engleski

Selenium deficiency in regional soils affecting animal and human health in Balkan and other European countries

Selenium (Se) has essential importance for human and animal health. In many areas of the world, the concentration of Se in soil is low, which affects level of Se in feed and food plants and accordingly animal and human health. The concentration of Se in food and feed plants is a reflection of the concentration of Se in soil and its bioavailability. Selenium is not essential element for most of the crop species but has a positive effect on plants, particularly in stress conditions, where it acts as an antioxidant. Concentration of Se in feed and food plants is very important for normal functioning of animals and humans metabolisms. The minimal required Se concentration in animal feed is 0.05–0.10 μg/g DM. In Serbia, Croatia, and in almost all Balkan region, very low levels of Se in forage feeds, cereals, fruit and vegetables has been reported. Selenium deficiency in animals is frequently linked with several pathologies or diseases. Low Se concentrations in soils and feed and food plants in Balkan region and many other areas in Europe resulted in low Se status in humans and animals. The lowest concentration of Se in blood and plasma GPx activities has been reported for animals without Se supplementation. Furthermore, the symptoms of Se deficiency e.g. WMD, retained placenta, is well known in the Eastern Europe and Balkan region, particularly for young animals dominantly feeding on pasture. Therefore, Se supplementation or Se-biofortified feed is necessary to maintain the Se concentration in animals at an adequate level. Although Se supplementation of animals has had positive results, high variation in Se concentration between animals supplemented with Se reflects different farm management including different types and amounts of Se supplementation used. Additionally, difficulties in general Se supplementation of animal always brings potential risk of Se toxicity due to overdose, which has been occasionally documented in the region. In order to enhance Se levels in plants, animals and humans, Se supplementation has to be improved. Agronomic biofortification through Se fertilization of soil and plant has to be considered a safer way to enhance the Se status of feed and fodder crops and subsequently of animals and humans, with possibly less problems related to overdosing. Some countries (i.e. Finland, New Zealand) have adopted such Se fertilization with good results in raising the Se status of animals and humans. Our results from several field experiments in Croatia and Serbia showed that e.g. for wheat foliar Se applications were more effective in increasing the Se than soil application, although both, Se foliar- and soil- fertilization increased Se concentration in grains from to 2.6- to 4.6- fold. Positive effects of Se fertilization of feed crops are also widely known.

selenium ; deficiency ; soil ; feed ; animal ; human health ; daily intake

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