Nitrogen bound to manure fiber is increased by applications of simple phenolic acids

Authors: Halvorson, Jonathan; Kronberg, Scott; Christensen, Rachael; HAGERMAN, ANN - Miami University - Ohio; Archer, David

Submitted to: CABI Agriculture and Bioscience (CABI A&B)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2022
Publication Date: 2/22/2022
Citation: Halvorson, J.J., Kronberg, S.L., Christensen, R., Hagerman, A.E., Archer, D.W. 2022. Nitrogen bound to manure fiber is increased by applications of simple phenolic acids. CABI Agriculture and Bioscience (CABI A&B). 3:11. https://doi.org/10.1186/s43170-022-00078-7.
DOI: https://doi.org/10.1186/s43170-022-00078-7

Interpretive Summary: When livestock consume foliage rich in plant secondary compounds (PSM) such as tannins their feces contain more total nitrogen and may possess a higher concentration of nitrogen fixed to insoluble manure fiber (ADF-N) than when the animals consume low PSM feeds. A seemingly similar phenomenon occurs when some PSM are added to soils where it is likely that the PSM facilitate binding interactions between nitrogenous compounds and the soil. We hypothesized that simple PSM, such as phenolic acids, could increase ADF-N by reaction with manure in the absence of biological activation such as rumen digestion. In our first experiment we applied different concentrations of phenolic acids to dried pulverized manure and measured changes to ADF-N. Patterns of ADF-N were affected by complex but inconsistent relationships between treatment compounds and solution concentration. Further, we found little distinction between the treatment means and samples treated with only water. A second experiment featured more treatment compounds applied at a single concentration and added a nitrogen factor. Results showed ADF-N was not affected by treatment with water, benzoic or gallic acid when compared to untreated manure but was significantly increased by the other treatments. The highest concentrations of ADF-N observed in samples treated with a tannin, epigallocatechin gallate or ferulic acid were equivalent to increases of ADF-N of 32.6 and 34.1%, respectively. These studies suggest organic nitrogen in manure can readily complex with fibers in manure. So, some changes to manure composition associated with dietary tannins or related simple phenolic compounds do not depend on rumen fermentation and subsequent digestion. The amount of nitrogen bound to manure fibers may affect nutrient cycling.

Technical Abstract: Polyphenolics like tannins can increase nitrogen excreted in feces when consumed by ruminants but less often noted is increased nitrogen in fecal acid detergent fiber (ADFN). Relatedly, some simple phenolics appear to facilitate binding interactions between nitrogenous compounds and soil. We hypothesized that common phenolic acids, could increase ADF-N in the absence of rumen digestion. We applied solutions (0.001, 0.01, 0.1 M) of sodium benzoate (B0), sodium 4-hydroxybenzoate (B1), 3,4, dihydroxybenzoic acid (B2), gallic acid (B3), ammonium benzoate (AB), and ammonium chloride (AC) to dried pulverized manure and measured ADF-N. We found a significant interaction between treatment and concentration, but the simple effects were inconsistent and there was little distinction between the treatment means and samples treated with water. In a second experiment we modified the methodology, applying more compounds at a single concentration (0.001M) and added a nitrogen (NH 4 Cl) factor. We observed a strong treatment effect ( P <0.0001) but no influence of added nitrogen or interaction. Samples treated with water, B0, or B3 were similar and indistinguishable from untreated manure. Treatment with B1, caffeic acid, (CAF), or B2 increased ADF-N from 13.2-17.5% while +(-) catechin (CAT), and p - coumaric acid (p-COUM), increased it by 19.7 and 22.2% respectively. Epigallocatechin gallate (EGCG) and ferulic acid (FER) increased ADF-N most, 32.6 and 34.1%. These studies suggest nitrogen in manure can complex with ADF and that some of the changes to manure composition associated with dietary tannins or related phenolics do not depend on rumen fermentation and subsequent digestion.