Resource:    Dr. Ivan Rush, University of Nebraska - Scottsbluff
Dr. Rick Rasby, University of Nebraska - Lincoln

### Calculating Trace Minerals for Beef Cows

This calculator will help you determine if the desired daily trace mineral consumption of your cow herd is being met. If it is not being met, then the calculator will help you through the calculation to determine the percentage or concentration of that trace mineral needed in the mineral supplement to meet the desired trace mineral daily consumption.

Choose a Trace Mineral to evaluate :

Section 1

This section will help you estimate the feed capacity, in pounds, on a dry matter (DM) basis for the female that you are evaluating the Trace Mineral for. This is the total pounds of feed that the animal can eat each day. Dry matter basis means that all the water has been removed from the feed, which is not how feeds or forages are fed or consumed, but because all feeds differ in their moisture content, nutrient requirements for beef cattle are on a feed dry matter basis.

 Estimate or project the daily feed intake on a Dry Matter (DM) basis : lb/day (If you don't know how to estimate total dry matter capacity, which is the amount of feed that it takes to fill the rumen, fill in the following field for Cow Weight, select Forage Quality and Stage of Production, and the program will calculate feed intake on a DM basis for you.) Enter the Cow Weight : 800 - 1400 lb Choose the Forage Quality : Select quality Low Average High Choose the Stage of Production : non-lactating lactating Dry Matter feed capacity as a percent of body weight : %

Section 2

Estimate the amount of the Trace Mineral from the forage and/or feed consumed by the animal.

A. Estimating the amount of Trace Mineral from grazed forage.

 Enter the pounds of forage or hay consumed or fed daily on a DM basis : lb/day (The number entered here is based on the daily feed dry matter capacity estimated in Section 1. This number should not be greater than the number in Section 1. If the animal is consuming forage and no other feed, then enter the number estimated in Section 1. If the animal is eating forage and some other feed, then this number is somewhat less than the number estimated in Section 1.) Enter the concentration or percentage of the Trace Mineral in the forage or hay: ppm,  or      percent Amount of Trace Mineral supplied by the forage or hay : mg

B. Estimating the amount of the Trace Mineral from other feeds (hay, grain, protein supplement, etc.).

If there is another feed being consumed in addition to the grazed forage or hay, then fill in the following fields. The total amount of feed consumed daily by the animal from A and B in Section 2 should not exceed the amount estimated in Section 1. If there are no other feeds, then go to Section C.
 Enter the pounds of the feed consumed or fed on a DM basis : lb/day Enter the concentration or percentage of Trace Mineral in the Feed : ppm,  or      percent Amount of the Trace Mineral Supplied by this Feed : mg

(If there is another feed being fed in addition to the grazed forage, and the feed mentioned above, then fill in the following fields. If there are no other feeds, then go to section C.)

 Enter the pounds of feed consumed or fed daily on a DM basis : lb/day Enter the concentration or percentage of Trace Mineral in feed : ppm,  or      percent Amount of the Trace Mineral Supplied by this feed : mg

C. Estimating the amount of the Trace Mineral from the mineral supplement.

If you are feeding a mineral supplement, then fill in the following fields. The total amount of feed consumed daily by the animal from A, B, and C in Section 2 should not exceed the amount estimated in Section 1. If there is no mineral supplement being fed, you still need to estimate or project the amount of mineral that will be consumed on a per head basis. Most mineral supplements have a feed tag that indicates their estimate of daily intake. Most mineral supplements are consumed at a rate of 2 to 9 oz/head/day.

 Enter the daily amount of the supplement consumed : oz/head/day gm/head/day lb/head/day mg/head/day Supplement intake expressed in other units : oz/head/day gm/head/day lb/head/day mg/head/day Enter the concentration or percentage of Trace Mineral in supplement : ppm,  or      percent Amount of the Trace Mineral supplied by the supplement : mg

Section 3

This section will check the total amount of feed consumed on a dry matter basis. The DM intake estimated in Section 1 will be compared against the amount of feed that is being consumed in Section 2. If the DM intake estimated in Section 1 is within 1 pound of the sum of the estimated amounts of the feed being fed from Section 2, then proceed to Section 4. If not, go back to Section 2 and check the amount of each feed being consumed by the animal.

 Estimated DM intake from Section 1  lb DM intake from Section 2  lb

Section 4

This section will calculate the total amount of the Trace Mineral coming from all the feed sources that the animal is consuming. The number in the following field is the sum of the Trace Mineral consumed by the animal from the grazed forage, feed, and mineral supplement you listed above.

 Amount and concentration of the Trace Mineral consumed daily from the feeds and supplement listed above. : mg/head/day  ppm

Section 5

This section will help you determine if the daily desired Trace Mineral intake is being met with the diet that is currently being consumed by the animal.

 Enter Trace Mineral NRC Requirement or desired Trace Mineral intake as a concentration (ppm) or percent in the ration : ppm,  or      percent    NRC Recommendations (in ppm): Requirement Desired daily Trace Mineral consumption : mg/head/day (This number is calculated by multiplying the number in the first field in Section 5 and DM intake from Section 1) Amount of Trace Mineral from forage and feed : mg/head/day Amount of Trace Mineral from the mineral supplement : mg/head/day Is the daily Trace Mineral consumption adequate or deficient : mg/head/day

Section 6:

If the daily Trace Mineral consumption is deficient, this section will calculate the percentage of Trace Mineral needed in a mineral supplement that could be purchased to meet the desired daily consumption. If you are blending a mineral mix to be fed to the cow herd, this section will calculate the amount of the Trace Mineral source that needs to be included in the mix to meet the desired daily consumption

 The Supplement as a percent of the total ration : percent of total ration Percent or concentration of the Trace Mineral needed in supplement to meet the desired daily consumption : percent of supplement   ppm of supplement Trace Mineral Source and Percent of Trace Mineral in that compound: First select a Trace Mineral above Percent of Trace Mineral source needed in supplement to meet desired daily consumption : % Amount of Trace Mineral source needed in supplement to meet desired daily consumption : lb/ton mg/lb ppm

Use this calculator as a guide to Trace Mineral supplementation of your beef herd. No warranty of results is guaranteed because results will vary according to management style, bio availability of nutrients, and animal type.

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