Abstract

Aim:To investigate the inactivation ofSalmonella entericaserovar Typhimuri-um and the faecal indicatorEnterococcus faecalisin horse manure:soil mixturesby application of hydrated lime (Ca(OH)2).
Methods and Results:In laboratory incubations, the inhibitory effect of differ-ent concentrations of Ca(OH)2, as well as different application techniques, wastested. Other variables were horse manure:soil ratio, incubation temperature (6and  14 C) and soil type (sand⁄clay). Bacterial enumeration by the plate countmethod in samples taken at increasing intervals revealed that Ca(OH)2effectively reducedSalmonellaTyphimurium numbers. However, to achieve asufficient reduction, the Ca(OH)2had to be applied at a sufficient rate, and theamount required varied because of manure:soil ratio and incubation tempera-ture. The results showed that a pH above 11 was needed and that a high pHhad to be maintained for up to 7 days. An appropriate application techniquefor the Ca(OH)2was also important, so that a high pH was obtained through-out the whole material to be treated. In addition, a high manure:soil ratio incombination with a higher incubation temperature was found to rapidlyneutralize the pH and to increase the risk ofSalmonellare-growth.
Conclusions:Application of Ca(OH)2can be an efficient method for treating aSalmonella-contaminated horse paddock. A high pH is a key factor inSalmo-nellainactivation, and thus, monitoring the pH during the treatment period isnecessary. To avoid re-growth excess manure should be removed for separatetreatment elsewhere.
Significance and Impact of the Study:Persistence of Salmonellain horsepaddocks poses a risk of disease transmission to healthy animals and peoplewho come into contact with these animals. An efficient method to de-contami-nate aSalmonella-contaminated soil would be a valuable tool for animalwelfare and for public health.

Keywords

environmental health; microbial contamination; Salmonella; soil; veterinary

Published in

Journal of Applied Microbiology
2011, Volume: 110, number: 6, pages: 1515–1523

SLU Authors

• Vinnerås, Björn

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    
  • National Veterinary Institute (SVA)
UKÄ Subject classification

Pathobiology
Environmental Sciences related to Agriculture and Land-use
Animal and Dairy Science


Publication identifier

DOI: https://doi.org/10.1111/j.1365-2672.2011.05006.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/52842