Effects of dietary supplementation with selenium in organic form and iodine in dairy goats and their transfer to milk and dairy products

Abstract

This study evaluated the effects of dietary supplementation with selenium in organic form and iodine in dairy goats, aiming to obtain milk, cheese, and yogurt naturally enriched with these minerals and assessing the impact on animal health and performance. The control diet (CON) included 0.23 mg of inorganic selenium and 0.57 mg of iodine per kg of dry matter (DM). In contrast, the supplemented diet (SeI) included 0.46 mg of selenium (0.23 mg inorganic + 0.23 mg organic) and 5.68 mg of iodine per kg of DM. After 64 days of treatment, no adverse effects on health or productivity were observed. However, the SeI group exhibited elevated selenium and iodine concentrations in milk (p < 0.001), with 1.73 times more selenium (3.93 μg/100 g vs. 2.27 μg/100 g) and over 4 times more iodine (98.0 μg/100 g vs. 21.7 μg/100 g) compared to the CON group. A similar enrichment was observed in cheese (p < 0.001), where selenium content was approximately doubled (16.0 µg/100 g vs. 7.56 µg/100 g), and iodine quintupled (99.4 µg/100 g vs. 20.1 µg/100 g) in the SeI group. More than a 4-fold increase in iodine content was also observed in yogurt from the SeI group (106 µg/100 g vs. 24.4 µg/100 g; p < 0.001). Notably, selenium and iodine treatment did not affect the general characteristics or quality of milk and dairy products, supporting their use as a strategy to enhance the nutritional value of goat milk and derivatives.