The effect of birdsfoot trefoil (Lotus corniculatus) and white clover (Trifolium repens) in mixed pasture swards on incoming and established nematodeinfections in young lambs

Lotus corniculatus L., a leguminous plant containing condensed tannins, is now being evaluated in Sweden as a component of mixed pastures. This is bec ause of its high nutritive value, palatability, modest requirement for wate r, calcium and phosphorous and particularly because it has the ability to s urvive harsh weather conditions that typify northern Scandinavia. This tria l was undertaken to assess the possible parasitological benefits of using L . corniculatus when fed as a minor component in a mixed pasture award to yo ung sheep. This was compared with similar sheep that were fed pasture with a comparable legume content consisting of Trifolium repens L. Separate grou ps of lambs, maintained in pens and provided with fresh pasture cuts contai ning either L. corniculatus or T: repens each day, were trickle-dosed with infective larvae of mixed parasite species. For each pasture type, groups o f 6 lambs had either established worm burdens only, received incoming infec tions only, or had the combination of both adult and incoming infections. W orm burdens were monitored by serial faecal egg counts and at the terminati on of the study, all animals were slaughtered for worm recovery, identifica tion and enumeration. The results showed that there were no differential ef fects between L. corniculatus and T repens on the different stages of devel opment for a range of nematode parasite species recovered from these lambs. Several reasons may account for this: such as the low lever of condensed t annins in the L. corniculatus variety tested, the minor proportion of this plant in the diet and/or the variety of L. corniculatus used in this trial which do not provide any benefits to controlling parasites of sheep.