Discovery of Novel Traits to Improve Efficiency and Sustainability of Beef Cattle Production

Abstract Improving efficiency is essential for the sustainability of the US beef production system. However, achieving this goal is challenging due to many factors, including diet types, genetics, environments, and industry segmentation. One challenge is that efficiency can mean different things depending on the production system or the operation's goals. For cow-calf producers, improving reproductive efficiency is important for increasing economic output, while grazing and supplemental feed are the largest input costs. For cattle feeding operations, feed conversion efficiency is always important, yet factors such as death rates can have significant economic impacts. To address the difficulties and lack of commonality in efficiency metrics, it is critical to have a fundamental understanding of what contributes to efficient utilization of feed resources and nutrients, which can guide future genetic selection and production practices. Despite decades of progress, the regulation of feed intake in growing and finishing cattle remains incompletely understood, hindering advances in matching nutrient requirements and feed efficiency. Advances in molecular biology and mining of existing omics data could assist in the identification of novel phenotypes to explore for selection or manipulation. One example is the finding that RNA previously thought to be noncoding (i.e., long noncoding RNA) has been found to be translated into micropeptides, and these micropeptides can exhibit hormonal effects on metabolism and appetite regulation. In addition to further defining biological mechanisms regulating feed intake and growth, further research should focus on specific nutrient utilization. Nitrogen utilization efficiency is becoming increasingly important due to the significant economic and environmental ramifications of nitrogen inefficiency. There is growing evidence that precision feeding of protein to match requirements can reduce nitrogen excretion without compromising growth and efficiency. In conclusion, a better understanding of the underlying biology of nutrient utilization is crucial for improving the sustainability of US beef production.