Nematode parasitic infections constitute a serious health and welfare problem of sheep and goats in organic farming systems. Research will focus on non-chemical strategies for the control of these infections. Recommendations for the use of these strategies alone, or in combination with sheep and goats, will be developed and disseminated. Although primarily aimed for organic farming, guidelines will be equally applicable in conventional farms as a new, sustainable approach to parasite control.
The objectives of the project are:
1) to evaluate the potential benefits of bioactive plants or forages in mitigating the effects of gastrointestinal nematodes in sheep and goats in organic production
2) to investigate the potential of biological control of nematode parasites of sheep and goats by means of the nematode-destroying fungus Duddingtonia flagrans.
3) to collect the necessary baseline data on the population dynamics of the free-living stages of nematodes of sleep and goats, and to use these data for the design and evaluation of grazing management strategies for control
4) to perform field evaluation of parasite control strategies combining the elements mentioned above: bioactive forages, biological control and grazing management
5) to develop and provide recommendations for the use of non-chemical, sustainable parasite control measures in organic (or conventional) production of sheep and goats in Europe.
Progress to Date
The project is progressing as planned. The results of the project will enable us to provide guidelines to organic farmers regarding parasite control with little or no anthelmintics (dewormers). This will primarily ensure a high level of welfare in organic livestock (less disease), a higher level of productivity for the benefit of farmers, and help in the provision of products to consumers from animals that have not been subject to preventative medication. The results of the first two years covering two grazing seasons look promising for the use of bioactive forages (or herbal remedies), whereas nematophagous fungi (bio-control), especially for sheep, have so far been providing inconclusive results.
The studies focusing on the bioactive forages have revealed that plants with high levels of condensed tannins (e.g. sainfoin) and other plants with secondary metabolites (e.g. chicory) possess anti-parasitic activity against common gastrointestinal nematodes of small ruminants. Effects found in vivo in both goats and sheep with natural mixed infections or mono-specific experimental infections have been confirmed in vitro using, for example, larval feeding inhibition, larval development and larval migration inhibition assays. A feed ration with 5-6% of purified condensed tannins (e.g. quebracho) has reduced important nematode infections in goats. It was noteworthy that reduced egg counts persisted after the end of dosing with condensed tannins. The bioactive forage sainfoin conserved as hay also resulted in reduced faecal egg counts in naturally infected adult goats.
Plot studies and in vitro testing of the nematophagous fungus Duddingtonia flagrans have shown marked reductions in worm burdens of goats but, to summarise, three out of the four grazing trials in 2002 with ewes and suckling lambs under close-to-normal farming conditions showed little or no inconsistent effect on any of the parasitological parameters examined. However, preliminary results of several trials in 2003 indicate favourable reductions in nematode infections in sheep.
Evasive grazing (repeated moves of livestock to clean pastures) in sheep was investigated in 2001, and it was evident that a move every three weeks cannot be considered safe if the parasite Haemonchus contortus is prevailing. However, other parasite infections may well be controlled by this procedure.
Several partners have been engaged in practical advice and farmers' meetings in the reporting period. A project website (www.wormcops.dk) has been established.
ANIMALS, ARABLE CROPS
Scientist responsible for the project
Mr STIG MILAN THAMSBORG
1870 Frederiksberg C
Denmark - DK
Phone: +45 35282780
Fax: +45 35282774
||THE ROYAL VETERINARY AND AGRICULTURAL UNIVERSITY
||01 September 2001
||2 734 867 €
|Total EC contribution
||1 752 115 €
|Web address of the project