The time taken to achieve useful results. Convincing breeders to adopt technology. Correlation with other traits. Problems with testing procedures. Producers said the major advantages of an integrated programme were breeding for improved resistance and better pasture management with drenches used less often.
Biological control using fungi, vaccination, and use of good nutrition are options for the future.
New South Wales wool grower John McLaren has been selecting sheep for worm resistance for about five years with positive results. The McLaren family decided to participate in the Nemesis programme in an attempt to lower their dependence on chemical worm control options. The worms were becoming resistant to available drenches and as the property has a high summer rainfall worm problems were quite prevalent. In the programme, a faecal egg count is taken from the young rams once a year. The faecal egg counts allow the McLarens to compare how the young rams compare to their fathers.