Submitted to: International Congress of Scientific Knowledge
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2004
Publication Date: 10/26/2004
Citation: Purdy, C.W., Straus, D.C., Clark, R.N. 2004. Survival of enteric pathogens in manure removed from feedyard surface pens [abstract]. In: Proceedings of Second International Scientific Conference, October 26-27, 2004, Samarkand, Republic of Uzbekistan. p. 25.
Technical Abstract: The survival of pathogens in manure is important to the feedyard animal producer and to the public who may consume products which have been exposed to manure. For example, meat products can be contaminated during the slaughter process and vegetables can be contaminated during their growing period if manure is used as a soil amendment to enhance growth. Enteric pathogens found in manure are zoonotic pathogens which can infect many species of animals, including humans. In the Southern High Plains very little is known about how long pathogens survive in stockpiled manure. A study was conducted to determine how long four enteric pathogens (Campylobacter jejuni, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica serovar Dublin) and one index bacterium (Enterococcus faecalis) survived in three (one-ton) manure piles made from feedyard manure at two depths (4 cm and 44 cm) in the summer and winter. The concentration of each pathogen was determined after it was grown in the laboratory, and periodically after they were placed in the manure piles. The concentration of each pathogen was titered in triplicate from each manure pile. The pathogens were confined in PVC pipes, capped on each end with nylon filter fabric (0.45 micron pores) which allowed the exchange of moisture to be consistent with that of the pile. The Campylobacter died at both depths within 3 days in both the winter and summer. The remaining pathogens died at 4 cm in the summer by day 133, except for Salmonella which survived past day 217. In the summer (depth 44 cm) all pathogens died by day 77, and the index bacteria died by day 133. In the winter at 4 cm and at 44 cm depth there were differences in survival of the pathogens between piles. Listeria did not survive past 118 days in pile 3 at 4 cm depth, and neither Listeria or Salmonella survived 118 days in pile 3 at 44 cm depth. In pile 2 at 44 cm depth neither Listeria or Salmonella survived for 118 days. In conclusion, the survival of pathogens in manure from commercial feedyards was highly dependent upon rainfall. When experimentally formed manure piles were exposed to rain, thermophillic bacteria and fungi began to heat the piles and the temperature reached 70º C, which killed all the pathogens used. It was determined that the three experimental piles may have reacted differently to the microbial thermophillic activity even though they were in close proximity to each other. It was also determined that the 44 cm depth heated more rapidly than the 4 cm depth. In general, it appeared that most manure pathogens would be destroyed if commercial feedyards stored their manure long enough to receive adequate rainfall to start the microbial thermophilic activity.