TY - JOUR
T1 - Trapping efficacy of Duddingtonia flagrans against Haemonchus contortus at temperatures existing at lambing in Australia
AU - Kahn, Lewis
AU - Norman, T.M.
AU - Walkden-Brown, Stephen
AU - Crampton, Andrea
AU - O'Conner, Lauren
N1 - Imported on 12 Apr 2017 - DigiTool details were: Journal title (773t) = Veterinary Parasitology. ISSNs: 0304-4017;
PY - 2007
Y1 - 2007
N2 - The aim of this study was to determine the trapping efficacy of Duddingtonia flagrans against Haemonchus contortus at the temperature ranges experienced around lambing in the major sheep producing regions of Australia. Faeces were collected from Merino wethers, maintained in an animal house and which had received either D. flagrans chlamydospores for a 6-day period (DF)or not (NIL). Faeces were incubated at one of four daily temperature regimens which were composed of hourly steps to provide 6'19 8C, 9'25 8C, 14'34 8C and 14'39 8C to mimic normal diurnal air temperature variation. Enumeration of the number of preinfective and infective larvae that had migrated from or remained in faecal pellets was used to calculate percentage recovery and trapping efficacy of D. flagrans. Recovery of H. contortus larvae of both stages was significantly lower in DF faeces but the magnitude of the effect was considerably greater for infective larvae. Mean recovery of infective larvae from NIL and DF faeces was10.6 and 0.4%, respectively, indicating a mean trapping efficacy of 96.4%. The lowest trapping efficacy (80.7%) was observed at 6'19 8C but total recovery of infective larvae, from DF faeces, was greatest at the two highest temperature regimens, although still less than 0.9%. The results of this study indicate that typical Australian lambing temperatures should not be a barrier to the use of D. flagrans as an effective biocontrol of H. contortus in Australia.
AB - The aim of this study was to determine the trapping efficacy of Duddingtonia flagrans against Haemonchus contortus at the temperature ranges experienced around lambing in the major sheep producing regions of Australia. Faeces were collected from Merino wethers, maintained in an animal house and which had received either D. flagrans chlamydospores for a 6-day period (DF)or not (NIL). Faeces were incubated at one of four daily temperature regimens which were composed of hourly steps to provide 6'19 8C, 9'25 8C, 14'34 8C and 14'39 8C to mimic normal diurnal air temperature variation. Enumeration of the number of preinfective and infective larvae that had migrated from or remained in faecal pellets was used to calculate percentage recovery and trapping efficacy of D. flagrans. Recovery of H. contortus larvae of both stages was significantly lower in DF faeces but the magnitude of the effect was considerably greater for infective larvae. Mean recovery of infective larvae from NIL and DF faeces was10.6 and 0.4%, respectively, indicating a mean trapping efficacy of 96.4%. The lowest trapping efficacy (80.7%) was observed at 6'19 8C but total recovery of infective larvae, from DF faeces, was greatest at the two highest temperature regimens, although still less than 0.9%. The results of this study indicate that typical Australian lambing temperatures should not be a barrier to the use of D. flagrans as an effective biocontrol of H. contortus in Australia.
KW - Duddingtonia flagrans
KW - Haemonchus contortus
KW - Sheep
KW - Temperature
U2 - 10.1016/j.vetpar.2007.02.004
DO - 10.1016/j.vetpar.2007.02.004
M3 - Article
VL - 146
SP - 83
EP - 89
JO - Veterinary Parasitology
JF - Veterinary Parasitology
SN - 0304-4017
IS - 1-2
ER -