Location: Cell Wall Biology and Utilization Research
Project Number: 5090-21500-001-000-D
Project Type: In-House Appropriated
Start Date: Dec 12, 2023
End Date: Dec 11, 2028
Objective:
Objective 1. Assess the role of enzymes involved in forage cell wall assembly, structure, and composition to improve digestibility in ruminant systems.
Sub-objective 1A: Use genetic manipulation of sugar-nucleotide biosynthetic pathways to identify avenues for altering cell wall structural polysaccharides and matrix interactions.
Objective 2. Investigate the genetic and molecular mechanisms underpinning protein content and stability to improve the nutritional value of alfalfa.
Sub-objective 2A: Characterize the sulfur-containing amino acid profile of alfalfa under different growing conditions from varying germplasm to generate resources to improve nutrition.
Sub-objective 2B: Catalog proteases in alfalfa to understand the mechanisms of post-harvest protein degradation.
Sub-objective 2C: Interrogate the underlying genetics of post-harvest proteolysis to develop tools for decreasing post-harvest protein degradation in alfalfa for forage and novel uses.
Objective 3. Investigate the potential of condensed tannin-containing forage legumes in dairy production systems to increase nitrogen-use efficiency.
Sub-objective 3A: Determine the chemical basis for protection of protein during rumen digestion and provide elevated levels of escape protein into the hindgut by condensed tannins (CTs).
Sub-objective 3B: Determine the preferred method for forage preservation (silage, baleage, hay) for a CT-containing forage to improve animal health, productivity and environmental benefits.
Objective 4. Determine the role of microbial communities in dairy forage production systems to mitigate environmental impacts, optimize efficiency, and add value to harvested forages.
Sub-objective 4A: Develop optimized DNA extraction methods for silage to enable evaluation of amplicon-based sequencing biases and long-read metagenomics.
Sub-objective 4B: Evaluate novel inoculant and biochemical strategies like the Wood-Ljungdahl pathway for mitigating environmental and climate change impacts on silage and in animals fed silage.
Sub-objective 4C: Apply big data approaches to paired spectral and chemical data to inform new assays and novel prediction equations relevant to the dairy agroecosystem for subsequent empirical validation at laboratory- and field-scales.
Sub-objective 4D: Determine the extent to which structure, composition and concentration of condensed tannins impact mitigation of methane production in in vitro rumen digestion studies.
Sub-objective 4E: Provide subject matter expertise in feed conservation and storage and lead development of the Feed Storage Module of the Ruminant Farm Systems (RuFaS) Model.
Approach:
This work will apply a multidisciplinary approach combining plant physiology/biochemistry, chemistry, agronomy, microbiology, molecular biology, genetics, and computer modeling to improve forage utilization in integrated dairy systems. Production and post-harvest maintenance of high-quality forage as it relates to animal nutrition is a critical component of high-production, sustainable dairy systems. Forages, particularly perennials, provide opportunities to improve farm system sustainability and food security through their nutritional and environmental benefits. Enhancing nutritional value of forages as well as their management, harvest, and conservation could lead to greater use and value. Particularly important are maximizing the digestible energy and optimizing the preservation and quality of forage protein. This research will focus on identifying strategies for enhancing post-harvest forage digestibility through four primary objectives. Molecular biology techniques will be used to assess the role of enzymes involved in forage cell wall assembly, structure, and composition to improve digestibility in ruminant systems (Objective 1). Genetic and molecular mechanisms underpinning protein quality, content, and stability will be investigated to improve the nutritional value of alfalfa (Objective 2). Chemical analyses will be applied to understand the potential of plant specialized metabolites, primarily condensed tannins, in nutrient use efficiency (Objective 3). Microbiology, biogeochemistry, and process modeling will be used to better understand the role of microbial communities in dairy forage production systems to mitigate environmental impacts, optimize efficiency, and add value to harvested forages (Objective 4). This project plan makes use of cross-scale approaches, from farm- to molecular, to identify strategies for increasing efficiency in dairy forage systems. Expected outcomes include increased production efficiency and sustainability concomitant with reduced environmental impacts for dairy producers.
