Supplement Timing May Let Cattle Producers Get More for Less

 Based on preliminary research, cattle producers may be able to spend less on mineral supplementation if they supplement at the right time, says a Montana State University researcher.

Small quantities of minerals are believed to have an impact on both cattle reproduction and disease resistance, says Ray Ansotegui, a Montana State University beef cattle researcher. Maintaining adequate levels of copper and zinc, in particular, are thought to be important in both livestock reproduction and disease prevention.

In the past, beef cattle experts thought cattle did not keep these minerals in their bodies very long. However, results from Ansotegui's research indicate that the liver maintains minerals long enough for producers to give mineral supplements at only specific times of the year.

"Our tests show that supplementing between December 15 and July 1 maintained critical mineral levels in the livers of beef cows," says Ansotegui. "With the price of cattle so low, it may be that producers can strategically target mineral supplements rather than eliminating."

Ansotegui's single year of research took the unusual step of obtaining the level of trace minerals in a cow's liver, in addition to getting tests that showed mineral levels in the blood.

"We're beginning to believe that using the levels of minerals in blood is less reliable than using liver levels," says Ansotegui.

Giving copper and zinc mineral supplements from December 15 1994 to July 1 1995 gave a cow adequate nutrition before the birth of her calf and while the calf was suckling, but Ansotegui's work also showed that the levels of those minerals remained high in the animal into the winter of 1995-96.

If additional research supports his findings, it could mean that producers would not have to give mineral supplements when cows are on summer and fall range. Besides reducing the time during which livestock receive supplements, this would minimize the supplement used by wildlife.

Ansotequi's research was conducted on 60 cows on range near Norris, Montana. The research was reported July 25 at the national meetings of the American Society of Animal Science in South Dakota.