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There is continued research that points to the benefits of Magnesium-Mica and its various uses in agricultural animal feed. We have included a few brief studies that highlight the usefulness as a pellet binder, its efficacy during production, and its positive impacts on livestock evaluation. Click the links below to view the research, or contact our office by phone (620-537-7025) or email for more information.


The objective of this study was to examine the possibility of using Magnesium-Mica as a pelleting aid either by itself or in combination with sodium bentonite.


The diet used was a standard sorghum, grain - soybean meal based swine finisher diet (Appendix A). The batch size used was 500 lbs. The treatments were as follows: 1) control; 2) 2.5% Magnesium-mica; 3) 2.5% sodium bentonite; 4) 1.25% Magnesium-mica and 1.25% sodium bentonite. Each treatment was pelleted through a CPM Master model pellet mill equipped with a 3/16" X 2" straight bore die. We attempted to hold conditioning temperature at 70°C, however, when the bentonite was used, the temperature could not be held.

The samples for Pellet Durability Index (PDI) determinations were taken immediately after the die, cooled to room temperature and tested by the official procedure (ASAE S-261.5). The results are reported as an average of four determinations per treatment. Production rate was determined by dividing production weight by lapsed production time and reporting in pounds per hour. Energy consumption was determined and reported in terms of kwh/ton. The fines scalped from the pellets prior to packaging were weighed separately and reported as a percentage of total production.


The combined results of the trial are shown in Table 1. Serious production problems were encountered when the treatment with bentonite was pelleted. The results of this run are questionable because the desired condition temperature could not be reached.

When comparison of the results from diets A and B is made, it appears that the Magnesium-Mica resulted in some improvement in both production rate and pellet quality and a corresponding reduction in fines production rate and energy consumption. It should be stressed that only one run per treatment was made, therefore no statistically valid conclusion can be reached.

As previously indicated, the combination of Magnesium-Mica and sodium bentonite (Treatment C) resulted in a superior pellet and very low fines return, however, a loss in production rate and energy efficiency were sustained when the results are compared to Treatments A and B.


Again, the authors want to stress that no scientifically valid conclusions can be reached based on this study because of the lack of replication. It does appear, however, that Magnesium-Mica may offer some benefits in the pelleting operation but several additional trials should be conducted before one can be confident in the results.

Results of Pelleting Trials with Magnesium-Mica

Treatment Rate
A - control 3,333 88.3 6.8 9.7
B - 2.5% Magnesium-Mica 3,846 91.3 5.7 8.0
C* - 2.5% Bentonite 1,521 59.2 14.3 20.3
D - 1.25% Bentonite
1.25% Magnesium-mica
2,091 93.0 3.0 10.6

* - Serious problems were encountered with this run, therefore, the information presented may not be valid.

Journal of Animal Science.

2000 August; 78(8): 2135-43. doi: 10.2527/2000.7882135x.

J. K. Apple, C. V. Maxwell, B. deRodas, H. B. Watson, Z. B. Johnson


A total of 240 crossbred pigs were used in two experiments to determine the effect of feeding magnesium mica (MM) during the growing-finishing period on animal performance and pork carcass characteristics. All pigs were blocked by weight, and treatments were assigned randomly to pens (five pigs/pen) within blocks.

In each experiment, eight pens were allotted randomly to one of three treatments: 1) a negative control corn-soybean meal starter, grower, and finisher diet devoid of supplemental magnesium; 2) the control diets supplemented with 1.25% MM; and 3) the control diets supplemented with 2.50% MM.

In Exp. 1, pigs were slaughtered at the University of Arkansas Red Meat Abattoir, whereas pigs in Exp. 2 were transported to a commercial pork packing plant and slaughtered according to industry-accepted procedures. In both experiments, dietary supplementation of MM had no (P > .10) effect on ADG, ADFI, or gain:feed ratio at any phase during the growing-finishing period. In Exp. 1, MM supplementation had no (P > .10) effect on carcass fatness or muscling. Moreover, Japanese color scores were not (P > .10) affected by feeding pigs MM; however, American color scores increased linearly (P < .01) with increasing levels of MM in the diet. Although MM supplementation did not (P > .10) affect L* and b* values for the longissimus muscle (LM), there was a linear increase (P < .05) in LM a* and chroma values associated with increased MM levels in swine diets.

In Exp. 2, carcasses from pigs fed 1.25% MM had less (P < .05) fat opposite the LM at the 10th rib than untreated controls and pigs fed 2.50% MM and higher (P < .10) percentages of muscle than carcasses of untreated controls. Moreover, the LM from pigs fed 1.25% MM was less (P < .05) red and less (P < .05) yellow than the LM from pigs fed the control or 2.50% MM-supplemented diets. Drip loss from the LM was unaffected (P > .10) by inclusion of MM in the diet.

Results from this study confirm that inclusion of Magnesium-Mica, an inexpensive, inorganic magnesium source, in diets of growing-finishing swine has beneficial effects on pork carcass cutability and quality with no deleterious effects on live animal performance.

Kansas State University. Agricultural Experiment Station and Cooperative Extension Service

Cattleman's Day. 1996; Kansas Agricultural Experiment Station contribution; no. 96-334-S.

K. P. Coffey, F. K. Brazle, Lyle W. Lomas


Seventy-two mixed breed steers (679 lb avg BW) grazing smooth bromegrass pastures for 112 days were fed 2.2 lb/day of either a control supplement (PC) or one containing .075 lb/day of magnesium-mica (PMM). Following the grazing period, steers were placed in a feedlot with pasture groups split such that two of the groups fed each pasture supplement were fed a control supplement (FC) and two groups were fed a supplement containing 10% magnesium-mica (FMM). Steers fed PMM tended to gain faster than those fed PC during the pasture phase (2.41 vs. 2.32 lb/day). Steers fed PMM had higher dressing percentage (P<.05) and net carcass values (P<.06 ). Percent grading Choice was 41.7 for PMM vs. 27.8 for PC, and that difference also was reflected in marbling scores. No differential effect of feedlot supplement was detected for carcass measurements. Magnesium-Mica fed during a pasture phase may affect subsequent marbling scores.


Although steers fed .075lb/day of Magnesium-Mica (PMM) gained faster during the pasture period (2.41 lb per day), the difference was no statistically significant. No significant pasture treatment feedlot treatment interactions were detected (P>.05) for any of the performance or carcass measurements. Therefore, feedlot data were pooled across the main effects of pasture treatment and feedlot treatment. Neither pasture nor feedlot treatment affected feedlot gain, efficiency, or cost of gain (Table 3). These data are in agreement with those from a previous SEARC study.

Feedlot supplements had no effect on any of the carcass measurements evaluated in this study. However, steers fed PMM had heavier (P=.11) hot carcass weights and higher (P<.06) dressing percentages than those fed PC (control supplement). Fifty percent more steers graded USDA Choice in the groups fed PMM (.075lb/day Mag-Mica) compared to those fed the control supplement. These factors combined to produce a $19.92 higher (P<.06) net carcass value.

Considering these data with previous data, we conclude that Magnesium-Mica fed at a level of 9-10 lb/ton of dry matter should have minimal effects on gain and efficiency of feedlot steers, but feeding Magnesium-Mica during the grazing or feedlot period may have a significant impact on carcass marbling score and, therefore, value of the cattle.

Full Report with Tables

Kansas State University. Department of Dairy and Poultry Science.

Robert C. Dobson


The effects of magnesium (Mg) supplementation on body mineral balances and blood concentrations of Ca, Mg, P, and K were studied in six lactating Holstein cows. Magnesium from MgO (Magnesium-Oxide) and from Magnesium-Mica (Micro-Lite sourced) were added to a basal concentrate ration containing .224% Mg to increase its Mg content to .343 and .381% respectively. Two 3 x 3 Latin square designs were used where each cow was fed each ration for one of three 3-week periods. Average daily Mg consumption per cow over all periods was 30.1, 38.7, and 41.5 g for control, MgO, and Magnesium-Mica treatments respectively. Analysis of variance showed no significant relationships of treatments with body balances of Mg, Ca, P, or K; however, Mg intake was significantly (P .01) correlated with magnesium balance (r=.78).

Blood samples were collected twice weekly through the trial. While supplementation did significantly increase whole blood and serum Mg concentrations over controls, no other significant effects on blood or milk were observed. However, Mg supplementation exhibited a trend toward increasing milk fat test. Interrelationships of blood constitutents were examined. There were few correlations which were significant either statistically or in magnitude of correlation. Average whole blook (WB) and serum (S) values and standard deviations found in mg/100 ml for the various constituents were WB Ca, 9.92 +/- 1.87; S Ca, 10.64 +/- .56; WB Mg, 2.13 +/- .44; S Mg, 2.43 +/- .28; WB P, 18.74 +/- 1.87; S P, 7.15 +/- 2.38; S K, 14.17 +/- 1.64; and WB NH3, .017 +/- .76. Serum ionic Ca, probablyt the physiologically active form of Ca, had a mean value of 1.21 +/- .97 mM and was less variable than S Ca and was only partially significantly correlated with either WB Ca (r=.152) or S Ca (r=.274, P .05) in these lactating cows.

From balance data it would appear that current allowances for Ca and K are satisfactory while Mg and particularly P are slightly low. Magnesium-Mica appeared to be an entirely satisfactory Mg supplement. Its palatability and desirability as a free choice supplement should also be examined. Its application to the increasing incidience of grass tetany may prove useful. Even though the disease is not a simple Mg deficiency, Mg supplementation usually prevents severe outbreaks.

Story in Brief

Magnesium-Mica was added to a test feed mixture at levels of 0, 2.5, 5.0 and 7.5 percent. The product increased pellet mill production .51 tons per hour for each one percent addition. At the highest level, this represented an increase of 100 percent in the production rate of the test mill.

When adding Magnesium-Mica to a formula, each percent added will increase the level of elemental magnesium in the formula 0.08 percent. In many cases this is desirable in livestock supplements which only make up a small percentage of the diet. When added to complete formulas only 5 percent Magnesium-Mica would by itself cause the magnesium in the formula to exceed the NRC recommended maximum of 0.4 percent. The addition of Magnesium-Mica to a 20 percent protein range cube greatly improved both production rate and pellet quality.


The objective of the experiment was to determine if Magnesium-Mica would increase the production rate of a pellet mill while holding pellet quality constant as other production parameters varied to optimize input and pelleting consistency.

A test was conducted to evaluate the effect of adding Magnesium-Mica at 0, 2.5, 5.0, and 7.5 percent of the mixture on the production rate and pellet quality of a 20 percent protein range cube. Equipment used was Century model 100 horse power California pellet mill. The feed was pelleted through a 3/4 inch die and the pellets were cooled using a Hays & Stokes double pass cooler. To maintain the same protein level, the ratio of mids to cottonseed meal was altered when more Magnesium-Mica was added. (see figure 1)

Figure 1

Magnesium-Mica level0 2.5 5.0 7.5
Wheat Middlingss 76.00 72.00 67.75 63.50
Cottonseed meal 19.00 20.50 22.25 24.00
Molasses-masonex 4.96 4.96 4.96 4.96
Vitamin A-30,000 0.04 0.04 0.04 0.04
Magnesium-Mica 2.50 5.00 7.50

Results and Discussion

The addition of Magnesium-Mica significantly increased production rates of the test feed. The addition of more cottonseed meal to maintain a constant 20 percent protein content of the test feeds as Magnesium-Mica increased also may have had a slight beneficial effect on pellet quality and production.

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