This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Varel, V. H. Articles by Hashimoto, A. G. Search for Related Content PubMed PubMed Citation Articles by Varel, V. H. Articles by Hashimoto, A. G. Agricola Articles by Varel, V. H. Articles by Hashimoto, A. G.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1981 January; 41(1): 29-34

Effect of Dietary Monensin or Chlortetracycline on Methane Production from Cattle Waste

U.S. Department of Agriculture, Science and Education Administration, Agricultural Research, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska 68933

ABSTRACT

Wastes from feedlot cattle fed finishing diets containing either monensin, chlortetracycline, or no antibiotic were investigated as substrates for methane production. We used continuously mixed anaerobic fermentors with 3-liter working volumes at 35 and 55°C; these fermentors were fed once per day. Within a few days after waste from animals fed monensin was added, the volume of methane produced began to decrease in the 55°C fermentors. After 9 days of daily feeding, methane production was severely inhibited, the pH dropped from 7.6 to 5.9, and the concentration of volatile acids increased from 543 to 6,300 mg/liter (as acetate). Although additions of waste from cattle fed monensin were discontinued after 9 days, the fermentors did not resume gas production within 8 weeks. The addition of waste from cattle which had been fed chlortetracycline reduced the methane production rate approximately 20%; however, pH and volatile acid values were comparable to control fermentor values after 40 days. Similar effects were observed with the 35°C fermentors. In a batch fermentation experiment in which 50-g portions of volatile solids from waste of animals fed monensin, chlortetracycline, or no antibiotics were added to fermentors, monensin delayed the onset of methane production for about 40 days, but then these fermentors began to produce methane at a rate comparable to the control rate. The ultimate methane yields from the three types of waste after 180 days were not significantly different. These studies indicate that monensin has a detrimental effect on the conversion of feedlot wastes to methane, unless microorganisms can be adapted to the levels that are present in these wastes.