Poultry red mites in Swedish laying hen flocks : occurrence and efficacy to a selection of acaricides
The poultry red mite Dermanyssus gallinae is a blood-feeding ectoparasite commonly found in poultry facilities. It has an adverse effect on health and welfare of laying hens around the world. A common method used for control of D. gallinae is the use of acaricides (pesticides used against mites). Th...
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| Formato: | H2 |
| Lenguaje: | Inglés sueco |
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SLU/Dept. of Animal Nutrition and Management (until 231231)
2017
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| Sumario: | The poultry red mite Dermanyssus gallinae is a blood-feeding ectoparasite commonly found in poultry facilities. It has an adverse effect on health and welfare of laying hens around the world. A common method used for control of D. gallinae is the use of acaricides (pesticides used against mites). There are few acaricides available for control of D. gallinae today and concerns are raised regarding reduced effect of these due to development of tolerance in the mites. There are limited information regarding the occurrence of D. gallinae in Swedish layer flocks and efficacy in D. gallinae to acaricides. The aims of this study were therefore to investigate the occurrence of D. gallinae in laying hen flocks in different housing systems in Sweden by the use of questionnaires and collection of mites in traps. In addition, a test was conducted in laboratory environment where the efficacy of D. gallinae to the acaricides phoximand cypermethrin was examined. The data from the survey, with a response rate of 38%, showed that the prevalence of D. gallinae is widespread throughout Sweden in all types of housing systems and is causing varying degrees of problems for Swedish egg producers and their hens. The questionnaire indicated that 63% of the producers had mites in their layer flocks. Of those reporting presence of mites, 73% experienced some sort of problem related to the mites. The most common problems linked to mites were bloodspots on the eggshell, stressed hens, personal being attacked, feather pecking and increased mortality in hens. According to the questionnaire survey the majority, 77%, of the egg producers, used control measures against D. gallinae during on-going production. The most common measures were use of silica based preparations, the acaricide based compound Baymite®, combined with dry cleaning, wet cleaning or combined wet- and dry cleaning. Fifty-seven percent of the producers used control measures against D. gallinae between production cycles, i.e., in empty houses. The most common methods then were use of Baymite® and silica based preparations combined with dry cleaning. Measures against mites during ongoing egg production or between production cycles were considered to be effective. Fifteen percent of the producers reported that the mites had disappeared and 72% that the problems with mites had decreased, whereas 12% experienced that the control methods had poor or no effect. In the mite count study, mites were recovered from traps placed in 46 different units (unit defined as a laying hen facility enclosed by solid walls) in 25 farms. The material used when monitoring the degree of mites was traps made of pre-cut white semi-transparent rectangular pieces of “corrugated plastic” (100 x 70 x 2 mm) with transverse funnels. Results of the mite count shows that the majority, 65% of the egg producers units had a low abundance of mites, 11% of the units had abundant amount of mites, 9% had moderate abundance and 15% had no mites detected in their units. In the efficacy test the two acaricides phoxim and cypermethrin were used in the dilution recommended by the manufacturer for use in poultry. The result from the efficacy test showed that phoxim inactivated all mites from 15 out of 18 flocks and that cypermethrin inactivated all mites from only 7 out of 18 flocks after 48 hours. |
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