Can extract from Norwegian Bark extract control coccidiosis in suckling lambs?

Summary

Coccidiosis is a serious disease in young lambs in Norway and other countries. The disease leads to decreased animal welfare and has huge economic impact on the farm industry. The common preventive measures in Norway are pasture rotation and anticoccidial chemical. Reduced efficacy against toltrazuril has been demonstrated in sheep farming in Norway. Condensed tannins (CT) from different plants have showed effect against nematodes and coccidia in several trials. Bark is a rich source of CT, and bark from species cultured in Scandinavia has relatively high concentrations of CT.
The aim of this project was to investigate if supplementation of bark extract with CT reduces the burden of coccidia in suckling lambs.
We infected 16 young lambs with oocysts from Eimeria spp. and tested the effect of extract from fresh winter bark from Norwegian spruce (Picea abies) to 8 of these lambs. Performance and oocyst secretion were measured. A control group of 8 lambs was not infected and not given bark extract.
Individually faeces samples were collected before infection and daily at day 9-22 after infection and analysed for faecal score and oocysts. In this trial the bark extract was found to have a significant effect on the development of coccidia of Eimeria spp. in the lamps measured by counting oocysts per gram faeces (p<0,001).
Bark extract from Picea abies may be a potential useful anticoccidium in young lambs. We need more research to see if this effect is due to CT or other biological components in the bark and to see if the effect is permanent and how this influences the performance of the lambs in a longer perspective. If this should be transferred into practical use for the farmers, we need to find a simple and secure method for application and a practically, technically and economically viable method for extract production.