Journal of the NACAA
ISSN 2158-9429
Volume 13, Issue 1 - June, 2020


Smith, D. , County Director/Agriculture & 4-H Youth Programs, USU Extension
Hall, J., D.V.M., Head of Diagnostic Laboratory, USU Extension


Postmortem diagnostics by Dr. Hall and the rest of his team at the Utah Veterinary Diagnostic Laboratory in Logan, Utah, showed that when producers decrease or completely stop vitamin and mineral supplementation, an increase in vitamin and mineral deficiencies occur. These deficiencies can result in a reduction in growth rates, weak immune system function, inadequate response to vaccinations, increased cases of infectious diseases, increased death losses, and mediocre reproductive performance in herds. Dr. Hall was working with two producers in Idaho. One producer felt an excellent mineral package was essential, and the other thought it was a waste of money. The rancher who considered a mineral package essential had a 10% better breed back rate, and calf weights on average were 70 lbs. heavier.


Excellent reproductive efficiency is essential for profitable cattle operations. Most of the time range, forage, and winter feed without vitamin and mineral supplementation does not contain the needed nutrients for proper growth, development, maintenance, and reproductive performance. First, it is essential to determine what the cow's present nutritional needs are and what is being supplied by forage currently being consumed by the cow. After determining dietary needs, a vitamin and mineral package must be formulated to meet any deficiencies. Liver samples of 10% of the herd taken by a veterinarian can identify deficiencies that may be occurring due to improper supplementation.



An early research study conducted on the King Ranch in Texas, (1930's-40's) demonstrated the importance of supplimenting cattle with phosphorus. "In Trials 1 and 2, percent calf crop weaned increased 40 and 41 percent, weaning weight increased 69 and 49 pounds, and calf weight weaned per cow exposed increased 156 and 165 pounds, respectively, with phosphorous supplementation (Appendix Table 1; Herd, 1997)". The return on per dollar invested depended on which phosphorus suppliment was used. In the study, the phosphorus suppplements that were fed to the cattle returned between $3.95 to $12.35 per dollar invested. As a result of the King Ranch Study, many cattlemen began supplementing their livestock at a rate of six pounds of phospersous per year on native rangeland that is not fetilized (Herd, 1997). Cows grazing on improved and fertilized pastures however, do not need this much added phosphorous because the forage may contain up to  three times the amount of phosphorus found in native pasture . Taking forage samples of what the cattle are eating and sending the forage to a lab for nutrient content analysis is more reliable than using book values for most forages. Depending on the producer's feeding program, it makes sense to have at least two different minerals throughout the year. It may make economic sense to have up to four, depending on your operation.




The following table identifies some of the clinical signs that become apparent when copper, manganese, selenium, zinc, Vitamin A and Vitamin E are deficient. This is a summary of the work done by Dr. Hall at the Utah Veterinary Diagnostic Laboratory in Logan, Utah (Table 1).



Table 1. Clinical signs associated with copper, manganese, selenium, zinc, vitamin A, and vitamin E are deficiencies.



The above table is evidence of the importance of sufficient levels of micronutrients in a brood cows diet. Cattlemen do not want any of the clinical signs showing up in their herds because it reduces the number of cows that are pregnant and prohibits proper growth and development of calves, which in turn decreases net return. Beef cows require macro minerals such as calcium, phosphorous, sodium, chlorine, potassium, and magnesium. According to Chris Reinhardt from Kansas State University, "Clinical deficiencies of minerals occur when a required mineral has been deficient in the diet for an extended period. Producers can see these deficiencies in obvious outward symptoms showing the animal lacks a mineral or minerals" (Reinhardt, 2015).

An example of this is when an intense phosphorous deficiency in the western range states resulted in cattle chewing on bones. One of the clinical signs that indicate a cow is exceptionally deficient of phosphorus is that "she will not breed or have a calf. A cow cannot reproduce without adequate phosphorus" (Reinhardt, 2015). "Nutrition is the most critical factor in getting cows pregnant" (Waldner, 2019). It is cost-effective to have cattle at a level plane of nutrition most of the year. There are times when there are fewer resources available, and it may make sense to let the cow's condition slip a little if they can gain the weight back before calving and breeding season. 



There may be several reasons why cows often do not consume enough of the mineral to meet their needs. If the animals have too much salt in their mineral or water source, it may be limiting how much mineral they will consume. The placement and availability of minerals will also have a bearing on how much mineral cows will consume. For example, if the mineral is miles from the water source and the cows never go there, it will not get consumed. Another reason for mineral defficiencies is that some minerals are antagonistic, meaning too much of one mineral will prohibit the absorption of another mineral. For example, "Mineral imbalances, rather than simple mineral deficiencies, were frequently found. Sulfur (>.3 percent) and iron (>250 PPM) levels were often high in diets antagonistic to copper and selenium utilization. Molybdenum, a well-known copper antagonist, was not extremely high but would reach 2 to 3 PPM, which is a problem when combined with high sulfur" (Herd, 1997).




As previously mentioned, Dr. Hall was working with two producers. One producer considered a good mineral package to be important, and the other thought it was a waste of money. The rancher who believed that a mineral package was important had a 10% better breed back rate, and calf weights were 70 lbs. heavier (Hall, n.d.). The cost of a good mineral program is between $25.00 and $35.00 per cow depending on location. The following scenario uses a 500-cow operation as an example. For 500 cows, it will cost $17,500 to have a good mineral program. The improved pregnancy rate on 500 cows will have a cost savings of $41,071 because there will be 50 fewer cull cows and replacement heifers—this improved pregnancy is a reduction of $821.42 per head. $821.42 is the cost of replacement heifers minus the income from selling cull cows. A conservative increase of 50 lbs. in weaning weight on 425 cows at $1.50 per pound results in $31,875 additional income from the extra lbs. gained. The total additional income from a good mineral program was $72,946, with a cost of $17,500. The net income is $55,446. To figure the return on investment $55,446/$17,500 X 100 = 316% return on investment.

There are other benefits of having a healthy cow herd, such as less time and money spent on treating sick cattle and a lower death loss. Utah Veterinary Diagnostic Laboratory found that over 90% of the calves diagnosed with "summer pneumonia" or "dust pneumonia" have a copper deficiency, selenium deficiency, or both (Hall n.d). Cows that are in poor health because of improper mineral supplementation do not respond to vaccines and other medications.



Proper vitamin and mineral supplementation can get cows to breed back promptly. The key to having a successful mineral program is determining the present needs of the cow, finding out what is lacking in the forage, or feeds the cattle are consuming and supplementing them to meet those needs. By implementing a good mineral program, producers will see a significant positive impact in return-on-investment.




Hall, J. (n.d.). Common Vitamin and Mineral Abnormalities in Beef Cattle, Utah Veterinary Diagnostic Laboratory,Department of Animal, Dairy, and Veterinary Sciences, Utah State University.

Herd, D. (1997). Mineral Supplementation of Beef Cows in Texas (1997) Texas A&M Agrilife Extension [online]

Reinhardt, C. (2015). Mineral Needs of Cattle Throughout the Year (2015). News story Kansas State [On-line].

Waldner, C. (2019). Preventing Reproductive Failure in Cow-Calf Herds (2019). Beef Cattle Research Council website. [On-line]