TRIGG Romney Newsletter-oct 2006.pdf (799KB) 

Triggs Parasite Programme

Resilience is a term used to describe animals that have the ability to be productive despite the presence of internal parasites.  This is because for many internal parasites the actual decrease in production seen in growing lambs is due to the immune response that is mounted due to the internal parasites, not due to the direct impact of the parasite (although exceptions like the blood sucking Barbers Pole do exist).

Animals that are resistant will potentially still be shedding eggs, but their performance is comparable to animals that have been treated with anthelmintics.  Testing for resilience simply involves not drenching growing lambs and monitoring their growth rates, those lambs that are showing resilience will maintain normal growth rates, and not be daggy.

This is the approach that TRIGG is taking through testing all stud lambs with no drenching taking place until their autumn weight is recorded.  At this time animals that have shown resilience will be selected and fecal egg counts will be made, as the ideal situation is to actually select for animals that have reduced fecal egg counts at the same time as maintaining production, as this will decrease pasture contamination.