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OJVRTM
Online Journal of Veterinary Research©
(Including Medical and Laboratory Research)
Established 1994
ISSN 1328-925X
Volume 30 (4): 243-252, 2026.
Effect of neem wool wax formulations on sheep lice.
VH Guerrini.
Pestsearch International,
Research Division, Queensland, Australia
ABSTRACT
Guerrini VH., Effect of neem wool wax formulations on sheep lice.
Onl J Vet Res, 30 (4):
243-252, 2026. Azadirachtin neem seed
extract is a powerful insect growth regulator, feeding deterrent and repellent
with low toxicity. However, azadirachtin degrades
rapidly in light, excessive heat or alkalinity. Effects of normal and UV protected azadirachtin on Damalinia
ovis were evaluated on
sheep in a lice contaminated environment for 6 months. Retention,
lice control and repellency was evaluated by periodically counting lice in
treated sheep tied to untreated lousy sheep. Sheep infested by Damalinia ovis were sprayed
once with methanolic neem seed extracts of 40, 80,
160, 320, 640, 1280 ppm azadirachtin and tween-wool
wax formulations containing 2000 ppm azadirachtin.
For 6 days after treatment, increased azadirachtin
concentrations correlated (P < 0.0001) with reductions in lice. After Day 6,
azadirachtin concentrations ranging from 80 to 1280
ppm reduced lice 98-100% and prevented re-infestation for 6 months. In tween or
wool fat, azadirachtin reduced lice 100% from Day 2
to 95 and 94-96% from Day 96 to Day 170. The findings suggest that relatively
low concentrations of azadirachtin inhibit lice on
sheep for long periods. On long wooled sheep, azadirachtin may be retained in lanolin and be protected
from UV light and oxidation.
Key words: Azadirachtin, Damalinia
ovis, sheep.
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