CALF_News_June_July_2018

26 CALF News • June | July 2018 • www.calfnews.net T he stocker industry is a critical link between cow-calf and feedlot producers. During drought, those experienced in raising stocker calves apply management strategies, including mineral supplementation and testing forage and water for mineral con- tent. Producers can improve their bottom lines by adding minerals to ensure good weight gains and healthy calves. A balanced mineral program meets animal needs and feeds the rumen’s microflora. According to Stephanie Hansen, Ph.D., feedlot nutrition- ist at Iowa State University, although cattle do not require cobalt, rumenal microbes convert this trace mineral to vitamin B12. When these “bugs” wash downstream to the small intestine, they become a great B12 source for cattle. “There’s good evidence that B12 and cobalt are linked to fiber digestion,” Hansen explains.“Cobalt is probably one of the most important minerals to think about in terms of digesting poor-quality forage.” Typically, as forages mature their min- eral content decreases. However, during drought conditions, grasses often have higher levels of minerals than during years of normal precipitation, thanks to a concentration effect. During a prolonged dry spell, purchased feedstuffs tend to be low in protein, energy and other nutrients cattle require for health and productivity. “Be careful not to overgraze; it’s hard to come back from that,” Hansen advises. “Think of the future of the forage base and keep an eye on calf health. There can be more problems with respiratory issues because there’s more dirt and dust. Either send calves to the feedlot sooner or supplement earlier so they don’t have to regain the performance they’ve lost along the way.” Producers may ensure their animals get available nutrients from stored feedstuffs by providing a balanced mineral program, including chelated trace minerals. Minerals such as copper, zinc, manganese or selenium attach to an organic compound, such as an amino acid, during the manufacturing process. Chelated or organic minerals pass intact from the rumen to the small intestine where they are easily absorbed, providing the animal with much-needed nutrients. John Richeson, Ph.D., conducts feedlot research at West Texas A&M University. He says chelated minerals are less susceptible to antagonists, such as iron, molybdenum and sulfur. “Heat often accompanies drought, and the water intake of your animals will be much higher,” Richeson explains.“If your water contains high levels of iron or sulfur, [they can] bind zinc and copper. If water consumption increases signifi- cantly and the water source is unusually high in antagonists like iron or sulfur, that can cause additional concerns with the trace mineral status of those animals consuming an oral mineral. In that case, be sure the minerals you’re giving are chelated trace minerals.” Chelated trace minerals are particu- larly important for animal health during nutritional stress, especially if calves are transported to a new pasture or the feedyard. Stockers require copper, zinc, manganese and selenium to beef up the immune system, immune response and growth. “We group infection, inflammation and stress together, but they’re unique components stocker cattle are usually subjected to,” Richeson reports.“Those components can actually impact trace mineral use in the animal, especially during pathogenic infection. The immune response against pathogenic infection uses up trace mineral stores. That’s  LEFT: Injectable trace minerals are an ideal way to provide stockers with copper, zinc, selenium and manganese that are quickly available for use by the animal. Photo courtesy Multimin, USA. BELOW: Producers can provide injectable trace minerals during processing upon arrival. Photo courtesy John Richeson, Ph.D., WTAMU. By Gilda V. Bryant Contributing Editor Mineral Supplements Vital for Stockers During Drought