U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Food and Feed Safety Research: College Station, TX
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area College Station, Texas Southern Plains Agricultural Research Center Food and Feed Safety Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Anderson, Robinitem
                                            Ripley, Lauraitem
                                            BOWMAN, JAN - Montana State Universityitem
                                            Callaway, Todditem
                                            Genovese, Kenneth

                                                         - *Ken*item
                                            Beier, Rossitem
                                            Harvey, Rogeritem
                                            Nisbet, David
  Submitted to: Frontiers in Veterinary Science
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 7/28/2016
                                    Publication  Date: 8/11/2016
                                    Publication URL: http://handle.nal.usda.gov/10113/63136Citation: Anderson, R.C., Ripley, L.H., Bowman, J.G., Callaway, T.R., Genovese, K.J., Beier, R.C., Harvey, R.B., Nisbet, D.J. 2016. Ruminal fermentation of anti-methanogenic nitrate- and nitro-containing forages in vitro. Frontiers in Veterinary Science. 3:62. doi: 10.3389/fvets.2016.00062.Interpretive Summary: Methane production by microbes in the gut of cows, sheep, and goats is an inefficient digestive process that results in the loss of as much as 16% of the dietary energy consumed by the animal and contributes nearly 20% of the United States' emission of this greenhouse gas.  The chemicals nitrate, 3-nitro-1-propionic acid (NPA), and 3-nitro-1-propanol (NPOH) are recognized as potent inhibitors of methane production by microbes in the gut of cows, sheep, and goats and thus have the potential to reduce economic and environmental costs associated with this digestive inefficiency.  These chemicals can accumulate naturally in forages that can be fed to animals, and thus can possibly be part of a green technology to reduce methane production.  However, if fed at too high an amount, the forages containing these chemicals can potentially be poisonous to animals, and thus research is needed to learn how to safely use these forages.  In the present experiment, we found that nitrate-, NPA-, or NPOH- containing forages effectively decreased methane production by populations of bacteria from the gut of cows.  Methane-producing bacterial populations were inhibited most effectively with the NPA- and NPOH-containing forages.  Hydrogen, an end product of forage digestion, accumulated in bacterial populations incubated with forages containing nitrate, NPA, or NPOH but was dramatically higher in populations incubated with the NPA-containing forage.  This finding provides evidence of a specific mechanism of action for NPA, implicating its effects on a specific hydrogen-using enzyme within the bacterial population.  Accumulations of other endproducts revealed compensatory adaptations by the microbial populations incubated with the nitrate-containing and NPA- and NPOH-containing forages, which provides further evidence of how these chemicals affect the microbial population.  These results demonstrate that forages containing nitrate, NPA, and NPOH can be used to inhibit methanogenesis and provide important information on the mechanism of action of the anti-methane chemicals in these forages.  Ultimately, this research can be used to develop feeding strategies that help farmers and ranchers increase production of safe and wholesome meat and milk at lower cost, while at the same time decreasing the global carbon footprint of American agriculture.
                                Technical Abstract: Nitrate, 3-nitro-1-propionic acid (NPA), and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if fed at high enough amounts.  These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard.  Presently, we found that nitrate-, NPA-, or NPOH- containing forages effectively decreased methane production, by 34 to 98%, during in vitro fermentation by mixed populations of ruminal microbes compared to fermentation by populations incubated similarly with alfalfa.  Methane production was further decreased, although not necessarily significantly, during incubation of populations inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to reductively metabolize nitrate, NPA, and NPOH.  Inhibition of methanogen populations was greatest with the NPA- and NPOH-containing forages.  Hydrogen accumulated in all ruminal populations incubated with forages containing nitrate, NPA, or NPOH, but was dramatically higher, exceeding 40 μmol hydrogen/mL, in non D. detoxificans-inoculated populations incubated with NPA-containing milkvetch.  This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of the added 50 μmol formate/mL to hydrogen.  Accumulations of volatile fatty acids revealed compensatory changes in fermentation in the nitrate-containing and NPA- and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases higher accumulations of butyrate.  Accumulations of ammonia, iso-buytrate, and in some cases iso-valerate, were also lower in incubations with nitrate-, NPA-, and NPOH-containing forages than with alfalfa, thus indicating a potential alteration of amino acid fermentation.  Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available with ruminal incubations to inhibit methanogenesis.  Further research is needed to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation in ruminant methane emissions without adversely affecting fermentative efficiency.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov