Investigations for iodine concentration in the blood serum of milk cows from Saxonia as well as in cow's milk and milk products (baby food)

Within the framework of investigations into the metabolism of Saxon dairy-cows, more than 3300 analyses of blood serum total iodine concentrations have been carried out between 1997 and 2003. The total iodine concentration proved as suitable parameter for the recognition of the iodine supply situation of the milk cows. While to first two years 28,5% of the samples were rated below the recommended minimum level (0,04 mg/l), thus indicating deficiencies, the total iodine concentration then rose demonstrably, even indicating an oversupply in some herds (>= 0,20 mg/l). The iodine concentration in 117 independently tested milk samples (official food monitoring) confirmed this situation. An adequate iodine supplementation in feedstuffs is of great significance for the bovine metabolism as well as for the iodine concentrations in milk and therefore the iodine intake of the population. Of the negative consequences of an uncritically excessive iodine supplement particularly for high milk-yield cows one warns. This can lead to precariously high iodine concentrations in milk and dairy products. Further tests of blood total iodine levels in dairy herds on selective animals as well as analysis of milk and dairy products are recommended.