicity in adult cattle is uncommon.  2.0% zinc in dairy feed has killed mature cows.  Zinc at 6-8 PPM in drinking water may adversely affect cattle.  Pancreatitis occurs with > 1600 PPM dietary zinc.  500 PPM zinc in milk replacer or 1.5-2.0 grams of zinc per/head/day for 30 days is toxic to preruminant calves.  High zinc intake interferes with calcium metabolism. 120 milligrams of zinc (as oxide) per kg of body weight for 3 days can cause hypocalcaemia.

Toxicity Signs:

Young calves are more susceptible than adults.  Excessive bawling, increased milk replacer consumption, diarrhea and polyuria followed by pica, then reduced appetite, submandibular edema and emaciation.  Pneumonia, ocular signs, bloat and cardiac errhythmias may occur, terminating in tonic-clonic convulsions, nystagmus and lack of sensorium.  Increased incidence of arthritis and milk fever may occur in adults.

Zinc requirements for cows range from 1200 to 1600 milligrams per day.
Purchased minerals that contain 3000 PPM will have 85.22 milligrams per ounce.
Purchased minerals with 1.9% zinc will contain 539.6 milligrams per ounce.


Deficiency Signs:

Deficiency linked to silent heat, reduced conception, abortions, reduced birth weight, increased percentage of male calves, paralysis and skeletal damage.


Indicated by reduced appetite and growth rate, anemia and abdominal discomfort.  Abortion and cystic ovaries may be associated with excess manganese. Manganese is excreted in bile at rate of 12.7 umol/kg liver.

Daily requirements for Manganese range around 1200 milligrams per/cow/day.
Purchased minerals that contain 2500 PPM will have 71.02 milligrams manganese per ounce.


Deficiency Signs and Effects:

Irritability, trembling, frothing at mouth, hyperaesthesia, tetany, incoordination, convulsions and death.  Death is often sudden with no prior signs.  Sub-clinical hypomagnesemia may reduce food intake and adversely affect milk yield and heart function.  Magnesium appears to play a role in activation of vitamin D.  Hypomagnesemia reduces calcium mobilization in steers, non-pregnant lactating cows and cows at parturition. 


Excess dietary magnesium reduces feed intake, retards growth rate and produces diarrhea and emaciation.  BUN and serum creatinine levels become greatly elevated, and serum calcium is reduced.

Magnesium dietary requirements for cows range from 5,000 to 10,000 milligrams per head/day.
Purchased minerals that contain 5% magnesium contain 1420 milligrams per/ounce.

Formula for Converting % to Milligrams per Ounce (mg/oz.)

Example: The mineral bag label list the Phosphorus to be 12%.
                1. 12% X 284 (conversion factor) = 3408 mg/ounce  
                The percent X 284 (conversion factor) = mg/ounce
If the feeding instructions call for 4 ounces./head/day than 3408 milligrams/ounce X 4 ounces would equal 13632 milligrams of phosphorus - the amount your cows would consume a day with that mineral.

Formula for Converting PPM to Milligrams per Ounce (mg/oz.)

Example: Tag on mineral bag indicates the selenium content to be at 26 PPM per serving.
1.    26 PPM X .0284 (conversion factor) = 0.7384 mg/ounce.  
If the feeding instructions call for 4 ounces/head/day than 0.7384 milligrams/ounce X 4 ounces would equal 2.95 milligrams - the amount of selenium your cows would consume a day with that mineral.  Do you think their systems would be deficient, adequate or toxic with this amount of selenium?

Are you starting to get the idea why it is so important to read and understand labels?

Here is a summary table for the mineral requirements discussed above.

Daily Mineral Requirements for a Cow

Calcium              7500 to 8500     mg/per/day
Phosphorus        4000                   mg/per/day
Copper               250 - 450            mg/per/day
Manganese        1200                    mg/per/day
Zinc                     1200 to 1600      mg/per/day
Selenium             4 to 6                   mg/per/day
Iodine                  25-28                   mg/per/day
Magnesium         5000 to 10,000  mg/per/day

Often times it is necessary to buy individual minerals and add additional amounts of them to a mix already put together in order to get the required amounts up to where they need to be.   The content of the mineral in that “individual” mineral bag is typically given as a percent.

If needing to add extra:  Calcium - look for Calcium Carbonate with a content of 38%.

Calcium and Phosphorus – look for Dicalcium Phosphate with the content of 21% calcium & 18% Phosphorus or Mono Calcium Phosphate with the content of 18% calcium & 21% phosphorus.

Copper – look for Copper Sulfate with a content of 25.2%.

Magnesium – look for Magnesium Sulfate with a content of 31.5%.

Zinc – look for Zinc Sulfate with a content of 35.5%.
You should now be able to read most any mineral bag label or batch mix tag that a mill prepares and determine, using the formulas above, what amounts of each mineral your cattle are taking in assuming they  ingest the recommended daily amount.  The last point I wish to make is that some sources of minerals are more biologically available then others and certain minerals are antagonistic to others which means one may counteract the effect of another.  Start with the information presented here and I am confident you will see favorable results.

So now you have the basic information that helped me go from overwhelming sickness in my herds to the virtual elimination of several diseases, to the return of sustainable profits.  It was a challenge for me then and I challenge each you now to educate yourself, to learn about mineral nutrition and animal health and reproduction.  If you train yourself to recognize the signs caused by mineral imbalances (especially mineral deficiencies) that your livestock exhibit then you too can take action and significantly minimize the occurrence of those illnesses that rob us on a daily basis.   ©  2006 Gearld Fry.

NOTE:  Many cattlemen are finding it increasingly difficult to purchase individual minerals in bulk.  If this is your experience we suggest you contact LancasterAG in Lancaster, Pennsylvania.  They have very reasonable rates and do ship.
"Only be strong and very courageous, that you may observe to do according to all the law which Moses My Servant commanded you; do not turn to the right hand or to the left that you may prosper where ever you go."  Joshua 1:7