- Assistant Professor
Biography
Pursuing new tools and systems to enhance environmental sustainability is fundamental for the continued advancement of animal agriculture and global food security. The dairy industry is uniquely positioned to both contribute to the nation’s food security and provision of energy and fertilizer. Dairies also play a crucial role in the circular bioeconomy through use of food waste. In this lab we are excited to conduct research and outreach which supports the sustainability and efficiency of dairy cattle production systems. More specifically, research focuses on strategies to improve dairy cattle’s nutrient utilization and reduce manure nutrient excretion and losses to the environment. This includes developing and quantifying the impact of technologies which lower enteric methane and gaseous hydrogen emissions. We also evaluate the use of byproducts feeds within ration formulations in the effort to reduce food waste. Additional areas of research involve assessing the flow of energy and nitrogen within the production system and quantifying nutrient outputs in manure.
Developing, testing, and transferring data to the dairy industry is essential for connecting scientific innovation with on-farm application. Since its origins in the 1800s, extension has aimed to return the practical benefits of research to the communities that drive it. With a background in energy and nitrogen utilization my goal is to educate and give producers recommendations on the efficient use of nutrients to support milk production while reducing nutrient excretion to the environment. This aspect of education serves to most importantly provide producers with new and innovative tools both aligning with economic and environmental sustainability and resiliency. However, the educational material will not be limited to only my expertise, as the extension programming should be aimed at the broader needs of the dairy sector in the areas of sustainability and resilient dairy management practices. Dairy production is technologically advanced and capital intensive thus, pursuit of sustainability and resiliency encompasses a vast array of topics and perspectives. I will aim to align myself with agriculture extension specialists and educators both within the state of Washington and from bordering and nearby states. Collaboration will provide added multidisciplinary value to programming materials for the wide scope of needs found within the dairy industry. Together the research and extension areas translate into practical strategies for dairy producers and industry partners to improve environmental sustainability and operational efficiency.
Specific Research Areas
- Evaluating strategies to reduce enteric methane and gaseous hydrogen emissions while maintaining dairy productive efficiency
- Incorporating byproduct feeds in dairy rations to reduce food waste
- Quantify the influence of ration formulation nutrient excretion and subsequent manure biogas production
- Using controlled laboratory and on farm methodologies to quantify energy and nitrogen utilization in dairy cattle and associated manure excretion
Specific Extension Objectives
- Engage directly with producers and key allied industry members to better understand areas of need at both the state and regional level
- Use relevant, timely, and actionable materials to educate dairy producers, those in allied industry, and the public on sustainability of dairy production systems
- Collaborate with both Washington State University and regional extension educators and specialists in the development of programs to address challenges in the sustainability of the dairy industry
Selected publications
- Neff AK, Buse KK, Carroll AL, Brown-Brandl T, Kononoff PJ (2025). “Comparative evaluation of bags used to collect respiratory and enteric gas samples needed for indirect calorimetry.” (Journal of Dairy Science Communications, https://www.jdscommun.org/article/S2666-9102(25)00102-4/fulltext)
- Carroll et al. (2025). “Derivation of the maintenance energy requirements in growing Jersey heifers.” (Journal of Dairy Science, https://www.sciencedirect.com/science/article/pii/S0022030225002863?via%3Dihub)
- Knoell AL, Carroll AL, Judy JV, Wilson HC, Morris DL, Herrick KJ, Fernando SC, Kononoff PJ (2024). “Energy utilization in lactating Jersey cows consuming a mixture of DDGS and straw replacing alfalfa hay” (Journal of Dairy Science, https://doi.org/10.3168/jds.2024-25024)
- Carroll et al. (2024). “Partitioning among-animal variance of energy utilization in lactating Jersey cows.” (Journal of Dairy Science, https://doi.org/10.3168/jds.2024-24740)
- Carroll et al. (2024). “Estimation of the nutrient variation in feed delivery and impacts on lactating dairy cattle.” (Journal of Dairy Science Communications, https://doi.org/10.3168/jdsc.2024-0564)