Background
Dermanyssus gallinae , or poultry red mite (PRM), is an important ectoparasite in laying hens, having a significant welfare and economic impact. Testing novel control compounds typically involves in vitro methodologies before in vivo assessments. Historically, in vitro methods have involved PRM feeding on hen blood through a membrane. The use of hen blood requires multiple procedures (bleeds) to provide sufficient material and the use of a larger species (e.g. geese), could serve as a refinement in the use of animals in research.
Methods
The existing in vitro feeding device, employing a Parafilm™ M membrane [1] and adult females was used to investigate any differences in mite feeding, egg laying and mortality when fed goose or hen blood. Effects on these parameters when PRM were fed through either; Parafilm™ M, Baudruche membrane, and a combination of these with an overlaid polyester mesh were then tested using goose blood.
Results
PRM fed equally well on goose or hen blood through a Parafilm™ M membrane, no significant differences in mortality of PRM fed with either blood type was demonstrated. A significant increase (t-test: t =3.467, df =4, P = 0.03). in eggs laid per fed mite when using goose blood was demonstrated. A 70% increase in PRM feeding was observed when mites were fed on goose blood through a Baudruche membrane when compared to the Parafilm™ M membrane. Addition of an overlaid polyester mesh did not improve feeding rates. A significant increase (ANOVA: F (3, 20) =3.193, P = 0.04) in PRM egg laying was observed in mites fed on goose blood through Baudruche membrane, compared to those fed through Parafilm™ M. A mean of 1.22 (SEM ± 0.04) eggs per fed mite was obtained using the Baudruche feeding device compared to only 0.87 (SEM ±0.3) eggs per fed mite using the Parafilm™ M device when neither had a polyester mesh overlay.
Conclusion
The in vitro feeding of adult female poultry red mite can be readily facilitated through the use of goose blood in feeding devices with Baudruche membrane.