Intensive Rotational Grazing And It's Role As A Tool For Barber's Pole Worm Control In The New England

Abstract

Sheep on Farmlet C – Intensive Rotational Grazing (IRG): • have lower faecal worm egg counts than A and B in all classes of sheep • have a lower percentage of Barber’s Pole Worm ('Haemonchus contortus') • are exposed to lower numbers of larvae on pasture • have lower resistance to worms • have no discernable production losses attributable to worms The reduction in faecal worm egg counts is due to interruption of the nematode lifecycle in its free-living stages and is not due to better host resistance or resilience on Farmlet C. Intensive rotational grazing works in 2 ways: • Preventing autoinfection by removing sheep from pasture before they re-infect themselves (short grazing periods). • Presenting a low number of infective larvae available on pasture for ingestion by sheep (long rest periods). Farmlet C seems to be more effective against Barber’s Pole worm than against the other major worm species. This is likely, due to the specific climatic conditions required by Barber’s Pole worm eggs to hatch and develop into infective larvae. Other major worm species such as Black scour worm ('Trichostrongylus spp.') and Small brown stomach worm ('Teladorsagia circumcincta') have much hardier eggs which can survive longer in the absence of optimal moisture and temperature conditions.