STEPHEN PATTON
Agricultural Experiment Station Research Annual Report 2013 Kentucky College of Agriculture, Food and Environment
(l-r) Phil Bridges, Jamie Matthews, and Roy Burris evaluated the most metabolically effective form of selenium for cattle.
Form Matters Cattle consuming forages grown in Kentucky may not be getting necessary amounts of selenium, a trace element that’s necessary for growth, reproduction, and immune status. Producers often need to add supplements to their cattle’s diets. An interdisciplinary team of UK Animal and Food Sciences researchers consisting of Jamie Matthews, nutritional physiologist; Roy Burris, extension beef specialist; and reproduction physiologist Phil Bridges, conducted a series of mineral intake trials to evaluate the most metabolically effective form of selenium to include in cattle mineral mixes. They conducted a three-year study with grazing beef cattle at UK’s Research and Education Center in Princeton. The team used Calan gates, a specialized piece of equipment used to control and record feed intake, to measure individual animal intake of mineral mixes containing selenium. They then expanded the pilot trials to production herd-sized experiments. The researchers used DNA microarray analysis, a process that allowed them to isolate genetic contents of cells and determine which genes were expressed, or turned on. Of particular interest were genes involved with growth, reproduction, and immunity.
The principal take-home message from these trials was that each different form of supplemental selenium consumed, whether inorganic, organic, or a mixture of the two, affects gene expression in the liver, cows’ skeletal muscles, and testes of their newborn calves. Since the trial found that gene expression of newborn calf testes was dependent on the form of selenium consumed by their dams, the team is conducting an experiment to determine if the form of selenium can improve fertility in sexually mature bulls. “One of the things we are most proud of about this study is we are getting both the molecular and the practical, and the more we do that, the quicker the translation to the farmer,” said Matthews. And getting the results of the research into the hands of beef producers is important to the team. “We have to have enough confidence in our research to make a recommendation, and we feel that we are doing solid research that matters,” Burris said. The college and the Alltech-University of Kentucky Animal Nutrigenomics Alliance jointly funded the research. —Jeff Franklin 23