Ecological observation of the 137Cs-contamination in beef of animals from the southern-Bavarian area.

Certain climatic and edaphic conformations in the Bavarian sub-alpine mountains and in the Alps favor above all the development of a land utilization system and farm structures similar to those in the northern part of Scandinavia. In 1963/64, the years of the highest environmental contamination up to the present, we established in 600 beef samples from the round or shoulder of male and female cattle (mainly Highland cattle) close connections between the 137Cs-contamination of green crop and the long lastnig yearly precipitation quantities, as well as certain relations between the 137Cs-contamination of meat and differences in the feeding and keeping of the animals. During summer-seasons (April-October), beef of cattle from pastures with heavy rainfall (Alps) was contaiminated by 137Cs up to 15 times more than that of confined animals. Hereby the rate of 137Cs-contamination in the meat of grazing cattle was nearly proportional to the quantities of precipitation. When confined cattle were fed on pastures in autumn after harvesting for 2 to 3 weeks, a quick increase of 137Cs-contamination of the meat was caused within this time up to values which in this district were otherwise only observed in grazing cattle. The lower 137Cs-content in meat of cattle housed during the summer season is due to the more varied fodder, which is at that time less contaminated than green crop. During the winter season (November to March), the highest contaminations in the meat of confined (Bohemian Forest) or grazing cattle (Alps) was measured when the animals in these districts were almost exclusively fed with fodder from the own farmground or with leafy silage. The highest contamination was almost regularly noticed in January, February and March, as generally during these months the highly contaminated first cut hay is fed. Here the meat was often even more contaminated than that of grazing cattle. After the quick decrease of 137Cs in fallout noticed in the years 1964 and 1965, in 1965/66 a dependance in the 137Cs-contamination of beef on the methods of keeping and feeding could still be observed in only the extreme cases (Alps, Bavarian- and Bohemian Forest); though in general, meat of animals from districts with heavy rainfall was slightly more contaminated than meat of animals from regions with less precipitation.