TY - JOUR
T1 - Survival of Ascaris suum and Ascaridia galli eggs in liquid manure at different ammonia concentrations and temperatures
AU - Katakam, Kiran Kumar
AU - Mejer, Helena
AU - Dalsgaard, Anders
AU - Kyvsgaard, Niels Christian
AU - Thamsborg, Stig Milan
N1 - Copyright © 2014 Elsevier B.V. All rights reserved.
PY - 2014/8/29
Y1 - 2014/8/29
N2 - Eggs of Ascaris suum from pigs are highly resistant and commonly used as a conservative indicator of pathogen inactivation during slurry storage. Eggs of Ascaridia galli, the poultry ascarid, are also known to be highly resistant but the suitability as an indicator of pathogen inactivation has never been tested. Pig slurry has to be stored for several months to inactivate pathogens but chemical treatment of slurry may reduce this time. The suitability of A. galli as an indicator of slurry sanitation was tested by comparing the survival of eggs of A. suum and A. galli in pig slurry. In addition, the effect of urea treatment on inactivation of ascarid eggs in relation to storage time was also tested. Nylon bags with 10,000 eggs of either species were placed in 200ml plastic bottles containing either urea-treated (2%) or untreated pig slurry for up to 120 days at 20°C, 6 days at 30°C, 36h at 40°C or 2h at 50°C. At all the temperatures in both slurry types, A. galli eggs were inactivated at a significantly faster rate (P<0.05) compared to A. suum eggs. For each 10°C raise in temperature from 20°C, T50 (time needed to inactivate 50% of eggs) for both types of eggs was reduced markedly. At all temperatures, viability of eggs of both species was significantly higher (P<0.05) in untreated slurry compared to urea-treated slurry except A. galli eggs at 20°C where no significant difference was detected. In untreated slurry, the levels of pH (6.33-9.08) and ammonia (0.01-1.74mM) were lower (P<0.0001) compared to that of urea-treated slurry (pH: 8.33-9.28 and ammonia 1-13mM). The study demonstrated that A. galli eggs are more sensitive to unfavourable conditions compared to A. suum eggs. The use of A. galli eggs as hygiene indicator may thus be suitable to assess inactivation of pathogens that are more sensitive than A. galli eggs. Addition of urea may markedly reduce the storage time of slurry needed to inactivate A. suum and A. galli eggs.
AB - Eggs of Ascaris suum from pigs are highly resistant and commonly used as a conservative indicator of pathogen inactivation during slurry storage. Eggs of Ascaridia galli, the poultry ascarid, are also known to be highly resistant but the suitability as an indicator of pathogen inactivation has never been tested. Pig slurry has to be stored for several months to inactivate pathogens but chemical treatment of slurry may reduce this time. The suitability of A. galli as an indicator of slurry sanitation was tested by comparing the survival of eggs of A. suum and A. galli in pig slurry. In addition, the effect of urea treatment on inactivation of ascarid eggs in relation to storage time was also tested. Nylon bags with 10,000 eggs of either species were placed in 200ml plastic bottles containing either urea-treated (2%) or untreated pig slurry for up to 120 days at 20°C, 6 days at 30°C, 36h at 40°C or 2h at 50°C. At all the temperatures in both slurry types, A. galli eggs were inactivated at a significantly faster rate (P<0.05) compared to A. suum eggs. For each 10°C raise in temperature from 20°C, T50 (time needed to inactivate 50% of eggs) for both types of eggs was reduced markedly. At all temperatures, viability of eggs of both species was significantly higher (P<0.05) in untreated slurry compared to urea-treated slurry except A. galli eggs at 20°C where no significant difference was detected. In untreated slurry, the levels of pH (6.33-9.08) and ammonia (0.01-1.74mM) were lower (P<0.0001) compared to that of urea-treated slurry (pH: 8.33-9.28 and ammonia 1-13mM). The study demonstrated that A. galli eggs are more sensitive to unfavourable conditions compared to A. suum eggs. The use of A. galli eggs as hygiene indicator may thus be suitable to assess inactivation of pathogens that are more sensitive than A. galli eggs. Addition of urea may markedly reduce the storage time of slurry needed to inactivate A. suum and A. galli eggs.
KW - Faculty of Health and Medical Sciences
KW - Slurry
KW - Viability
KW - Ascaris suum eggs
KW - Ascaridia galli eggs
KW - Temperature
KW - Ammonia
U2 - 10.1016/j.vetpar.2014.05.017
DO - 10.1016/j.vetpar.2014.05.017
M3 - Journal article
C2 - 24893691
SN - 0304-4017
VL - 204
SP - 249
EP - 257
JO - Veterinary Parasitology
JF - Veterinary Parasitology
IS - 3-4
ER -