Milk Iodine Content in Slovakia

Abstract

The aim of this work was to map actual iodine status and its seasonal differences in raw milk of dairy cows, sheep, and goats in various regions of Slovakia. Iodine concentrations were determined in 457 samples of raw milk from dairy cows, 78 samples of sheep, and 16 samples of goat milk collected in various regions of Slovakia from 2002 to 2007. Among all the 457 samples of bovine milk, iodine content below 50 μg l-1 was recorded in 114 samples (24.94%); 294 samples (64.33%) ranged between 50 and 200 μg l-1; 19 samples (4.16%) from 200 to 500 μg l-1; 17 samples (3.72%) between 500 and 1 000 μg l-1, and 13 samples (2.85%) showed iodine concentrations over 1 000 μg l-1. regional concentrations showed the highest values in the Western, then Middle and Eastern Slovakia, and the lowest values in Northern Slovakia (p < 0.05, p < 0.01). In sheep and goat milk samples, we found iodine concentrations below 80 μg l-1 in 49 sheep (62.8%) and in 6 goats below 60 μg l-1 (37.5%), which are indicative of iodine deficiency. When comparing seasonal differences, sheep and goat milk had higher iodine content during the winter feeding period, however, in dairy cows we recorded the opposite ratio. Except for goat milk (p < 0.01) the seasonal differences were not significant.