Lice Control
/Off shears and pre-lamb, before the next generation of lice residences arrives, is the best opportunity to deal with lice.
Jetting off-shears with short acting knock-down chemical such as Extinosad or Seraphos is cheaper, but jetting is never 100% effective. It just does not totally wet the skin enough. Can’t be that pleasant off -shears in winter conditions.
Off shears pour-on options include Zapp Encore, Magnum, Expo Pour-On and Wipe-out. The IGR in Magnum and Zapp Encore gives persistent activity for 2-3 months. With Zapp Encore there is also a knock down imidacloprid which gives instant kill, this differentiates Zapp Encore from other straight IGR based chemicals. It does have limitations with cover-comb shorn merinos however. Double dose Expo Pour-On may be the best knock-down for lice in fine wool.
The trick is to treat all sheep and do it properly. Don’t leave an island sanctuary around the head and neck for lice to survive.