*John D. Arthington is with the University of Florida Range Cattle Research & Education Center in Ona, Fla. To expedite answers to questions concerning this column, please direct inquiries to Feedstuffs, Bottom Line of Nutrition, 5810 W. 78th St., Suite 200, Bloomington, Minn. 55439, or email [email protected]
CATTLE have a specific nutritional requirement for trace minerals, which are known to support physiological functions related to growth, reproduction and immunity.
For grazing cattle, forage is the primary source of trace minerals, with secondary sources being water and ingested soil. In almost all cases, these sources will not fully supply the requirements of grazing cattle, which can result in a deficiency in one or more of the trace mineral nutrients.
Understanding the specific deficiency and devising a management plan for successful supplementation is the key to optimizing trace mineral nutrition and, thus, overall cattle performance.
Supplementation of trace minerals may occur through a variety of means, including free-choice loose-mineral mixes, trace mineral blocks and fortified energy/protein supplements. Injectable trace minerals (ITMs) are another method of supplementation. ITMs have been available for many years, but the technology, targeted application and scientific assessment of efficacy have been a subject of attention more recently among cattle producers, veterinarians and researchers.
An advantage of ITMs over traditional oral supplementation methods is the targeted delivery of a known amount of trace minerals to individual animals. This removes the variability associated with annual fluctuations in voluntary intake, which is common among cattle that are provided a free-choice mineral mix (Arthington and Swenson, 2004).
In addition, ITMs can be used within production environments that might experience difficulty managing the routine delivery of free-choice mineral mixes, such as extensive rangeland systems, seasonal grazing of mountain meadows and seasonally flooded pastures.
Further, the contribution of wildlife to the overall consumption and disappearance of free-choice mineral mixes can cause complications in these production environments and add further value to the use of ITMs.
My research group's interest in investigating ITMs originated from research findings of colleagues at other universities that reported increased mineral status (Pogge et al., 2012) with increased feed efficiency (Clark et al., 2006), reduced treatments for illness (Berry et al., 2000) and reduced morbidity treatment costs (Richeson et al., 2009) in stressed feeder calves.
The specific aim in the current studies was to assess measures of mineral status, performance and immune competence in beef calves receiving an ITM or a control injection of sterile saline.
In experiment 1, either a single 7 mL subcutaneous injection of an ITM (MultiMin) — containing 15 mg/mL of copper, 40 mg/mL of zinc and 10 mg/mL of manganese as disodium EDTA chelates and 5 mg/mL of selenium as sodium selenite — or 7 mL of sterile saline (control) was administered to weaned steer calves concurrently with a single dose of a commercially available modified live vaccine (Arthington and Havenga, 2012).
All calves enrolled in the study were determined to be seronegative for the key viral pathogens targeted by the vaccine: bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus-1 (BVDV-1) and BVDV-2. As a response variable, serum neutralizing antibody titers were measured following vaccination.
On the day of vaccination and treatment administration, serum concentrations of copper, zinc, manganese and selenium were similar among all steers, and all values were within the sufficient range for cattle, suggesting that there were no pre-existing mineral deficiencies among the group of steers utilized in this study.
By day 14 after treatment administration, steers receiving the saline control treatment experienced a decrease in serum zinc and selenium concentrations, and on that sampling day, those levels were less than steers receiving ITMs.
Neutralizing antibody concentrations to BVDV-1, BVDV-2 and BHV-1 (the primary causative pathogen for infectious bovine rhinotracheitis) increased in all steers following vaccination. Antibody titers against BHV-1 were greatest for steers receiving ITMs versus the control on days 14, 30 and 60 post-vaccination (Figure 1).
Additionally, there were no visible signs of injection site inflammation that were sometimes common in earlier ITM preparations, particularly copper-containing injectable supplements (Boila et al., 1984; Chirase et al., 1994).
In experiment 2, 34 yearling heifers were randomly assigned to receive four 2.5 mL injections of ITM or sterile saline (control) on days 0, 51, 83 and 127 of the study (Moriel et al., 2012).
The ITM product used in experiment 2 contained 15 mg/mL of copper, 60 mg/mL of zinc and 10 mg/mL of manganese as disodium EDTA chelates and 5 mg/mL of selenium as sodium selenite (MultiMin 90).
The heifers grazed winter-stockpiled limpograss pastures and were provided free-choice stock salt with no added trace minerals. On day 51, at the time of the second injection, all heifers were challenged with a 10 mL injection of a 25% porcine red blood cell (RBC) solution as a novel pathogen exposure.
The production of antibodies against porcine RBC (via hemagglutination procedures) was found to be greater for heifers receiving the ITM than the control (Figure 2).
At the end of the study, liver biopsy samples were collected from all heifers to determine trace mineral status. Heifers receiving the ITM had a 21% greater average daily gain than control heifers: 0.69 lb. versus 0.57 lb. per day.
In addition, by the end of the evaluation, heifers receiving the ITM had greater liver concentrations of selenium compared to control heifers: 0.88 mg versus 0.48 mg/kg on a dry matter basis.
Collectively, these findings suggest that the trace mineral status of cattle can be increased by the administration of ITMs. Additionally, antibody production in response to vaccine administration appears to be heightened in calves receiving ITMs. These responses appear to be evident even in calves exhibiting adequate trace mineral status.
It is unclear, therefore, if these observed increases in antibody titers are a response to increased trace mineral status or a priming response to the immune system. Nonetheless, this heightened immune response may be an important contributing factor to the improved measures of health and performance reported by other investigators in previous studies.
The Bottom Line
Trace mineral injections are not to be used as sole replacements for more traditional nutritional sources of minerals but as a complement to a properly formulated mineral nutrition program that also addresses the animals' needs for supplemental macro-minerals, such as salt, phosphorus, potassium and magnesium.
In some circumstances, particularly with stressed calves or growing animals, the use of ITMs may improve performance and immune competence. Also, production systems whose animals have difficulty with voluntary consumption of free-choice minerals or struggle with the presence of mineral antagonists (i.e., sulfur and molybdenum) may find benefits from the inclusion of ITMs in their management systems.
Arthington, J.D., and L.J. Havenga. 2012. Effect of injectable trace minerals on the humoral immune response to multivalent vaccine administration in beef calves. J. Anim. Sci. 90:1966-1971.
Arthington, J.D., and C.K. Swenson. 2004. Effects of trace mineral source and feeding method on the productivity of grazing Braford cows. Prof. Anim. Sci. 20:155-161.
Berry, B.A., W.T. Choat, D.R. Gill, C.R. Krehbiel and R. Ball. 2000. Efficacy of MultiMin in improving performance and health in receiving cattle. Oklahoma State University. Anim. Sci. Res. Rep. p. 61-64. Accessed March 18, 2012, at www.ansi.okstate.edu/research/research-reports-1/2000/2000-1%20Berry%20Research%20Report.pdf.
Boila, R.J., J. Devlin, T.J. Drysdale and L.E. Lillie. 1984. Injectable Cu complexes as supplementary Cu for grazing cattle. Can. J. Anim. Sci. 64:365-378.
Chirase, N.K., D.P. Hutcheson, G.B. Thompson and J.W. Spears. 1994. Recovery rate and plasma zinc and copper concentrations of steer calves fed organic and inorganic zinc and manganese sources with or without injectable copper and challenged with infectious bovine rhinotracheitis virus. J. Anim. Sci. 72:212-219.
Clark, J.H., K.C. Olson, T.B. Schmidt, R.L. Larson, M.R. Ellersieck, D.O. Alkire, D.L. Meyer, G.K. Rentfrow and C.C. Carr. 2006. Effects of respiratory disease risk and a bolus injection of trace minerals at receiving on growing and finishing performance by beef steers. Prof. Anim. Sci. 22:1-7.
Moriel, P., P.G.M.A. Martins, G.C. Lamb, L.J. Havenga and J.D. Arthington. 2012. Effects of injectable trace minerals on the humoral immune response to porcine red blood cell challenge and fertility in beef heifers. J. Anim. Sci. 90(E-Suppl. 3):333 (abstr.).
Pogge, D.J., E.L. Richter, M.E. Drewnoski and S.L. Hansen. 2012. Mineral concentrations of plasma and liver after injection with a trace mineral complex differ among Angus and Simmental cattle. J. Anim. Sci. 90:2692-2698.
Richeson, J.T., E.B. Kegley, D.L. Galloway Sr. and J.A. Hornsby. 2009. Supplemental trace minerals from injection (Inject-A-Min vs. Mineral MaxII) for shipping-stressed cattle. J. Anim. Sci. 87(E-Suppl. 3):27 (abstr.).