USDFRC | Current Research Information System

Improving Digestion of Forage Nutrients (PDF)

A one-page description of the digestion research focus at the U.S. Dairy Forage Research Center.


Project Number: 3655-31000-021-00D Project Type: Appropriated Start Date: Oct. 31, 2007 End Date: Oct. 30, 2012	Scientists:	David Mertens Richard Muck J. Mark Powell Mary Beth Hall	Geoffrey Brink Paul Weimer Hans Jung Neal Martin
Objectives:
Identify and measure plant chemical and physical characteristics and dietary interactions that may alter nutrient digestibility and excretion by lactating dairy cattle. Determine the effects of level of intake and digestion kinetics on diet component digestibility with current industry-representative lactating cows. Measure the impact of fermentative digestion on nutrient utilization, quantify the transformations of nutrients into end-products of fermentation, and use molecular techniques to characterize and quantify changes in populations of ruminal bacterial species as affected by diet and animal. Develop an integrated system for evaluating forage genotypes and validate the usefulness of in vitro, in situ, and small ruminant digestibility in assessing the utilization of nutrients by lactating dairy cows representing current levels of production.
Approach:
The effects of PPO-modified plants, silage inoculants and lauric acid on protein utilization will be studied. Digestibility of corn silage with altered lignin/phenolic characteristics and alfalfa with down-regulated COMT and CCOMT to modify lignin will be evaluated with lambs and lactating cows. Intake and digestibility from lactating cow trials will be compiled and digestibility of dry matter, fiber and soluble organic matter will be regressed on intake. Digestion kinetics will be measured on ration ingredients from trials. In vitro fermentations using mixed ruminal microbes will be used to measure changes in digestion kinetics and microbial populations associated with direct-fed microbials, monensin, non-fiber carbohydrate sources, forage species, and pH. In vitro, lamb, and lactating cow digestibilities will be compared to develop an integrated system for evaluating new forage genotypes.

Feed Evaluation Methods (PDF)

A one-page description of the feed evaluation methods research focus at the U.S. Dairy Forage Research Center.


Project Number: 3655-31000-022-00 Project Type: Appropriated Start Date: Oct. 10, 2007 End Date: Oct. 09, 2012	Scientists:	Mary Beth Hall Glen Broderick David Mertens	Vacant (chemist) Matthew Digman Neal Martin
Objectives:
Improve accuracy, reproducibility, and ease of measuring/estimating feed digestibility for fiber and protein for use in developing feeding strategies for improving animal performance. Develop rapid methods for measuring feed qualities to improve on-farm precision of feeding. Establish methods to measure feed characteristics of nutritional relevance in dairy cattle diets.
Approach:
The approaches for the diverse projects in this research will also be diverse. They will include evaluation of feed evaluation equipment and methods used on the farm and in the laboratory to measure specific feed components or their digestibility. We will compare the results of the experimental approaches to values for the feed components measured with standard measurement systems, or to digestibility data from studies with dairy cattle.

Basic Forage Research (PDF)

A one-page description of the basic forage research focus at the U.S. Dairy Forage Research Center.


Project Number: 3655-21000-46-00 Project Type: Appropriated Start Date: March 27, 2008 End Date: March 26, 2013	Scientists:	Ronald Hatfield Vacant (chemist) Michael Sullivan	John Grabber Heathcliffe Riday Neal Martin
Objectives:
Identify chemical, biochemical, and genetic factors of plant development that alter biomass production and identify how changing environmental conditions alter these processes. Determine the impact of genetic modifications in biosynthetic pathways upon fundamental physiological, biochemical, and anatomical development of plants to uncover key structural/functional relationships that affect forage quality, digestion, and biomass conversion efficiency. Determine the biochemical/chemical/genetic basis for biological systems needed to inhibit degradation of forage proteins during harvest, storage and utilization to minimize nitrogen waste.
Approach:
Cell wall screening methods will be developed based on 2D-NMR and FTIR applying chemometric approaches to relate specific structural/compositional information to cell wall utilization (e.g., cell wall digestion, ethanol conversion efficiencies, formation of bioproducts). Basic molecular approaches will be utilized to identify key steps in complex metabolic processes such as cell wall biosynthesis, sugar nucleotide biosynthesis and lignin biosynthesis that altered plant structure and function. Combinations of agronomic and molecular approaches will be used to define the roles of polyphenols and polyphenol oxidases in the preservation of forage protein during on-farm storage and degradation in the rumen. New strategies may include guidelines for management of crops to optimize harvest/storage conditions and development of genetic approaches to produce new plants with improved protein characteristics. Molecular techniques afford a selective approach to test for changes in metabolic pathways (e.g., cell wall biosynthetic pathways) resulting in positive or negative impacts upon digestibility and agronomic characteristics. Altering plant developmental characteristics will have to strike a balance between improved feed characteristics and resistance to environmental stresses.

Redesigning Forages and Forage Systems (PDF)

A one-page description of the applied forage research focus at the U.S. Dairy Forage Research Center.


Project Number: 3655-21000-047-00 Project Type: Appropriated Start Date: March 27, 2008 End Date: March 26, 2013	Scientists:	Michael Casler Heathcliffe Riday Geoffrey Brink John Grabber	Richard Muck Wayne Coblentz Peter Vadas Neal Martin
Objectives:
Overcome the production and profitability problems suffered in grazing-based systems because of poor plant persistence, inconsistent forage quality, and lack of resilience/stability. Develop new alfalfa (Medicago sativa L.) production systems that are less costly, more productive, and of greater value for livestock and biomass conversion. Develop improved understanding of the fundamental physiological, anatomical, and genetic controls that affect forage quality during plant development and digestion in the rumen. Broaden the range of alternative forage cropping systems to fulfill dietary needs, reduce environmental risk, and improve management flexibility.
Approach:
We propose to develop new and more efficient management strategies and new forage cultivars, focused on four basic research themes related to forage plants and systems: (1) grass-based management-intensive rotational grazing systems, (2) harvested alfalfa as a bioenergy feedstock or livestock feed, (3) selection criteria for improving forage quality of pastures and harvested forages, and (4) alternative establishment methods and forage cropping systems. Hypothesis-driven research will be conducted largely with field trials designed to test new or improved cropping systems, management strategies, establishment methods, or germplasms in direct comparison to current or existing treatments. Field studies will be supplemented with laboratory analyses of forage characteristics related to nutritional value, plant cell walls, physical traits of stems and leaves, or DNA markers to identify functional relationships of field observations with expected ruminal livestock performance. New forage cultivars and management strategies will be used to streamline forage production systems, increasing profitability and sustainability, while lessening environmental impact.

Managing Manure Nutrients (PDF)

A one-page description of the manure nutrient research focus at the U.S. Dairy Forage Research Center.


Project Number: 3655-12630-002-00 Project Type: Appropriated Start Date: Feb. 05, 2008 End Date: March 31, 2011	Scientists:	Bill Jokela Vacant Wayne Coblentz J. Mark Powell	Peter Vadas Michael Russelle Neal Martin
Objectives:
The primary objective of the project is to address knowledge gaps in understanding and managing the nutrient cycles of modern dairy farms. Under this broad research umbrella are five specific objectives: To determine the effects of dairy diets and herd management on manure nutrient excretions and nutrient losses to the environment. To determine the effects of manure and crop management practices on nutrients, sediment, and pathogens in surface runoff and other pathways. To determine the effects of season, dairy diet, and field management of manure on gaseous emissions of ammonia, nitrous oxide, carbon dioxide, methane, and volatile organic compounds. To determine the effects of mechanical application of dairy manure on nutrient uptake and nutritional characteristics of annual and perennial forages. To develop conventional and organic crop management strategies to facilitate the exchange of nitrogen, phosphorus, and potassium as manure and feed between neighboring dairy and cash grain farms.
Approach:
Improved management of dairy farms requires successfully managing its nutrient flows, both to maximize nutrient use by animals and crops (to optimize profit), and to minimize nutrient loss to the environment (to optimize sustainability). We will investigate most aspects of nutrient cycling throughout the dairy farm system with a variety of methods and at different scales (replicated field plots, field-scale paired watersheds, feeding trials with replicated pens of heifers, etc.). Some experiments also include non-nutrient elements such as eroded sediment and pathogens.

Value Added Products (PDF)

A one-page description of the value added and bioenergy research focus at the U.S. Dairy Forage Research Center.


Project Number: 3655-41000-004-00D Project Type: Appropriated Start Date: June 24, 2004 End Date: June 3, 2009	Scientists:	Paul Weimer Matthew Digman Peter Vadas Michael Casler	Ronald Hatfield Michael Sullivan Neal Martin
Objectives:
Develop harvesting, fractionation and storage processes for forages and bioenergy crops that are economical, and that retain product quality. Identify specific varieties of energy crops that display maximum fermentability when grown at specific locations under defined environmental conditions. Develop switchgrass germplasm having broad adaptation to the northern USA and improved fermentability for conversion to value-added products. Develop and improve fermentations for direct bioconversion of cellulosic biomass to value-added products (viz., ethanol, chemical feedstocks, and novel bioadhesive components).
Approach:
New harvesting strategies will be developed that economically separate forages and bioenergy crops into higher and lower-value fractions. An in vitro ruminal fermentation assay will be used to rapidly screen large numbers of biomass samples from several bioenergy crop species, provided by ARS agronomists from throughout the U.S. The data will be correlated to ethanol bioconversion capability, and NIRS calibration equations will be developed for ruminal fermentability and ethanol production. Switchgrass germplasm improvement will be carried out by recurrent phenotypic selection for vigor, lodging and disease resistance to extend adaptation and biomass yield in several eco-regions. Switchgrass hybrids will be selected for enhanced biomass yield and fermentability. Consolidated bioprocessing of bioenergy crops, using anaerobic bacteria that produce their own cellulolytic enzymes and ferment the products to ethanol and other valuable products, will be improved through optimization of strains and culture conditions. Value-added co-products, such as adhesives produced by the fermentative bacteria, will be identified and their utility will be determined.

Research

Current Research Information System

Six Main Research Projects (CRIS)