Recirculating elutriator for extracting gastrointestinal nematode larvae from pasture herbage samples
K A Cassida1, E C Lester, J G Foster
1United States Department of Agriculture, Agricultural Research Service, Appalachian Farming Systems Research Center, 1224 Airport Rd., Beaver, WV 25813, USA. kacassida@gmail.com
Veterinary Parasitology
|April 14, 2012
Summary
A new elutriation method rapidly extracts gastrointestinal nematode (GIN) larvae from pasture herbage. This faster technique offers comparable accuracy and precision to traditional methods, aiding pasture management.
Area of Science:
- Veterinary Parasitology
- Ruminant Production
- Pasture Management
Background:
- Gastrointestinal nematode (GIN) parasites significantly limit ruminant production globally.
- Current methods for quantifying GIN larvae on pastures are slow, labor-intensive, and require specialized equipment.
- Inefficient data collection hinders the development of effective pasture management strategies to reduce parasite infectivity.
Purpose of the Study:
- To modify a soil elutriator for efficient extraction of GIN larvae from fresh herbage.
- To compare the elutriator method with the Baermann funnel technique for larvae recovery.
- To evaluate the speed, accuracy, and precision of the elutriator for GIN larvae extraction.
Main Methods:
- A soil elutriator was adapted using readily available materials for herbage sample processing.
- The elutriator extraction efficiency was compared against the standard Baermann funnel sedimentation method.
- Extraction times, larvae recovery rates, accuracy, and precision were systematically assessed.
Main Results:
- The elutriator processed significantly more samples per day (8 min/sample) compared to the Baermann method (24 h/sample).
- Larvae recovery rates were comparable between the elutriator (62.3%) and Baermann method (69.8%), with no statistically significant difference.
- Elutriation demonstrated high precision, sensitivity (detecting differences as low as 8 larvae/g DM), and was unaffected by forage type or canopy layer.
Conclusions:
- The modified elutriator provides a rapid, accurate, and precise method for extracting infective GIN larvae from pasture herbage.
- This technique overcomes the limitations of traditional methods, offering a faster alternative for data collection.
- Elutriation shows significant promise for improving pasture management strategies aimed at controlling GIN infections in ruminants.
