Ag Notes: Monitor mineral consumption in beef herds

August 19, 2003|JERRY LITTLE

All problems in beef cattle are not due to minerals, but it's still important to improve forage quality and to insure cows receive adequate energy and protein to match their nutritional demands during pregnancy, nursing, rebreeding and weaning periods.

Monitor mineral consumption. The very best mineral formula will not work if cattle don't consume it. Mineral consumption varies during the year, but average consumption should be near the level for which the mineral was designed.

Work with mineral dealers. Ask questions. Avoid making hasty decisions. Mineral nutrition is not an easy topic, and you may need a specialized supplement, prepared on a custom basis.

It is possible to have too much of a good thing. Most beef cattle breeds are relatively tolerant of the levels of copper commonly available, but Jersey cattle and sheep are susceptible to copper toxicity. Selenium toxicity is possible, but unlikely due to legal levels allowed in mineral supplements.


Some cow herds may have higher mineral requirements. Genetically superior cattle, with more potential for milk production and calf growth, may have increased mineral requirements (also protein and energy).

Imbalances can be corrected. If sulfur levels are high, additional copper in the supplement can correct the problem. The form of copper used is almost as important as the level. Copper oxide is a poor source of copper and should be avoided. Copper sulfate and copper chloride are commonly used inorganic sources.

Organic copper sources (such as chelates) are more expensive, but may have an important role in correcting copper-sulfur imbalance problems.

Selenium could be a problem, if not properly supplemented. In a recent study, 30 forage samples were analyzed for selenium and more than 93 percent of them were in the deficient range. Other studies have shown that selenium deficiency can be a problem in this region.

Sulfur is also antagonistic to selenium, so deficiencies might be expected. Symptoms of selenium deficiency range from increased incidence of retained placenta to compromised immune functions (more sickness under stress). Most companies that market mineral mixes have products that incorporate selenium at or near the legal limit. Again, ask questions and compare labels.

If it ain't broke, don't fix it. If calving rate is good (90 to 95 percent calf crop), if cattle have healthy hair coats and if there is little sickness, you may not need to change your mineral program.

Jerry Little is Boyle County extension agent for agriculture and natural resources.

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