Effects of condensed tannins and sesquiterpene lactones
extracted from chicory on the viability of deer lungworm larvae
A.L. Molan, A. Duncan, T.N. Barry and W.C. McNabb
Nutrition and Behaviour Group, AgResearch, Grassland Research
Centre, Private Bag 11008, Palmerston North, New Zealand
Proceedings of the New Zealand Society of Animal Production.
2000 60: 26-29
The objective of this study was to determine the effects of
condensed tannins (CT) and a crude extract containing sesquiterpene
lactones (CSL) extracted from chicory (Cichorium intybus) on the
viability of the first (L1) and third stage (L3) larvae of deer
lungworm, Dictyocaulus viviparus in vitro using the larval migration
inhibition (LMI) assay. The CT and CSL immobilised larvae and inhibited
their migration through 25 mm nylon mesh sieves. Incubation of L1 larvae
in rumen fluid (collected from deer fed pasture) containing 100, 400,
and 1000 mg CT/ml, inhibited 12%, 28% and 41% of the larvae from passing
through the sieves, respectively while the incubation of L3 larvae with
rumen fluid containing the same concentrations inhibited 26%, 37% and
67% of L3 larvae from passing through the sieves, respectively. CT were
more effective (P<0.001) at reducing the viability of lungworm L1 and
L3 larvae when added to the rumen fluid (pH 6.6) than when added to the
abomasal fluid (pH 3.0). L3 larvae were more sensitive to the action of
CT than L1 larvae. Addition of 2 mg polyethylene glycol/mg CT eliminated
most of the inhibitory effect of CT against L1 and L3 larvae especially
during incubation in rumen fluid. The CSL extract showed similar
inhibitory activity in both fluids, indicating that this extract was not
affected by the pH of the fluid, and they were more effective against L3
than L1 larvae.
Keywords: NZSAPAB;
Condensed tannins; crude sesquiterpene lactones; chicory; lungworm; deer.
Last Updated 12-07-2000
