INFLUENCE OF DIET ON THE OCCURRENCE OF INTRAEPITHELIAL MICROABSCESSESAND FOREIGN-BODIES IN THE RUMINAL MUCOSA OF REINDEER CALVES (RANGIFERTARANDUS TARANDUS)

The forestomach mucosa was examined for pathological lesions in 12 hea lthy free-ranging reindeer calves at different seasons, and in 32 rein deer calves fed lichen (n = 3), baled grass silage (12 = 24) or pellet ed feed (ii = 5). No gross lesions mere seen. Samples for histology we re taken from reticulum, omasum and four sites in rumen. In histologic al sections a total of 182 intraepithelial microabscesses (IEMAs) and 16 foreign body lesions (FBLs) were observed in the ruminal mucosa, wh ile 1 IEMA was found in omasum and no lesions in reticulum. The number of animals having 0, 1-10, 11-20 and > 20 IEMAs per four ruminal sect ions (one from each sample site) was 19, 19, 5 and 1, respectively. No ne of the free-ranging or lichen-fed animals had more than 1 IEMA per four ruminal sections, while 58% (14/24) of the animals fed silage and 40% (2/5) of the animals fed pelleted feed had 2 or more IEMAs per 1 ruminal sections. FBLs occurred more frequently in animals with high n umbers oi IEMAs, and it is suggested that both IEMAs and FBLs are caus ed by plant particles penetrating the ruminal epithelium. The lesions did not seem to indicate an inferior diet nor influence the health of the animals.