Effect of forage legumes containing condensed tannins on lungworm (Dictyocaulus sp.) and gastrointestinal parasitism in young red deer (Cervus elaphus)

To investigate the effect of feeding forage legumes containing condensed ta nnins (CT) on internal parasitism, red deer calves were fed either lucerne (Medicago sativa; 0.1 per cent CT), birdsfoot trefoil (Lotus corniculatus; 1.9 per cent CT) or sulla (Hedysarum coronarium; 3.5 per cent CT) and trick le-infected with deer-origin gastrointestinal nematode and lungworm (Dictyo caulus sp.) larvae for 5 weeks, then slaughtered at 7 weeks. There was a si gnificant negative linear relationship between dietary CT concentration and abomasal nematode burdens. No significant differences in faecal egg counts , lungworm burdens or voluntary feed intake were found. Deer fed sulla had higher liveweight gain, carcass weight and carcass dressing-our percentage, higher serum total protein and albumin concentration and lower serum gastr in concentration and faecal lungworm larval count, compared with lucerne-fe d deer. inclusion of sulla in diets for young red deer may reduce the impac t of internal parasites and/or reduce the dependence on anthelmintic treatm ent.