A multi-faceted approach is recommended to achieve effective flystrike control. This includes breeding for flystrike resistance, appropriate timing of shearing and crutching and strategic use of chemical treatment. Breech modifications can also be used, but can gradually be eliminated with the combination of other strategies.
Breeding is the only practice to create permanent change in your flock and can provide useful improvements relatively quickly—even in the first generation—if wrinkle-free rams are selected.
The 3 key breeding strategies involve reducing skin wrinkle, decreasing breech cover and reducing dag.
Firstly, consider whether your flock is already very plain or still has many sheep with wrinkle, be it on the breech, body or neck.
1. Use rams with low breech wrinkle (it is strongly related to body and neck wrinkle)
2. Select less wrinkled ewes
3. Mating Strategy — mate selected rams with selected ewes
For less wrinkled flocks decrease the breech cover (wool cover around the anus and vulva) and the amount of dag.
Also take into account ASBVs for other traits important to you to ensure that you achieve a balanced selection.
You can find the Wrinkle Scores in the Sheep Visual Scores publication on the Sheep Genetics website.