How to eliminate lice from laying hens? - briefly
Treat the flock with a licensed acaricide applied as a spray or dust, adhering to label‑specified dosage and withdrawal periods. Combine chemical treatment with thorough cleaning of housing, regular litter replacement, and routine health inspections to prevent reinfestation.
How to eliminate lice from laying hens? - in detail
Lice infestations in egg‑producing chickens cause feather loss, reduced egg quality, and decreased productivity. The most common species are Menacanthus stramineus and Lipeurus caponis.
Identification relies on visual inspection of the vent area, feather shafts, and skin folds. Adult lice appear as flattened, wingless insects, 2–3 mm long, with a brownish hue. Nymphs are smaller and translucent. A hand‑lens examination of a sample of birds (approximately 10 % of the flock) provides reliable prevalence data.
Immediate control options include:
- Synthetic insecticides: pyrethroids (e.g., permethrin 0.5 % spray), organophosphates (e.g., malathion 0.5 % solution). Apply according to label dosage, ensuring thorough coverage of the vent region and feather bases. Observe withdrawal periods for eggs.
- Avermectins: ivermectin administered via drinking water at 0.2 mg kg⁻¹ body weight. Effective against all life stages; repeat after 7 days to target newly hatched lice.
- Phenylpyrazoles: fipronil dust applied to perches and nesting boxes at 2 g m⁻². Use protective equipment to avoid residue contamination.
Non‑chemical measures complement chemical treatment:
- Environmental sanitation: remove litter weekly, replace with fresh bedding, and disinfect coops with a 1 % quaternary ammonium solution.
- Dust baths: provide fine sand or diatomaceous earth (≥ 95 % purity) in shallow trays; birds self‑administer, causing mechanical desiccation of ectoparasites.
- Biological control: introduce predatory mites (Androlaelaps casalis) that feed on lice eggs and nymphs; maintain humidity between 55–65 % for optimal predator activity.
A typical treatment protocol:
- Day 0: administer ivermectin in drinking water; spray permethrin on all birds.
- Day 7: repeat ivermectin dose; re‑apply permethrin to address emergent lice.
- Day 14: conduct a post‑treatment inspection; if lice persist, perform a third ivermectin cycle and consider fipronil dusting.
Preventive management reduces reinfestation risk:
- Conduct fortnightly inspections of a random sample of birds.
- Rotate litter and clean perches monthly.
- Limit external access to the flock; enforce foot‑dip stations for personnel and equipment.
- Maintain optimal nutrition and stress‑reduction practices to support the birds’ immune response.
Monitoring for resistance involves rotating active ingredients every 6–12 months and recording treatment efficacy. If efficacy declines below 80 % after a standard protocol, submit samples for laboratory susceptibility testing and adjust the control regimen accordingly.