Fly strike in sheep is one of those things that is best to put the effort into prevention. Coming back from Christmas holidays to find fly blown lambs and ewes is very demoralising. Even a 50c piece size area of fly strike can stop a ewe cycling for a month. For lambs the loss of growth, suffering and deaths, along with the time dealing with the mess, are enough for many to vow to get things sorted before Christmas next year….
The obvious measures are to ensure stock are clean and don’t get wormy. So crutching and a regular effective drenching program are essential pillars to preventing fly.
There are generally 3 waves of fly pressure, the first few appearing around December, then the second and bigger wave in mid-summer and the third wave mid-autumn. This is important when planning your program especially in relation to persistent activity and application time.
Your fly-lice program for your sheep flock can be complex with the range of chemicals now available. There is a general move towards being more aware of chemical resistance and using these resources in a planned and sustainable way.