McAnulty, RWGreer, Andrew2018-07-022012-10https://hdl.handle.net/10182/9976This project was run on the organic land at the Lincoln biological Husbandry Unit (LBHU) to provide the necessary information needed to develop practical, cost effective programmes for nematode worm control in lambs grazing in organic systems. The ability to identify and then remove individual animals suffering from parasitism and subsequently graze them on bioactive forages (chicory, plantain) should provide a chemical free method of reducing the impact of parasitism. Trial area consisted of a 4 ha block that was split into two blocks (2 ha). Each block had 1.5 ha sown in ryegrass (AR1) and 0.5 ha in a mixed sward lay of chicory/plantain and white cover. 60 weaned lambs were allocated on liveweight to one of two block (n=30), and were rotational grazed across each block on the ryegrass sward, from November 2011. One block had been seeded with Teladorsagia circumcincta eggs and the second block had been seeded with Trichostrong/yus colubriformis eggs. Animals were monitored at two weekly inteivals for li.veweight using an electronic tag reader, automatic weighing and , drafting platform, to identify those animals whose performance was below their target weight, and these animals were then drafted off and allowed to graze the bioactive swards. Individual faecal samples (FEC) were taken fortnightly; pasture production measured weekly and was used to set liveweight targets determined by 'happy factor' algorithm (Greer et al 2010). Overall growth rates on the lambs grazing on the T. circumcincta and T. colubriformis infected blocks were 252 g/d and 292 g/d respectively. Mean FEC were high (> 2000 epg) for both sets of lambs, there were no significant differences in FEC between animals grazing the main or hospital paddocks. For both pasture suites there was a significant paddock time (p<0.05) early on that reflected a benefit of hospitalisation on LWG. Of animals that required hospitalisation on either pasture suite over 80% had recovered after 4 weeks grazing. However due to the poor establishment /growth of clover, chicory and plantain it is not possible to judge the effectiveness of the bioactive forages on LWG or in reducing worm burdens. Improved lamb performance is more likely to be a result of reduced larval challenge.pp.22-23enforagelambsorganicConference Contribution - published