Beef cow record summaries have typically shown that herds with the lowest feed costs tend to be in the high third in profitability. Feed efficiency is the single most important production measure in feedlot cattle in relation to cost of production.
Feed efficiency also contributes to more efficient resource use and a lowered carbon footprint. This has become a metric for environmental sustainability improvements.
There are several approaches to improve feed efficiency. Management of feed resources before and during feeding, proper supplementation to meet requirements, sorting cattle into similar management groups, feed testing and analysis, and more precise weighing and delivery of feed are examples of nutritional approaches to improve the efficiency of cattle. Control of parasites and disease improves feed efficiency. Technologies such as ionophores, implants and beta agonists are used explicitly to improve efficiency.
What has remained elusive is genetic improvements in feed efficiency. Some efficiency gains can be found through selection for growth rate, but direct selection requires the collection of individual feed intake data.
This month marks the beginning of the final year for the five-year, $5 million project, the National Program for the Genetic Improvement of Feed Efficiency in Beef Cattle. This USDA integrated project on evaluating feed efficiency in beef cattle is led by Dr. Jerry Taylor at the University of Missouri and includes 20 researchers and extension specialists from 10 universities.
The project measured individual feed intake phenotypes of more than 8,000 head of cattle while capturing the high-density genetic profiles of those same cattle. Nutritionists on the project found that efficient cattle had improved feed digestibility and that cattle selected for feed efficiency generally will be more efficient on both forage and grain based diets.
Results from genetic analysis found important genes that explain differences in feed efficiency. Interestingly, these genes differ between breeds, so there will not be a one-size-fits-all test for feed efficiency. Look for this information to be incorporated into commercial DNA tests and breed association EPDs for efficiency in the very near future.
Simple and cheap genetic tests for sorting feedlot cattle into management groups has proved more elusive but remains a goal for the future. More information on this project can be found at the project’s website. 
This originally appeared in the Iowa State University Growing Beef enewsletter.
Dan Loy
Director
Iowa State University – Iowa Beef Center
