Update on the WHA forage-based bull performance and efficiency test | TSLN.com

Update on the WHA forage-based bull performance and efficiency test

Steve Paisley

As grain prices continue to rise, and ethanol production continues to dramatically impact demand for corn, affecting all feed grains, beef production will continue to shift more towards forage-based production systems.

We have certainly experienced this trend in Wyoming, as our statewide cow-calf inventory continues to contract, and the number of summer and winter yearling cattle has grown dramatically. As relative feed prices continue to shift, sustainable beef systems will require animals that grow and gain well on either grazed forage or roughage-based diets. Selecting seedstock animals that gain efficiently on high forage diets is one of the first steps.

Two years ago the Wyoming Hereford Association (WHA), with the help of Scott Keith of the Wyoming Business Council, began planning a forage-based bull test at the James C. Hageman Sustainable Agriculture Research and Extension Center (SAREC) utilizing the GrowSafe feeding system, which allows for individual animal feed intake and feed efficiency to be calculated. The ultimate goal was to produce performance and residual feed intake (RFI) values for a cross-section of bulls, helping seedstock producers investigate and better understand feed efficiency traits to aid in breeding and selection decisions.

Our objective is to evaluate bulls in a 90-day forage-based performance and feed efficiency test, producing individual performance, feed efficiency and RFI rankings for these bulls on a predominantly forage diet. The purpose of the forage-based diet is not to maximize performance, but to develop bulls on a diet that is more reflective of what they will experience as “working bulls” in commercial herds. Forage-based diets also create more separation in performance and feed intake among the bulls on test. This creates a tougher evaluation environment to rank bulls based on average daily gain, feed intake, feed efficiency and RFI.

RFI is one of the important measurements that we are interested in. RFI is basically an index that helps rank or characterize all of the bulls within a specific test. It works best when only used to evaluate bulls within the test. Because of differences in environment, management and diets between different bull tests, it is difficult and not advisable to make comparisons from one test to another. RFI tries to identify efficient animals by comparing individual data against the group.

For example, an efficient bull with a negative RFI indicates an animal that achieves a daily gain consuming less feed (negative RFI) than expected, based on overall group performance. A positive RFI bull is a less efficient animal that actually consumes more feed than expected for his actual daily gain. A graphic example can be found in Figure 1.

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At our SAREC GrowSafe facility, we hope to continue to evaluate cattle not only for grant-funded research projects but also to try and meet some of the local demand for feed intake and RFI testing. Results from RFI and feed efficiency tests over the last three years really suggest that while we have made dramatic improvements in performance and daily gain, we haven’t had the ability to directly select for individual efficiency. Animals with similar performance may have as much as 2.5 times difference in actual feed intake.

Feed efficiency and RFI will continue to be an important trait in our industry. Feed prices will continue to be impacted by regional droughts, demands for starch and cellulosic-based ethanol production and higher input costs. Understanding and managing for efficiency will help us remain competitive. If you have any questions about our facility or tests, please give us a call or stop by anytime. We are tentatively planning an open house at our SAREC feedlot on Friday, Sept. 16 near Lingle, WY, to discuss feed intake and RFI testing. If you are interested or would like more information, please e-mail me at spaisley@uwyo.edu.

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