The overall goal of this cooperative, multi-state, multidisciplinary, research and outreach project is to improve beef cattle nutrient utilization efficiency through a more complete understanding of the biological mechanisms that contribute to its variation. The scope of this project includes studies of molecular and systems physiology, genetics/genomics, nutritional and behavioral interactions that drive variation in nutrient utilization efficiency measured in terms of both Gain: Feed (G: F) and residual feed intake (RFI). With a strong integrated outreach program, this regional project will coordinate efforts across the nation to provide leadership and interact with industry to cooperatively disseminate this important information to US beef cattle producers.

This proposal to replace the soon to expire W-3010 project describes the collaborative effort of research from Agricultural Experiment Stations across the country to characterize specific aspects of the molecular, physiological, and genomic mechanisms that regulate beef cattle nutrient utilization efficiency. The proposed project addresses a major agricultural need. Improving the efficiency of meat production in beef cattle is essential to meet consumer demands for high-quality products, ensure profitability and minimize natural resource use. 

In an era of increasing costs of feedstuffs and less available land for food production, the importance of finding new ways to maintain production with reduced demand for feed has a direct effect on rural prosperity and contributes to the sustainability of the beef industry. Reducing the demand for feedstuffs for similar production levels will also facilitate the distribution of feedstuffs for broader utilization. These technologies are readily transferable to beef production systems throughout the world and thus have the potential to contribute to both national and global food security. Realized reductions to the costs of producing beef translated to more competitively priced beef products in the global market.

• National importance of building this multi-state project: Across the nation, individual and outreach efforts with nutrient utilization efficiency are expanding at a rapid rate. Industry at multiple levels is embracing feed and nutrient utilization efficiency as a priority for research and development. In addition, the synergy that will be developed across this team of researchers will convert projects with local or regional impact to having a national and international impact.

• All projects outlined in the following methods section are technically sound and are in different stages of progress. Many of these have been peer-reviewed and are presently contributing impact at the state, regional, or local levels.

• This project is both multi-state and a multidisciplinary effort. It involves investigators with broad expertise across the nation and international collaborators in Australia and Canada. The Principal Investigators represent a variety of science disciplines and outreach expertise that complement each other and provide the skill-sets necessary to complete the objectives.

• The project involves strong cooperative efforts between the various units including the exchange of reagents, genomic data, a feed efficiency phenotype database as well as the exchange of knowledge and techniques, joint use of equipment and techniques available at particular experiment stations and joint publication of research results. A number of collaborative projects are described in the procedures for this proposal. The committee feels that as we are reaching out to encourage broader participation this will only increase. In addition, without a funded regional project, the collaborations would be substantially more difficult to initiate and maintain.

• The members of this committee have been successful in obtaining outside support to fund research. Funding from the NIFA and other granting agencies, foundations, and industry sources has been needed to carry out the work and to maintain the high level of productivity demonstrated by the previous group and this record of outside funding is expected to continue.

• This proposal describes a research and outreach approach to an increasingly important agricultural problem. Both the members of the previous project and the projected members of this project have demonstrated a high level of productivity and this is expected to continue with the new project.

• The impacts from the completion of this multi-state project will be national and international in scope. This project will contribute scientific rigor in elucidating the molecular mechanisms that underpin variation in beef cattle nutrient utilization efficiency and contribute to the development of biologically based predictors and improve the accuracy and reliability of mathematical models to predict feed intake and nutrient use in beef cattle, including grazing beef cattle. Producers will benefit from the development of molecular technologies that enhance conventional EPD estimates. The developed technologies will add value to conventional phenotyping for feed efficiency which is costly and time-consuming. Thus, the technologies are expected to lead to a long-term reduction in costs of overall FE testing and improve the nutrient utilization of beef cattle resulting in a lower impact on the environment and reducing costs to the producer for similar levels of beef production.  

• The W-3010 Committee has been highly productive. Over 100 papers, book chapters/theses and abstracts have resulted from years 2020-2024 of the previous five-year project, and additional publications are expected through the 2025 termination date. In addition, substantial progress has been made under each of the specific objectives of the previous project.