Trace minerals are important for keeping cattle healthy

Deficiencies of trace minerals like phosphorus, copper and selenium in beef cattle can have some serious ramifications, not the least of which are reproduction problems for breeding cows. But with proper care antd maintenance, experts say, these deficiencies can usually be avoided.

Beef cattle with phosphorus deficiencies will appear gaunt, lethargic, have reduced appetites, loss of bone and have a rough hair coat. Cows will also show signs of reduced intake, reduced conception rates, anestrous, reduced milk production and their calves will have a reduced rate of gain.

The most serious phosphorus deficiency in breeding cows shows up in reproduction problems.

Daniel Drake, University of California Cooperative Extension farm advisor for Siskiyou County, said that's the most common thing and animals wouldn't get bred at a rate a producer would expect.

Phosphorus is a relatively common deficiency, particularly with dry mature feed, and because reproduction is so important, it has often been added just to be on the safe side. But because phosphorus has become more expensive, producers are taking a closer look at that practice, Drake said.

Phosphorus has always been the most expensive ingredient in the trace mineral mixes, but it's gotten even more expensive recently, Drake said. This makes it more important for ranchers to pinpoint whether feed needs phosphorus rather than arbitrarily adding it in.

A copper deficiency can also be a problem for beef cattle and symptoms can include chronic diarrhea, weight loss, poor weight gains in calves, sudden death in adult cattle, swollen joints, broken bones (ribs and legs), light hair coat (gray in Angus, yellow in Herefords) and increased susceptibility to disease.

Copper deficiencies are actually two problems, Drake said. In some cases, it's a frank deficiency where there's just not very much copper. The other problem is that sometimes there are reasonably normal levels of copper in forages, but there are also high molybdenum levels. Molybdenum interferes with a cow's ability to absorb copper, Drake explained.

Selenium deficiencies can also be harmful, and they can cause white muscle disease in calves, abortions, infertility, retained placenta (afterbirth), chronic diarrhea, weight loss, poor weight gains and decreased immune function, which makes cattle more susceptible to disease and decreases their response to vaccines.

White muscle disease affects the muscle, particularly the muscle of the heart, Drake said.

"They'll be white striations and white stripes in there," he said.

A selenium deficiency can also result in retained placentas. A retained placenta will keep the cows from coming back into heat.

"That's sort of a heads up if you have retained placentas. They'll often end up with a long time period to recover from expelling the placenta. That can be a problem," Drake said.

The symptoms for mineral deficiencies are often not definitive for one problem alone, Drake said. For instance, a rough hair coat that's not very lustrous can be an indication of several possible problems.

If a producer suspects a mineral deficiency, where does he or she start?

"The trace mineral page is a real good place to start and see if your area has historically had problems with a specific mineral," Drake said.

Drake and his extension colleagues have put together a trace mineral page that is available online at http://animalscience.ucdavis.edu/MineralProject/. Producers can go to the webpage, type in any county in California, and find out about the levels of phosphorous, selenium and copper for that particular county.

The webpage tells producers if there's a good likelihood they're seeing mineral problems, how to sample, and ways to supplement, Drake said.

Mineral deficiencies are more of a problem with beef cattle because they typically don't consume feeds from any other sources.

"If the local area is deficient, then the animals will be deficient also," Drake said. "In general, if the soils are deficient, then all of the folks in that immediate area are going to have deficiency problems."

Part of the process should include talking to other ranchers, veterinarians and farm advisors to find out if there are mineral shortages in the area, he said.

If a producer suspects a mineral deficiency, the next step is to test the animals, Drake said.

"Testing the animal itself is a much better way because then you know what's actually been absorbed and what's in the animal, in the blood or in the liver," Drake said. "The ideal method for copper is through liver samples. Those can either be done through a veterinarian, or you can do it with animals that you're processing."

Drake said the next best testing for copper is blood samples.

"The bottom line is, you really need to check your individual animals, and typically sampling about 10 head in a management group is representative," Drake said.

There is a danger of over supplementing, he said.

"Almost anything you can give too much, and so you do need to follow some guidelines, and follow the recommendations that the various products have so that you don't overdo it," Drake said. "After a mineral supplement program has been implemented, it has to be tested again to see if the supplements were adequate. Are we still too low? Or did we get too much? And so it's very important to come back and do that check."

He emphasized that the levels need to be monitored to ensure the cattle are where they need to be. Tests are expensive, and so it's good to use all the other information first. If a mineral deficiency doesn't appear to be the problem, then don't spend money on testing, Drake said.

If, however, the information suggests a mineral deficiency, then it's a good idea to check your animals, Drake said, adding that a mineral deficiency is bad, but too much isn't good either.

(Kathy Coatney is a reporter in Corning. She may be contacted at kacoatney@gmail.com.)