Influence of pine bark tannin on bacterial pathogens growth and nitrogen compounds on changes in composted poultry litter

Authors: ARZOLA-ALVAREZ, CLAUDIO - UNIVERSIDAD AUTONOMA DE CHIHUAHUA; CASTILLO-CASTILLO, YAMICELA - UNIVERSIDAD AUTONOMA DE CHIHUAHUA; Anderson, Robin; HUME, MICHAEL; RUIZ-BARRERA, OSCAR - UNIVERSIDAD AUTONOMA DE CHIHUAHUA; MIN, BYENG RYEL; ARZOLA-RUBIO, ALEJANDRO - UNIVERSIDAD AUTONOMA DE CHIHUAHUA; BEIER, ROSS; SALINAS-CHAVIRA, JAIME - UNIVERSITY OF TAMAULIPAS

Submitted to: Brazilian Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2020
Publication Date: 6/5/2020
Citation: Arzola-Alvarez, C., Castillo-Castillo, Y., Anderson, R.C., Hume, M.E., Ruiz-Barrera, O., Min, B., Arzola-Rubio, A., Beier, R.C., Salinas-Chavira, J. 2020. Influence of pine bark tannin on bacterial pathogens growth and nitrogen compounds on changes in composted poultry litter. Brazilian Journal of Poultry Science. 22(1):eRBCA-2018-0911. https://doi.org/10.1590/1806-9061-2018-0911.
DOI: https://doi.org/10.1590/1806-9061-2018-0911

Interpretive Summary: Poultry litter produced during the rearing of chickens can contain high amounts uric acid and ammonia which, when applied appropriately to fields, can serve as a good nitrogen-fertilizer. The poultry litter can also be a good crude protein feedstuff for cattle. However, because the litter can also contain high amounts of pathogenic and antimicrobial resistant bacteria such as Salmonella and E. coli, it must be treated before being spread to the field. Composting is an effective and affordable treatment strategy to kill pathogens in poultry litter, but this process causes the loss of uric acid which is degraded by the microbes to ammonia that eventually evaporates into the atmosphere or leaches into the soil. In this study, we examined the antimicrobial and uric acid-preserving activity of pine bark tannin on poultry litter composting. We found that the pine bark tannin caused nearly 10-fold decreases in numbers of Salmonella in the litter and helped prevent the destruction of uric acid to ammonia by nearly 2-fold. Results suggest that pine bark tannin treatment may preserve uric acid and reduce ammonia volatilization in composted litter while aiding in Salmonella control.

Technical Abstract: This study examined the antimicrobial and uric acid-preserving activity of pine bark tannin on poultry litter during composting. Antibiotic-free wood chip-based poultry litter was distributed (11 g) to 50-mL conical centrifuge tubes (n = 3 tubes/treatment) and amended with 0.4 M sodium phosphate buffer (control) or treated with 1.3 mL of condensed tannins from pine bark (Pinus palustris; 9% tannin wt/vol). All tubes were inoculated with a novobiocin and naladixic acid-resistant Salmonella Typhimurium (STNN) to achieve 3.0 log10 CFU/g and incubated at 37C for 3 days. Enumeration of wildtype E. coli and the challenge STNN strain and determinations of ammonia, uric acid, and urea concentrations were made at 0 d and 3 d of composting. Pine bark tannin decreased (P less than 0.01) STNN populations in the litter by 0.6 log units compared to controls. Wildtype E. coli populations were unaffected by tannin treatment (P greater than 0.05). Ammonia accumulation decreased (P less than 0.01) 23% in tannin-treated litter compared to the control (2.8 ± 0.1 µmol/g). Conversely, the residual uric acid concentration was 1.6-fold higher (P = 0.02) in litter treated with the pine bark tannin than in the control litter. Urea concentrations were unaffected by tannin treatment (P greater than 0.05). Results suggest that pine bark tannin treatment may preserve uric acid and reduce ammonia volatilization in composted litter while aiding in Salmonella control.