Iodine concentration in raw sheep milk from Slovak farms - preliminary results

Šimon Mikláš, Vladimír Tančin, Róbert Toman, Ivan Imrich, Jan Trávníček


Received: 2021-05-18 | Accepted: 2021-07-19 | Available online: 2021-12-31

The aim of the study was to assess iodine concentration in raw sheep milk from chosen farms in Slovakia and to evaluate the factors that are involved. The assessed factors were as follows: effect of farm, iodine supplementation, farming system (conventional/ organic). The bulk milk samples were collected (June-August 2020) from seven sheep farms located in various districts of Slovakia. The analyses were carried out using the spectrophotometric method of Sandell-Kolthoff. The average milk iodine concentration of analysed bulk milk (26 samples) was 121.4±24.4 μg.l-1. The concentration of iodine in milk was significantly affected by the farm (P <0.05). There was observed large variability among the average milk iodine concentrations of samples ranging from 52.4±9.5 μg.l-1 to 511.6±48 μg.l-1. Similarly, iodine supplementation via mineral licks in farms significantly affected milk iodine concentration (P <0.01). This might be demonstrated by the lowest values in milk from the unsupplemented farm, ranging from 23.0 to 74.6 μg I.l-1, which indicate iodine deficiency. The farming system did not significantly affect the concentration of iodine in raw sheep milk. However, we observed lower milk iodine concentrations in organic farms as compared with conventional (94.4±25.9 μg.l-1 vs 131.4±32.0 μg.l-1, respectively.). To conclude, our results might suggest the important role of iodine supplementation on milk iodine concentration, as well as the significant impact of the farm as an important source of milk iodine concentration variability, which deserves attention regarding milk products and human nutrition.



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