Mineral

[kyblockhead]

The University of TN did a study of 1021 forage samples from 2001 to 2004 to determine the trace mineral levels in the forages in Tennessee. They found zinc to range from 21.5 - 28 ppm with adequate level determined to be 30 ppm. They found copper ranging from 5 to 8 ppm with adequate determined to be 10 ppm. They found manganese to range from 106 to 131 ppm with adequate at 40 ppm. They found sulfur in the range of 0.27 -0.28% with antagonist problems above 0.25%. Determining the trace mineral content of forage is the first step but then you also have to take into account the actual availability of those minerals to livestock.

Trace Mineral Supplementation for Kentucky Beef Cattle, ASC-155, November 2003 gave the following anticipated availabilities:
Copper 5 to 25% available
Selenium 28 - 32% available
Iron 30 to 70% available
Manganese 3 - 4% available.

From the forage samples taken by the University of Tennessee you find most trace minerals to be deficient but even manganese which had a much higher level than that determined to be adequate. When you factor that only 3 - 4% of that manganese is available you find you are still actually deficient in meeting the animals needs.

The referenced trace mineral study above indicated that you should never assume that more than 50% of the trace mineral found in forage is actually available to cattle.

 

[cowcamp]

we use a mineral with no salt, then we add the salt to get them to eat want we want them to, right now i mix 5 lbs of white salt to 50 lbs of 16/16 mineral, toget them to eat 4 ozs. aday, when grass is washy in the spring i have to mix a lot more salt to keep them at 3 to 4 ozs. aday.