Hopp til hovedinnholdet

Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2020

Abstract

Coccidiosis is a serious disease caused by Eimeria spp. in young lambs in Norway. Re-sistance against anticoccidial chemicals has been demonstrated in conventional sheep farm-ing. In organic farming we are looking for natural plant sources to increase animal health and welfare. Condensed tannins (CT) have showed effect against coccidia in several trials. Extract from Norwegian spruce bark (Picea abies), a waste product from the wood industry, was shown to contain CT in a Norwegian study. In our trial we tested the effect of bark extract from Norwegian spruce against Eimeria spp in young lambs. The extract was prepared by hot water extraction followed by evaporation and freeze drying. 24 naïve lambs were randomly grouped, 16 of them were inoculated with 100 000 Eimeria oocysts each for three days at 3 weeks of age, and eight of the 16 were treated with bark extract for 12 successive days post infection. The CTg per lamb per day correspond to 0.05% BMW. A control group of eight lambs was not infected or treated. Individually faeces samples were collected and analysed for faecal score and oocysts. Clinically observations and weight gain were measured. In this trial the bark extract was found to have a significant effect on the development of Eime-ria spp. oocysts in the lambs (p<0,001). The extract was given by a stomach tube, and had a negative effect on the lambs appetite as long as it was administered.

Abstract

Mountain grazing conditions represent a constraint on lamb growth performance for various reasons. One approach to counteract these effects is to graze lambs on improved pastures. We tested the effects of grazing ewes and/or their lambs on established grass-clover (GCM), chicory alone (CHA), and grassclover-chicory (GCC) stands on spring (Exp.1) and summer (Exp.2) pastures on lamb performance. We hypothesized that CHA and GCC would sustain higher spring and autumn daily gain of lambs compared with GCM. In Exp.1, 12 twin-rearing ewes together with their 24 lambs were randomly allocated into three sward types replicated twice (n=2 ewes, 4 lambs/replicate) and monitored for 25 d before sending to mountain pasture. In Exp.2, 24 weaned lambs from the mountain pasture were again randomly allocated to one of the above pasture types and grazed for 28 d. We observed differences in chemical composition and estimated energy values between swards containing chicory and GCM swards. However, these did not affect lamb performance during both experiments, contrary to our previous findings, suggesting that grazing sheep either selected against chicory, or the observed differences in chemical composition among sward types were not strong enough to influence performance, or a combination of the two possible effects