Trávníček J. author Kroupová V. author Šoch M. author text journal article 2004 In 1997-2001 a total of 304 samples of bulk feeds were analysed. Iodine was determined spectrophotometrically by Sandell and Kolthoff's method (Bednář et al., 1964). The highest content of iodine was determined in grass silage (213.3 ± 169.3 µg/kg DM). The lowest concentration was measured in maize silage (110.0 ± 97.2) and hay (112.1 ± 93.9). Pasture herbage contained on average 148.9 ± 105.1. Feeds originating from foothill areas of western Bohemia (geological bedrock built of crystalline schists and igneous intrusions of earlier granite) contained a higher amount of iodine than feeds from foothill areas of southern Bohemia (geological bedrock in which crystalline schists prevail). The largest difference in iodine content in relation to feed origin was found out in hay: western Bohemia 168.0, southern Bohemia 78.0 (P < 0.01). From May to July pasture herbage contained 101.3 ± 73.6 and from August to October 214.5 ± 107.3 µg/kg DM (P < 0.01). pasture herbage; hay; grass silage; maize silage 10.17221/4335-CJAS https://cjas.agriculturejournals.cz/artkey/cjs-200411-0003.php https://cjas.agriculturejournals.cz/artkey/cjs-200411-0003.php continuing 49 11 483 488 2004 12121819 periodical academic journal