Radiocesium uptake in reindeer on natural pasture.

In an experiment initiated after the Chernobyl accident, a herd of reindeer was followed before and after a temporary move from a highly contaminated area (greater than 20 kBq 137 Cs/m2) to a less contaminated area (less than 3 kBq 137Cs/m2) of natural pasture. The animals grazed in a highly contaminated area until they were moved to the low contaminated area where they grazed from late November to late April. The level of 137Cs in meat was about 12 kBq/kg at the time when the animals were moved (Nov.) to the low contaminated area and it decreased to about 3 kBq/kg with an effective half-time of about 1 month, after the animals were moved. In the low contaminated area the fractional transfer, fm, of 137Cs was determined to be 0.65 d/kg during winter pasture, mainly on lichens, and 0.30 d/kg during summer pasture, in the fields. The actual intake of radiocesium was determined by measurement of ruminal samples from slaughtered animals. The maximal radiation dose to reindeer in Sweden after the Chernobyl accident was estimated to less than 200 mSv/a with a dose rate of less than 1mSv/d during the winter period of maximum tissue concentration of radiocesium.

[Efficacy of mebendazole on Elaphostrongylus rangiferi in reindeer (author's transl)]. / Effekten av mebendazol på Elaphostrongylus rangiferi hos ren.

Elaphostrongylus rangiferi is a very common parasite in Scandinavian reindeer, causing losses due to cerebral nematodiasis and granulomatous parasitic pneumonias and also causing a discard of parts of the carcass at meat inspection. In limited experiments, the efficacy of mebendazole on E. rangiferi has been tested. It was found that daily treatment during a period of 10 days with 6 mg/kg body weight, given as medicated feed, resulted in a decreased fecal larval count at the 10th day and a total cessation of excretion of larvae at the 43rd day, indicating a good anthelmintic effect of mebendazole on E. rangiferi. Single dose treatment with 40 mg/kg body weight was not adequate against E. rangiferi. This dose level, however, completely eliminated excretion of gastrointestinal parasite eggs, as did the 10 day treatment with 6 mg/kg body weight of mebendazole. This dose is double that of the recommended dose for wild ruminants and the need of higher dose is discussed to be due to the dominance of older females of the flock, giving less access to the food for the low-ranked animals. Long-time treatment of reindeer, comparable to the method used, is possible during periods of supplementary feeding during spring-time and then not interfering with the normal management. Deworming will then also intervene with the peak of larvae excretion. Thus it seems possible to considerably decrease the number of larvae on the pastures.