EFFECTS OF TIME, FROM COLLECTION TO PROCESSING, ON THE RECOVERY OF HAEMONCHUS-CONTORTUS 3-STAGE LARVAE FROM HERBAGE

Being able to obtain accurate estimates for the number of Haemonchus c ontortus third-stage larvae (L3) on pasture is essential to any type o f strategy intended for control. The objective of this experiment was to study the effect of the time, from collection to processing, on the recovery rate of H. contortus L3 from herbage. Separate herbage sampl es were inoculated with two treatments of a known amount of larvae on Day 1 and then samples were processed from Day 1 to Day 30. This simul ated infective herbage was collected, refrigerated, and processed over a period of 1 month. A drop in the recovery rate over time was found. Treatment 2 (5000 L3) exhibited a sharper decline in recovery rate th an Treatment 1 (1800 L3). These findings suggest that the effect of ti me, from collection to processing, as well as larval concentration on the herbage, must be considered when performing any type of larval rec overy technique.