INTEGRATING DNA INFORMATION INTO BEEF CATTLE PRODUCTION SYSTEMS

NON-TECHNICAL SUMMARY: Few of the over 800,000 cattle producers in the United States are familiar with recent developments in DNA-based technologies, or how DNA information could be used to benefit beef cattle production systems. Investment in sequencing of the bovine genome has resulted in the development of DNA-based approaches to select which animals are likely to produce the best offspring. This project seeks to compare different ways to estimate the genetic merit of young herd bulls on commercial beef ranches, and aims to determine both the practical and economic feasibility of using these approaches in the field. It also includes the development of producer -oriented educational materials and delivery of extension programs about DNA-based technologies. The overall goal of the project is to provide beef cattle producers with the background information and research-derived data they need to make informed decisions about the use of DNA-technologies in the context of commercial cow-calf operations. Outcomes are expected to include the increased understanding and adoption of cost-effective DNA-based technologies by beef cattle producers resulting in improved product quality and production efficiency.

OBJECTIVES: A large investment has been made in developing DNA-based tools for the beef cattle industry. Although DNA testing provides an opportunity for increased genetic gain and provides new management opportunities, its use does not provide a guaranteed return on investment. The overall objective of this project is to evaluate different DNA-enabled approaches for predicting the genetic merit of herd sires on commercial beef ranches. The research objective is to compare the current means of genetic prediction of herd sires, which is the use of breed-based expected progeny differences (bEPDs), with whole-genome scan genetic predictions (molecular breeding values, MBVs), and "commercial ranch" genetic evaluations (rEPDs) based on the performance of their offspring under field conditions. Moving to an approach that incorporates a DNA-based estimate of genetic merit needs to be assessed for its technical merit (i.e. which estimate of breeding value provides the best prediction of the performance of future progeny), feasibility (i.e. can it be practically implemented on commercial ranches), and economic viability (i.e. does it have a positive return on investment). The costs and benefits associated with the application of these different DNA-based technologies on commercial beef operations will be analyzed. The extension objectives of this project are twofold. The first objective is to develop an intensive educational program for the ranch cooperators participating on this project. This will include the interpretation of the new DNA-enabled information developed during this project and measurement of any responsive changes that occur in their management and genetic programs during the course of the 4 year project. The second objective is to develop and deliver educational materials to a national audience on the integration of DNA information into beef cattle selection programs. Given the rapid progress in DNA testing, now is an ideal time to examine the use of DNA-technologies in the context of commercial beef operations, and develop both background information and project-inspired outreach materials to expand producer knowledge and understanding of DNA-based technologies.

APPROACH: Research: Four cow-calf herds representing a total of ~ 1900 cows that are using predominately Angus sires will participate in this 4 year trial. A total of 80 registered Angus bulls that will be herd sires during the course of this project. All will be genotyped on the 50k Illumina bovine panel and molecular breeding values (MBVs) for growth and carcass traits will be obtained from collaborators at the US Meat Animal Research Center by accumulating prior estimated substitution effects according to the alleles that are present at each SNP locus in the 50k panel. Calves sired by these bulls in multi-sire pastures will be DNA sampled and individually identified using RFID tags prior to being shipped from each ranch and fed as a contemporary group, until harvest. Feedlot performance and individual carcass data will be collected on all animals, and DNA information will be used to assign progeny groups to sires. Progeny phenotypes, along with bull pedigrees, will be used to compute "commercial ranch" genetic evaluations (rEPDs) for performance and carcass traits. Additionally, breed-based expected progeny differences (bEPDs) for the 80 sires will be obtained from the American Angus Association. At the completion of the trial there will be traits for which we will have three independent estimates of the genetic merit (bEPD, MBV, rEPD) of the bulls on the trial. Our goal is to determine which of these selection tools provides the most accurate means of identifying superior individuals in a commercial cow-calf setting. We will test the null hypothesis that is that there is no difference between the methods of breeding value estimation in their ability to predict the phenotype of a future progeny." The costs and benefits associated with the application of these different DNA-based technologies on commercial beef operations will be analyzed. Extension: A series of written and audiovisual beef industry-targeted educational materials detailing the basic principles of 1) SNPS and DNA-based genotyping, 2) Marker-assisted selection 3) Details of commercially-available genetic tests, 4) Whole-genome enabled selection, 5) DNA-based progeny testing and the development of commercial ranch (rEPDs), and 6) Value of improving the accuracy of yearling bull genetic evaluations will be developed. The cooperators on the research component of this project will serve as a stakeholder focus group to determine where educational needs exist with regards to DNA-based technologies. Additionally, we will monitor any research-inspired changes that occur in their management and genetic programs during the course of the project. Presentations will be developed for national and regional educational venues (eg Beef Improvement Federation, Cattlemen's College at National Cattlemen's Beef Association, National Beef Cattle Evaluation Consortium (NBCEC) workshops). It is likely that during the course of this project, a lot of information about the accuracy and use of genomic predictions will be published by other research groups. These new research findings, along with those derived from this project, will be incorporated into the development of additional educational materials.

PROJECT CONTACT:

Name: Van Eenennaam, A.
Phone: 530-752-7942
Fax: 530-752-0175
Email: ALVanEenennaam@ucdavis.edu