Copper in diet vital during gestation
Cow-calf producers defy nature every spring.
“Look at evolution and natural cycles,” says Jeff Hall, Utah State University Veterinary Diagnostic Laboratory associate professor.
“By calving in February and March, we have shifted the natural cycle to a period of low forage quality and body reserves; plus, we expect the cow to produce a healthy calf and breed back every year,” Hall says.
Hall’s program at Utah State University receives hundreds of blood and tissue samples from throughout the nation. His ICP Mass Spectrometer analyzes minute amounts of minerals in reduced-sized samples and is one of the few in the nation available to livestock producers and supplement companies.
“In the spring of 2008, we saw half as many deficiency cases as 10 years earlier,” he says. “In 2009, those numbers doubled the level 10 years ago.”
Hall attributes increases to the tight economy. “Many people cut their mineral programs to save a buck. Now we are seeing calf health and calving problems related to mineral deficiencies. In Idaho and nationwide, 95% of the animals in herds not supplemented are deficient in copper,” he says. “And in herds supplemented, 20% are deficient.”
• Copper is the most common deficiency in beef cattle.
• Cattle need added copper during the last trimester of gestation.
• Many operators in Idaho feed custom supplement rations.
Signs of copper deficiency
According to Hall, copper is essential for the formation of strong connective tissue in cell walls. “Milk is a poor source of copper,” he says. “Calves should be born with enough in their liver to double their birth weight. It is critical to get enough copper during that last trimester.”
Poor growth rates and reduced immunity are common symptoms of copper deficiency. “Cell walls are weakened and less efficient,” Hall says. “So they absorb less and pass more nutrients out in the feces. Copper-deficient calves will exhibit increased diarrhea and pneumonia”
Routine testing for copper deficiency is rare. “Liver biopsy is the sample of choice,” he says. “Copper is stored only in the liver. Blood levels are fairly constant until the liver runs out of copper, so blood tests only indicate the most extreme cases.”
Concentration of trace minerals in block supplements is not enough, says Hall. “It is better to feed free choice during the last trimester than try to keep minerals in front of cattle on scattered ranges. Animals will eat the same amount of minerals if fed for three months or year round.”
“We are expecting our cows to produce 150% of what they produced 25 years ago with the same groceries to do it with,” says Hall. “Producers need to work with a good nutrient company that will supply what they need.”
Tews writes from Shoshone, Idaho.
This article published in the February, 2010 edition of WESTERN FARMER-STOCKMAN.