Long-Term Supplementation of Laying Hen Diets with Various Selenium Sources as a Method for the Fortification of Eggs with Selenium

Abstract

The following study focuses on a comparison of the effectiveness of egg content enrichment with selenium (Se) via application of sodium selenite (Na-selenite), selenium-enriched yeast (Se-Yeast), or selenomethionine (Se-Met) in laying hen diets. Two hundred sixteen laying hens were divided into four treatments, each comprising eighteen replications, and each with three hens per cage. Animals were fed a basal diet without Se supplementation (control: selenium content 0.058 mg/kg), with the addition of Na-selenite, Se-Yeast, or Se-Met in amounts equivalent to 0.3 mg/kg of added selenium. The egg quality, the selenium content in eggs after the third and the fifth months of using Se supplementation, and the selenium level in the liver were determined. Enrichment of egg content with selenium was the most effective (382 μg/kg) via application of dietary Se-Met. Application of Na-selenite and Se-Yeast led to a similar effect on Se-accretion in egg content (255.9 and 258.9 μg/kg, respectively). Additionally, the calculated average Se concentration in one fresh egg was also higher in eggs from hens that received selenium additives in their diet and was far higher, almost three times higher for Se-Met addition, than the concentrations in controls. Se-accretion in the liver wet tissue was greater following application of Se-Yeast in the diet than following other treatments. These results indicate that the use of selenomethionine in the laying hen diet is the best method of enriching eggs with this micronutrient. In turn, the eggs obtained in this way can be an excellent source of highly bioavailable selenium in the human diet.